ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • evolution  (302)
  • Evolution  (274)
  • Inversion
  • Rat
  • Springer  (827)
  • Inst. f. Geophys., Ruhr-Univ. Bochum  (2)
  • 3
  • Wiley
  • 1995-1999  (538)
  • 1980-1984  (291)
Collection
Keywords
Publisher
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Is the inversion effect in rhesus monkeys face-specific? (1999)
    Springer
    Animal cognition 2 (1999), S. 123-129 
    Details
    ISSN: 1435-9456
    Keywords: Key words Face recognition ; Inversion ; Expertise ¶effect ; Matching-to-sample ;  Macaca mulatta
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This study investigated the face inversion effect in rhesus monkeys (Macaca mulatta). Face stimuli consisted of ten black-and-white examples of unfamiliar rhesus monkey faces, brown capuchin faces, and human faces. Two non-face categories included ten examples of automobiles and abstract shapes. All stimuli were presented in a sequential matching-to-sample format using an automated joystick-testing paradigm. Subjects performed significantly better on upright than on inverted presentations of automobiles, rhesus monkey and capuchin faces, but not human faces or abstract shapes. These results are inconsistent with data from humans and chimpanzees that show the inversion effect only for categories of stimuli for which subjects have developed expertise. The inversion effect in rhesus monkeys does not appear to be face-specific, and should therefore not be used as a marker of specialized face processing in this species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s100710050032
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Specificity of a Y-linked gene in the flea beetle Phyllotreta nemorum for defences in Barbarea vulgaris (1999)
    Springer
    Entomologia experimentalis et applicata 91 (1999), S. 359-368 
    Details
    ISSN: 1570-7458
    Keywords: Barbarea vulgaris ssp. arcuata ; Cruciferae ; Phyllotreta nemorum ; Chrysomelidae ; Alticinae ; flea beetle ; plant defence ; host plant range ; near-isogenic ; Y-linkage ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A Y-linked gene (R-gene) in the flea beetle Phyllotreta nemorum L. (Coleoptera: Chrysomelidae: Alticinae) confer the ability of larvae to survive on types of the plant Barbarea vulgaris R.Br. (Brassicaceae) which are immune to attack by susceptible conspecifics. Two near-isogenic flea beetle lines were developed. The YE-line contained the Y-linked R-gene, and male larvae from this line survived on B. vulgaris. The ST-line did not contain the gene and did not survive on the plant. The YE-line had been developed through 8–9 generations of backcrosses (YE-males with ST-females) and the two lines were considered to be isogenic except for genes located on the Y-chromosome. A single copy of the Y-linked gene is sufficient to transfer a susceptible genotype (ST) into a resistant genotype (YE) which is able to utilize a plant that is immune to attack by specimens without R-genes. The Y-linked gene had no effects on survival on other plant species tested. The gene did not have any effect on developmental times and weights of adult beetles reared on other plants than B. vulgaris. Developmental times of larvae with the Y-linked gene were longer on B. vulgaris than on normal host plants, R. sativus and S. arvensis, but the adults obtained the same size on these plant species. No trade-offs of the Y-linked gene were discovered. The results suggest that the occurrence of the Y-linked gene is a derived trait which has enabled the flea beetle to expand its host plant range. The evolution of a host shift to B. vulgaris seems not to be favoured by the presence of this single gene.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003622512914
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Specialist deterrent chemoreceptors enable Pieris caterpillars to discriminate between chemically different deterrents (1999)
    Springer
    Entomologia experimentalis et applicata 91 (1999), S. 29-35 
    Details
    ISSN: 1570-7458
    Keywords: chemoreception ; deterrents ; Pieris ; Brassicaceae ; cardenolides ; host-plant selection ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Pieris butterflies (Lepidoptera: Pieridae) are specialist herbivores of cruciferous plants. They exploit glucosinolates, secondary plant metabolites chemotaxonomically characteristic for this plant family, as token stimuli. In addition to particular glucosinolates, some genera of the Cruciferae contain cardenolides, steroidal allelochemicals that act as potent feeding and oviposition deterrents to several Pieris species. We investigated the sensory mechanisms by which these compounds are perceived in larvae. Pieris caterpillars and many other lepidopterous species are endowed with so-called generalist deterrent receptors, that respond to a broad spectrum of secondary plant substances. In Pieris caterpillars we found a second type of deterrent chemoreceptor in maxillary styloconic taste sensilla. This neuron is very sensitive to cardenolides (threshold 0.1–0.3 μM). The generalist deterrent receptor also responds to these substances but its threshold lies at 50–100× higher concentrations. In behavioural preference experiments Pieris brassicae L. caterpillars preferred cardenolide-treated cabbage leaf discs when confronted with a choice between them and a deterrent substance that does not occur in the Brassicaceae. The cardenolides acted as potent deterrents when offered against untreated cabbage leaf discs. This demonstrates that the balance of activity elicited in the two types of deterrent chemoreceptors determines the behavioural decision.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003645222599
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    On the Adaptive Value of Some Mate Selection Strategies (1999)
    Springer
    Acta biotheoretica 47 (1999), S. 29-40 
    Details
    ISSN: 1572-8358
    Keywords: Sexual selection ; mate selection ; gamete selection ; evolution ; ploidy ; asssortative mating
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Results of an agent-based computer simulation of the evolution of diploid sexual organisms showed that several mate selection strategies confer much higher average fitness to the simulated populations, and higher evolutionary stability to the alleles coding for these strategies, than random mating. Strategies which select for 'good genes' were very successful, and so were strategies based on assortative mating. The results support the hypothesis that mating is not likely to be random in nature and that the most successful mate selection strategies are those based on assortative mating or on advantageous genes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1002022126388
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Purification and characterization of an ADP-dependent phosphofructokinase from Thermococcus zilligii (1999)
    Springer
    Extremophiles 3 (1999), S. 121-129 
    Details
    ISSN: 1433-4909
    Keywords: Key words Thermococcus ; Pyrococcus ; Thermophilic ; Phosphofructokinase ; Evolution ; ADP ; Glycolysis ; ATP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The ADP-dependent phosphofructokinase (PFK) from Thermococcus zilligii has been purified 950 fold; it had a specific activity of 190 U mg−1. The enzyme required Mg2+ ions for optimal activity and was specific for ADP. The forward reaction kinetics were hyperbolic for both cosubstrates (pH optimum of 6.4), and the apparent K m values for ADP and fructose-6-phosphate were 0.6 mM (apparent V max of 243 U mg−1) and 1.47 mM (apparent V max of 197 U mg−1), respectively. Significantly, the enzyme is indicated to be nonallosteric but was slightly activated by some monovalent cations including Na+ and K+. The protein had a subunit size of 42.2 kDa and an estimated native molecular weight of 66 kDa (gel filtration). Maximal reaction rates for the reverse reaction were attained at pH 7.5–8.0, and the apparent K m values for fructose-1,6-bisphosphate and AMP were 0.56 mM (apparent V max of 2.9 U mg−1) and 12.5 mM, respectively. The biochemical characteristics of this unique ADP-dependent enzymatic activity are compared to ATP and pyrophosphate-dependent phosphofructokinases.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s007920050107
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Isolation of a chymotrypsinogen B-like enzyme from the archaeon Natronomonas pharaonis and other halobacteria (1999)
    Springer
    Extremophiles 3 (1999), S. 153-161 
    Details
    ISSN: 1433-4909
    Keywords: Key wordsNatronomonas pharaonis ; Natronobacteria ; Archaea ; Serine protease ; Chymotrypsinogen ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A protease of a molecular mass of approximately 30 kDa was isolated and purified from the haloalkaliphilic archaeon Natronomonas (formerly Natronobacterium) pharaonis. The enzyme hydrolyzed synthetic peptides, preferentially at the carboxyl terminus of phenylalanine or leucine, as well as large proteins. Hydrolysis occurred over the range of pH from 6 to 12, with an optimum at pH 10. The temperature optimum was 61°C. The enzyme was nearly equally active over the range of salt concentration from 0.5 to 4 M (NaCl or KCl). A strong cross-reaction with a polyclonal antiserum against human chymotrypsin was observed. Enzymatic activity was inhibited by typical serine protease inhibitors. There was significant homology between N-terminal and internal sequences from autolytic fragments and the sequence of bovine chymotrypsinogen B; the overall amino acid composition was similar to that of vertebrate chymotrypsinogens. Evidence for a zymogen-like processing of the protease was obtained. Cell extracts from other halobacteria exhibited similar proteolytic activity and immunoreactivity. The data suggested a widespread distribution of a chymotrypsinogen B-like protease among halo- and haloalkaliphilic Archaea.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s007920050111
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Syntax as an Emergent Characteristic of the Evolution of Semantic Complexity (1999)
    Springer
    Minds and machines 9 (1999), S. 309-346 
    Details
    ISSN: 1572-8641
    Keywords: language ; grammar ; syntax ; semantics ; evolution ; emergence ; brain size
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Philosophy
    Notes: Abstract It is commonly argued that the rules of language, as distinct from its semantic features, are the characteristics which most clearly distinguish language from the communication systems of other species. A number of linguists (e.g., Chomsky 1972, 1980; Pinker 1994) have suggested that the universal features of grammar (UG) are unique human adaptations showing no evolutionary continuities with any other species. However, recent summaries of the substantive features of UG are quite remarkable in the very general nature of the features proposed. While the syntax of any given language can be quite complex, the specific rules vary so much between languages that the truly universal (i.e. innate) aspects of grammar are not complex at all. In fact, these features most closely resemble a set of general descriptions of our richly complex semantic cognition, and not a list of specific rules. General principles of the evolutionary process suggest that syntax is more properly understood as an emergent characteristic of the explosion of semantic complexity that occurred during hominid evolution. It is argued that grammatical rules used in given languages are likely to be simply conventionalized, invented features of language, and not the result of an innate, grammar-specific module. The grammatical and syntactic regularities that are found across languages occur simply because all languages attempt to communicate the same sorts of semantic information.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008360020568
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    The Evolution of a Scientific Concept (1999)
    Springer
    Journal for general philosophy of science 30 (1999), S. 37-58 
    Details
    ISSN: 1572-8587
    Keywords: protein ; experimentation ; conceptual variation and selection ; evolution ; Mulder ; Liebig ; Pflüger ; Nägeli
    Source: Springer Online Journal Archives 1860-2000
    Topics: Philosophy , Nature of Science, Research, Systems of Higher Education, Museum Science
    Notes: Abstract A philosophically comprehended account is given of the genesis and evolution of the concept of protein. Characteristic of this development were not shifts in theory in response to new experimental data, but shifts in the range of questions that the available experimental resources were fit to cope with effectively. Apart from explanatory success with regard to its own range of questions, various other selecting factors acted on a conceptual variant, some stemming from a competing set of research questions, others from an altogether different field of inquiry, and still others from the external environment. These results are best explained on, hence support, an evolutionary model of the progress of experimental investigation, whose outlines are briefly discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008246507186
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Multiple class I loci expressed by the quail Mhc (1999)
    Springer
    Immunogenetics 49 (1999), S. 456-460 
    Details
    ISSN: 1432-1211
    Keywords: Key words Antigen processing ; Evolution ; Cell surface molecules ; Mhc ; Class I antigens
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050519
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Identification and characterization of a fish natural resistance-associated macrophage protein (NRAMP) cDNA (1999)
    Springer
    Immunogenetics 50 (1999), S. 60-66 
    Details
    ISSN: 1432-1211
    Keywords: Key words NRAMP ; Fish ; Carp ; Evolution ; Expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The mouse Lsh/Ity/Bcg locus regulates natural resistance to intracellular pathogens, and the Nramp1 gene was isolated as its candidate. Nramp is part of a small family of at least two genes, Nramp1 and Nramp2. In the present study, a full-length cDNA for carp NRAMP has been isolated and characterized. Nucleotide and predicted amino acid sequence analysis indicate that the carp NRAMP encodes a 548 amino acid membrane protein with 12 putative transmembrane domains, two N-linked glycosylation sites, and an evolutionarily conserved consensus transport motif. The peptide sequence identity among carp and human NRAMP2 is 78%, and 65% with human NRAMP1. Reverse transcription-polymerase chain reaction revealed that carp NRAMP is ubiquitously expressed. Phylogenetic analysis, using neigbor-joining, showed that the carp NRAMP protein clustered together with mammalian NRAMP2 proteins.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050686
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Diversity and evolution of T-cell receptor variable region genes in mammals and birds (1999)
    Springer
    Immunogenetics 50 (1999), S. 301-308 
    Details
    ISSN: 1432-1211
    Keywords: Key words T-cell receptors ; Variable region genes ; Evolution ; Phylogeny ; Diversity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The receptor of a T lymphocyte (TCR) recognizes nonself antigens in the company of major histocompatibility complex (MHC) molecules presented to it by the antigen-presenting cell. The variable region of TCR is encoded by either a concatenation of variable region (TCR-V), diversity region (TCR-D), and joining region (TCR-J) genes, or a concatenation of TCR-V and TCR-J genes. The TCR-V genes exist as a multigene family in vertebrate species. Here we study the evolutionary relationships of TCR-V genes from humans, sheep, cattle, rabbits, mice, and chicken. These six species can be classified into two groups according to the frequency of γδ T-cells in their peripheral T-cell populations. The "γδ low" group of species includes humans and mice, in which γδ T-cells constitute very limited portion of the T-cell population. The "γδ high" group includes sheep, cattle, rabbits, and chicken, in which γδ T-cells comprise up to 60% of the T-cell population. Here, we compiled TCR-V sequences from the six species and conducted a phylogenetic analysis. We identified various TCR-V gene subgroups based on the analysis. We found that humans and mice have representatives from nearly all of the subgroups identified, while other species have lost subgroups to different extent. Therefore, the γδ low species have a high degree of diversity of TCR-V genes, while γδ high species all have limited diversity of TCR-V genes. This pattern is similar to that found for immunoglobulin variable region (IGV) genes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050606
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Marsupial light chains: IGK with four V families in the opossum Monodelphis domestica (1999)
    Springer
    Immunogenetics 50 (1999), S. 329-335 
    Details
    ISSN: 1432-1211
    Keywords: Key words Marsupials ; Light chains ; Variable regions ; IGK ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  A full-length and several partial cDNAs encoding IGK light chains from the marsupial South American opossum, Monodelphis domestica, were isolated and characterized. Using these clones as a starting point, the expressed IGKV repertoire was sampled by anchored polymerase chain reaction using an IGKC-specific primer. Based on nucleotide sequences of twenty unique, expressed IGKV-J combinations, there are at least four IGKV families and two J segments. Southern blot analysis revealed each IGK-V family contains multiple gene segments totaling at least thirty-five IGKV in the opossum genome. No evidence for particular, recurrent IGKV-J combinations in the opossum IGK repertoire was seen, rather the V-J combinations appeared random and diverse. Each of the four IGKV families appear more closely related to V segments from placental mammals than to each other, suggesting the duplication of the IGKV families prior to the separation of marsupials and placental mammals more than one-hundred-million years ago. Overall, the complexity of opossum light chain V segments appears greater than that found in the heavy chain, and light chains are likely to contribute significantly to Ig diversity in this species.With this report, the homologues encoding all three classes of eutherian Ig chains, IGH, IGL, and IGK, have been described in a non-placental mammal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050609
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Major histocompatibility complex-linked MIC genes in rhesus macaques and other primates (1999)
    Springer
    Immunogenetics 50 (1999), S. 358-362 
    Details
    ISSN: 1432-1211
    Keywords: Key words MHC ; MIC ; Nonhuman primates ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050614
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Isolation and mapping of the rabbit DM genes (1999)
    Springer
    Immunogenetics 49 (1999), S. 295-302 
    Details
    ISSN: 1432-1211
    Keywords: Key words Major histocompatibility complex ; Class II ; Antigen processing ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Proper peptide presentation by major histocompatibility complex (MHC)-encoded class II antigens is dependent on the products of the MHC DM loci. We identified the rabbit orthologues (RLA-DMA and -DMB) of human HLA-DMA and -DMB and found that they have 76.9% and 78.8% identity with HLA-DMA and -DMB, respectively. Like classical class II MHC genes, RLA-DM genes are more closely related to human HLA-DM genes than to mouse H2-DM. Among the DM family, there is a high degree of variability at the amino terminus of the DMa chains, and length variability in the cytoplasmic tails of both DMα and DMβ. The rabbit DM genes are coexpressed with class II genes in lymphoid tissues, as are the DM genes of other mammals. The RLA-DM locus maps to the class II region of the rabbit MHC, and is flanked by the DP and DOB loci. Despite having some similarities to class II genes of bony fishes, the DM family represents a separate branch of the MHC class II family.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050496
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    New family of Mhc class II A genes identified from cDNA sequences in the cichlid fish Aulonocara hansbaenschi (1999)
    Springer
    Immunogenetics 49 (1999), S. 544-548 
    Details
    ISSN: 1432-1211
    Keywords: Key words Mhc ; Class II A ; Cichlid ; Fish ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050533
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Characterization of beta2-microglobulin in a primitive fish, the Siberian sturgeon (Acipenser baeri) (1999)
    Springer
    Immunogenetics 50 (1999), S. 79-83 
    Details
    ISSN: 1432-1211
    Keywords: Key words Beta2-microglobulin ; Evolution ; Sturgeon ; cDNA ; Genomic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050690
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    A nose that looks like a hand and acts like an eye: the unusual mechanosensory system of the star-nosed mole (1999)
    Springer
    Journal of comparative physiology 185 (1999), S. 367-372 
    Details
    ISSN: 1432-1351
    Keywords: Key words Cortical magnification ; Somatosensory cortex ; Development ; Evolution ; Behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The star-nosed mole (Condylura cristata) has a snout surrounded by 22 fleshy and mobile appendages. This unusual structure is not an olfactory organ, as might be assumed from its location, nor is it used to manipulate objects as might be guessed from its appearance. Rather, the star is devoted to the sense of touch, and for this purpose the appendages are covered with thousands of small mechanoreceptive Eimer's organs. Recent behavioral studies find that the star acts much like a tactile eye, having a small behavioral focus, or “fovea” at the center – used for detailed explorations of objects of interest. The peripheral and central nervous systems of the mole reflect these behavioral specializations, such that the small behavioral focus on the nose is more densely innervated in the periphery, and has a greatly enlarged representation in the somatosensory cortex. This somatosensory representation of the tactile fovea is not correlated with anatomical parameters (innervation density) as found in other species, but rather is highly correlated with patterns of behavior. The many surprising parallels between the somatosensory system of the mole, and the visual systems of other mammals, suggest a convergent and perhaps common organization for highly developed sensory systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003590050396
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Peripheral frequency mis-match in the primitive ensiferan Cyphoderris monstrosa (Orthoptera: Haglidae) (1999)
    Springer
    Journal of comparative physiology 184 (1999), S. 543-551 
    Details
    ISSN: 1432-1351
    Keywords: Key words Auditory physiology ; Insect ; Frequency discrimination ; Evolution ; Song recognition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Peripheral auditory frequency tuning in the ensiferan insect Cyphoderris monstrosa (Orthoptera: Haglidae) was examined by comparing tympanal vibrations and primary auditory receptor responses. In this species there is a mis-match between the frequency of maximal auditory sensitivity and the frequency content of the species' acoustic signals. The mis-match is not a function of the mechanical properties of the tympanum, but is evident at the level of primary receptors. There are two classes of primary receptors: low-tuned and broadly tuned. Differences in the absolute sensitivity of the two receptor types at the male song frequency would allow the auditory system to discriminate intraspecific signals from sounds containing lower frequencies. Comparisons of tympanal and receptor tuning indicated that the sensitivity of the broadly tuned receptors did not differ from that of the tympanum, while low-tuned receptors had significantly narrower frequency tuning. The results suggest that the limited specialization for the encoding of intraspecific signals in the auditory system of C. monstrosa is a primitive rather than a degenerate condition. The limited specialization of C. monstrosa may reflect the evolutionary origin of communication-related hearing from a generalized precursor through the addition of peripheral adaptations (tympana, additional receptors) to enhance frequency sensitivity and discrimination.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003590050354
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Comparison of morphology and physiology of two plurisegmental sound-activated interneurones in a bushcricket (1999)
    Springer
    Journal of comparative physiology 185 (1999), S. 199-205 
    Details
    ISSN: 1432-1351
    Keywords: Key words Hearing ; Orthoptera ; Phaneropteridae ; Cercal system ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The unusual morphology of a sound-activated plurisegmental ascending interneurone (AN5-AG7) in an insect (Ancistrura nigrovittata, Ensifera, Phaneropteridae) is described. This neurone's soma is located in the penultimate abdominal ganglion. The most prominent arborisations with smooth endings are found in the prothoracic ganglion. The neurone terminates with numerous beaded endings in the brain (protocerebrum). All abdominal ganglia including the penultimate contain only tiny side branches of beaded appearance. The neurone's morphology is compared to the morphology of a `typical' sound-activated plurisegmental neurone of bushcrickets with its soma in the prothorax. In the prothoracic ganglion and in the brain the arborisations of the two cells are very similar. Graded potentials and action potentials are generated in the prothoracic portion of both neurones. Both receive excitation mainly by ultrasound, and inhibition by soma-ipsilateral stimuli. Neither wind, substrate vibration nor touch of the abdomen evoke responses in AN5-AG7. It is assumed that early in evolution this neurone had its dendrites in the ganglion which houses the cell body (like cercal interneurones of this neuromere). Profound evolutionary changes probably have taken place to bring about this neuron's modern morphology.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003590050378
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Spatial discrimination of pheromones and behavioural antagonists by the tortricid moths Cydia pomonella and Adoxophyes orana (1999)
    Springer
    Journal of comparative physiology 185 (1999), S. 419-425 
    Details
    ISSN: 1432-1351
    Keywords: Key wordsCydia pomonella ; Adoxophyes orana ; Sex pheromone ; Interspecific interruption ; Evolution ; AbbreviationsZ9-14:Ac (Z9)-tetradecenylacetate Z11-14:Ac (Z11)-tetradecenylacetate ; E8, E10-12:OH (E8, E10)-dodecadienol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Male moths responding to their species-specific sex pheromone, may cease their upwind flight when pheromone components of sympatric species are added to the mixture. The interspecific interaction between the pheromone response of the tortricid moths Cydia pomonella and Adoxophyes orana was investigated in field-trapping and wind-tunnel studies. Addition of the A. orana pheromone [(Z9)-tetradecenylacetate and (Z11)-tetradecenylacetate] to a source containing the C. pomonella pheromone [(E8, E10)-dodecadienol] resulted in a significant inhibition of attraction by male C. pomonella. It is demonstrated that this behavioural antagonist for C. pomonella must be emitted from the same point source to induce this inhibitory effect. A spatial separation of the two interspecific pheromones (at 14 cm, 5 cm and 0.5 cm crosswind) restored the attraction of the conspecific pheromone for male C. pomonella. In contrast to C. pomonella, male A. orana were not inhibited by point sources releasing both the C. pomonella and A. orana pheromone. We suggest that the discrepancy in the interspecific pheromone interaction between these two tortricids can be explained if we consider the evolutionary ecology of interspecific pheromone communication in C. pomonella and A. orana.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003590050402
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    Robert Chambers and Thomas Henry Huxley, Science Correspondents: The Popularization and Dissemination of Nineteenth Century Natural Science (1999)
    Springer
    Journal of the history of biology 32 (1999), S. 343-383 
    Details
    ISSN: 1573-0387
    Keywords: agnosticism ; Darwinian ; evolution ; materialism ; Malthusian ; nebular hypothesis ; popularization ; professionalization ; transitional forms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , History
    Notes: Abstract Robert Chambers and Thomas Henry Huxley helped popularize science by writing for general interest publications when science was becoming increasingly professionalized. A non-professional, Chambers used his family-owned Chambers' Edinburgh Journal to report on scientific discoveries, giving his audience access to ideas that were only available to scientists who regularly attended professional meetings or read published transactions of such forums. He had no formal training in the sciences and little interest in advancing the professional status of scientists; his course of action was determined by his disability and interest in scientific phenomena. His skillful reporting enabled readers to learn how the ideas that flowed from scientific innovation affected their lives, and his series of article in the Journal presenting his rudimentary ideas on evolution, served as a prelude to his important popular work, Vestiges of the Natural History of Creation. Huxley, an example of the new professional class of scientists, defended science and evolution from attacks by religious spokesmen and other opponents of evolution, informing the British public about science through his lectures and articles in such publications as Nineteenth Century. He understood that by popularizing scientific information, he could effectively challenge the old Tory establishment -- with its orthodox religious and political views -- and promote the ideas of the new class of professional scientists. In attempting to transform British society, he frequently came in conflict with theologians and others on issues in which science and religion seemed to contradict each other but refused to discuss matters of science with non-professionals like Chambers, whose popular writing struck a more resonant chord with working class readers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004616403134
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Risk and evolution (1999)
    Springer
    Economic theory 13 (1999), S. 329-343 
    Details
    ISSN: 1432-0479
    Keywords: Keywords and Phrases: Risk ; Evolution ; Entrepreneur. ; JEL Classification Numbers: C72 ; D81.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Economics
    Notes: Summary. I examine a Knightian (1921) model of risk using a general equilibrium model of investment and trade. A population of agents with various preference types can choose between a safe production technology and a risky production technology. In addition, the distribution of types of agents changes through a standard evolutionary dynamic. For a given population distribution, the equilibrium is in general inefficient, however, by allowing the population distribution to change in response to market generated rewards, the population will converge to one where the equilibrium is efficient and where the population as a whole behaves as if all agents were risk neutral.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001990050257
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    Evolution of groundwater chemical composition under human activity in an oilfield (1999)
    Springer
    Environmental geology 38 (1999), S. 34-46 
    Details
    ISSN: 1432-0495
    Keywords: Key words Alkaline/acid/neutral water ; Acid rain ; Geochemical modeling ; Brine ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract  Analysis and hydrogeochemical modeling of hydrocarbonate groundwater, including its buffering geochemical properties, have demonstrated that this water has undergone a geochemical transformation almost throughout the whole of one industrial region. It is known that hydrocarbonate groundwater possesses a high protective natural geochemical potential, supporting neutralization of acid atmospheric precipitation. Natural hydrocarbonate water undergoes three stages of anthropogenic transformation caused by acid atmospheric precipitation over more than 50 years. The first stage is transformation of neutral hydrocarbonate water into alkaline water, accompanied by calcite precipitation and sodium carbonate dissolution from the unsaturated zone. The second stage is transformation of alkaline water into neutral hydrocarbonate water; the hydrocarbonate content, being less than the lower limit for background concentrations, showed reduced water buffering properties or protective potential relative to acid precipitation. The third stage is transformation of neutral hydrocarbonate water into acidic water, with a complete loss of protective geochemical potential. This unfavorable ecological situation with natural geochemically hydrocarbonate groundwater shows that natural groundwater less protected from the impact of acid atmospheric precipitation is in a worse ecological condition, which is confirmed by observations in northern and Western Europe and other regions of the world.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002540050398
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Evolution of homeobox genes: Q50 Paired-like genes founded the Paired class (1999)
    Springer
    Development genes and evolution 209 (1999), S. 186-197 
    Details
    ISSN: 1432-041X
    Keywords: Key words Cnidaria ; Paired class ; Paired-like ; Homeobox gene ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The genes belonging to the Paired class exert primary developmental functions. They are characterized by six invariant amino acid residues in the homeodomain, while the residue at position 50 can be a serine, glutamine or lysine as in the Pax-type, Q50 Paired-like or the K50 Paired-like homeodomains respectively. Genes in this class emerged early in animal evolution: three distinct Pax genes and two Q50 Paired-like genes have recently been characterised from cnidarians. Phylogenetic molecular reconstructions taking into account homeodomain and paired-domain sequences provide some new perspectives on the evolution of the Paired-class genes. Analysis of 146 Paired-class homeodomains from a wide range of metazoan taxa allowed us to identify 18 families among the three sub-classes from which the aristaless family displays the least diverged position. Both Pax-type and K50 families branch within the Q50 Paired-like sequences implying that these are the most ancestral. Consequently, most Pax genes arose from a Paired-like ancestor, via fusion of a Paired-like homebox gene with a gene encoding only a paired domain; the Cnidaria appear to contain genes representing the ’before’ and ’after’ fusion events.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004270050243
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    Rapid divergence in the course of Drosophila evolution reveals structural important domains of the Notch antagonist Hairless (1999)
    Springer
    Development genes and evolution 209 (1999), S. 155-164 
    Details
    ISSN: 1432-041X
    Keywords: Key words Notch pathway ; Antagonist ; Hairless ; Orthologue ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Hairless is a member of the Notch signalling pathway, where it acts as antagonist by binding to Suppressor of Hairless [Su(H)], thereby inhibiting Notch target gene activation. The pathway and its members are highly conserved in metazoans from worms to humans. However, a Hairless orthologue from another species has not yet been identified. The identification of Hairless in largely diverged species by cross-hybridization has failed so far probably due to a low degree of conservation. Therefore, we turned to D. hydei where a Hairless mutation has been described before. The D. hydei Hairless orthologue is reasonably well conserved with regard to gene structure and expression. The prospective Hairless protein orthologues share several highly conserved regions which are separated by quite diverged stretches. As to be expected, the largest region of high conservation corresponds to the Su(H) binding domain. This region is also functionally conserved, since this D. hydei protein domain binds very strongly to the D. melanogaster Su(H) protein. The other conserved regions support our earlier structure-function analysis since they nicely correspond to previously defined, functionally important protein domains. Most notably, the very C-terminal domain which is very sensitive to structural alterations, is nearly identical between the two species. In summary, this evolutionary study improves the knowledge on functionally significant domains of the Hairless protein, and may be helpful for the future identification of homologues in other animals, especially in vertebrates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004270050239
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Maternal factors and the evolution of developmental mode: Evolution of oogenesis in Heliocidaris erythrogramma (1999)
    Springer
    Development genes and evolution 209 (1999), S. 275-283 
    Details
    ISSN: 1432-041X
    Keywords: Key words Echinoid ; Oogenesis ; Development ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Evolutionary change in developmental mode in sea urchins is closely tied to an increase in maternal provisioning. We examined the oogenic modifications involved in production of a large egg by comparison of oogenesis in congeneric sea urchins with markedly different sized oocytes and divergent modes of development. Heliocidaris tuberculata has small eggs (95 µm diameter) and the ancestral mode of development through feeding larvae, whereas H. erythrogramma has large eggs (430 µm diameter) and highly modified non-feeding lecithotrophic larvae. Production of a large egg in H. erythrogramma involved both conserved and divergent mechanisms. The pattern and level of vitellogenin gene expression is similar in the two species. Vitellogenin processing is also similar with the gonads of both species incorporating yolk protein from coelomic and hemal stores into nutritive cells with subsequent transfer of this protein into yolk granules in the developing vitellogenic oocyte. Immunocytology of the eggs of both Heliocidaris species indicates they incorporate similar levels of yolk protein. However, H. erythrogramma has evolved a highly divergent second phase of oogenesis characterised by massive deposition of non-vitellogenic material including additional maternal protein and lipid. Maternal provisioning in H. erythrogramma exhibits recapitulation of the ancestral vitellogenic program followed by a novel oogenic phase with hypertrophy of the lipogenic program being a major contributor to the increase in egg size.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004270050253
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    Identification and genetic mapping of Xenopus TAP2 genes (1999)
    Springer
    Immunogenetics 49 (1999), S. 171-182 
    Details
    ISSN: 1432-1211
    Keywords: Key words MHC ; Transporter ; Evolution ; PCR cloning ; Allelic lineage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The amphibian Xenopus laevis is one non-mammalian vertebrate in which the major histocompatibility complex (MHC) has been analyzed extensively. Class IIβ, class Ia, LMP2, LMP7, HSP70, C4, Factor B, and Ring3 genes have been identified and mapped to the MHC. Here, we report the isolation of a transporter associated with antigen processing (TAP) gene, TAP2, and demonstrate its linkage to the MHC. While the ATP-binding region of Xenopus TAP2 is highly conserved in evolution, amino acid identity to other vertebrate TAP proteins was not detected in the N-terminal region. Segregation analysis of 34 individuals from two families showed exact restriction fragment length polymorphism matching between the MHC class Ia gene and the one TAP2 gene demonstrating linkage conservation since the mammalian/amphibian divergence ∼350 million years ago. In addition, one non-MHC-linked TAP2–hybridizing fragment was detected in approximately half of the individuals tested. Interestingly, TAP2 allelic lineages appear to match those of LMP7 and classical class I, which previously were categorized into two highly divergent groups that emerged at least 60 million years ago. Similar to LMP7 and class Ia,TAP2 is expressed ubiquitously with highest levels in intestine and spleen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050478
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    Organization of the genes encoding the human proteasome activators PA28α and β (1999)
    Springer
    Immunogenetics 49 (1999), S. 438-445 
    Details
    ISSN: 1432-1211
    Keywords: Key words PA28 ; Proteasome ; Gene structure ; Evolution ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Two proteasome activators PA28α and β, which have been implicated in antigen processing for loading class I MHC molecules, are synthesized in response to Ifn-γ. The human genes encoding these activators (PSME1 and PSME2, respectively) were analyzed by sequencing. Each gene comprised 11 exons, consistent with gene duplication during vertebrate evolution. The intron/exon organization of both genes was highly conserved, the major difference being the absence of the exon encoding the lysine and glutamic acid-rich 'KEKE' motif in PA28β. Two other genes of relevance to the immune system were located close to those for PA28 at 14q11.2 including ISGF3G, a protein involved in transcription after IFNα signalling. These sequences were also characterized.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050517
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    Variation in the number of expressed MHC genes in different cattle class I haplotypes (1999)
    Springer
    Immunogenetics 50 (1999), S. 319-328 
    Details
    ISSN: 1432-1211
    Keywords: Key words Cattle ; MHC class I ; Haplotypes ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Analysis of cattle major histocompatibility complex (MHC) (BoLA) class I gene expression using serological and biochemical methods has demonstrated a high level of polymorphism. However, analysis of class I cDNA sequences has failed to produce conclusive evidence concerning the number and nature of expressed genes. Such information is essential for detailed studies of cattle immune responses, and to increase our understanding of the mechanisms of MHC evolution. In this study a selective breeding programme has been used to generate a number of MHC homozygous cattle expressing common serologically defined class I specificities. Detailed analysis of five class I haplotypes was carried out, with transcribed class I genes identified and characterized by cDNA cloning, sequence analysis, and transfection/expression studies. Surface expression of the gene products (on lymphocytes) was confirmed using monoclonal antibodies of defined BoLA specificity. Phylogenetic analysis of available transcribed cattle MHC class I sequences revealed complex evolutionary relationships including possible evidence for recombination. The study of individual haplotypes suggests that certain groupings of related sequences may correlate with loci, but overall it was not possible to define the origin of individual alleles using this approach. The most striking finding of this study is that none of the cattle class I genes is consistently expressed, and that in contrast to human, haplotypes differ from one another in both the number and composition of expressed classical class I genes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050608
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    A divergent non-classical class I gene conserved in salmonids (1999)
    Springer
    Immunogenetics 49 (1999), S. 479-490 
    Details
    ISSN: 1432-1211
    Keywords: Key words Comparative immunology ; Evolution ; MHC class I ; Molecular biology ; Salmonids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Complementary DNA for two class I genes of the rainbow trout, Oncorhynchus mykiss, were characterized. MhcOnmy-UBA*01 is similar to Onmy-UA-C32 and the classical major histocompatibility complex class I genes of other fish species, whereas Onmy-UAA*01 is divergent from all class I genes so far characterized. Onmy-UAA*01 is expressed at lower levels than Onmy-UBA*01. Although Onmy-UAA*01 exhibits restriction fragment length polymorphism on Southern blotting, the encoded protein is highly conserved. Two allotypes, which differ only by substitution at amino acid position 223 of the α3 domain, have been defined. Onmy-UAA*01 has an exon-intron organization like other class I genes and contains a Tc1-like transposon element in intron III. Orthologues of Onmy-UAA*01 have been characterized in four other species of salmonid. Between four species of Oncorhynchus, UAA*01 proteins differ by only 2–6 amino acids, whereas comparison of Oncorhynchus with Salmo trutta (brown trout) reveals 14–16 amino acid differences. The Onmy-UAA*01 gene has properties indicative of a particularly divergent non-classical class I gene.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050524
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    Nucleotide sequences of three distinct complementary DNA clones encoding rat class II major histocompatibility complex RT1.D β-chain proteins (1999)
    Springer
    Immunogenetics 49 (1999), S. 735-737 
    Details
    ISSN: 1432-1211
    Keywords: Key words Class II MHC sequence ; Rat ; Cloning ; RT-PCR ; Polymorphism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050676
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    Evolution of the Mhc class I region: the framework hypothesis (1999)
    Springer
    Immunogenetics 49 (1999), S. 362-367 
    Details
    ISSN: 1432-1211
    Keywords: Key words Major histocompatibility complex ; Class I region ; Evolution ; Orthology ; Olfactory receptor genes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  A comparison of the major histocompatibility complex (Mhc) region between human and mouse highlights both stability and differences. The class II and class III regions are orthologous; they probably existed in the ancestor in a similar organization and were not subjected to major rearrangement. The class I genes, by contrast, are definitely paralogous, having been reorganized several times. As long as only class I genes were identified, the class I regions of human and mouse were difficult to compare directly. The identification of non-class I genes has allowed a comparative map to be drawn, which shows that the class I region is orthologous between human and mouse as well. The lack of orthology specifically applies to the class I sequences. However, the comparative map shows that the non-orthologous class I sequences occupy homologous locations with regard to the conserved genes. I propose a model to explain this paradox. The conserved genes may represent samples of a dense "framework" of genes whose alterations are deleterious. The homologous positions occupied by class I genes would thus represent the few permissive places allowing major perturbations. The evolution of the class I sequences, by duplication and deletion, independently in the two species, has taken place within the scope defined by the framework: insertion at the permissive places, and expansion by creation of class I-related DNA by duplication, thus pushing back the boundaries of the framework.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050507
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    Gene organization of the quail major histocompatibility complex (MhcCoja) class I gene region (1999)
    Springer
    Immunogenetics 49 (1999), S. 384-394 
    Details
    ISSN: 1432-1211
    Keywords: Key words Antigen processing ; Evolution ; Cell surface ; molecules ; Mhc ; Transporters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Class I genomic clones of the quail (Coturnix japonica) major histocompatibility complex (MhcCoja) were isolated and characterized. Two clusters spanning the 90.8 kilobase (kb) and 78.2 kb class I gene regions were defined by overlapping cosmid clones and found to contain at least twelve class I loci. However, unlike in the chicken Mhc, no evidence for the existence of any Coja class II gene was obtained in these two clusters. Based on comparative analysis of the genomic sequences with those of the cDNA clones, Coja-A, Coja-B, Coja-C, and Coja-D (Shiina et al. 1999), these twelve loci were assigned to represent one Coja-A gene, two Coja-B genes (Coja-B1 and -B2), four Coja-C genes (Coja-C1-C4), four Coja-D genes (Coja-D1-D4), and one new Coja-E gene. A class I gene-rich segment of 24.6 kb in which five of these genes (Coja-B1, -B2, -D1, -D2 and -E) are densely packed were sequenced by the shotgun strategy. All of these five class I genes are very compact in size [2089 base pairs (bp)–2732 bp] and contain no apparent genetic defect for functional expression. A transporter associated with the antigen processing (TAP) gene was identified in this class I gene-rich segment. These results suggest that the quail class I region is physically separated from the class II region and characterized by a large number of the expressible class I loci (at least seven) in contrast to the chicken Mhc, where the class I and class II regions are not clearly differentiated and only at most three expressed class I loci so far have been recognized.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050511
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    Evidence for an HLA-C-like locus in the orangutan Pongo pygmaeus (1999)
    Springer
    Immunogenetics 49 (1999), S. 865-871 
    Details
    ISSN: 1432-1211
    Keywords: Key words Orangutan ; MHC class I ; HLA-C ; natural killer cells ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  HLA-B and C are related class I genes which are believed to have arisen by duplication of a common ancestor. Previous study showed the presence of orthologues for both HLA-B and C in African apes but only for HLA-B in Asian apes. These observations suggested that the primate C locus evolved subsequent to the divergence of the Pongidae and Hominidae. From an analysis of orangutan Tengku two HLA-C-like alleles (Popy C*0101 and Popy C*0201) were defined as well as three HLA-B-like (Popy-B) alleles. By contrast, no Popy-C alleles were obtained from orangutan Hati, although three Popy-B alleles were defined. Thus an HLA-C-like locus exists in the orangutan (as well as a duplicated B locus), implying that the primate C locus evolved prior to the divergence of the Pongidae and Hominidae and is at least 12–13 million years old. Uncertain is whether all orangutan MHC haplotypes contain a C locus, as the failure to find C alleles in some individuals could be due to a mispairing of HLA-C-specific primers with certain Popy-C alleles. These results raise the possibilities that other primate species have a C locus and that the regulation of natural killer cells by C allotypes evolved earlier in primate evolution than has been thought.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050566
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    MHC class I genes in a New World primate, the cotton-top tamarin (Saguinus oedipus), have evolved by an active process of loci turnover (1999)
    Springer
    Immunogenetics 49 (1999), S. 196-205 
    Details
    ISSN: 1432-1211
    Keywords: Key words New world primates ; MHC ; Evolution ; Gene duplication
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Lymphocytes of a New World primate, the cotton-top tamarin (Saguinus oedipus), express classical G–related major histocompatibility complex (MHC) class I molecules with unusually limited polymorphism and variability. Three G-related loci, an F locus, an E locus, and two pseudogenes (So-N1 and So-N3) have been identified by cDNA library screening and extensive PCR analysis of both cDNA and genomic DNA from the cotton-top tamarin. Furthermore, each genus of the subfamily Callitrichinae (tamarins and marmosets) appears to express its own unique set of MHC class I genes, likely due to a rapid turnover of loci. The rapid emergence of unique MHC class I genes in the Callitrichinae genera, resulting from an active process of duplication and inactivation of loci, may account for the limited diversity of the MHC class I genes in the cotton-top tamarin. To determine the nature of the entire complement of MHC class I genes in the cotton-top tamarin, we synthesized a genomic DNA library and screened it with MHC class I-specific probes. We isolated nine new MHC class I pseudogenes from this library. These newly isolated tamarin G–related MHC class I pseudogenes are not closely related to any of their functional counterparts in the tamarin, suggesting that they do not share a recent common ancestral gene with the tamarin's currently expressed MHC class I loci. In addition, these tamarin sequences display a high rate of nonsynonymous substitutions in their putative peptide binding region. This indicates that the genes from which they have derived were likely subject to positive selection and, therefore, were once functional. Our data support the notion that an extremely high rate of loci turnover is largely responsible for the limited diversity of the MHC class I genes in the cotton-top tamarin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050480
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    Evolution of a new nonclassical MHC class I locus in two Old World primate species (1999)
    Springer
    Immunogenetics 49 (1999), S. 86-98 
    Details
    ISSN: 1432-1211
    Keywords: Key words MHC ; Primates ; Reproduction ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  HLA-G is a nonclassical major histocompatibility complex (MHC) class I molecule that is expressed only in the human placenta, suggesting that it plays an important role at the fetal-maternal interface. In rhesus monkeys, which have similar placentation to humans, the HLA-G orthologue is a pseudogene. However, rhesus monkeys express a novel placental MHC class I molecule, Mamu-AG, which has HLA-G-like characteristics. Phylogenetic analysis of AG alleles in two Old World primate species, the baboon and the rhesus macaque, revealed limited diversity characteristic of a nonclassical MHC class I locus. Gene trees constructed using classical and nonclassical primate MHC class I alleles demonstrated that the AG locus was most closely related to the classical A locus. Interestingly, gene tree analyses suggested that the AG alleles were most closely related to a subset of A alleles which are the products of an ancestral interlocus recombination event between the A and B loci. Calculation of the rates of synonymous and nonsynonymous substitution at the AG locus revealed that positive selection was not acting on the codons encoding the peptide binding region. In exon 4, however, the rate of nonsynonymous substitution was significantly lower than the rate of synonymous substitution, suggesting that negative selection was acting on these codons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050467
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    Opposite orientation of the α- and υ-chain constant region genes in the immunoglobulin heavy chain locus of the duck (1999)
    Springer
    Immunogenetics 49 (1999), S. 692-695 
    Details
    ISSN: 1432-1211
    Keywords: Key words Duck ; Immunoglobulin genes ; IgH locus ; Class switching ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050666
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Sequences and evolution of mammalian RH gene transcripts and proteins (1999)
    Springer
    Immunogenetics 49 (1999), S. 15-25 
    Details
    ISSN: 1432-1211
    Keywords: Key words Rh blood group system ; Phylogenesis ; RH genes ; Evolution ; Nonhuman primates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The presence of Rh30-like polypeptides with an apparent relative molecular mass of 33 000 in the erythrocyte membranes from nonhuman primates and nonprimate mammals (mouse, rat, and dog) was demonstrated by immunoblotting. Nonhuman primates (orangutan, baboon, New World monkeys, lemur) and mouse Rh-like transcripts were amplified and sequenced. Analysis of the deduced amino acids sequences allowed us to determine the amino acid variability of Rh-like polypeptides which correlated with the hydrophylicity indexes. Hence, the putative transmembrane domains exhibited low indexes of variability, while the highest indexes were observed on extramembrane loops with a maximum on the sixth external loop. The cDNA sequences were compared with those previously reported in human, nonhuman primates, and cattle. The time of coalescence of mammalian Rh cDNA sequences was estimated by phylogenetic analysis to be 100 million years.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050459
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    The catalytic group-I introns of the psbA gene of Chlamydomonas reinhardtii : core structures, ORFs and evolutionary implications (1999)
    Springer
    Current genetics 36 (1999), S. 69-78 
    Details
    ISSN: 1432-0983
    Keywords: Key wordsChlamydomonas ; Chloroplast ; Evolution ; Group-I introns ; psbA gene ; Self-splicing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The sequences and predicted secondary structures of the four catalytic group-I introns in the psbA gene of Chlamydomonas reinhardtii, Cr.psbA-1–Cr.psbA-4, have been determined. Cr.psbA-1 and Cr.psbA-4 are subgroup-IA1 introns and have similar secondary structures, except at the 3′ end where Cr.psbA-1 contains a large inverted-repeat domain. Cr.psbA-4 is closely related to intron 1 of the Chlamydomonas moewusii psbA gene, with which it shares the same location, high nucleotide identity in the core, and an identically placed ORF that shows 58% amino-acid identity. Cr.psbA-2 is a subgroup-IA3 intron, and shows similarities to the Chlamydomonas eugametos rRNA intron, Ce.LSU-1. Cr.psbA-3 is a subgroup-IA2 intron, and is remarkably similar to the T4 phage intron, sunY. Interestingly, a degenerate version of Cr.psbA-3 is located in the intergenic region between the chloroplast petA and petD genes. All four introns contain ORFs, which potentially code for basic proteins of 11–38 kDa. The ORFs in introns 2 and 3 contain variants of the GIY-YIG motif; however, the Cr.psbA-2 ORF is free-standing, whereas the Cr.psbA-3 ORF is contiguous and in-frame with the upstream exon. The Cr.psbA-4 ORF contains an H-N-H motif, and possibly a GIY-YIG motif. These data indicate that the C. reinhardtiipsbA introns have multiple origins, and illustrate some of the evolutionary DNA dynamics associated with group-I introns in Chlamydomonas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002940050474
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    The [2Fe-2S] protein I (Shetna protein I) from Azotobacter vinelandii is homologous to the [2Fe-2S] ferredoxin from Clostridium pasteurianum (1999)
    Springer
    JBIC 4 (1999), S. 311-317 
    Details
    ISSN: 1432-1327
    Keywords: Key words Iron-sulfur ; Nitrogen fixation ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract  The [2Fe-2S] protein from Azotobacter vinelandii that was previously known as iron-sulfur protein I, or Shethna protein I, has been shown to be encoded by a gene belonging to the major nif gene cluster. Overexpression of this gene in Escherichia coli yielded a dimeric protein of which each subunit comprises 106 residues and contains one [2Fe-2S] cluster. The sequence of this protein is very similar to that of the [2Fe-2S] ferredoxin from Clostridium pasteurianum (2FeCpFd), and the four cysteine ligands of the [2Fe-2S] cluster occur in the same positions. The A. vinelandii protein differs from the C. pasteurianum one by the absence of the N-terminal methionine, the presence of a five-residue C-terminal extension, and a lesser number of acidic and polar residues. The UV-visible absorption and EPR spectra, as well as the redox potentials of the two proteins, are nearly identical. These data show that the A. vinelandii FeS protein I, which is therefore proposed to be designated 2FeAvFdI, is the counterpart of the [2Fe-2S] ferredoxin from C. pasteurianum. The occurrence of the 2FeAvFdI-encoding gene in the nif gene cluster, together with the previous demonstration of a specific interaction between the 2FeCpFd and the nitrogenase MoFe protein, suggest that both proteins might be involved in nitrogen fixation, with possibly similar roles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s007750050317
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    From Chemical to Population Ecology: Infochemical Use in an Evolutionary Context (1999)
    Springer
    Journal of chemical ecology 25 (1999), S. 31-49 
    Details
    ISSN: 1573-1561
    Keywords: Chemical ecology ; evolution ; variation ; population dynamics ; community ; species interactions ; infochemical ; semiochemical ; parasitoid ; foraging behavior ; learning ; phenotypic plasticity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The marriage of chemistry with ecology has been a productive one, providing a wealth of examples of how chemicals play important roles in the loves and lives of living organisms. At first the marriage may have been a simple and monogamous one with the major scientific aim of making proximate analyses of chemically mediated, individual level interactions. But times have changed and chemical ecology is broadening, embracing different approaches and disciplines. There is, for example, increasing appreciation of variability in the systems under study and an increase in evolutionary thinking. Another promising development is greater recognition of the potential importance of chemically mediated interactions for population dynamics and for structuring communities and species coexistence. The latter is an utterly underexplored area in chemical ecology. The field of chemical ecology of insect parasitoids shows some of these promising developments. Responses of parasitoids to infochemicals are increasingly studied with an integrated approach of mechanism and function. This integration of “how” and “why” questions significantly enhances the evolutionary and ecological understanding of stimulus–response patterns. The future challenge in chemical ecology is to demonstrate how chemically mediated interactions steer ecological and evolutionary processes at all levels of ecological organization. To reach this goal there is a need for interdisciplinary collaboration among chemists and ecologists working at different levels of organization and with different approaches, with other disciplines as partners.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1020833015559
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    The Amino Acid Sequence of Ribitol Dehydrogenase-F, a Mutant Enzyme with Improved Xylitol Dehydrogenase Activity (1999)
    Springer
    The protein journal 18 (1999), S. 489-495 
    Details
    ISSN: 1573-4943
    Keywords: Klebsiella aerogenes ; ribitol dehydrogenase ; evolution ; mutant structures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A mutant ribitol dehydrogenase (RDH-F) was purified from Klebsiella aerogenes strain F which evolved from the wild-type strain A under selective pressure to improve growth on xylitol, a poor substrate used as sole carbon source. The ratio of activities on xylitol (500 mM) and ribitol (50 mM) was 0.154 for RDH-F compared to 0.033 for the wild-type (RDH-A) enzyme. The complete amino acid sequence of RDH-F showed the mutations. Q60 for E60 and V215 for L215 in the single polypeptide chain of 249 amino acid residues. Structural modeling based on homologies with two other microbial dehydrogenases suggests that E60 → Q60 is a neutral mutation, since it lies in a region far from the catalytic site and should not cause structural perturbations. In contrast, L215 → V215 lies in variable region II and would shift a loop that interacts with the NADH cofactor. Another improved ribitol dehydrogenase, RDH-D, contains an A196 → P196 mutation that would disrupt a surface α-helix in region II. Hence conformational changes in this region appear to be responsible for the improved xylitol specificity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1020601011846
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    Detecting self-organisational change in economic processes exhibiting logistic growth (1999)
    Springer
    Journal of evolutionary economics 9 (1999), S. 109-133 
    Details
    ISSN: 1432-1386
    Keywords: Key words: Discontinuity ; Evolution ; Logistic diffusion ; Non-linearity ; Non-stationarity ; Self-organisation ; Spectral methods ; JEL-classification: C4; C5; N1; N2
    Source: Springer Online Journal Archives 1860-2000
    Topics: Economics
    Notes: Abstract. This paper offers an econometric methodology for the detection of self-organisational change (defined in terms of the presence of time irreversibility, structural change and fundamental uncertainty) in economic processes that follow logistic diffusion growth paths in historical time. The approach we adopted is built upon recent developments in `moving window' spectral methods which are applied to the scaled residuals generated by estimated logistic diffusion models. We illustrate the use of such methods by examining the case of a financial instrument, namely, the Australian Building Society Deposit, which experienced logistic growth in its market share until bank deregulation was enacted in the 1980s. We show that there is clear evidence that self-organisational change is present over the historical period considered.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001910050077
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    A note on evolutionary stability of Bertrand equilibrium (1999)
    Springer
    Journal of evolutionary economics 9 (1999), S. 367-371 
    Details
    ISSN: 1432-1386
    Keywords: Key words: Bertrand ; Oligopoly ; Evolution ; Evolutionary stability ; JEL-classification: D43 ; L13 ; C72
    Source: Springer Online Journal Archives 1860-2000
    Topics: Economics
    Notes: Abstract. It is shown that the equilibrium notion of an evolutionary stable strategy (ESS) does have predictive power for standard models of Bertrand competition. This is in contrast to a recent claim by Qin and Stuart (1997). The claim is based on the observation that the solution concept ESS behaves discontinuously when finite (discrete) action games approach an infinite (continuous) action game in the limit. Furthermore, it is argued that from a model-theoretic point of view evolutionary stability in prices (i.e. in the Bertrand model) is quite different from evolutionary stability in quantities (i.e. in the Cournot model).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001910050087
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    Phylogenetic classification and molecular evolution of knotted1 homeobox genes (1999)
    Springer
    Theoretical and applied genetics 99 (1999), S. 203-209 
    Details
    ISSN: 1432-2242
    Keywords: Key words Homeobox gene ; KNOTTED1 ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Homeobox genes encode a family of DNA-binding regulatory proteins which are crucial for development. The first plant homeobox gene identified was knotted1 which plays a major role in leaf development. The knotted1 gene has a homeobox which encodes a homeodomain (HD) and HD proteins have been shown to function as transcription factors. A phylogenetic classification of the KNOTTED1 HD is presented. Here, we report six kn1 HDs from the cereals oat, barley, wheat, rye and rice. The KN1 class-I and -II genes can be divided into two distinct clades. Further, we hypothesize that KN1 and BELL1/MEIS HDs, (the closest non-KN1 class HDs) evolved from a common ancestor after divergence from the common precursor of all the homeobox genes. Our analysis clearly shows the presence of an ancestral KN1 HD from which all the known plant kn1 class of genes evolved.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001220051226
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    Identification of genetic factors controlling domestication-related traits of rice using an F2 population of a cross between Oryza sativa and O. rufipogon (1999)
    Springer
    Theoretical and applied genetics 98 (1999), S. 243-251 
    Details
    ISSN: 1432-2242
    Keywords: Key words Common wild rice ; Cultivated rice ; Evolution ; Genetic analysis ; Molecular marker
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Domesticated rice differs from the wild progenitor in large arrays of morphological and physiological traits. The present study was conducted to identify the genetic factors controlling the differences between cultivated rice and its wild progenitor, with the intention to assess the genetic basis of the changes associated with the processes of rice domestication. A total of 19 traits, including seven qualitative and 12 quantitative traits, that are related to domestication were scored in an F2 population from a cross between a variety of the Asian cultivated rice (Oryza sativa) and an accession of the common wild rice (O. rufipogon). Loci controlling the inheritance of these traits were determined by making use of a molecular linkage map consisting of 348 molecular-marker loci (313 RFLPs, 12 SSRs and 23 AFLPs) based on this F2 population. All seven qualitative traits were each controlled by a single Mendelian locus. Analysis of the 12 quantitative traits resolved a total of 44 putative QTLs with an average of 3.7 QTLs per trait. The amount of variation explained by individual QTLs ranged from a low of 6.9% to a high of 59.8%, and many of the QTLs accounted for more than 20% of the variation. Thus, genes of both major and minor effect were involved in the differences between wild and cultivated rice. The results also showed that most of the genetic factors (qualitative or QTLs) controlling the domestication-related traits were concentrated in a few chromosomal blocks. Such a clustered distribution of the genes may provide explanations for the genetic basis of the “domestication syndrome” observed in evolutionary studies and also for the “linkage drag” that occurs in many breeding programs. The information on the genetic basis of some desirable traits possessed by the wild parent may also be useful for facilitating the utilization of these traits in rice-breeding programs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001220051064
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    Structural chromosome differentiation between Triticum timopheevii and T. turgidum and T. aestivum (1999)
    Springer
    Theoretical and applied genetics 98 (1999), S. 744-750 
    Details
    ISSN: 1432-2242
    Keywords: Key words Chromosome pairing ; Translocations ; T. timopheevii ; T. turgidum ; T. aestivum ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract.  Chromosome pairing at metaphase-I was analyzed in F1 hybrids among T. turgidum (AABB), T. aestivum (AABBDD), and T. timopheevii (AtAtGG) to study the chromosome structure of T. timopheevii relative to durum (T. turgidum) and bread (T. aestivum) wheats. Individual chromosomes and their arms were identified by means of C-banding. Homologous pairing between the A-genome chromosomes was similar in the three hybrid types AAtBG, AAtBGD, and AABBD. However, associations of B-G were less frequent than B-B. Homoeologous associations were also observed, especially in the AAtBGD hybrids. T. timopheevii chromosomes 1At, 2At, 5At, 7At, 2G, 3G, 5G, and 6G do not differ structurally from their counterpart in the A and B genomes. Thus, these three polyploid species inherited translocation 5AL/4AL from the diploid A-genome donor. Chromosome rearrangements that occurred at the tetraploid level were different in T. turgidum and T. timopheevii. Translocation 4AL/7BS and a pericentric inversion of chromosome 4A originated only in the T. turgidum lineage. The two lines of T. timophevii studied carry four different translocations, 6AtS/1GS, 1GS/4GS, 4GS/4AtL, and 4AtL/3AtL, which most likely arose in that sequence. These structural differences support a diphyletic origin of polyploid wheats.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001220051130
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    p-SINE1-like intron of the CatA catalase homologs and phylogenetic relationships among AA-genome Oryza and related species (1999)
    Springer
    Theoretical and applied genetics 98 (1999), S. 853-861 
    Details
    ISSN: 1432-2242
    Keywords: Key words Catalase ; Oryza ; Rice ; Evolution ; p-SINE1
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Intron-2 of the Oryza sativa CatA catalase gene is similar in nucleotide sequence to p-SINE1, a retroposon, and seems to have been added to the ancestral genome of rice. To examine when the p-SINE1-like intron was inserted into CatA during the evolutionary divergence of Oryza species, and to elucidate the evolutionary relationships among Oryza species using the sequence of the intron as a marker, we performed polymerase chain reaction (PCR) analyses of 32 accessions of 17 Oryza species with various genome types. Agarose-gel electrophoresis of the PCR products revealed that all the Oryza species with an AA genome have the CatA homolog with the intron, whereas other Oryza species have the CatA homolog without the intron. These results indicate that intron-2 of CatA is a good marker for distinguishing species with an AA genome among Oryza species. Sequencing of the PCR products showed that all the introns are similar to p-SINE1, though with slight variations in length. We also performed PCR analyses using four accessions of three species in genera related to Oryza, and found that there is an intron in the CatA homolog of Leersia perrieri. On the other hand, the CatA homolog of Porteresia coarctata has no intron. Sequence data showed that the L. perrieri homolog has a p-SINE1-like intron similar to that in Oryza species with an AA genome. These results suggest that the p-SINE1-like intron was already present in the common ancestor of Oryza and L. perrieri and was then lost in the ancestors of P. coarctata and of the Oryza species other than those with an AA genome. The phylogenetic tree of Oryza species with an AA genome based on the nucleotide sequences of the introns leads us to propose that Oryza species with an AA genome evolved from an ancestor of Oryza longistaminata.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001220051144
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    Uses and usefulness of endosperm balance number (1999)
    Springer
    Theoretical and applied genetics 98 (1999), S. 478-484 
    Details
    ISSN: 1432-2242
    Keywords: Key words Endosperm development ; Evolution ; 2n gametes ; Breeding ; Potato
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The Endosperm Balance Number (EBN) hypothesis was developed in the early ’80s to explain the basis for normal seed development after intra- and inter-specific crosses, first in the potato and then in several other crop species. According to this hypothesis, each species has a genome-specific effective ploidy, the EBN, which must be in a 2 : 1 maternal to paternal ratio in the hybrid endosperm for normal development of the endosperm itself. This paper reviews how the EBN may act as a powerful isolating mechanism in sexual reproduction, maintaining the genome integrity of the species and playing an important role in the speciation of polyploids from diploids. We also provide further evidence that EBN is more important than chromosome ploidy in determining the success or failure of interspecific crosses. In fact, results from inter-ploidy and inter-EBN crosses to infuse 1EBN Solanum commersonii into 4EBN S. tuberosum demonstrated that the knowledge and manipulation of EBN is a useful tool in designing breeding schemes and in predicting the offspring ploidy and EBN. In this paper we also discuss the exceptions to the 2 : 1 EBN ratio, and report the evidence for endomitosis in the polar nuclei to explain exceptions to the EBN model in the potato.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001220051095
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Cytokine-induced conversion of mesencephalic-derived progenitor cells into dopamine neurons (1999)
    Springer
    Cell & tissue research 296 (1999), S. 235-246 
    Details
    ISSN: 1432-0878
    Keywords: Key words Transplantation ; Parkinson’s disease ; CNS fetal development ; CNS differentiation ; Neurotrophic factors ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract We have previously shown that a combination of the cytokines interleukin (IL)-1, IL-11, leukemia inhibitory factor (LIF), and glial cell line-derived neurotrophic factor (GDNF) can convert rat fetal (E14.5) mesencephalic progenitor cells into tyrosine hydroxylase (TH)-immunoreactive (ir) neurons in vitro. The experiments described here characterize the mesencephalic progenitor cells and their cytokine-induced conversion into dopamine (DA) neurons. For all experiments, we used bromodeoxyuridine (BrdU)-ir cultures of (E14.5) mesencephalic progenitor cells that had been expanded at least 21 days. We first demonstrated that IL-1 induced DA neuron conversion in mesencephalic progenitors, but not in striatal progenitors (P〈0.001). Thus, these cells should be classified as lineage-restricted progenitors, and not omnipotent stem cells. To further characterize cell populations in these cultures, we used monoclonal antibodies against Hu (an early marker for neurons), growth-associated protein (GAP)-43 (a marker for neuronal process extension), TH (a marker for DA neurons), and glial fibrillary acidic protein (GFAP, a marker for astrocytes). We assessed (E14.5) mesencephalic progenitor cell cultures (plated at 125,000 cells/cm2) incubated in the cytokine mixture (described above) or in complete media (CM, negative control). Following 7 days incubation, GFAP-positive cells formed a nearly confluent carpet in both types of cultures. However, numbers of Hu-ir and GAP-43-ir cells in the cytokine-incubated cultures far exceeded those in CM-incubated controls (P=0.0003, P=0.0001, respectively), while numbers of TH-ir cells were 58-fold greater in the cytokine-incubated cultures versus CM-incubated controls. The TH phenotype persisted for 7 days following withdrawal of the differentiation media. Numerous double-labeled cells that were BrdU-ir and also TH-ir, or Hu-ir and also TH-ir, were observed in the cytokine-incubated cultures. These data suggest that cytokines ”drive” the conversion of progenitor cells into DA neurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051285
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    Isograft and xenograft of the subcommissural organ into the lateral ventricle of the rat and the formation of Reissner’s fiber (1999)
    Springer
    Cell & tissue research 296 (1999), S. 457-469 
    Details
    ISSN: 1432-0878
    Keywords: Key words Subcommissural organ ; Isograft ; Xenograft ; Reissner’s fiber ; Cerebrospinal fluid ; Rat ; Bovine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The subcommissural organ (SCO) secretes glycoproteins into the cerebrospinal fluid (CSF) that aggregate and form Reissner’s fiber (RF). The factors involved in this aggregation are not known. One factor may be the hydrodynamics of the CSF when flowing through the aqueduct. This hypothesis was tested by isografting rat SCO and xenografting bovine SCO into the lateral ventricle of rats. Xenografts were either fresh bovine SCO or explants cultured for 30 days before transplantation. The grafts were investigated by electron microscopy and immunocytochemistry using antibodies against RF glycoproteins, serotonin and the glucose transporter I. Maximal time of transplantation was 43 days for isografts and 14 days for xenografts. The isografts were not reinnervated but were revascularized; they secreted into the ventricle RF glycoproteins that became progressively packed into pre-RF and RF structures identical to those formed by the SCO in situ. RF was confined to the host ventricle and at its distal end the constituent proteins disassembled. Xenografts were neither reinnervated nor revascularized and secreted into the host ventricle a material that never formed an RF. These findings indicate that the CSF factor responsible for the formation of RF is species specific, and that this process does not depend on the hydrodynamics of the CSF. The blood vessels revascularizing the isografted SCO acquired the characteristics of the vessels irrigating the SCO in situ, namely, a tight endothelium displaying glucose transporter I, and a perivascular space containing long-spacing collagen, thus indicating that basal release of glycoproteins may also occur in the grafted SCO.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051306
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    Evolution of extreme polyandry in the honeybee Apis mellifera L. (1999)
    Springer
    Behavioral ecology and sociobiology 45 (1999), S. 269-275 
    Details
    ISSN: 1432-0762
    Keywords: Key words Polyandry ; Evolution ; Social insects ; Apis mellifera ; Task allocation ; Division of labor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A number of hypotheses have been proposed to explain the evolution of multiple mating in the honeybee queen. In particular, the consequences of reduced intracolonial relatedness provide plausible explanations for multiple mating with up to ten drones, but fail to account for the much higher mating frequencies observed in nature. In this paper, we propose an alternative mechanism which builds on non-linear relationships between intracolonial frequencies in genotypic worker specialization and colony fitness. If genes for any worker specialization confer an advantage on colony fitness only when they are rare, this would require a stable mix of sperm from a few drones which contribute that trait, and many which do not. To ensure both specific, low within-colony proportions of “rare specialist” genes, and to reduce random variation of these proportions would require mating with high numbers of drones. The quantitative implementation shows that moderate to very high numbers of matings are required to exploit colony advantages from genotypic allocation of workers to rare tasks. Extreme polyandry thus could result from colony selection dependent on the intracolonial frequency of rare genetic specialists.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002650050561
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    Hox genes in digit development and evolution (1999)
    Springer
    Cell & tissue research 296 (1999), S. 19-25 
    Details
    ISSN: 1432-0878
    Keywords: Key wordsHoxA ; HoxD ; Limb ; Development ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Homeobox genes located in the 5’ part of the HoxA and HoxD complexes are required for proliferation of skeletal progenitor cells of the vertebrate limb. Specific combinations of gene products determine the length of the upper arm (genes belonging to groups 9 and 10), the lower arm (groups 10, 11 and 12) and the digits (groups 11, 12 and 13). In these different domains, individual gene products quantitatively contribute to an overall protein dose, with predominant roles for groups 11 and 13. Quantitative reduction in the gene dose in each set results in truncations of the corresponding anatomical regions. The physical order of the genes in the HoxA and HoxD complexes, as well as a unidirectional sequence in gene activation, allow for completion of the process in a precise order, which in turn makes possible the sequential outgrowth of the respective primordia. While the skeletal patterns of upper and lower limb are relatively stable throughout the tetrapods, more variation is seen in the digits. Molecular analysis of the underlying regulatory processes promises further exciting insights into the genetic control of development, pathology and the course of evolution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051262
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    Origin of neuronal-like receptors in Metazoa: cloning of a metabotropic glutamate/GABA-like receptor from the marine sponge Geodia cydonium (1999)
    Springer
    Cell & tissue research 296 (1999), S. 395-404 
    Details
    ISSN: 1432-0878
    Keywords: Key words Metabotropic glutamate/GABA-like receptor ; Evolution ; Geodia cydonium (Porifera)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract To date, no conclusive evidence has been presented for the existence of neuronal-like elements in Porifera (sponges). In the present study, isolated cells from the marine sponge Geodia cydonium are shown to react to the excitatory amino acid glutamate with an increase in the concentration of intracellular calcium[Ca2+]i. This effect can also be observed when the compounds L-quisqualic acid (L-QA) or L-(+)-2-amino-4-phosphonobutyric acid (L-AP-4) are used. The effect of L-QA and L-AP-4, both agonists for metabotropic glutamate receptors (mGluRs), can be abolished by the antagonist of group I mGluRs, (RS)-α-methyl-4-carboxyphenylglycine. These data suggest that sponge cells contain an mGluR-like protein. A cDNA encoding rat mGluR subtype 1 has been used to identify the complete nucleotide sequence of G. cydonium cDNA coding for a 528-amino-acid-long protein (59 kDa) that displays marked overall similarity to mGluRs and to γ-amino-butyric acid B receptors. The deduced sponge polypeptide, termed putative mGlu/GABA-like receptor, displays the highest similarity to the two families of metabotropic receptors within the transmembrane segment. The N-terminal part of the sponge sequence shows similarity to mGluR4 and mGluR5. These findings suggest that the earliest evolutionary metazoan phylum, the Porifera, possesses a sophisticated intercellular communication and signaling system, as seen in the neuronal network of higher Metazoa.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051299
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    Axonal and dendritic transport in Purkinje cells of cerebellar slice cultures studied by microinjection of horseradish peroxidase (1999)
    Springer
    Cell & tissue research 295 (1999), S. 55-64 
    Details
    ISSN: 1432-0878
    Keywords: Key words Axonal transport ; Purkinje cell ; Organotypic culture ; Microinjection ; Antimitotic drugs ; Cytoskeleton ; Dendritic transport ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Axonal and dendritic transport in single Purkinje neurons of cerebellar slice cultures was quantified as single transport distances. Examination of the cells within a vital tissue was regarded as being an approach to the in situ condition. The Purkinje cells were organotypically integrated in the in vitro tissues and extended long axonal projections connecting synapses to the target neurons. The tracer horseradish peroxidase (HRP) was applied via microinjection to the somata of the Purkinje cells and the injected neurons were incubated thereafter for defined time-intervals. The tracer was transported anterogradely into the neuron processes. The measurements on both the axonal and the dendritic transport of microinjected HRP revealed continuous transportation with increasing times of postincubation. This transport was reduced by the use of microtubule-depolymerizing drugs. The axonal transport of the tracer was either retarded in colchicine-treated cells or continuously reduced for up to 50% in vinblastine-treated neurons. Thus, a correlation of axonal transport to the microtubules was demonstrated. The dendrites were filled with the tracer after 60 min of postincubation. Dendritic transport was reduced by the use of vinblastine, and not significantly by colchicine. The results strongly support the dependence of neuronal transport on microtubules as a component of the cytoskeleton.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051212
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    Cellular and subcellular distribution of the calcium-binding protein NCS-1 in the central nervous system of the rat (1999)
    Springer
    Cell & tissue research 295 (1999), S. 395-407 
    Details
    ISSN: 1432-0878
    Keywords: Key words Neurofilament ; Basket cell ; Pinceau ; Golgi apparatus ; Calcium binding protein ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract NCS-1 (neuronal calcium sensor) is a recently characterized member of a highly conserved neuron-specific family of calcium-binding proteins, which also includes frequenin and recoverin. The cellular and subcellular distributions of NCS-1 in the rat nervous system were investigated using light- and electron-microscopic immunohistochemistry. NCS-1 immunoreactivity was localized to neuronal cell bodies and axons throughout the brain and spinal cord but not to glial cells. The most intense labeling was observed in myelinated axons, the axonal ramifications of the basket cell in the cerebellar cortex, and large neurons in the brainstem and pons. These same structures were also characterized by heavy labeling for neurofilament protein, as determined by double-labeling experiments. Most axon terminals were unlabeled or only lightly labeled. The most remarkable subcellular staining occurred in the perikarya where intense labeling was associated with the membranes of the trans saccules of the Golgi apparatus. The widespread distribution of NCS-1 indicates that it may be active in a variety of calcium-dependent neuronal functions, whereas the specific subcellular localization to the Golgi apparatus and neurofilament-rich structures suggests a specialized role in calcium regulated protein trafficking and cytoskeletal interactions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051246
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    Expression of neurotrophins, GDNF, and their receptors in rat thyroid tissue (1999)
    Springer
    Cell & tissue research 295 (1999), S. 467-475 
    Details
    ISSN: 1432-0878
    Keywords: Key words Glial cell line-derived neurotrophic factor ; GDNF ; Ret ; GDNFR-α ; Brain-derived neurotrophic factor ; BDNF ; NT-3 ; NT-4 ; trk receptors ; Thyroid tissue ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Levels of mRNA for neurotrophins (brain-derived neurotrophic factor, BDNF; neurotrophin 3, NT-3; neurotrophin 4, NT-4) and their receptors (trkA, trkB, trkC) and for glial cell line-derived neurotrophic factor (GDNF) and its receptors (ret, GDNFR-α) were measured in rat thyroid tissue by ribonuclease protection assays. In thyroid tissue the NT-3 mRNA level was threefold lower and the NT-4 mRNA level sixfold higher than those detected in adult rat hippocampus, while BDNF mRNA was undetectable. Very low levels of mRNA for truncated trkB and trkC receptors and no catalytic trkA, trkB or trkC were found. In conclusion NT-3 and NT-4, but not the corresponding functional receptors, are expressed in the thyroid tissue. Therefore, it is unlikely that these factors serve a direct local autocrine or paracrine function in thyroid cell types, and a target-derived mode of action on neurons innervating the thyroid tissue is suggested. An opposite result has been found for the neurotrophic factor GDNF: thyroid tissue showed a high level of transcripts for the GDNF receptor subunits (GDNFR-α and Ret), while GDNF mRNA was undetectable. The in situ hybridization analysis of GDNFR-α and ret mRNA revealed an interesting difference in the cell distribution of these transcripts: ret mRNA is selectively expressed in a subpopulation of cells scattered in the follicular epithelium and in the interfollicular spaces, while GDNFR-α expression is more homogeneous and widespread, including the more abundant cell type of the thyroid gland: the follicular cell. Double-labeling in situ hybridization/immunocytochemistry experiments, with a specific marker (calcitonin), showed that parafollicular cells express ret but not GDNFR-α. This differential distribution of the GDNF receptor components (GDNFR-α and ret) may reflect a peculiar biological role in intercellular communication in the thyroid gland.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051252
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    Aquaporin-5 (AQP5), a water channel protein, in the rat salivary and lacrimal glands: immunolocalization and effect of secretory stimulation (1999)
    Springer
    Cell & tissue research 295 (1999), S. 513-521 
    Details
    ISSN: 1432-0878
    Keywords: Key words Water channel protein ; Aquaporin ; AQP5 ; Rat ; Salivary glands ; Immunolocalization ; Secretory stimulation ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Aquaporin-5 (AQP5) is a water channel protein and is considered to play an important role in water movement across the plasma membrane. We raised anti-AQP5 antibody and examined the localization of AQP5 protein in rat salivary and lacrimal glands by immunofluorescence microscopy. AQP5 was found in secretory acinar cells of submandibular, parotid, and sublingual glands, where it was restricted to apical membranes including intercellular secretory canaliculi. In the submandibular gland, abundant AQP5 was also found additionally at the apical membrane of intercalated duct cells. Upon stimulation by isoproterenol, apical staining for AQP5 in parotid acinar cells tended to appear as clusters of dots. These results suggest that AQP5 is one of the candidate molecules responsible for the water movement in the salivary glands.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051257
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    Isolation and functional characterisation of a novel type of carotenoid biosynthetic gene from Xanthophyllomyces dendrorhous (1999)
    Springer
    Molecular genetics and genomics 262 (1999), S. 453-461 
    Details
    ISSN: 1617-4623
    Keywords: Key words Phytoene synthase ; Lycopene cyclase ; Complementation ; Astaxanthin ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The red heterobasidiomycetous yeast Xanthophyllomyces dendrorhous (perfect state of Phaffia rhodozyma) contains a novel type of carotenoid biosynthetic enzyme. Its structural gene, designated crtYB, was isolated by functional complementation in a genetically modified, carotenogenic Escherichia coli strain. Expression studies in different carotenogenic E. coli strains demonstrated that the crtYB gene encodes a bifunctional protein involved both in synthesis of phytoene from geranylgeranyl diphosphate and in cyclisation of lycopene to β-carotene. By sequence comparison with other phytoene synthases and complementation studies in E. coli with various deletion derivatives of the crtYB gene, the regions responsible for phytoene synthesis and lycopene cyclisation were localised within the protein.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004380051105
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    Seed oil fatty acid patterns of theAconitum-Delphinium-Helleborus complex (Ranunculaceae) (1999)
    Springer
    Plant systematics and evolution 215 (1999), S. 37-47 
    Details
    ISSN: 1615-6110
    Keywords: Ranunculaceae ; Aconitum ; Delphinium ; Helleborus ; Nigella ; Seed oil ; fatty acids ; phylogeny ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Many members ofRanunculaceae contain unusual fatty acids in their seed oils. This leads to rather typical genus-specific fatty acid patterns or “fingerprints” in these seed oils. The members of theDelphinioideae and/orHelleboroideae, however, do not contain highly unusual fatty acids. Nevertheless, their seed oil fatty acid fingerprints are also fairly typical and genus-specific, and the patterns found are rather consistent throughout several species of one genus. It was found that species ofAconitum do not contain fatty acids with 20 carbon atoms.Delphinium, Consolida, Helleborus, Nigella and others do contain C20 fatty acids. In allHelleborus species, for example, there was a consistent C20 fatty acid pattern of 20:0≪20:1≫20:2〉20:3. Species ofNigella andGaridella contain high levels,Helleborus low levels, of 20:2n-6 in their seed oils.Delphinium andAconitum both contain low levels of 18:3n-3, whereasHelleborus spp. consistently show high levels of this fatty acid. The genus-specific fatty acid patterns found are discussed, and a correlation with the subfamily and tribe affiliation of the genera investigated here is attempted.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00984646
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    Fruit differentiation, palynology, and systematics in theScabiosa group of genera andPseudoscabiosa (Dipsacaceae) (1999)
    Springer
    Plant systematics and evolution 216 (1999), S. 135-166 
    Details
    ISSN: 1615-6110
    Keywords: Dipsacaceae ; Pseudoscabiosa ; Scabiosa ; Sixalix ; Lomelosia ; Pycnocomon ; Scabiosiopsis ; Tremastelma ; Epicalyx ; fruit anatomy ; evolution ; systematics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Fruits ofDipsacaceae are single-seeded, have bristle-shaped calyx segments and are tightly enclosed by four fused bracts forming an epicalyx. Comparative morphological and anatomical studies reveal a great diversity of epicalyx and calyx, often relevant to fruit dispersal. The present contribution deals with theScabiosa group of genera, the core of theScabioseae tribe. Most of its taxa develop a diaphragma from a meristem on the inside of the epicalyx. This diaphragma, together with the lower part of the epicalyx encloses the fruit proper, whereas the upper parts form a so-called “epi-diaphragma” (ed) and a ± hyaline corona. Differences of the epicalyx with respect to the size and position of the ed, elaboration of the corona, origin of pits (=foveoles) and other morphological and anatomical specializations can be demonstrated. Together with palynological and karyological data these new facts support an improved concept of relationships and systematics for the taxa studied:Scabiosa sect.Scabiosa and sect.Cyrtostemma are closely related and should be united to form the genusScabiosa s. str.;Pycnocomon can be maintained as an independent genus, sister toScabiosa sect.Trochocephalus which then has to be treated as a genus,Lomelosia. In contrast, the following genera have to be included inLomelosia:Tremastelma asLomelosia sect.Callistemma, andScabiosiopsis as part ofLomelosia sect.Lomelosia. Pseudoscabiosa deviates in so many features that it has to be excluded from the redefinedScabioseae s. str.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00985103
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    Allozyme differentiation in the Mediterranean firs (Abies, Pinaceae). A first comparative study with phylogenetic implications (1999)
    Springer
    Plant systematics and evolution 216 (1999), S. 289-307 
    Details
    ISSN: 1615-6110
    Keywords: Gymnosperms ; Pinaceae ; A. alba ; A. cephalonica ; A. borisii-regis ; A. bornmuelleriana ; A. nordmanniana ; A. equi-trojani ; A. pinsapo ; A. numidica ; A. cilicica ; Allozyme variation ; genetic diversity ; phylogenetic relationships ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Nineteen natural Mediterranean fir populations, belonging to eight species and to one natural hybrid (A. ×borisii-regis), were investigated by starch and polyacrylamide gel electrophoresis. A total of 31 alleles was scored at eight loci (IDH-B, ACP-A, PER-B, 6PGD-A, 6PGD-B, MNR-B, PGI-B, PGM-A. Great variation was observed in the heterozygosity among the population studied and ranged from 0.010 (A. pinsapo) to 0.328 (A. cephalonica). The interpopulation genetic diversity was about 26% of the total genetic diversity. From the dendrogram, new phylogenetic relationships were revealed. High affinity was observed between the Calabrian fir population and the one from north-west Greece as well as betweenA. equi-trojani grown in Asia Minor and the southern Greek populations. Species specific alleles were found inA. cilicica. From the findings of the present work, a new hypothesis concerning the taxonomy, distribution and evolution ofAbies species in the Balkan Peninsula is supported.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01084404
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    The flagellar apparatus structure inMicrospora (Chlorophyceae) confirms a close evolutionary relationship with unicellular green algae (1999)
    Springer
    Plant systematics and evolution 217 (1999), S. 11-30 
    Details
    ISSN: 1615-6110
    Keywords: Chlorococcales ; Microsporales ; Microspora ; Absolute configuration ; classification ; evolution ; flagellar apparatus ; ultrastructure ; zoospore
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The spatial configuration of the flagellar apparatus of the biflagellate zoospores of the green algal genusMicrospora is reconstructed by serial sectioning analysis using transmission electron microscopy. Along with the unequal length of the flagella, the most remarkable characteristics of the flagellar apparatus are: (1) the subapical emergence of the flagella (especially apparent with scanning electron microscopy); (2) the parallel orientation of the two basal bodies which are interconnected by a prominent one-piece distal connecting fiber; (3) the unique ultrastructure of the distal connecting fiber composed of a central tubular region which is bordered on both sides by a striated zone; (4) the different origin of the d-rootlets from their relative basal bodies; (5) the asymmetry of the papillar region which together with the subapical position of the basal bodies apparently cause the different paths of corresponding rootlets in the zoospore anterior; (6) the presence of single-membered d-rootlets and multi-membered s-rootlets resulting in a 7-1-7-1 cruciate microtubular root system which, through the different rootlet origin, does not exhibit a strict 180° rotational symmetry. It is speculated that the different basal body origin of the d-rootlets is correlated with the subapical implant of flagella. It is further hypothesized that in the course of evolution the ancestors ofMicrospora had a flagellar papilla that has migrated from a strictly apical position towards a subapical position. Simultaneously, ‘ancestral’ shift of flagella along the apical cell body periphery has taken place as can be concluded from the presence of an upper flagellum overlying a lower flagellum in the flagellar apparatus ofMicrospora. The basic features of the flagellar apparatus of theMicrospora zoospore resemble those of the coccoid green algal generaDictyochloris andBracteacoccus and also those of the flagellate green algal genusHeterochlamydomonas. This strengthens the general supposition thatMicrospora is evolutionarily closely related to taxa which were formerly classified in the traditionalChlorococcales.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00984919
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    The cost of selfing inEncyclia cochleata (Orchidaceae) (1999)
    Springer
    Plant systematics and evolution 219 (1999), S. 55-64 
    Details
    ISSN: 1615-6110
    Keywords: Evolution ; Encyclia cochleata ; inbreeding depression ; isozymes ; Orchidaceae ; outcrossing ; phenotype ; population genetics ; selfing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract To determine whether inbreeding depression accounts for the maintenance of outcrossing in populations of the self-compatible orchidEncyclia cochleata, the estimated selective advantage of selfing was compared to a measure of inbreeding depression. Individuals from three populations ofE. cochleata and some of their progeny were phenotyped using isozyme analysis. The electrophoretic data were used to estimate the outcrossing rate and the theoretical cost of outcrossing. Inbreeding depression was estimated by comparing the fitness of the progeny resulting from both types of pollinations. The seeds from outcrossed and selfed hand-pollinations and naturally pollinated seeds from a population of the triandrous form ofE. cochleata were grown aseptically on culture media, and their development over the next three years recorded. Inbreeding was common, particularly in one population (outcrossing rate 40%). However, the level of inbreeding depression was only 1–2%, considerably less inbreeding depression than expected.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01090299
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    The species fitness method for the evolution of cooperative behavior in a group task (1999)
    Springer
    Artificial life and robotics 3 (1999), S. 127-132 
    Details
    ISSN: 1614-7456
    Keywords: Evolution ; Cooperative behavior ; Communication ; Species fitness ; Reciprocative
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract This paper considers the evolution of cooperative behaviors as the interaction among agents using a genetic algorithm to improve the performance of the task in a group (group performance). Previous research often usedthe group fitness method, which evaluates group performance for the evolution of multiple groups in parallel. However, this entails large simulation costs and the evolution speed is slow.The individual fitness method that evaluates theindividual performance of the task entails a smaller simulation cost. However, it can not improve the group performance since each agent behaves selfishly. To optimize the group performance, it is important to include bothcompetition andsharing. Therefore, this paper presentsthe species fitness method, which shares the individual performances of agents belonging to the same species in a group that all have the same chromosomes. We show comparative experiments on these three methods on the evolutionary simulation of a foraging task in a group. To test the interaction among the agents, four kinds of species are evolved which show their communication ability by demonstrating whether the agent can send or receive the signal for food. Experimental results show that evaluating the species variance fitness leads the agents into reciprocative actions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02481127
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    Computational evolution of human bipedal walking by a neuro-musculo-skeletal model (1999)
    Springer
    Artificial life and robotics 3 (1999), S. 133-138 
    Details
    ISSN: 1614-7456
    Keywords: Bipedal walking ; Evolution ; Neuro-musculoskeletal model ; Genetic algorithms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract The acquisition process of bipedal walking in humans was simulated using a neuro-musculo-skeletal model and genetic algorithms, based on the assumption that the shape of the body has been adapted for locomotion. The model was constructed as 10 two-dimensional rigid links with 26 muscles and 18 neural oscillators. Bipedal walking was generated as a mutual entrainment between neural oscillations and the pendulous movement of body dynamics. Evolutionary strategies incorporated, for example, as fitness in the genetic algorithms were assumed to decrease energy consumption, muscular fatigue, and load on the skeletal system. An initial population of 50 individuals was created, and an evolutionary simulation of 5000 steps was conducted. As a result, the shape of the body changed from that of a chimpanzee to that of a modern human, and the body size nearly reached the size of a modern human. These simulation results show that improving locomotive efficiency and reducing the load on the musculo-skeletal system are important factors affecting the evolution of the human body shape and bipedal walking. Such computer simulations help us to understand the process of evolution and adaptation for locomotion in humans.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02481128
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    Some personal reflections on the history of Bioeconomics (1999)
    Springer
    Journal of bioeconomics 1 (1999), S. 13-18 
    Details
    ISSN: 1573-6989
    Keywords: Malthus ; Darwin ; evolution ; policy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Economics
    Notes: Abstract This is a rather impressionist report of my recollections of the history of the bioeconomics field.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1010001905194
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    Bioeconomics as economics from a Darwinian perspective (1999)
    Springer
    Journal of bioeconomics 1 (1999), S. 19-34 
    Details
    ISSN: 1573-6989
    Keywords: Darwinian world view ; evolution ; evolutionary economics ; development ; subjectivism ; natural selection ; analogy ; adaptation ; evolutionary progress ; preferences ; genetic endowment ; growth of consumption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Economics
    Notes: Abstract Bioeconomics—the merging of views from biology and economics—on the one hand invites the 'export' of situational logic and sophisticated optimization developed in economics into biology. On the other hand, human economic activity and its evolution, not least over the past few centuries, may be considered an instance for fruitfully applying ideas from evolutionary biology and Darwinian theory. The latter perspective is taken in the present paper. Three different aspects are discussed in detail. First, the Darwinian revolution provides an example of a paradigm shift which contrasts most significantly with the 'subjectivist revolution' that took place at about the same time in economics. Since many of the features of the paradigmatic change that were introduced into the sciences by Darwinism may be desirable for economics as well, the question is explored whether the Darwinian revolution can be a model for introducing a new paradigm in economic theory. Second, the success of Darwinism and its view of evolution have induced economists who are interested in an evolutionary approach in economics to borrow, more or less extensively, concepts and tools from Darwinian theory. Particularly prominent are constructions based on analogies to the theory of natural selection. Because several objections to such analogy constructions can be raised, generalization rather than analogy is advocated here as a research strategy. This means to search for abstract features which all evolutionary theories have in common. Third, the question of what a Darwinian world view might mean for assessing long term economic evolution is discussed. Such a view, it is argued, can provide a point of departure for reinterpreting the hedonistic approach to economic change and development. On the basis of such an interpretation bioeconomics may not only go beyond the optimization-cum-equilibrium paradigm currently prevailing in economics. It may also mean adding substantial qualifications to the subjectivism the neoclassical economists, at the turn of the century, were proud to establish in the course of their scientific revolution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1010054006102
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    Fixing Content and Function in Neurobiological Systems: The Neuroethology of Electroreception (1999)
    Springer
    Biology and philosophy 14 (1999), S. 395-430 
    Details
    ISSN: 1572-8404
    Keywords: adaptationism ; Daniel C. Dennett ; electric fish ; electroreception ; evolution ; evolutionary function ; indeterminism ; mental content ; neuroethology ; sensory modality ; underdetermination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Philosophy
    Notes: Abstract Are attributions of content and function determinate, or is there no fact of the matter to be fixed? Daniel Dennett has argued in favor of indeterminacy and concludes that, in practice, content and function cannot be fixed. The discovery of an electrical modality in vertebrates offers one concrete instance where attributions of function and content are supported by a strong scientific consensus. A century ago, electroreception was unimagined, whereas today it is widely believed that many species of bony fish, amphibians, sharks, skates, and rays possess this non-human sensory modality. A look at the history of science related to this discovery reveals a highly interdisciplinary endeavor, encompassing ethology, behavioral analysis, neuroscience, and evolutionary biology. While each area provides important evidence, none is sufficient on its own to fix content and function. Instead, I argue that an interdisciplinary, neuroethological approach is required to carry out such determinations. Further, a detailed consideration of biological research suggests that while content and function claims are empirically underdetermined and uncertain, there is insufficient reason to believe in an additional problem of indeterminism. In particular, Dennett's indeterminism arises from a research methodology -- logical adaptationism -- that generates evidence from only one of the areas of neuroethology. However, logical adaptationism does not reflect adaptationism as it is practiced in contemporary biology. I conclude that Dennett is faced with a dilemma: On the one hand, he can hold to logical adaptationism and the indeterminism that results from it, while giving up the relevance of his arguments to biological practice. On the other, he can embrace a more accurate version of adaptationism -- one which plays a role in a larger neuroethological framework -- but from which no strong indeterminacy claims follow.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006594531789
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    Evolutionary Change and Epistemology (1999)
    Springer
    Biology and philosophy 14 (1999), S. 561-584 
    Details
    ISSN: 1572-8404
    Keywords: change ; evolution ; evolutionary epistemology ; selection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Philosophy
    Notes: Abstract This paper is concerned with the debate in evolutionary epistemology about the nature of the evolutionary process at work in the development of science: whether it is Darwinian or Lamarckian. It is claimed that if we are to make progress through the many arguments that have grown up around this issue, we must return to an examination of the concepts of change and evolution, and examine the basic kinds of mechanism capable of bringing evolution about. This examination results in two kinds of processes being identified, dubbed ‘direct’ and ‘indirect’, and these are claimed to exhaust all possibilities. These ideas are then applied to a selection of the debates within evolutionary epistemology. It is shown that while arguments about the pattern and rate of evolutionary change are necessarily inconclusive, those concerning the origin of novel variations and the mode of inheritance can be resolved by means of the distinctions made here. It is claimed that the process of selection in the evolution of science can also be clarified. The conclusion is that the main process producing the evolution of science is a direct or Lamarckian one although, if realism is correct, an indirect or Darwinian process plays a vital role.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006568200814
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    Preadaptation and the Explanation of Human Evolution (1999)
    Springer
    Biology and philosophy 14 (1999), S. 65-82 
    Details
    ISSN: 1572-8404
    Keywords: adaptation ; explanation ; evolution ; preadaptation ; specialization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Philosophy
    Notes: Abstract The concept of preadaptation, though useful, continues to trouble evolutionary scientists. Usually, it is treated as if it were really adaptation, prompting such diverse theorists as Gould and Vrba, and Dennett to suggest its removal from evolutionary theory altogether. In this paper, I argue that the as-if sense is ill-founded, and that the sense of preadaptation as a process may be defended as unequivocal and generally useful in evolutionary explanations, even in such problem areas as human evolution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006539827648
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    Modus Darwin (1999)
    Springer
    Biology and philosophy 14 (1999), S. 253-278 
    Details
    ISSN: 1572-8404
    Keywords: ancestry ; Bayesianism ; creationism ; Darwin ; evolution ; likelihood ; natural selection ; phylogeny ; probability ; Reichenbach
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Philosophy
    Notes: Abstract Modus Darwin is a principle of inference that licenses the conclusion that two species have a common ancestor, based on the observation that they are similar. The present paper investigates the principle's probabilistic foundations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006626115852
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    Retelling Experiments: H.B.D. Kettlewell's Studies of Industrial Melanism in Peppered Moths (1999)
    Springer
    Biology and philosophy 14 (1999), S. 39-54 
    Details
    ISSN: 1572-8404
    Keywords: experiment ; evolution ; industrial melanism ; natural selection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Philosophy
    Notes: Abstract H. B. D. Kettlewell's field experiments on industrial melanism in the peppered moth, Biston betularia, have become the best known demonstration of natural selection in action. I argue that textbook accounts routinely portray this research as an example of controlled experimentation, even though this is historically misleading. I examine how idealized accounts of Kettlewell's research have been used by professional biologists and biology teachers. I also respond to some criticisms of David Rudge to my earlier discussions of this case study, and I question Rudge's claims about the importance of purely observational studies for the eventual acceptance and popularization of Kettlewell's explanation for the evolution of industrial melanism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006576518561
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    A Model for the Dynamic Interaction Between Evolution and Learning (1999)
    Springer
    Neural processing letters 10 (1999), S. 181-193 
    Details
    ISSN: 1573-773X
    Keywords: evolution ; learning ; ontogeny ; neural development ; structure optimization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract The interaction between learning and evolution has elicited much interest particularly among researchers who use evolutionary algorithms for the optimization of neural structures. In this article, we will propose an extension of the existing models by including a developmental phase – a growth process – of the neural network. In this way, we are able to examine the dynamical interaction between genetic information and information learned during development. Several measures are proposed to quantitatively examine the benefits and the effects of such an overlap between learning and evolution. The proposed model, which is based on the recursive encoding method for structure optimization of neural networks, is applied to the problem domain of time series prediction. Furthermore, comments are made on problem domains which associate growing networks (size) during development with problems of increasing complexity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018724306675
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    The Histidine Decarboxylase (HDC) Gene of Tetrahymena Pyriformis is Similar to the Mammalian One. A Study of HDC Expression (1999)
    Springer
    Bioscience reports 19 (1999), S. 73-79 
    Details
    ISSN: 1573-4935
    Keywords: Histidine decarboxylase ; Tetrahymena ; gene sequencing ; evolution ; histamine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract RNA was isolated from Tetrahymena pyriformis GL and using human histidine decarboxylase (HDC) gene primers, the RT-PCR product was sequenced. A fraction containing 207 base pairs was compared to the published sequences of prokaryotic and mammalian (rat, mouse and human) HDC cDNA (exons). The HDC-cDNA fraction of Tetrahymena was similar to the mammalian cDNA-s and it was completely different from the prokaryotic HDC-gene. The results indicate the presence of a mammalian-like HDC-gene already in a unicellular eukaryote organism and demonstrates also that the divergence of the prokaryotic–eukaryotic common gene took place already at this low evolutionary level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1020102308791
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    Retrotransposon 1731 in Drosophila melanogaster changes retrovirus-like expression strategy in host genome (1999)
    Springer
    Genetica 107 (1999), S. 73-77 
    Details
    ISSN: 1573-6857
    Keywords: D. melanogaster ; evolution ; frameshifting ; retrotransposon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Earlier related to parasitic elements, retrotransposons of eukaryotes have been demonstrated to participate in general cell processes such as chromosome repair and evolution of gene expression (Teng et al., 1996; McDonald, 1993). Here, we report the existence of two class of genomic copies of retrotransposon 1731 with different expression strategies, one of which might be driven by natural selection. The first class uses conventional translation frameshifting known to ensure expression of revere transcriptase (RT) open reading frame (ORF), depending on the efficiency of frameshifting. The bulk of genomic copies are related to the second class where the frameshift is prevented as a result of the substitution of a rare codon recoginsing rare tRNA by a codon preferred by host genome, whereas the RT ORF is restored by downstream single nuclotide deletion. We suggest that natural selection has driven the switching of 1731 expression strategy from retrovirus-like to the fussion-ORF expression. This observation is in accordance with the detection in testes of fused Gag-RT polypetide encoded by 1731. The abundance of RT in testes may serve for normal development of host tissue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003969625694
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    The bioavailability of magnesium from Wakame ( Undaria pinnatifida) and Hijiki (Hijikia fusiforme) and the effect of alginic acid on magnesium utilization of rats (1999)
    Springer
    Plant foods for human nutrition 53 (1999), S. 265-274 
    Details
    ISSN: 1573-9104
    Keywords: Bioavailability ; Magnesium ; Hijiki ; Sodium alginate ; Rat ; Wakame
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The bioavailability of magnesium from Wakame and Hijiki, and the effects of alginic acid on absorption of dietary magnesium were examined in five groups of rats fed either control, Wakame, Hijiki, AW (containing the same amount of alginate as in the Wakame) and AH (containing the same amount of alginate as in the Hijiki) diets, and animals fed a low magnesium diet (LMg) (twentieth amount of magnesium in the original mineral mixtures as the control). Food intake and body weight gain were decreased by adding sodium alginate to the diets. A large amount of calcium accumulated only in the kidneys of the rats fed the LMg diet. Serum magnesium concentration decreased only in the LMg group. The magnesium content in the defatted left femurs did not differ between the control and Wakame fed animals and also among the animals eating Wakame, Hijiki and AW diets. The breaking force of the right femurs did not differ among all the groups except the LMg group. The ratio of apparent magnesium absorption (%) of the control, LMg, Wakame, Hijiki, AW and AH groups was 82.2, 72.7, 66.9, 50.8, 69.3 and 54.2 in the first experimental period, and was 75.3, 52.1, 57.7, 46.9, 62.6 and 60.5 in the second experimental period, respectively. It was clear that the bioavailability of magnesium in the Wakame fed rats was higher than in those eating the Hijiki. Large amounts of sodium alginate lowered magnesium absorption from the diet.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008082112178
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    Allozyme variation in relation to morphology and taxonomy inMedicago sect.Spirocarpos subsect.Intertextae (Fabaceae) (1999)
    Springer
    Plant systematics and evolution 214 (1999), S. 29-47 
    Details
    ISSN: 1615-6110
    Keywords: Fabaceae ; Medicago ; Systematics ; evolution ; allozymes ; isozymes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Medicago intertexta andM. ciliaris have been controversially recognized as separate species. The only reliable diagnostic character, gland-tipped trichomes on the fruits inM. ciliaris, is controlled by presence of a single dominant allele, and such one-character taxonomies are debatable. Contributing to the difficulty,M. muricoleptis andM. granadensis, the other two species ofMedicago sectionSpirocarpos subsectionIntertextae, are sometimes confusingly similar toM. intertexta or to each other. Allozyme differences provided 95% verification of the suitability of the gland-tipped trichome character for separatingM. intertexta andM. ciliaris, thus corroborating their recognition as separate taxa. Several measures of allozyme variation indicated thatM. intertexta is more polymorphic than its sister species. Heterozygosity was also highest inM. intertexta, suggestive of a higher outcrossing rate, which is also consistent with larger floral size. Heterozygosity ofM. intertexta was concentrated in Sicily and nearby countries. Taxonomic difficulties in identifying SicilianM. intertexta are well known, and may be the result of interspecific hybridization and introgression.Medicago muricoleptis differed from the above two species in the frequency of several alleles, whileM. granadensis possessed numerous unique alleles consistent with its complete absence of genetic exchange with the other three substantially interfertile species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00985730
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    The bicolor unit — homology and transformation of an inflorescence structure unique to coreMalvales (1999)
    Springer
    Plant systematics and evolution 214 (1999), S. 187-198 
    Details
    ISSN: 1615-6110
    Keywords: Malvales ; Sterculiaceae ; Tiliaceae ; Bombacaceae ; Malvaceae ; Inflorescence morphology ; epicalyx ; systematics ; homology ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A broad comparative analysis reveals that the inflorescences of coreMalvales, familiesSterculiaceae, Tiliaceae, Bombacaceae andMalvaceae, include characteristic repeating units. The basic repeating unit is called bicolor unit (afterTheobroma bicolor, where it was first observed). It is determinate and bears three bracts, one of which is invariably sterile, whereas the others subtend lateral cymes or single flowers. Through the demonstration of intermediate steps in closely related taxa the triad of bracts within a bicolor unit and the trimerous malvalean epicalyx are shown to be homologous. Various possibilities for an origin of the bicolor unit are discussed. Bicolor units are variously arranged to form complete inflorescences. In many taxa they are terminal on modules that comprise two (or fewer) prophylls. These modules may be arranged in elongated anthocladia or condensed sympodia, which in turn may constitute components of higher order inflorescence structures. The presence of the bicolor unit or its derivatives linksSterculiaceae, Tiliaceae, Bombacaceae andMalvaceae. It is absent from all other families included in a broader defined orderMalvales and represents one of the rare morphological synapomorphies of coreMalvales. Furthermore, inflorescence morphology provides characters of systematic significance for various taxa within coreMalvales.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00985738
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    Genetic variation and putative hybridization inSalix alba andS. fragilis (Salicaceae): Evidence from allozyme data (1999)
    Springer
    Plant systematics and evolution 215 (1999), S. 169-187 
    Details
    ISSN: 1615-6110
    Keywords: Salicaceae ; Salix alba ; S. fragilis ; Allozymes ; clones ; population structure ; hybridization ; polyploidy ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Genetic variability was estimated by enzyme electrophoresis in 239 Belgian clones from theSalix alba-S. fragilis complex. This morphological complex suggested a high frequency of hybrids. To test this hypothesis, the clones were pooled as a single co-adapted species complex and secondly as belonging to either species, i.e. beingS. alba-like orS. fragilis-like. The standard genetic variability measures showed higher values for the complex than for the separate species. However, the observed mean heterozygosity was lower in the putative hybrid complex than for each of the species separately. The fixation indices were more variable at the species level and indicated that mostS. fragilis locations appeared fixed forlap-1, whereas no fixation occured inS. alba locations. Averaged at the regional (i.e. catchment) level, this difference between the two species remained and values ranged from 0.457 to 0.617 inS. alba and were much higher, fixed homozygous or monomorph inS. fragilis. Hierarchical F-statistics revealed that most of the differentiation occured at the lower levels of localities and tributaries and that there was no further differentiation between catchments. Tributaries which are 10–25km in length were proposed as the most likely entities for further examination of putative hybridization and events of allelic fixations. By considering the two abovementioned approaches of data input, it could be suggested that most of the allozyme differentiation was between the species and less between the regions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00984654
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    Phylogenetic study on wild allies of Lima bean,Phaseolus lunatus (Fabaceae), and implications on its origin (1999)
    Springer
    Plant systematics and evolution 218 (1999), S. 43-54 
    Details
    ISSN: 1615-6110
    Keywords: Fabaceae ; Phaseolus ; Phaseolus lunatus ; Taxonomy ; germplasm ; evolution ; origin ; allozyme ; Latin America
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract An investigation was made of the phylogenetic relationships among wild accessions of Lima bean (Phaseolus lunatus) and wild allies of Mesoamerican and Andean origins, using electrophoresis of seed storage proteins and isozymes. Mesoamerican wild species are phylogenetically more distant fromP. lunatus than Andean species, and apparently belong to the tertiary gene pool of Lima bean. The Andean wild species, which are investigated for the first time, reveal a high similarity to the Lima bean, and particularly with its Mesoamerican gene pool. These Andean species probably constitute a secondary gene pool of Lima bean, and are thus of considerable interest in the context of genetic improvement of the crop. Based on these observations, an Andean origin is suggested for the Andean wild species and forP. lunatus. These results point out the importance of collecting and conserving AndeanPhaseolus germplasm.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01087033
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    Floral scent chemistry and pollination ecology in phytelephantoid palms (Arecaceae) (1999)
    Springer
    Plant systematics and evolution 217 (1999), S. 279-297 
    Details
    ISSN: 1615-6110
    Keywords: Arecaceae ; Phytelephantoideae ; Aleocharinae ; Baridinae ; Derelomini ; Mystrops ; Xanthopygus ; Brood-site pollination ; dioecy ; evolution ; floral scents ; flower-breeding ; pollination ; thermogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The subfamilyPhytelephantoideae comprises three genera (Ammandra, Aphandra, andPhytelephas) and seven species of dioecious palms. The floral scents ofAmmandra dasyneura, A. decasperma, Aphandra natalia, Phytelephas aequatorialis, P. macrocarpa, andP. seemannii were analyzed by gas chromatography-mass spectrometry. We studied the pollination biology ofA. natalia, P. aequatorialis, andP. macrocarpa, and tested how the synthetically produced main constituents of the floral scents ofAphandra andPhytelephas attracted insects in two natural populations ofPhytelephas. The genera are distinct in terms of floral scents.Ammandra has sesquiterpenes,Aphandra (+)-2-methoxy-3-sec-butylpyrazine, andPhytelephas p-methyl anisol. These constituents dominated the scents quantitatively and qualitatively. The similarity between scents of male and female inflorescences was 76.5% inAmmandra, 84.2% inAphandra, and 〉99% inPhytelephas. Different species ofAleocharinae (Staphylinidae) pollinateAphandra natalia andPhytelephas species and reproduce in their male inflorescences.Derelomini (Curculinoidae) andMystrops (Nitidulidae) only visit and pollinatePhytelephas in which male inflorescences they reproduce. A species ofBaridinae (Curculionidae) only visits and pollinatesAphandra natalia, and reproduces in its female inflorescence. The apparent reliance on one or a few floral scent constituents as attractants and few and specific pollinators may indicate co-evolution. Sympatric species ofPhytelephantoideae have different scents. We suggest that species with similar scents have allopatric distributions due to the absence of a pollinator isolation mechanism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00984371
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    A monophyletic origin of the B chromosomes ofBrachycome dichromosomatica (Asteraceae) (1999)
    Springer
    Plant systematics and evolution 219 (1999), S. 127-135 
    Details
    ISSN: 1615-6110
    Keywords: Asteraceae ; Brachycome ; B chromosome ; polymorphism ; evolution ; karyotyping ; centromere
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The A and B chromosomes of different karyotype variants (cytodemes A1, A2, A3 and A4) ofBrachycome dichromosomatica were analysed by computer-aided chromosome image analysis and fluorescencein situ hybridisation (FISH). Ribosomal DNA and the B chromosome-specific sequence Bd49 were detected on all B chromosomes. In addition to minor size variation of the Bs, polymorphism of the rDNA and Bd49 position and copy number revealed two major types of B chromosomes. The B chromosomes of all the cytodemes were indistinguishable from each other in length, but that of A3 showed evidence of rearrangements consistent with its long-term geographic isolation. The results presented suggest a monophyletic origin of the B chromosomes ofB. dichromosomatica.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01090304
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    Phylogenetic relationships of the enigmatic fern families Hymenophyllopsidaceae and Lophosoriaceae: Evidence fromrbcL nucleotide sequences (1999)
    Springer
    Plant systematics and evolution 219 (1999), S. 263-270 
    Details
    ISSN: 1615-6110
    Keywords: Hymenophyllopsis ; Lophosoria ; molecular systematics ; evolution ; rbcL ; phylogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Nucleotide sequences fromrbcL were used to infer relationships of Lophosoriaceae and Hymenophyllopsidaceae. The phylogenetic positions of these two monotypic fern families have been debated, and neither group had been included in recent molecular systematic studies of ferns. Maximum parsimony analysis of our data supported a sister relationship betweenLophosoria andDicksonia, and also betweenHymenophyllopsis andCyathea. Thus, both newly-examined families appear to be part of a previously characterized and well-supported clade of tree ferns. The inferred relationships ofLophosoria are consistent with most (but not all) recent treatments. However,Hymenophyllopsis includes only small delicate plants superficially similar to filmy ferns (Hymenophyllaceae), very different from the large arborescent taxa. Nevertheless, some synapomorphic characteristics are shared with the tree fern clade. Further studies on gametophytes ofHymenophyllopsis are needed to test these hypotheses of relationship.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00985583
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    A Tourist element in the 5′-flanking region of the catalase gene CatA reveals evolutionary relationships among Oryza species with various genome types (1999)
    Springer
    Molecular genetics and genomics 262 (1999), S. 493-500 
    Details
    ISSN: 1617-4623
    Keywords: Key words Catalase ; Oryza ; Rice ; Evolution ; Tourist
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Tourist-OsaCatA, a transposable element, was found in the 5′-flanking region of the rice gene CatA. The characteristics of this element are similar to those of the other Tourist elements so far found in Oryza sativa. PCR and sequence analyses of 37 accessions of 18 species revealed that all the Oryza species examined, except for one accession, have either a full-length or a partial Tourist element at this locus. Unlike the Tourist elements previously reported, this Tourist element is found in all four Oryza species complexes in the Oryzeae tribe. All AA genome Oryza species, except O. longistaminata, contain the full-length Tourist element. O. longistaminata and the species of the O. officinalis, O. meyeriana and O. ridleyi complexes contain the partial element. A phylogenetic tree of Oryza species based on the nucleotide sequences of these Tourist elements was constructed. The O. longistaminata accessions were placed near the neighboring cluster of the officinalis complex. We propose that the ancestor of O. longistaminata and that of other species with the AA genome diverged, and the ancestor(s) of the O. officinalis, O. ridleyi and O. meyeriana complexes then diverged from the ancestor of O. longistaminata in the course of the evolution of the Oryza species. The Tourist elements associated with CatA and its orthologs thus provide useful tools for examining evolutionary relationships among Oryza species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004380051110
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    Representational difference analysis identifies a strain-specific LPS biosynthesis locus in Bordetella spp. (1999)
    Springer
    Molecular genetics and genomics 262 (1999), S. 189-198 
    Details
    ISSN: 1617-4623
    Keywords: Key wordsBordetella spp. ; Evolution ; Lipopolysaccharide biosynthesis ; Pulsed-field gel electrophoresis ; Representational difference analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Bordetella pertussis and B. bronchiseptica are genetically very closely related but differ significantly in their virulence properties. Using Representational Difference Analysis (RDA), 11 DNA fragments specific for B. pertussis Tohama I or B. bronchiseptica BB7865 were identified. All B. bronchiseptica BB7865-derived fragments also hybridized with chromosomal DNA from B. parapertussis but not from the B. pertussis strains Tohama I and W28, underlining the close phylogenetic relationship between B. bronchiseptica and B. parapertussis. The B. pertussis type strain BP18323 is a special case, as it contains DNA sequences characteristic for both B. pertussis and B. bronchiseptica. As demonstrated by pulsed-field gel electrophoresis, several of the BB7865-derived fragments are present on a single 30-kb XbaI fragment. Based on the sequences of putative coding regions, four of these fragments may code for proteins involved in carbohydrate metabolism or transport. In agreement with this notion, a mutant for one of these loci synthesizes a significantly altered lipopolysaccharide that lacks the O-specific side chains. The analysis of the corresponding genomic region in various Bordetella species showed that this locus is present in B. bronchiseptica and B. parapertussis but not in B. pertussis. This confirms that the RDA approach has identified a novel strain-specific LPS biosynthesis locus which accounts for the differences between the LPS structures elaborated by different Bordetella species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004380051074
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    Evidence for functional convergence of redox regulation in G6PDH isoforms of cyanobacteria and higher plants (1999)
    Springer
    Plant molecular biology 40 (1999), S. 487-494 
    Details
    ISSN: 1573-5028
    Keywords: cysteine positions ; evolution ; gene duplication ; glucose-6-phosphate dehydrogenase ; isoform classes ; redox regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In a recent paper (Wenderoth et al., J Biol Chem 272: 26985–26990, 1997) we reported that the positions of the two redox regulatory cysteines identified in a plastidic G6PD isoform from potato (Solanum tuberosum L.) differ substantially from those conserved in cyanobacterial G6PDH sequences. To investigate the origin of redox regulation in G6PDH enzymes from photoautotrophic organisms, we isolated and characterized several G6PD cDNA sequences from higher plants and from a green and a red alga. Alignments of the deduced amino acid sequences showed that the cysteine residues cluster in the coenzyme-binding domain of the plastidic isoforms and are conserved at three out of six positions. Comparison of the mature proteins and the signal peptides revealed that two different plastidic G6PDH classes (P1 and P2) evolved from a common ancestral gene. The two algal sequences branch off prior to this class separation in higher plants, sharing about similar amino acid identity with either of the two plastidic G6PDH classes. The genes for cytosolic plant isoforms clearly share a common ancestor with animal and fungal G6PDH homologues, whereas the cyanobacterial isoforms branch within the eubacterial G6PDH sequences. The data suggest that cysteine-mediated redox regulation arose independently in G6PDH isoenzymes of eubacterial and eukaryotic lineages.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006257230779
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    Phylogeny of Vicia Subgenus Vicia (Fabaceae) Based on Analysis of RAPDs and RFLP of PCR-Amplified Chloroplast Genes (1999)
    Springer
    Genetic resources and crop evolution 46 (1999), S. 149-161 
    Details
    ISSN: 1573-5109
    Keywords: evolution ; genetic resources ; PCR-RFLP ; RAPDs ; Vicia ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract We report the results of two methods of DNA analysis to elucidate phylogenetic relationships among 29 Vicia subgen. Vicia species in comparison with two species of subgenus Vicilla sect. Vicilla. The methods employed were RAPD analysis of total genomic DNA and PCR-RFLP analysis of five chloroplast genes, rbcL, rpoB, 16S, psaA and trnK. The results of each method were similar and complementary, and support the current taxonomic systems of subsp. Vicia. According to RAPD and PCR-RFLP analysis the Narbonensis complex can be considered a well separated section, which may be related to section Vicia. Sections Vicia, Atossa and Wiggersia are separate, but closely related sections. Species of the section Hypechusa form a single monophyletic section, where V. lutea, V. anatolica and V. hyrcanica are quite remote from other species. Our results suggest that within the subgenus Vicia, V. faba is more closely related to V. bithynica and that these two species are most closely related to section Peregrinae. We found that PCR-RFLP of cp DNA provided more precise information concerning relationships between Vicia sections than RAPD analysis. However, RAPD analysis was more informative concerning diversity of closely related Vicia taxa, such as the variable groups, section Narbonensis and V. sativa aggregate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008640322198
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    Cytogenetic relationships between Avena insularis (2n=28) and both A. strigosa (2n=14) and A. murphyi (2n=28) (1999)
    Springer
    Genetic resources and crop evolution 46 (1999), S. 501-504 
    Details
    ISSN: 1573-5109
    Keywords: cytogenetics ; evolution ; interspecific hybrids ; oat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The newly discovered tetraploid oat Avena insularis was crossed with the diploid A. strigosa and the tetraploid A. murphyi. Considerably reduced chromosome association at meiosis and a low average number of chiasmata per cell of the A. strigosa × A. insularis hybrids indicated that the diploid A. strigosa did not participate in the creation of A. insularis. From A. murphyi, A. insularis differed by four chromosomal rearrangements and the hybrids between them were sterile. The tetraploids A. magna, A. murphyi and A. insularis share the two to four floret large diaspore, which is adapted to heavy alluvial soil. They all, however, diverge from one another by four chromosomal rearrangements. At this point it is not possible to determine whether they have diverged from a single tetraploid progenitor, or developed from different diploid species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008728316354
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    Conservation and innovation in spiralian development (1999)
    Springer
    Hydrobiologia 402 (1999), S. 255-265 
    Details
    ISSN: 1573-5117
    Keywords: evolution ; spiral cleavage ; Spiralia ; cell lineage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract It is clear that the spiralian developmental program represents a highly flexible platform for the generation of diverse larval and adult body plans. The widespread occurrence of this pattern of early development attests to its tremendous evolutionary success. Despite the large degree of conservation in the spiral cleavage pattern and other basic aspects of early development, changes in cell fate maps and in the mechanisms of blastomere specification have arisen. While we have learned a great deal about this mode of development, a number of important questions remain to be answered. To what extent do these conditions apply to the lesser studied spiralian phyla? What constraints have led to the preservation of the early spiral cleavage program? How has this developmental program been adapted for the construction of the various spiralian body plans (e.g. the segmental body plans of annelids or to the potential secondary loss of segmentation)? Are most changes associated with the elaboration of these different larval and adult body plans restricted to the late period of development? What molecular/genetic processes underlie this developmental program? Clearly, the spiralian phyla represent an important group of organisms for further studies on development and evolution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003756912738
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    Lumbriculids, branchiobdellidans and leeches: an overview of recent progress in phylogenetic research on clitellates (1999)
    Springer
    Hydrobiologia 406 (1999), S. 281-290 
    Details
    ISSN: 1573-5117
    Keywords: evolution ; Branchiobdellida ; Hirudinea ; Clitellata ; Lumbriculidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The debates about the relationship among clitellate taxa at research conferences on aquatic oligochaetes have provided two alternative hypotheses. While both involve cladistic analyses, the differences focus on questions of homology. A single unique synapomorphy supports a taxon consisting of Branchiobdellida plus Lumbriculidae. Muscle ultrastructure provides a potential autapomophy for Lumbriculidae within the clade, while Branchiobdellida has many autapomophies. Some proposed synapomorphies for a Branchiobdellida plus Hirudinea grouping (jaws, oral sucker) are not based on homologous structures. Others (loss of chaetae, median male pore) are not unique, or are based on potentially convergent characters. Initial molecular analyses support a Branchiobdellida - Hirudinea grouping. A preliminary manually drawn cladogram based on re-evaluated characters supports Lumbriculidae, Branchiobdellida, Acanthobdella and Euhirudinea as a monophyletic taxon. Observations on sperm ultrastructure support this hypothesis. If substantiated, a very considerable change in nomenclature will result. However, before any nomenclatural changes are proposed, a resolution of the apparently paraphyletic Oligochaeta is necessary.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003717107907
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    Alternative Ways to Become a Juvenile or a Definitive Phenotype (and on Some Persisting Linguistic Offenses) (1999)
    Springer
    Environmental biology of fishes 56 (1999), S. 17-38 
    Details
    ISSN: 1573-5133
    Keywords: embryo ; larva ; metamorphosis ; indirect or direct development ; life-history model ; altricial ; precocial ; allometry ; fish biologists vs. fishery biologists ; alprehost ; ontogeny ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Lack of knowledge of early and juvenile development often makes it difficult to decide when a fish becomes a juvenile or, for that matter, a definitive phenotype. According to the established life-history model, a fish develops naturally in a saltatory manner, its entire life consisting of a sequence of stabilized self-organizing steps, separated by distinct less stabilized thresholds. Changes are usually introduced during thresholds. In principle, there are two ways to reach the juvenile period: by indirect or by direct development. Indirectly developing fishes have a distinct larva period that ends in a cataclysmic or mild remodeling process, called metamorphosis, from which the fishes emerge as juveniles. During metamorphosis, most temporary organs and structures of the embryos and larvae are replaced by definitive organs and structures that are also possessed by the adults. In contrast, directly developing fishes have no larvae. Their embryos develop directly into juveniles and do not need major remodeling. Consequently, the beginning of their juvenile period is morphologically and functionally less distinct than in indirect development. The life-history model helps to find criteria that identify the natural boundaries between the different periods in the life of a fish, among them, the beginning of the juvenile period. Looking at it from a different angle, when ontogeny progresses from small eggs with little yolk, larvae are required as the necessary providers of additional nutrients (‘feeding entities’ similar to amphibian tadpoles or butterfly caterpillars) in order to accumulate materials for the metamorphosis into the definitive phenotypes. Directly developing fishes start with large demersal eggs provided with an adequate volume of high density yolk and so require no or little external nutrients to develop into the definitive phenotype. These large eggs are released and develop in concentrated clutches. It therefore becomes possible and highly effective to guard them in nests or bear them in external pouches, gill chambers or the buccal cavity. Viviparity is the next natural step. Now the maternal investment into large yolks can be supplemented or replaced by direct food supply to the developing embryos like, for example, the secretion of uterine histotrophe or nutrient transfer via placental analogues. When the young of guarders and bearers start exogenous feeding, they are much larger or better developed than larvae of nonguarders and the larva period in the former is reduced to a vestige or eliminated entirely. In the latter case, the juvenile period begins with the first exogenous feeding. Such precocial fishes are more specialized and able to survive better in competitive environments. In contrast, altricial forms retain or revert to a life-history style with indirect development and high fecundity when dispersal is advantageous or essential. Fishes become juveniles when the definitive phenotype is formed in most structures, either indirectly from a larva via metamorphosis or directly from the embryo.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007502209082
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    Phylogeny, evolution and classification of the Branchiopoda (Crustacea) (1999)
    Springer
    Hydrobiologia 412 (1999), S. 191-212 
    Details
    ISSN: 1573-5117
    Keywords: Branchiopoda ; paleontology ; phylogeny ; evolution ; classification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We present a cladistic analysis of all branchiopod groups, using a total of 42 morphological characters. The class Branchiopoda is composed of five superorders and 11 orders (nine recent, two fossil). The orders Ctenopoda, Anomopoda and Onychopoda form a monophyletic group, combined in the superorder Cladocera. The order Haplopoda, the fourth so-called cladoceran order (s. lat.), belongs to a new monotypic superorder, the Leptodorida. The circumtropical Cyclesteria hislopi is the sole representative of a new conchostracan order, the Cyclestherida.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003894207100
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    Comparative Chromosome Painting Between Marsupial Orders: Relationships with a 2n = 14 Ancestral Marsupial Karyotype (1999)
    Springer
    Chromosome research 7 (1999), S. 509-517 
    Details
    ISSN: 1573-6849
    Keywords: chromosome painting ; evolution ; karyotype ; marsupials
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A 2n = 14 karyotype is shared by some species in each of the marsupial orders in Australian and American superfamilies, suggesting that the ancestral marsupial chromosome complement was 2n = 14. We have used chromosome painting between distantly related marsupial species to discover whether genome arrangements in 2n = 14 species in two Australian orders support this hypothesis. Cross-species chromosome painting was used to investigate chromosome rearrangements between a macropodid species Macropus eugenii (2n = 16) and a wombat species in a different suborder (Lasiorhinus latifrons, 2n = 14), and a dasyurid species in a different order (Sminthopsis macroura, 2n = 14). We demonstrate that many chromosome regions are conserved between all three species, and deduce how the similar 2n = 14 karyotypes of species in the two orders are related to a common ancestral 2n = 14 karyotype.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009233327176
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    Is the evolution of transposable elements modular? (1999)
    Springer
    Genetica 107 (1999), S. 15-25 
    Details
    ISSN: 1573-6857
    Keywords: DDE signature ; env ; evolution ; gag ; transposable elements
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The evolution of transposable element structures can be analyzed in populations and species and by comparing the functional domains in the main classes of elements. We begin with a synthesis of what we know about the evolution of the mariner elements in the Drosophilidae family in terms of populations and species. We suggest that internal deletion does not occur at random, but appears to frequently occur between short internal repeats. We compared the functional domains of the DNA and/or amino acid sequences to detect similarities between the main classes of elements. This included the gag, reverse transcriptase, and envelope genes of retrotransposons and retroviruses, and the integrases of retrotransposons and retroviruses, and transposases of class II elements. We find that each domain can have its own evolutionary history. Thus, the evolution of transposable elements can be seen to be modular.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004026821539
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    Structure and Function of the A1A0-ATPases from Methanogenic Archaea (1999)
    Springer
    Journal of bioenergetics and biomembranes 31 (1999), S. 15-27 
    Details
    ISSN: 1573-6881
    Keywords: archaea ; methanogens ; bioenergetics ; ATPases ; ATP synthases ; evolution ; proteolipids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Physics
    Notes: Abstract Recent molecular studies revealed nine to ten gene products involved infunction/assembly of the methanoarchaeal ATPase and unravel a closerelationship of the A1A0-ATPase and theV1V0-ATPase with respect to subunit composition and thestructure of individual subunits. Most interestingly, there is anastonishing variability in the size of the proteolipids in methanoar chaealA1A0-ATPases with six, four, or two transmembranehelices and a variable number of conserved protonizable groups per monomer.Despite the structural similarities the A1A0-ATPasediffers fundamentally from the V1V0-ATPase by itsability to synthesize ATP, a feature shared withF1F0-ATPases. The discovery of duplicated andtriplicated versions of the proteolipid in A1A0-ATPsynthases questions older views of the structural requirements for ATPsynthases versus ATP hydrolases and sheds new light on the evolutionof these secondary energy converters.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005451311009
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    Genomes were forged by massive bombardments with retroelements and retrosequences (1999)
    Springer
    Genetica 107 (1999), S. 209-238 
    Details
    ISSN: 1573-6857
    Keywords: evolution ; genomic symbionts ; host defense ; impact on genomes ; retronuons ; reverse transcription ; template switching
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Retroposition is an efficient route to move coding regions around the genome ‘in search’ of novel regulatory elements and to shotgun regulatory elements into the genome ‘in search’ of new target genes. The templates for such retrogenes are mRNAs, and for regulatory retronuons (nuon=any definable nucleic acid sequence) usually small non-mRNAs. An example in support of the ‘master gene’ model for SINEs (short interspersed repetive elements) is provided with neuronal BC1 RNA. Furthermore, an alternative explanation of LINE (long interspersed repetive elements) involvement in the generation of SINEs is given. I will also argue that the status of transposable elements with respect to the host resembles more symbiosis than parasitiasis and that host defense is often lenient as if even to ‘tolerate or support’ retronuons. Finally the paradox of evolution's lack of foresight and the future exaptive use of retronuons is being dealt with by referring to W.F. Doolittle's ‘Hierarchical Approaches to Genome Evolution’.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004018519722
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    Evolution of Acoustic Communication Signals of Mammals: Friendly Close-Range Vocalizations in Felidae (Carnivora) (1999)
    Springer
    Journal of mammalian evolution 6 (1999), S. 129-159 
    Details
    ISSN: 1573-7055
    Keywords: acoustic communication ; cats ; evolution ; Felidae ; vocalization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The distribution of the three friendly close-range vocalization types known in the Felidae was plotted on a recently published phylogeny of the cat family (Felidae) based on sequence comparisons of two mitochondrial DNA genes and other molecular and biochemical characters, with extrapolated divergence ages of its various lineages. It was found to be congruent with this phylogeny. One of the sound types is likely to be present in 30 species of the family (documented in 22 so far), another is present in 4, and the third in 2 species only; these sound types represent a phylogenetic transformation series. The latter two vocalization types also differ considerably from the first in the mode of sound production. From this, evolutionary conservatism over a long epoch for the one widespread vocalization type can be inferred, and less conservatism in the type present in four species, while the emergence of the least common type is evidence of relatively considerable and rapid evolutionary change. Thus, acoustic communication signals in a group of taxa can evolve at considerably different rates, and for a specific character this rate can differ between different lineages of that group. The ultimate causes of the evolutionary stability or of the subsequent relatively rapid change in sound structure and mode of sound production in these felid vocalizations are unknown.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1020620121416
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    Does evolution reduce the body size? A study of the four members of newly evolved nasuta‐albomicans complex of Drosophila (1999)
    Springer
    Genetica 105 (1999), S. 1-6 
    Details
    ISSN: 1573-6857
    Keywords: Drosophila ; nasuta-albomicans ; complex ; cytoraces ; body size ; fertility ; ovariole number ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Our long range interracial hybridization experiments between a pair of cross fertile races, Drosophila nasuta (2n = 8) and D.albomicans (2n = 6) have resulted in the evolution of two new karyotypic strains under laboratory conditions, which are named as Cytorace 1 and Cytorace 2. These Cytoraces harbor chromosomes from both parents. Here, we compare the body size of the parental races and newly evolved Cytoraces and the relationship between the body size and fitness. Analysis reveals that the parental races have reduced fertility and are larger in body size than newly evolved Cytoraces. Thus, the newly evolved Cytoraces show reduced body size and better fitness in the course of their evolution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003762826116
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    Evolution and Analysis of Model CPGs for Walking: II. General Principles and Individual Variability (1999)
    Springer
    Journal of computational neuroscience 7 (1999), S. 119-147 
    Details
    ISSN: 1573-6873
    Keywords: central pattern generators ; dynamical modules ; computational neuroethology ; walking ; biomechanics ; evolution ; dynamical systems theory
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Medicine , Physics
    Notes: Abstract Are there general principles for pattern generation? We examined this question by analyzing the operation of large populations of evolved model central pattern generators (CPGs) for walking. Three populations of model CPGs were evolved, containing three, four, or five neurons. We identified six general principles. First, locomotion performance increased with the number of interneurons. Second, the top 10 three-, four-, and five-neuron CPGs could be decomposed into dynamical modules, an abstract description developed in a companion article. Third, these dynamical modules were multistable: they could be switched between multiple stable output configurations. Fourth, the rhythmic pattern generated by a CPG could be understood as a closed chain of successive destabilizations of one dynamical module by another. A combinatorial analysis enumerated the possible dynamical modular structures. Fifth, one-dimensional modules were frequently observed and, in some cases, could be assigned specific functional roles. Finally, dynamic dynamical modules, in which the modular structure itself changed over one cycle, were frequently observed. The existence of these general principles despite significant variability in both patterns of connectivity and neural parameters was explained by degeneracy in the maps from neural parameters to neural dynamics to behavior to fitness. An analysis of the biomechanical properties of the model body was essential for relating neural activity to behavior. Our studies of evolved model circuits suggest that, in the absence of other constraints, there is no compelling reason to expect neural circuits to be functionally decomposable as the number of interneurons increase. Analyzing idealized model pattern generators may be an effective methodology for gaining insights into the operation of biological pattern generators.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008920021246
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...