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
  • Articles  (242)
  • Evolution  (163)
  • stability
  • wheat
  • Springer  (242)
  • 1990-1994  (242)
  • Biology  (242)
  • 1
    Electronic Resource
    Electronic Resource
    Effect of experience on in-flight orientation to host-associated cues in the generalist parasitoidLysiphlebus testaceipes (1993)
    Springer
    Entomologia experimentalis et applicata 68 (1993), S. 219-229 
    Details
    ISSN: 1570-7458
    Keywords: Hymenoptera ; Aphidiidae ; Homoptera ; Aphididae ; Schizaphis graminum ; wheat ; tritrophic interactions ; learning ; host-habitat location
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of experience on the responsiveness of the aphidiid parasitoidLysiphlebus testaceipes (Cresson) (Hymenoptera: Aphidiidae) to host-associated cues was investigated using a wind-tunnel bioassay. Naive females were able to discriminate between uninfested wheat (Triticum aestivum L.) and wheat infested withSchizaphis gramimum (Rondani) (Homoptera: Aphididae), but oviposition experience significantly increased the parasitoid's propensity to respond to aphid-infested plants with upwind, targeted flight. The behavioural change associated with such experience was acquired rapidly (within five minutes) and persisted for at least 24 h. The parasitoid could be successfully conditioned to associate a novel odour with the presence of hosts, suggesting that the increase in response to aphid-infested plants which occurs as a result of experience is probably due to associative learning of olfactory cues from the plant-aphid complex.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02380774
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Stability properties of proliferatively coupled cell replication models (1991)
    Springer
    Acta biotheoretica 39 (1991), S. 1-14 
    Details
    ISSN: 1572-8358
    Keywords: Hematological diseases ; first order partial differential equations ; stability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract To address the possibility that proliferative disorders may originate from interactions between multiple populations of proliferating and maturing cells, we formulate a model for this process as a set of coupled nonlinear first order partial differential equations. Using recent results for the asymptotic behaviour of the solutions to this model, we demonstrate that there exists a region of coupling coefficients, maturation rates, and proliferation rates that will guarantee the stable coexistence of coupled cellular populations. The analysis shows that increases in the coupling between populations may ultimately lead to a loss of stability. Furthermore, the analysis indicates that increases (decreases) in the maturation and/or proliferation rates above (below) critical levels will lead either to instability in the populations or the destruction of one population and the persistence of the other.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00046404
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    The influence of a flood event on phytoplankton succession (1990)
    Springer
    Aquatic sciences 52 (1990), S. 330-344 
    Details
    ISSN: 1420-9055
    Keywords: Flood ; phytoplankton succession ; reversion ; stability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of the August 1987 River Reuss flood event on the phytoplankton biocoenosis in Lake Uri (Urnersee, part of Lake Lucerne, Switzerland) was investigated firstly by comparing biological, chemical and physical data sampled before the event with equivalent data sampled after the event; and secondly by comparing the phytoplankton succession in 1987 with that occurring in the “floodfree” year 1989. As a consequence of the flood, the physical and chemical environment of the phytoplankton was found to have undergone a change which resulted in an alteration in the composition of the phytoplankton community. The phytoplankton community existing previous to the flood event, which had been dominated byTabellaria fenestrata sensu Husted 1930 (K-strategist), was replaced by a biocoenosis characterized mainly by various species of flagellates, which represent a typical spring successional stage (r-strategists). After the externally-imposed perturbation, the return to stable physical and chemical conditions was followed by the re-establishment of the successional stage which had existed before the flood (termed “reversion” by Reynolds, 1980).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00879761
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    DNA in wheat seeds from European archaeological sites (1994)
    Springer
    Cellular and molecular life sciences 50 (1994), S. 571-575 
    Details
    ISSN: 1420-9071
    Keywords: Ancient DNA ; archaeobotany ; carbonized grain ; DNA sequences ; glutenin alleles ; seed proteins ; Triticum ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract We have used hybridization analysis to detect ancient DNA in wheat seeds collected from three archaeological sites in Europe and the Middle East. One of these samples, carbonizedT. spelta dated to the first millennium BC, has yielded PCR products after amplification with primers directed at the leader regions of the HMW (high molecular weight) glutenin alleles. Sequences obtained from these products suggest that the DNA present in the Danebury seeds is chemically damaged, as expected for ancient DNA, and also indicate that it should be possible to study the genetic variability of archaeological wheat by ancient DNA analysis. Finally, we describe a PCR-based system that enables tetraploid and hexaploid wheats to be distinguished.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01921727
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Vesicular-arbuscular mycorrhizae of epiphytes (1993)
    Springer
    Mycorrhiza 4 (1993), S. 1-4 
    Details
    ISSN: 1432-1890
    Keywords: Tropics ; Mycotrophy ; Spore dispersal ; Community composition ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This article introduces reports concerning the occurrence of mycorrhizae on epiphytes in Costa Rica, Ethiopia, Venezuela, Malaysia, and Mexico. Association of vesicular-arbuscular mycorrhizal fungi with the roots of epiphytes is not well known. Vesicular-arbuscular mycorrhizal fungi (VAM) do occur in the canopy, but are uncommon except in certain sites and host taxa. Occurrence of VAM on epiphytes may be constrained by mineral nutrient availability and spatial heterogeneity in the canopy. Nevertheless, epiphytes present unique opportunities to study influences of mycorrhizae on vascular plant community composition and on the evolution of mycorrhizal associations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00203242
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Kuehneltiella terricola gen. nov., sp. nov. — a carnivorous ciliate (Protozoa, Ciliophora) from a sandy soil in Australia (1990)
    Springer
    Biology and fertility of soils 9 (1990), S. 110-118 
    Details
    ISSN: 1432-0789
    Keywords: Kuehneltiella terricola gen. nov., sp. nov. ; Soil ciliates ; Colpodidae ; Systematics ; Evolution ; Australia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The morphology and biology of the colpodid ciliate Kuehneltiella terricola gen. nov., sp. nov. has been investigated using living organisms, various silver impregnation methods, and scanning electron microscopy. The new species has been isolated in soil from central Australia and might be endemic to this continent. The new genus Kuehneltiella differs from its nearest relative, Bresslaua, in having a right oral polykinetid composed of a single row of dikinetids. A reinvestigation of Lynn's slides of Bresslaua insidiatrix showed that, contrary to the statement of Lynn (1979), this species has a typic colpodid right oral polykinetid, i.e., composed of many short, disordered kineties. A brief review of the literature suggests that simple, single-rowed, right oral polykinetids are apomorphic in the colpodids s. str. Further, this special character has obviously evolved independently several times within the class Colpodea and even within the colpodids s. str. An illustrated key to the genera of the family Colpodidae is provided.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00335792
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Evolutionary studies on the Assulina-Valkanovia complex (Rhizopoda, Testaceafilosia) in Sphagnum and soil (1990)
    Springer
    Biology and fertility of soils 9 (1990), S. 95-100 
    Details
    ISSN: 1432-0789
    Keywords: Assulina-Valkanovia ; Testacea ; Polymorphism ; Genotypes ; Evolution ; Spruce forest ; Sphagnum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The taxonomy and evolution of the Assulina-Valkanovia complex were investigated in a spruce forest soil which included a Sphagnum plot (GDR, Thuringia). In both habitats Assulina muscorum occurred in two colour forms (brown and colourless) and four shapes. A quantified phenospectrum from Assulina muscorum was obtained. The four shapes were distributed differently between the brown and the colourless forms in Sphagnum and soil. The shell measurements showed statistically significant differences between the brown and the colourless forms. Even between the two brown populations there were some significant differences. Each of the four shape types of brown and of colourless Assulina can be kept in clonal cultures for some time. However, without selection, single cultures eventually revert to mixed types. The four shape types show different degrees of stability. These colour and shape forms are genotypes, which can also occur for short periods in the natural habitats. The brown populations in Sphagnum and in the soil were dominated by different shape types during the period of investigation. Valkanovia elegans cannot be distinguished from Assulina muscorum type 4, but Valkanovia can inhabit both upper and lower soil horizons, whereas Assulina and its forms lives exclusively in the upper horizon (litter). Valkanovia from the lower horizon is constant in clonal culture. The conclusion of the present investigation is that there are stable and unstable constellations within a changeable genome, which give asexual groups both a taxonomic structure and a continuum of forms. Selection can increase stability, by polygenic control of features.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00335790
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Cloning of the PYR4 gene encoding orotidine-5′-phosphate decarboxylase in Cephalosporium acremonium (1990)
    Springer
    Current genetics 17 (1990), S. 223-227 
    Details
    ISSN: 1432-0983
    Keywords: Orotidine-5′-phosphate decarboxylase ; Cephalosporium acremonium ; Recombinant DNA ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have cloned the Cephalosporium acremonium pyr4 gene by cross-hybridization with the equivalent gene from Neurospora crassa, the closest relative from which this gene is available. The C. acremonium pyr4 gene complements an E. coli pyrF mutant lacking orotidine-5′-phosphate decarboxylase (OMPdecase), and most probably does not contain introns. Maxicell analysis in E. coli shows that it encodes a 46 kDa polypeptide. The C. acremonium OMPdecase contains a highly conserved pentadecapeptide characteristic for this category of enzyme. Extensive sequence comparison suggests an important role of this region in enzymatic activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00312613
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Phylogenetic analysis of the RNA polymerases of Trypanosoma brucei, with special reference to class-specific transcription (1990)
    Springer
    Current genetics 18 (1990), S. 547-551 
    Details
    ISSN: 1432-0983
    Keywords: Trypanosomes ; RNA polymerase ; Transcription ; Evolution ; Phylogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have sequenced the genes encoding te largest subunits of the three classes of DNA-dependent RNA polymerases of Trypanosoma brucei. The nucleotide and deduced amino acid sequences were compared and aligned with the corresponding sequences of other eukaryotes. Phylogenetic relationships were subsequently calculated with a distant matrix, a bootstrapped parsimony and a maximum-likelihood method. These independent calculations resulted in trees with very similar topologies. The analyses show that all the largest subunits of T. brucei are evolutionarily distant members within each of the three RNA polymerase classes. An early separation of the trypanosomal subunits from the eukaryotic lineage might from the fundamental basis for the unusual transcription process of this species. Finally, all dendrograms show a separate ramification for the largest subunit of RNA polymerase I, II and III. RNA polymerase II and/or III form a bifurcation with the archaebacterial lineage. RNA polymerase I, however, arises separately from the eubacterial β′ lineage. This suggests that the three eukaryotic RNA polymerase classes are not simply derived by two gene duplications of an ancestral gene with subsequent differentiation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00327026
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Cyanellar Ferredoxin-NADP+-oxidoreductase of Cyanophora paradoxa is encoded by the nuclear genome and synthesized on cytoplasmatic 80S ribosomes (1990)
    Springer
    Current genetics 17 (1990), S. 265-267 
    Details
    ISSN: 1432-0983
    Keywords: Cyanophora paradoxa ; Ferredoxin-NADP+-oxidoreductase ; Protein-import ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Cyanophora paradoxa is an important model organism for the study of the transition from endocytobiontic cyanobacteria to factual eukaryotic cell organelles. The cyanelles of these organisms possess cyanobacterial, as well as plastidic, characteristics. Although the transfer of cyanellar proteins from cytosolic into cyanellar space has been shown, the process of translocation of a known protein across the peptidoglycan layer and the envelope membranes has not been characterized. In this study we demonstrate that a specific and obligate cyanelle protein —Ferredoxin-NADP+-oxidoreductase (FNR) — is coded on the nuclear genome, synthesized on 80S ribosomes and transported from the eukaryotic cell compartment into the cyanelles of Cyanophora paradoxa, an original intracellular host-guest relation. These results indicate a gene transfer from guest to host genome and support the view that, in spite of their cyanobacterial origin, cyanelles have been evolved to cell organelles comparable to plastids.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00312619
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Evolutionary origin of aminoglycoside phosphotransferase resistance genes (1990)
    Springer
    Journal of molecular evolution 30 (1990), S. 489-492 
    Details
    ISSN: 1432-1432
    Keywords: Actinomyces ; Phosphotransferase ; Aminoglycoside ; Phylogenetic tree ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The protein sequences of seven 3′-aminoglycoside phosphotransferases falling into the six identified types and three 6′-aminoglycoside phosphotransferases were analyzed to give a rooted phylogenetic tree. This tree supports the origin of these groups of enzymes in an ancestor closely related to the actinomycetes, and that horizontal transfer of the resistance genes occurred, possibly via transposons. The implications for genetic engineering of a novel antibiotic are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02101103
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Nucleotide sequence of nine protein-coding genes and 22 tRNAs in the mitochondrial DNA of the sea starPisaster ochraceus (1990)
    Springer
    Journal of molecular evolution 31 (1990), S. 195-204 
    Details
    ISSN: 1432-1432
    Keywords: Mitochondrial DNA ; Evolution ; Echinoderms ; Sea stars ; DNA sequence ; Mitochondrial proteins ; Mitochondrial tRNA genes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have cloned and sequenced over 9 kb of the mitochondrial genome from the sea starPisaster ochraceus. Within a continuous 8.0-kb fragment are located the genes for NADH dehydrogenase subunits 1, 2, 3, and 4L (ND1, ND2, ND3, and ND4L), cytochrome oxidase subunits I, II, and III (COI, COII, and COIII), and adenosine triphosphatase subunits 6 and 8 (ATPase 6 and ATPase 8). This large fragment also contains a cluster of 13 tRNA genes between ND1 and COI as well as the genes for isoleucine tRNA between ND1 and ND2, arginine tRNA between COI and ND4L, lysine tRNA between COII and ATPase 8, and the serine (UCN) tRNA between COIII and ND3. The genes for the other five tRNAs lie outside this fragment. The gene for phenylalanine tRNA is located between cytochrome b and the 12S ribosomal genes. The genes for tRNAglu and tRNAthr are 3′ to the 12S ribosomal gene. The tRNAs for histidine and serine (AGN) are adjacent to each other and lie between ND4 and ND5. These data confirm the novel gene order in mitochondrial DNA (mtDNA) of sea stars and delineate additional distinctions between the sea star and other mtDNA molecules.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02109496
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Genome variations in the transition from amphibians to reptiles (1991)
    Springer
    Journal of molecular evolution 33 (1991), S. 68-75 
    Details
    ISSN: 1432-1432
    Keywords: DNA ; Genome size ; Repetitive DNA ; Amphibians ; Reptiles ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Many characters differentiate amphibian from reptilian genomes. The former have, on the average, larger and more variable genome sizes, a greater repetitive DNA percentage, and a higher interspersion level among DNAs with different degrees of repetitivity. Reptiles have more reduced and uniform genome sizes, a repetitive DNA percentage generally lower than 50%, and a lower interspersion level. Other differences can be observed in the chromosome banding and in the correlations between genome size and other morphometric and functional parameters of the cell. The differences found in amphibians and reptiles seem to indicate that in these two vertebrate classes there is a different tendency toward or tolerance of the accumulation and preservation of genetically dispensable DNA fractions. This might depend either on a different propensity toward genic amplification or on the appearance, in reptiles, of stricter and more efficient constraints regulating genome size.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02100197
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Evolution and sequence analysis of a human Y-chromosomal DNA fragment (1991)
    Springer
    Journal of molecular evolution 33 (1991), S. 133-141 
    Details
    ISSN: 1432-1432
    Keywords: Y-chromosome ; DNA ; Human ; Primate ; Evolution ; PUPPY sequence ; Alu element
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A Y-chromosomal DNA fragment has been isolated from a human Y-Charon 21A recombinant library. Evolutionary analysis of 1F5 indicates that the size and sequence of this fragment have been conserved in higher primates. Deletion mapping and in situ hybridization analysis have localized 1F5 to the middle euchromatic portion of the long arm of the human Y chromosome at Yq11.2. Sequence analysis revealed the presence of an atypical Alu element and two regions rich in polypyrimidine-polypurine residues.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02193627
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Evolutionary relationships among the permease proteins of the bacterial phosphoenolpyruvate: Sugar phosphotransferase system. Construction of phylogenetic trees and possible relatedness to proteins of eukaryotic mitochondria (1991)
    Springer
    Journal of molecular evolution 33 (1991), S. 179-193 
    Details
    ISSN: 1432-1432
    Keywords: Bacteria ; Sugars ; Phosphotransferase system ; Transport proteins ; Evolution ; Sequence comparisons ; NADH dehydrogenase ; Mitochondria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The amino acid sequences of 15 sugar permeases of the bacterial phosphoenolpyruvatedependent phosphotransferase system (PTS) were divided into four homologous segments, and these segments were analyzed to give phylogenetic trees. The permease segments fell into four clusters: the lactose-cellobiose cluster, the fructose-mannitol cluster, the glucose-N-acetylglucosamine cluster, and the sucrose-β-glucoside cluster. Sequences of the glucitol and mannose permeases (clusters 5 and 6, respectively) were too dissimilar to establish homology with the other permeases, but short regions of statistically significant sequence similarities were noted. The functional and structural relationships of these permease segments are discussed. Some of the homologous PTS permeases were found to exhibit sufficient sequence similarity to subunits 4 and 5 of the eukaryotic mitochondrial NADH dehydrogenase complex to suggest homology. Moreover, subunits 4 and 5 of this complex appeared to be homologous to each other, suggesting that these PTS and mitochondrial proteins comprise a superfamily. The integral membrane subunits of the evolutionarily divergent mannose PTS permease, the P and M subunits, exhibited limited sequence similarity to subunit 6 of the mitochondrial F1F0-ATPase and subunit 5b of cytochrome oxidase, respectively. These results suggest that PTS sugar permeases and mitochondrial proton-translocating proteins may be related, although the possibility of convergent evolution cannot be ruled out.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02193633
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Evolution of proteins of the cystatin superfamily (1990)
    Springer
    Journal of molecular evolution 30 (1990), S. 60-71 
    Details
    ISSN: 1432-1432
    Keywords: Cysteine endopeptidase ; Cysteine proteinase ; Inhibitor ; Cystatin ; Kininogen ; Evolution ; Amino acid sequence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have examined the amino acid sequences of a number of proteins that have been suggested to be related to chicken cystatin, a protein from chicken egg white that inhibits cysteine proteinases. On the basis of statistical analysis, the following proteins were found to be members of the cystatin superfamily: human cystatin A, rat cystatin A(α), human cystatin B, rat cystatin B(β), rice cystatin, human cystatin C, ox colostrum cystatin, human cystatin S, human cystatin SA, human cystatin SN, chicken cystatin, puff adder cystatin, human kininogen, ox kininogen, rat kininogen, rat T-kininogens 1 and 2, human α2HS-glycoprotein, and human histidine-rich glycoprotein. Fibronectin is shown not to be a member of this superfamily, and the c-Ha-ras oncogene protein p21(Val-12) probably is not a member also. It was convenient to divide members of the superfamily into four types on the basis of the presence of one, two, or three copies of cystatin-like segments and the presence or absence of disulfide bonds. Evolutionary dendrograms were calculated by three methods, and from these we have constructed a scheme depicting the sequence of events in the evolution of these proteins. We suggest that about 1000 million years ago a precursor containing disulfide loops appeared, and that all disulfide-containing cystatins are derived from this. We follow the evolution of the proteins of the superfamily along four main lineages, with special attention to the part that duplication of segments has played in the development of the more complex molecules.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02102453
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Evolution of protamine P1 genes in primates (1993)
    Springer
    Journal of molecular evolution 37 (1993), S. 426-434 
    Details
    ISSN: 1432-1432
    Keywords: Primate ; Evolution ; Protamine ; Polymerase chain reaction ; Sperm proteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Protamine P1 genes have been sequenced by PCR amplification and direct DNA sequencing from 9 primates representing 5 major families, Cebidae (new world monkeys), Cercopithecidae (old world monkeys), Hylobatidae (gibbons), Pongidae (gorilla, orangutan, and chimpanzee), and Hominidae (human). In this recently diverged group of primates these genes are clearly orthologous but very variable, both at the DNA level and in their expressed amino acid sequences. The rate of variation amongst the protamine Pls indicates that they are amongst the most rapidly diverging polypeptides studied. However, some regions are conserved both in primates and generally in other placental mammals. These are the 13 N-terminal residues (including a region of alternating serine and arginine residues (the motif SRSR, res. 10–13) susceptible to Ser phosphorylation), a tract of six Arg residues (res. 24–29) in the center of the molecule, and a six-residue region (RCCRRR, res. 39–44), consisting of a pair of cysteines flanked by arginines. Detailed consideration of nearest neighbor matrices and trees based on maximum parsimony indicates that PI genes from humans, gorillas, and chimpanzees are very similar. The amino acid and nucleotide differences between humans and gorillas. are fewer than those between humans and chimpanzees. This finding is at variance with data from DNA-DNA hybridization and extensive globin and mitochondrial DNA sequences which place human and chimpanzee as closest relatives in the super family, Hominoidea. This may be related to the fact that protamine Pls are expressed in germ line rather than somatic cells. In contrast to the variability of the exon regions of the protamine P1 genes, the sequence of the single intron is highly conserved.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00178872
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Molecular evolution of the HSP70 multigene family (1994)
    Springer
    Journal of molecular evolution 38 (1994), S. 1-17 
    Details
    ISSN: 1432-1432
    Keywords: HSP70 ; Heat shock ; Evolution ; Phylogeny ; Yeast ; Multigene family ; Subcellular compartmentalization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Eukaryotic genomes encode multiple 70-kDa heat-shock proteins (HSP70s). The Saccharomyces cerevisiae HSP70 family is comprised of eight members. Here we present the nucleotide sequence of the SSA3 and SSB2 genes, completing the nucleotide sequence data for the yeast HSP70 family. We have analyzed these yeast sequences as well as 29 HSP70s from 24 additional eukaryotic and prokaryotic species. Comparison of the sequences demonstrates the extreme conservation of HSP70s; proteins from the most distantly related species share at least 45% identity and more than one-sixth of the amino acids are identical in the aligned region (567 amino acids) among all proteins analyzed. Phylogenetic trees constructed by two independent methods indicate that ancient molecular and cellular events have given rise to at least four monophyletic groups of eukaryotic HSP70 proteins. Each group of evolutionarily similar HSP70s shares a common intracellular localization and is presumed to be comprised of functional homologues; these include heat-shock proteins of the cytoplasm, endoplasmic reticulum, mitochondria, and chloroplasts. HSP70s localized in mitochondria and plastids are most similar to the DnaK HSP70 homologues in purple bacteria and cyanobacteria, respectively, which is consistent with the proposed prokaryotic origin of these organelles. The analyses indicate that the major eukaryotic HSP70 groups arose prior to the divergence of the earliest eukaryotes, roughly 2 billion years ago. In some cases, as exemplified by the SSA genes encoding the cytoplasmic HSP70s of S. cerevisiae, more recent duplication events have given rise to subfamilies within the major groups. The S. cerevisiae SSB proteins comprise a unique subfamily not identified in other species to date. This subfamily appears to have resulted from an ancient gene duplication that occurred at approximately the same time as the origin of the major eukaryotic HSP70 groups.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00175490
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Molecular characteristics of the heterochromatic I elements from a reactive strain ofDrosophila melanogaster (1990)
    Springer
    Journal of molecular evolution 31 (1990), S. 424-431 
    Details
    ISSN: 1432-1432
    Keywords: Drosophila melanogaster ; Evolution ; Hybrid dysgenesis ; I elements ; Transposons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary There are two categories of strains inDrosophila melanogaster with respect to the I-R system of hybrid dysgenesis. The inducer strains contain particular transposable elements named I factors. They are not present in the strains of the other category called reactive (R) strains. Defective I elements are present in the pericentromeric regions of both categories of strains. This last subfamily of I sequences has not yet been described in detail and little is known about its origin. In this paper, we report that the defective I elements display an average of 94% of sequence identity with each other and with the transposable I factor. The results suggest that they cannot be the progenitors of the present day I factors, but that each of these two subfamilies started to evolve independently several million years ago. Furthermore, the sequence comparison of these I elements with an active I factor fromDrosophila teissieri provides useful information about when the deleted I elements became immobilized.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02106056
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Characterization of a species-specific satellite DNA family of Dolichopoda schiavazzii (Orthoptera, Rhaphidophoridae) cave crickets (1994)
    Springer
    Journal of molecular evolution 39 (1994), S. 274-281 
    Details
    ISSN: 1432-1432
    Keywords: Repetitive DNA ; Tandem repeats ; Sequence analysis ; Recombination ; Isolated populations ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The satellite DNA family pDoP102 is species specific for the cave cricket Dolichopoda schiavazzii, an endemic species of mainland and insular Tuscany. It consists of numerous tandemly arranged repeats, 102 bp in length, and evolved most probably after cladogenesis of D. schiavazzii from the D. baccettii-aegilion group within the last 2.3 ± 0.8 million years. A sequence comparison of 31 clones (53 repetition units) from three isolated populations reveals a very high degree of sequence homogeneity within the species with no evidence for any specific population features. This appears to be in contrast to the results of allozyme analyses which account for a relatively old evolutionary divergence of the Elba island population from the mainland ones. Since the assumption of actual gene flow and recent colonization is rejected, the observed sequence homogeneity is hypothesized to be maintained by recombination processes preventing fixation of newly introduced mutations on pDoP102 sequence clusters.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00160151
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    Prebiotic chemistry in clouds (1991)
    Springer
    Journal of molecular evolution 32 (1991), S. 296-303 
    Details
    ISSN: 1432-1432
    Keywords: Prebiotic chemistry ; Primordial soup ; Oparin hypothesis ; Evolution ; Impact catastrophism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In the traditional concept for the origin of life as proposed by Oparin and Haldane in the 1920s, prebiotic reactants became slowly concentrated in the primordial oceans and life evolved slowly from a series of highly protracted chemical reactions during the first billion years of Earth's history. However, chemical evolution may not have occurred continuously because planetesimals and asterioids impacted the Earth many times during the first billion years, may have sterilized the Earth, and required the process to start over. A rapid process of chemical evolution may have been required in order that life appeared at or before 3.5 billion years ago. Thus, a setting favoring rapid chemical evolution may be required. A chemical evolution hypothesis set forth by Woese in 1979 accomplished prebiotic reactions rapidly in droplets in giant atmospheric reflux columns. However, in 1985 Scherer raised a number of objections to Woese's hypothesis and concluded that it was not valid. We propose a mechanism for prebiotic chemistry in clouds that satisfies Scherer's concerns regarding the Woese hypothesis and includes advantageous droplet chemistry. Prebiotic reactants were supplied to the atmosphere by comets, meteorites, and interplanetary dust or synthesized in the atmosphere from simple compounds using energy sources such as ultraviolet light, corona discharge, or lightning. These prebiotic monomers would have first encountered moisture in cloud drops and precipitation. We propose that rapid prebiotic chemical evolution was facilitated on the primordial Earth by cycles of condensation and evaporation of cloud drops containing clay condensation nuclei and nonvolatile monomers. For example, amino acids supplied by, or synthesized during entry of, meteorites, comets, and interplanetary dust would have been scavenged by cloud drops containing clay condensation nuclei. Polymerization would have occurred within cloud systems during cycles of condensation, freezing, melting, and evaporation of cloud drops. We suggest that polymerization reactions occurred in the atmosphere as in the Woese hypothesis, but life originated in the ocean as in the Oparin-Haldane hypothesis. The rapidity with which chemical evolution could have occurred within clouds accommodates the time constraints suggested by recent astrophysical theories.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02102187
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Interspecific comparison of the unusually repetitiveDrosophila locusmastermind (1991)
    Springer
    Journal of molecular evolution 32 (1991), S. 415-420 
    Details
    ISSN: 1432-1432
    Keywords: Drosophila melanogaster ; Drosophila virilis ; mastermind ; Gene comparison ; Repetitive sequences ; Homopolymers ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Themastermind gene ofDrosophila melanogaster encodes a novel, highly repetitive nuclear protein required for neural development. To identify functionally important regions we have initiated an interspecific comparison of the gene inDrosophila virilis. Mastermind transcription and genomic organization are similar in both species and sequence analysis reveals significant conservation in a major cluster of charged amino acids. In contrast, extensive variation is noted in homopolymer domains that immediately flank the acidic cluster. Distinct patterns of evolutionary change can be identified: the major difference between unique regions are occasional amino acid substitutions whereas the repetitive areas are characterized by numerous large in-frame insertions/deletions and a nearly threefold higher rate of amino acid replacement. Conservation of the acidic domain suggests that it has an important functional role whereas the hypervariable homopolymer regions appear to be under less selective constraints than adjacent unique areas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02101281
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    Divergent evolution may link human immunodeficiency virus GP41 to human CD4 (1993)
    Springer
    Journal of molecular evolution 36 (1993), S. 448-457 
    Details
    ISSN: 1432-1432
    Keywords: Retrovirus ; HIV ; CD4 ; Minus strand ; Alternate reading frame ; Frameshift ; Divergence ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A local sequence similarity of HIV envelope proteins (gp120 and gp41) to immunoglobulins suggests that a mimicry phenomenon may form the basis of the HIV-cell membrane interaction and of HIV-induced autoimmune reaction. We explored the hypothesis of any deeper relationship between HIV env proteins and immunoglobulin family members. An overall DNA sequence similarity between gp41 coding region of env gene and the HIV-receptor CD4 gene was observed and a 14-base-long oligonucleotide, almost unique in the GenBank, was found in gp41 and CD4 genes. The alignment of env gene to CD4 gene and to 84 different sequences showed a significantly higher homology score and a nonrandom similarity in the CD4-env alignment. A significant similarity was also found between the env protein and the sequence encoded by an alternate reading frame of CD4 gene. Our observations suggest that gp41 coding region might have a different origin than the gp120 coding region of the env gene, and that a divergent evolution might link gp41 to CD4 or immunoglobulin family members. In this study the analysis of alternate-reading-frame products is also proposed as a novel approach to investigate evolutionary links and structure-function relationships.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02406721
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Evolutionary consequences of nonrandom damage and repair of chromatin domains (1992)
    Springer
    Journal of molecular evolution 35 (1992), S. 156-180 
    Details
    ISSN: 1432-1432
    Keywords: DNA damage ; DNA repair ; Chromatin ; Evolution ; Nucleosomes ; Nuclear matrix ; Active genes ; Z-DNA ; Sperm ; Mutation ; Molecular clock
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Some evolutionary consequences of different rates and trends in DNA damage and repair are explained. Different types of DNA damaging agents cause nonrandom lesions along the DNA. The type of DNA sequence motifs to be preferentially attacked depends upon the chemical or physical nature of the assaulting agent and the DNA base composition. Higher-order chromatin structure, the nonrandom nucleosome positioning along the DNA, the absence of nucleosomes from the promoter regions of active genes, curved DNA, the presence of sequence-specific binding proteins, and the torsional strain on the DNA induced by an increased transcriptional activity all are expected to affect rates of damage of individual genes. Furthermore, potential Z-DNA, H-DNA, slippage, and cruciform structures in the regulatory region of some genes or in other genomic loci induced by torsional strain on the DNA are more prone to modification by genotoxic agents. A specific actively transcribed gene may be preferentially damaged over nontranscribed genes only in specific cell types that maintain this gene in active chromatin fractions because of (1) its decondensed chromatin structure, (2) torsional strain in its DNA, (3) absence of nucleosomes from its regulatory region, and (4) altered nucleosome structure in its coding sequence due to the presence of modified histones and HMG proteins. The situation in this regard of germ cell lineages is, of course, the only one to intervene in evolution. Most lesions in DNA such as those caused by UV or DNA alkylating agents tend to diminish the GC content of genomes. Thus, DNA sequences not bound by selective constraints, such as pseudogenes, will show an increase in their AT content during evolution as evidenced by experimental observations. On the other hand, transcriptionally active parts may be repaired at rates higher than inactive parts of the genome, and proliferating cells may display higher repair activities than quiescent cells. This might arise from a tight coupling of the repair process with both transcription and replication, all these processes taking place on the nuclear matrix. Repair activities differ greatly among species, and there is a good correlation between life span and repair among mammals. It is predicted that genes that are transcriptionally active in germ-cell lineages have a lower mutation rate than bulk DNA, a circumstance that is expected to be reflected in evolution. Exception to this rule might be genes containing potential Z-DNA, H-DNA, or cruciform structures in their coding or regulatory regions that appear to be refractory to repair. This study supports the molecular clock hypothesis when applied to one gene within a group of related species and contends that evolutionary rates might vary between genes and gene segments not only as a result of differences in selective constraints but also as a result of differences in the rate of damage minus rate of repair among different segments of chromatin DNA.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00183227
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    The phylogeny of echinoderm classes based on mitochondrial gene arrangements (1993)
    Springer
    Journal of molecular evolution 36 (1993), S. 545-554 
    Details
    ISSN: 1432-1432
    Keywords: Echinoderms ; Evolution ; Phylogeny ; mtDNA ; Mitochondrial gene arrangements
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Previous analyses have demonstrated that, among the echinoderms, the sea star (class: Asteroidea) mitochondrial genome contains a large inversion in comparison to the mitochondrial DNA of sea urchins (class: Echinoidea). Polymerase chain reaction amplification, DNA cloning, and sequencing have been used to examine the relationships of the brittle stars (class: Ophiuroidea) and sea cucumbers (class: Holothuroidea) to the sea stars and sea urchins. The DNA sequence of the regions spanning potential inversion junctions in both brittle stars and sea cucumbers has been determined. This study has also revealed a highly modified tRNA cluster in the ophiuroid mitochondrial genome. Our data indicate mitochondrial gene arrangement patterns that group the sea cucumbers with sea urchins and sea stars with brittle stars. This use of molecular characters clarifies the relationships among these classes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00556359
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Characterization of two abundant satellite DNAs from the mealworm Tenebrio obscurus (1994)
    Springer
    Journal of molecular evolution 39 (1994), S. 489-495 
    Details
    ISSN: 1432-1432
    Keywords: Repetitive sequences ; Sequence variability ; Evolution ; Heterochromatin ; DNA curvature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Two highly abundant satellite DNAs comprise 36% of the Tenebrio obscurus (Tenebrionidae, Coleoptera) genome. They are designated as satellite I and satellite II with the monomer length of 344 and 142 base pairs (bp), respectively. Both satellites differ in their nucleotide (nt) sequences, but the frequency of point mutations, well-conserved length of monomer variants, stretches of shared mutations characteristic for the process of gene conversion, and distribution of both satellites in regions of centromeric heterochromatin of all chromosomes indicate that the same evolutionary processes act on both of them with the same, or similar, rate. While satellite I shares no sequence similarity with any other known nt sequence, satellite II is 79.7% homologous with the highly abundant satellite from closely related Tenebrio molitor. Difference in the frequency of point mutations and absence of shared mutations indicating gene conversion strongly suggest that in these two closely related species mutational processes affecting satellite DNAs seem to be changed. Retarded electrophoretic mobility, due to sequence-induced curvature of DNA helix axis, was observed for T. obscurus satellite II, but not for satellite I. Although evolutionary processes act with different rates in T. obscurus and T. molitor satellites the monomer length and sequence-induced curvature are well preserved in both 142-bp satellites, as well as in, at the nt sequence level completely divergent, Palorus ratzeburgii (Tenebrionidae) satellite, indicating potential importance of these parameters in their evolution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00173418
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    Convergent evolution of crystallin gene regulation in squid and chicken: The AP-1/ARE connection (1994)
    Springer
    Journal of molecular evolution 39 (1994), S. 134-143 
    Details
    ISSN: 1432-1432
    Keywords: Lens ; Crystallin ; Squid ; Chicken ; Gene ; Regulation ; AP-1 ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Previous experiments have shown that the minimal promoters required for function of the squid SL20-1 and SL11 crystallin genes in transfected rabbit lens epithelial cells contain an overlapping AP-1/antioxidant responsive element (ARE) upstream of the TATA box. This region resembles the PL-1 and PL-2 elements of the chicken βB 1-cry stallin promoter which are essential for promoter function in transfected primary chicken lens epithelial cells. Here we demonstrate by site-directed mutagenesis that the AP-1/ARE sequence is essential for activity of the squid SL20-1 and SL11 promoters in transfected embryonic chicken lens cells and fibroblasts. Promoter activity was higher in transfected lens cells than in fibroblasts. Electrophoretic mobility shift and DNase protection experiments demonstrated the formation of numerous complexes between nuclear proteins of the embryonic chicken lens and the AP-1/ARE sequences of the squid SL20-1 and SL11 crystallin promoters. One of these complexes comigrated and cross-competed with that formed with the PL-1 element of the chicken βB1-crystallin promoter. This complex formed with nuclear extracts from the lens, heart, brain, and skeletal muscle of embryonic chickens and was eliminated by competition with a consensus AP-1 sequence. The nonfunctional mutant AP-1/ ARE sequences did not compete for complex formation. These data raise the intriguing possibility that entirely different, nonhomologous crystallin genes of the chicken and squid have convergently evolved a similar cis-acting regulatory element (AP-1/ARE) for high expression in the lens.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00163802
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    Vertebrate protamine gene evolution I. Sequence alignments and gene structure (1990)
    Springer
    Journal of molecular evolution 30 (1990), S. 333-346 
    Details
    ISSN: 1432-1432
    Keywords: Protamine ; Evolution ; Nuclear protein ; DNA condensation ; Sperm proteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The availability of the amino acid sequence for nine different mammalian P1 family protamines and the revised amino acid sequence of the chicken protamine galline (Oliva and Dixon 1989) reveals a much close relationship between mammalian and avian protamines than was previously thought (Nakano et al. 1976). Dot matrix analysis of all protamine genes for which genomic DNA or cDNA sequence is available reveals both marked sequence similarities in the mammalian protamine gene family and internal repeated sequences in the chicken protamine gene. The detailed alignments of the cis-acting regulatory DNA sequences shows several consensus sequence patterns, particularly the conservation of a cAMP response element (CRE) in all the protamine genes and of the regions flanking the TATA box, CAP site, N-terminal coding region, and polyadenylation signal. In addition we have found a high frequency of the CA dinucleotide immediately adjacent to the CRE element of both the protamine genes and the testis transition proteins, a feature not present in other genes, which suggests the existence of an extended CRE motif involved in the coordinate expression of protamine and transition protein genes during spermatogenesis. Overall these findings suggest the existence of an avian-mammalian P1 protamine gene line and are discussed in the context of different hypotheses for protamine gene evolution and regulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02101888
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    Phylogeny of the major tetrapod groups: Morphological data and divergence dates (1990)
    Springer
    Journal of molecular evolution 30 (1990), S. 409-424 
    Details
    ISSN: 1432-1432
    Keywords: Phylogeny ; Tetrapods ; Morphology ; Cladistics ; Divergence ; Evolution ; Amphibians ; Reptiles ; Birds ; Mammals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The phylogeny of the major groups of tetrapods (amphibians, reptiles, birds, and mammals) has until recently been poorly understood. Cladistic analyses of morphological data are producing new hypotheses concerning the relationships of the major groups, with a focus on the identification of monophyletic groups. Molecular phylogenies support some of these views and dispute others. Geological dates of the major evolutionary branching points are recalculated on the basis of the cladograms and new fossil finds.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02101113
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    There appear to be conserved constraints on the distribution of nucleotide sequences in cellular genomes (1991)
    Springer
    Journal of molecular evolution 32 (1991), S. 24-30 
    Details
    ISSN: 1432-1432
    Keywords: Short sequence distribution ; Sequence constraints ; Averaged sequence ; Sequence structure ; Asymmetric nucleotide sequences ; GC content ; Evolution ; Evolutionary constraints
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The data from a genomic library can be sorted into the frequencies of every possible tetranucleotide in the sequence. This tabulation, a short sequence distribution, contains the frequency of occurrence of the 256 tetranucleotides and thus seems to serve as a vehicle for averaging sequence information. Two such distributions can be readily compared by correlation. Reported here are correlations (Spearmanr s) of the distributions from all of the genomic libraries in GenBank 44.0 with sizes equal to or larger than that ofSalmonella typhimurium, except for the data for mouse and humans. All of the organisms examined showed highly significant correlations between the two DNA strands (not the complementarity expected from base pairing). Of 155 comparisons between libraries, 132 showed significant correlations at the 99% confidence level. Application of the correlation coefficients as a similarity matrix clustered most organisms in a phenogram in a pattern consistent with other hypotheses. This suggests a highly conserved pattern underlying all other genetic information in cellular DNA and affecting both DNA strands, perhaps caused by interaction with conserved factors necessary for DNA packaging.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02099925
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    Mitochondrial DNA evolution in lagomorphs: Origin of systematic heteroplasmy and organization of diversity in European rabbits (1991)
    Springer
    Journal of molecular evolution 33 (1991), S. 92-102 
    Details
    ISSN: 1432-1432
    Keywords: Lagomorphs ; Rabbit ; Mitochondrial DNA ; Heteroplasmy ; Restriction site polymorphism ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A characterization was conducted on mitochondrial DNA (mtDNA) molecules extracted separately from 107 European rabbits (Oryctolagus cuniculus) both wild and domestic, 13 European hares (Lepus capensis), and 1 eastern cottontail (Sylvilagus floridanus). Experimentally this study took into account restriction site polymorphism, overall length variation of the noncoding region, and numbers of repeated sequences. Nucleotide divergences indicate that the mtDNAs from the three species derived from a common ancestor some 6–8 million years (Myr) ago. Every animal appeared heteroplasmic for a set of molecules with various lengths of the noncoding region and variable numbers of repeated sequences that contribute to them. This systematic heteroplasmy, most probably generated by a rate of localized mtDNA rearrangements high enough to counterbalance the cellular segregation of rearranged molecules, is a shared derived character of leporids. The geographic distribution of mtDNA polymorphism among wild rabbit populations over the western European basin shows that two molecular lineages are represented, one in southern Spain, the second over northern Spain, France, and Tunisia. These two lineages derived from a common ancestor some 2 Myr ago. Their present geographical distribution may be correlated to the separation of rabbits into two stocks at the time of Mindel glaciation. Finally the distribution of mtDNA diversity exhibits a mosaic pattern both at inter- and intrapopulation levels.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02100200
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    Structure and evolution of 5S rRNA genes and pseudogenes in the genusAspergillus (1991)
    Springer
    Journal of molecular evolution 33 (1991), S. 175-178 
    Details
    ISSN: 1432-1432
    Keywords: Aspergillus ; 5S rRNA genes ; 5S rRNA pseudogenes ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have cloned and determined the nucleotide sequence of 18 DNA fragments hybridizing to 5S rRNA from twoAspergillus species-A. wentii andA. awamori. Four of the analyzed sequences were pseudogenes. The gene sequences of these two species were very similar and differed fromAspergillus nidulans at both constant and microheterogeneous sites.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02193632
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    The use of bonding between tRNAs to implement early peptide synthesis (1991)
    Springer
    Journal of molecular evolution 33 (1991), S. 464-469 
    Details
    ISSN: 1432-1432
    Keywords: Evolution ; tRNA ; Ribosome ; Peptide bond ; Catalytic RNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Continuation of early evolutionary bonding between tRNAs would provide a solution to residence time problems between peptidyl-tRNA and mRNA. It could also improve the speed of peptide bond formation by holding the amino acid close to the growing peptide. The tRNA clover leaf structure would allow each tRNA to from a TΨC(GA)-loop bond to one side and a D-loop bond to the other, hence fixing itself within a group of tRNAs, all attached to the mRNA. This can be developed into a system for peptide elongation in which bonds are made and broken in an ordered sequence, with each step triggering the next. This leads to a model system that fits with some recent propsals for a three-site ribosome.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02103139
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    Two independent mutational events in the loss of urate oxidase during hominoid evolution (1992)
    Springer
    Journal of molecular evolution 34 (1992), S. 78-84 
    Details
    ISSN: 1432-1432
    Keywords: Urate oxidase ; Evolution ; Mechanism of inactivation ; Mutations ; Hominoids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Urate oxidase was lost in hominoids during primate evolution. The mechanism and biological reason for this loss remain unknown. In an attempt to address these questions, we analyzed the sequence of urate oxidase genes from four species of hominoids: human (Homo sapiens), chimpanzee (Pan troglodytes), orangutan (Pongo pygmaeus), and gibbon (Hylobates). Two nonsense mutations at codon positions 33 and 187 and an aberrant splice site were found in the human gene. These three deleterious mutations were also identified in the chimpanzee. The nonsense mutation at codon 33 was observed in the orangutan urate oxidase gene. None of the three mutations was present in the gibbon; in contrast, a 13-bp deletion was identified that disrupted the gibbon urate oxidase reading frame. These results suggest that the loss of urate oxidase during the evolution of hominoids could be caused by two independent events after the divergence of the gibbon lineage; the nonsense mutation at codon position 33 resulted in the loss of urate oxidase activity in the human, chimpanzee, and orangutan, whereas the 13-bp deletion was responsible for the urate oxidase deficiency in the gibbon. Because the disruption of a functional gene by independent events in two different evolutionary lineages is unlikely to occur on a chance basis, our data favor the hypothesis that the loss of urate oxidase may have evolutionary advantages.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00163854
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    Estimating the fraction of invariable codons with a capture-recapture method (1992)
    Springer
    Journal of molecular evolution 35 (1992), S. 253-260 
    Details
    ISSN: 1432-1432
    Keywords: Protein-coding sequences ; DNA sequences ; Evolution ; Evolutionary rates ; Rate heterogeneity ; Maximum likelihood ; Statistical testing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A codon-based approach to estimating the number of variable sites in a protein is presented. When first and second positions of codons are assumed to be replacement positions, a capture-recapture model can be used to estimate the number of variable codons from every pair of homologous and aligned sequences. The capture-recapture estimate is compared to a maximum likelihood estimate of the number of variable codons and to previous approaches that estimate the number of variable sites (not codons) in a sequence. Computer simulations are presented that show under which circumstances the capture-recapture estimate can be used to correct biases in distance matrices. Analysis of published sequences of two genes, calmodulin and serum albumin, shows that distance corrections that employ a capture-recapture estimate of the number of variable sites may be considerably different from corrections that assume that the number of variable sites is equal to the total number of positions in the sequence.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00178601
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    Molecular analysis of ependymins from the cerebrospinal fluid of the orders clupeiformes and salmoniformes: no indication for the existence of an euteleost infradivision (1993)
    Springer
    Journal of molecular evolution 36 (1993), S. 578-585 
    Details
    ISSN: 1432-1432
    Keywords: Evolution ; Teleostei ; Clupea harengus ; Esox lucius ; Fish ; Polymerase chain reaction ; Calcium binding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Ependymins represent the predominant protein constituents in the cerebrospinal fluid of many teleost fish and they are synthesized in meningeal fibroblasts. Here, we present the ependymin sequences from the herring (Clupea harengus) and the pike (Esox lucius). A comparison of ependymin homologous sequences from three different orders of teleost fish (Salmoniformes, Cypriniformes, and Clupeiformes) revealed the highest similarity between Clupeiformes and Cypriniformes. This result is unexpected because it does not reflect current systematics, in which Clupeiformes belong to a separate infradivision (Clupeomorpha) than Salmoniformes and Cypriniformes (Euteleostei). Furthermore, in Salmoniformes the evolutionary rate of ependymins seems to be accelerated mainly on the protein level. However, considering these inconstant rates, neither neighbor joining trees nor DNA parsimony methods gave any indication that a separate euteleost infradivision exists.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00556362
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    Sequences related to the ox pancreatic ribonuclease coding region in the genomic DNA of mammalian species (1993)
    Springer
    Journal of molecular evolution 37 (1993), S. 29-35 
    Details
    ISSN: 1432-1432
    Keywords: Ribonuclease ; Evolution ; Gene duplication ; Ruminants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Mammalian pancreatic ribonucleases form a family of homologous proteins that has been extensively investigated. The primary structures of these enzymes were used to derive phylogenetic trees. These analyses indicate that the presence of three strictly homologous enzymes in the bovine species (the pancreatic, seminal, and cerebral ribonucleases) is due to gene duplication events which occurred during the evolution of ancestral ruminants. In this paper we present evidence that confirms this finding and that suggests an overall structural conservation of the putative ribonuclease genes in ruminant species. We could also demonstrate that the sequences related to ox ribonuclease coding regions present in genomic DNA of the giraffe species are the orthologues of the bovine genes encoding the three ribonucleases mentioned above.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00170459
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Molecular evolutionary analysis based on the amino acid sequence of catalase (1993)
    Springer
    Journal of molecular evolution 37 (1993), S. 71-76 
    Details
    ISSN: 1432-1432
    Keywords: Evolution ; Catalase ; Phylogenetic tree
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Heme-containing catalase sequences from 20 different organisms representing prokaryotes, fungi, animals, and plants have been compiled for phylogenetic reconstruction. Phylogenies based on distance and parsimony analysis show that fungal and animal catalases can be derived from one ancestor, whereas bacterial catalases fail to form a monophyletic group. Plant catalases appear to form a second class of catalases that arose independently from a possible prokaryotic ancestor.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00170464
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    Conservation of human Y chromosome sequences among male great apes: Implications for the evolution of Y chromosomes (1994)
    Springer
    Journal of molecular evolution 39 (1994), S. 13-21 
    Details
    ISSN: 1432-1432
    Keywords: Y chromosome ; Great ape ; Human ; Evolution ; DNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Nine newly described single-copy and lowcopy-number genomic DNA sequences isolated from a flow-sorted human Y chromosome library were mapped to regions of the human Y chromosome and were hybridized to Southern blots of male and female great ape genomic DNAs (Gorilla gorilla, Pan troglodytes, Pongo pygmaeus). Eight of the nine sequences mapped to the euchromatic Y long arm (Yq) in humans, and the ninth mapped to the short arm or pericentromeric region. All nine of the newly identified sequences and two additional human Yq sequences hybridized to restriction fragments in male but not female genomic DNA from the great apes, indicating Y chromosome localization. Seven of these 11 human Yq sequences hybridized to similarly-sized restriction endonuclease fragments in all the great ape species analyzed. The five human sequences that mapped to the most distal subregion of Yq (deletion of which region is associated with spermatogenic failure in humans) were hybridized to Southern blots generated by pulsed-field gel electrophoresis. These sequences define a region of approximately 1 Mb on human Yq in which HpaII tiny fragment (HTF) islands appear to be absent. The conservation of these human Yq sequences on great ape Y chromosomes indicates a greater stability in this region of the Y than has been previously described for most anonymous human Y chromosomal sequences. The stability of these sequences on great ape Y chromosomes seems remarkable given that this region of the Y does not undergo meiotic recombination and the sequences do not appear to encode genes for which positive selection might occur.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00178245
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    The neuroethology of sound production in tiger moths (Lepidoptera, Arctiidae) (1992)
    Springer
    Journal of comparative physiology 170 (1992), S. 575-588 
    Details
    ISSN: 1432-1351
    Keywords: Moth ; Sensorimotor integration ; Neuroethology ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. Certain species of tiger moths emit clicks when stimulated by bat-like sounds. These clicks are generated by modified thoracic episterna (tymbals) (Fig. 1) and constitute a rhythmic behaviour activated by simple sensory input. 2. Tymbal periods are indirectly related to stimulus intensity and periods (Fig. 3). Moths initiate sounds with the tymbal opposite to the stimulated ear and once a sequence commences it continues in an undisrupted fashion. 3. The tymbal is innervated by a pleural branch (IIIN2a) of the metathoracic leg nerve, a similar anatomy to that in the unmodified episterna of silent moths (Fig. 5). Backfills of the IIIN2a in Cycnia tenera reveal sensory fibres and a cluster of 5–9 motor neurons with densely overlying dendritic fields (Fig. 6). 4. Extracellular recordings of the IIIN2a reveal a large impulse preceding each tymbal sound (Fig. 7). I suggest that this impulse results from the synchronous firing of 2–3 motor neurons and is the motor output of the tymbal central pattern generator (CPG). The spikes alternate (Figs. 9, 10) and are bilaterally co-related (Fig. 11) but with an phase asymmetry of 2–3 ms (Fig. 12). 5. Normal motor output continues in the absence of tymbal sounds (Fig. 13) and when all nerve-tymbal connections are severed (Fig. 14, Table 1) therefore this CPG operates independent of sensory feedback. A model is proposed for the tymbal circuitry based upon the present data and the auditory organization of related noctuid moths (Fig. 15). I propose that the tymbal response in modern arctiids evolved from either flight or walking CPGs and that preadaptive circuitry ancestral to tymbal movements still exists in modern silent Lepidoptera.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00199334
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    The evolutionary adaptation of flower colours and the insect pollinators' colour vision (1992)
    Springer
    Journal of comparative physiology 171 (1992), S. 171-181 
    Details
    ISSN: 1432-1351
    Keywords: Colour vision ; Flower colours ; Evolution ; Hymenoptera ; Pollination ecology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The evolutionary tuning between floral colouration and the colour vision of flower-visiting Hymenoptera is quantified by evaluating the informational transfer from the signalling flower to the perceiving pollinator. The analysis of 180 spectral reflection spectra of angiosperm blossoms reveals that sharp steps occur precisely at those wavelengths where the pollinators are most sensitive to spectral differences. Straight-forward model calculations determine the optimal set of 3 spectral photoreceptor types for discrimination of floral colour signals on the basis of perceptual difference values. The results show good agreement with the sets of photoreceptors characterized electrophysiologically in 40 species of Hymenoptera.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00188925
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    Did neural pooling for night vision lead to the evolution of neural superposition eyes? (1994)
    Springer
    Journal of comparative physiology 175 (1994), S. 289-302 
    Details
    ISSN: 1432-1351
    Keywords: Compound eye ; Open rhabdom ; Neural superposition ; Visual ecology ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Observations of the infrared deep pseudopupil, optical determinations of the corneal nodal point, and histological methods were used to relate the visual fields of individual rhabdomeres to the array of ommatidial optical axes in four insects with open rhabdoms: the tenebrionid beetle Zophobas morio, the earwig Forficula auricularia, the crane fly Tipula pruinosa, and the backswimmer Notonecta glauca. The open rhabdoms of all four species have a central pair of rhabdomeres surrounded by six peripheral rhabdomeres. At night, a distal pigment aperture is fully open and the rhabdom receives light over an angle approximately six times the interommatidial angle. Different rhabdomeres within the same ommatidium do not share the same visual axis, and the visual fields of the peripheral rhabdomeres overlap the optical axes of several near-by ommatidia. During the day, the pigment aperture is considerably smaller, and all rhabdomeres share the same visual field of about two interommatidial angles, or less, depending on the degree of light adaptation. The pigment aperture serves two functions: (1) it allows the circadian rhythm to switch between the night and day sampling patterns, and (2) it works as a light driven pupil during the day. Theoretical considerations suggest that, in the night eye, the peripheral retinula cells are involved in neural pooling in the lamina, with asymmetric pooling fields matching the visual fields of the rhabdomeres. Such a system provides high sensitivity for nocturnal vision, and the open rhabdom has the potential of feeding information into parallel spatial channels with different tradeoffs between resolution and sensitivity. Modification of this operational principle to suit a strictly diurnal life, makes the contractile pigment aperture superfluous, and decreasing angular sensitivities together with decreasing pooling fields lead to a neural superposition eye.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00192988
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    Functional elements and domains inferred from sequence comparisons of a heat shock gene in two nematodes (1990)
    Springer
    Journal of molecular evolution 31 (1990), S. 3-9 
    Details
    ISSN: 1432-1432
    Keywords: Caenorhabditis elegans ; Caenorhabditis briggsae ; hsp70 ; grp78 ; Gene comparison ; Evolution ; Regulatory elements
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Caenorhabditis elegans andCaenorhabditis briggsae are two closely related nematode species that are nearly identical morphologically. Interspecific cross-hybridizing DNA appears to be restricted primarily to coding regions. We compared portions of thehsp-3 homologs two grp 78-like genes, fromC. elegans andC. briggsae and detected regions of DNA identity in the coding region, the 5′ flanking DNAs, and the introns. Thehsp-3 homologs share approximately 98% and 93% identity at the amino acid and nucleotide levels, respectively. Using the nucleotide substitution rate at the silent third position of the codons, we have estimated a lower limit for the date of divergence betweenC. elegans andC. briggsae to be approximately 23–32 million years ago. The 5′ flanking DNAs and one of the introns contain elements that are highly conserved betweenC. elegans andC. briggsae. Some of the regions of nucleotide identity in the 5′ flanking DNAs correspond to previously detected identities including viral enhancer sequences, a heat shock element, and an element present in the regulatory regions of mammalian grp78 and grp94 genes. We propose that a comparison ofC. elegans andC. briggsae sequences will be useful in the detection of potential regulatory and structural elements.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02101786
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    Secondary structural elements exclusive to the sequences flanking ribosomal RNAs lend support to the monophyletic nature of the archaebacteria (1990)
    Springer
    Journal of molecular evolution 31 (1990), S. 25-32 
    Details
    ISSN: 1432-1432
    Keywords: Archaebacteria ; rRNA operons ; Secondary structure ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Several sequences flanking the large rRNA genes of several transcripts from extreme thermophiles, extreme halophiles, and methanogens were aligned and analyzed for the presence of common primary and secondary structural features, which would bear on the concept of monphyletic archaebacteria. Few sequences were common to all the archaebacterial transcripts, and these were confined to short regions generally flanking putative double helices. At a secondary structural level, however, in addition to the previously characterized processing stems of the 16S and 23S RNAs, four helices were detected that were common to the archaebacterial transcripts: two in the 16S RNA leader sequence and two in the 16S-23S RNA spacer. Although all of these helices vary in size and form from organism to organism, three of them contain double helical segments that are strongly supported by compensating base changes among the three archaebacterial groups. Three extreme halophiles exhibited two additional helices in their relatively large spacers and a further helix preceding the 5S RNA, which are also supported by compensating base changes. Ribosomal RNA transcripts from eubateria/chloroplasts and eukaryotes were also examined for secondary structural features with locations and forms corresponding to those of the archaebacteria, but none were detected. The analysis provides support for the monophyletic nature of the archaebacteria and reinforces their differences from eubacteria/chloroplasts and eukaryotes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02101789
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    Distribution of the salmonid Hpa 1 family in the salmonid species demonstrated by in vitro runoff transcription assay of total genomic DNA: A procedure to estimate repetitive frequency and sequence divergence of a certain repetitive family with a few known sequences (1991)
    Springer
    Journal of molecular evolution 32 (1991), S. 43-52 
    Details
    ISSN: 1432-1432
    Keywords: Retroposon ; Salmonid ; +RNA ; Evolution ; Average sequence divergence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary An in vitro runoff transcription assay of total genomic DNA was developed. As an example of use of this assay, analysis of a highly repetitive sequence in the cherry salmon (Oncorhynchus masou) is described. Total genomic DNA of the cherry salmon was completely digested with Hpa 1, whose site is known to be in the tRNA-unrelated region of the cherry salmon Hpa 1 family. On transcription of the digested DNA in a HeLa cell extract, a discrete-sized RNA of about 100 nucleotides, constituting 70% of the transcripts, was produced, whereas on transcription of the undigested total DNA, only smeared RNA was obtained. In a fingerprint, the oligonucleotides of the discrete transcript from the digested total DNA were very distinct and exactly corresponded to those of a transcript from an Hpa 1 digest of a cloned DNA, but with few extra oligonucleotides. These results showed that the cherry salmon Hpa 1 family constitutes a major repetitive family in the genome of the cherry salmon. For determination of the distribution of the salmonid Hpa 1 family in other salmonid species, the same analysis was applied to DNAs from the chum salmon (Oncorhynchus keta), brown trout (Salmo trutta), Japanese common charr (Salvelinus leucomaenis pluvius), and Japanese huchen (Hucho perryi). The results showed that the salmonid Hpa 1 family is widespread in the genomes of salmonid species. A method and equations are also presented for estimating the relationship between the ratio of a given repetitive family to all the Pol III genes and its average sequence divergence by calculating the molar ratio of the runoff transcript to all the in vitro Pol III transcripts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02099928
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    Evolution of RNA polymerases and branching patterns of the three major groups of archaebacteria (1991)
    Springer
    Journal of molecular evolution 32 (1991), S. 70-78 
    Details
    ISSN: 1432-1432
    Keywords: Phylogenetic tree ; Likelihood method ; RNA polymerase ; Archaebacteria ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The amino acid sequences of the largest subunits of the RNA polymerases I, II, and III from eukaryotes were compared with those of archaebacterial and eubacterial homologs, and their evolutionary relationships were analyzed in detail by a recently developed tree-making method, the likelihood method of protein phylogeny, as well as by the neighbor-joining method and the parsimony method, together with bootstrap analyses. It was shown that the best tree topologies predicted by the first two methods are identical, whereas the last one predicts a distinct tree. The maximum likelihood tree revealed that, after the separation from archaebacteria, the three eukaryotic RNA polymerases diverged from an ancestral precursor in the eukaryotic lineage. This result is contrasted with the published result showing multiple origins for the three eukaryotic polymerases. It was shown that eukaryotic RNA polymerase I evolved much more rapidly than RNA polymerases II and III: The N-terminal half of RNA polymerase I shows an extraordinarily high evolutionary rate, possibly due to relaxed functional constraints. In contrast the evolutionary rate of archaebacterial RNA polymerase is remarkably limited. In addition, including the second largest subunit of the RNA polymerase, a detailed analysis for the branching pattern of the three major groups of archaebacteria was carried out by the maximum likelihood method. It was shown that the three major groups of archaebacteria are likely to form a single cluster; that is, archaebacteria are likely to be monophyletic as originally proposed by Woese and his colleagues.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02099931
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    On the mode of evolution of alpha satellite DNA in human populations (1991)
    Springer
    Journal of molecular evolution 33 (1991), S. 42-48 
    Details
    ISSN: 1432-1432
    Keywords: Satellite DNA ; Mouse ; Human chromosomes 13 and 21 ; Evolution ; Saltatory amplification ; Homogenization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The hypothesis that highly reiterated satellite DNAs in present-day populations evolve by molecular mechanisms that create, by saltatory amplification steps, new long arrays of satellite DNA, and that such long arrays are used for homogenization purposes, has been tested both in mouse and in humans. In mouse, the data obtained are consistent with this hypothesis. This was tested in more detail on chromosomes 13 and 21 of the human genome. A Centre d'Etudes du Polymorphisme Humain family, which in some individuals exhibits strong supplementary DNA bands following TaqI restriction endonuclease digestion and conventional gel electrophoresis, was analyzed by pulse field gel electrophoresis following restriction by BamHI. The supplementary bands on chromosome 13 (18 times the basic alpha satellite DNA repeat) and on chromosome 21 (a 9.5-mer) segregated with centromeric alpha satellite DNA blocks of 5 and 5.3 megabases, respectively. These are by far the largest alpha satellite block lengths seen in all chromosome 13 and chromosome 21 centrometric sequences so far analyzed in this manner. The possibility that these supplementary alpha satellite sequences were created in single individuals by saltatory amplification steps is discussed in light of our own data and that published by others. It is proposed that deletion events and unequal cross-overs, which both occur in large satellite DNA arrays, contribute to the homogenization of size and sequence of the alpha satellite DNA on most chromosomes of humans.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02100194
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    Biogenesis as an evolutionary process (1991)
    Springer
    Journal of molecular evolution 33 (1991), S. 207-208 
    Details
    ISSN: 1432-1432
    Keywords: Evolution ; Vesicle ; Biogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The earliest fossil stromatolites present evidence of a complex ecosystem of photosynthetic organisms. Because the origin of present life can be dated within a few hundred million years prior to these fossils, their complexity poses a problem. A heuristic model outlines the first radiation leading to the universal ancestor.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02100670
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    Evolutionary origin of the class A and class C β-lactamases (1992)
    Springer
    Journal of molecular evolution 34 (1992), S. 345-350 
    Details
    ISSN: 1432-1432
    Keywords: Evolution ; β-Lactamase ; Phylogenetic tree ; Horizontal transfer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The protein sequences of 18 class A β-lactamases and 2 class C β-lactamases were analyzed to produce a rooted phylogenetic tree using the DD peptidase of Streptomyces R61 as an outgroup. This tree supports the penicillin-binding proteins as the most likely candidate for the ancestoral origin of the class A and class C β-lactamases, these proteins diverging from a common evolutionary origin close to the DD peptidase. The actinomycetes are clearly shown as the origin of the class A β-lactamases found in other non-actinomycete species. The tree also divides the β-lactamases from the Streptomyces into two subgroups. One subgroup is closer to the DD peptidase root. The other Streptomyces subgroup shares a common branch point with the rest of the class A β-lactamases, showing this subgroup as the origin of the non-actinomycete class A β-lactamases. The non-actinomycete class A β-lactamase phylogenetic tree suggests a spread of these β-lactamases by horizontal transfer from the Streptomyces into the non-actinomycete gram-positive bacteria and thence into the gram-negative bacteria. The phylogenetic tree of the Streptomyces class A β-lactamases supports the possibility that horizontal transfer of class A β-lactamases occurred within the Streptomyces.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00160242
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Organization and evolution of bacterial and bacteriophage primase-helicase systems (1992)
    Springer
    Journal of molecular evolution 34 (1992), S. 351-357 
    Details
    ISSN: 1432-1432
    Keywords: Primase-helicase systems ; Evolution ; Bacteria ; Bacteriophage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Amino acid sequences of primases and associated helicases involved in the DNA replication of eubacteria and bacteriophages T7, T3, T4, P4, and P22 were compared by computer-assisted methods. There are two types of such systems, the first one represented by distinct helicase and primase proteins (e.g., DnaB and DnaG proteins of Escherichia coli), and the second one by single polypeptides comprising both activities (gp4 of bacteriophages T7 and T3, and alpha protein of bacteriophage P4). Pronounced sequence similarity was revealed between approximately 250 amino acid residue N-terminal domains of stand-alone primases and the primase-helicase proteins of T7(T3) and P4. All these domains contain, close to their N-termini, a conserved Zn-finger pattern that may be implicated in template DNA recognition by the primases. In addition, they encompass five other conserved motifs some of which may be involved in substrate (NTP) binding. Significant similarity was also observed between the primase-associated helicases (DnaB, gp12 of P22 and gp41 of T4) and the C-terminal domain of T7(T3) gp4. On the other hand the C-terminal domain of P-alpha of P4 is related to another group of DNA and RNA helicases. Tentative phylogenetic trees generated for the primases and the associated helicases showed no grouping of the phage proteins, with the exception of the primase domains of bacteriophages T4 and P4. This may indicate a common origin for one-component primase-helicase systems. Two scenarios for the evolution of primase-helicase systems are discussed. The first one involves fusion of the primase and helicase components (T7 and T3) or fusion of the primase component with a different type of helicase domain (P4). The second possibility is the duplication of an ancestral gene encoding a gp4-like bifunctional protein followed by divergence of the copies, one of which retains the primase and the other the helicase domain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00160243
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    The isochore patterns of mammalian genomes and their phylogenetic implications (1993)
    Springer
    Journal of molecular evolution 37 (1993), S. 93-108 
    Details
    ISSN: 1432-1432
    Keywords: DNA ; Base composition ; Vertebrates ; Eutheria ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The compositional distributions of high molecular weight DNA fragments from 20 species belonging to 9 out of the 17 eutherian orders were investigated by analytical CsCl density gradient centrifugation and by preparative fractionation in Cs2SO4/BAMD density gradients followed by analysis of the fractions in CsCl. These compositional distributions reflect those of the isochores making up the corresponding genomes. A “general distribution” was found in species belonging to eight mammalian orders. A “myomorph distribution” was found in Myomorpha, but not in the other rodent infraorders Sciuromorpha and Histricomorpha, which share the general distribution. Two other distributions were found in a megachiropteran (but not in microchiropteran, which, again, shares the general distribution) and in pangolin (a species from the only genus of the order Pholidota), respectively. The main difference between the general distribution and all other distributions is that the former contains sizable amounts (6–10%) of GC-rich isochores (detected as DNA fragments equal to, or higher than, 1.710 g/cm3 in modal buoyant density), which are scarce, or absent, in the other distributions. This difference is remarkable because gene concentrations in mammalian genomes are paralleled by GC levels, the highest gene concentrations being present in the GC-richest isochores. The compositional distributions of mammalian genomes reported here shed light on mammalian phylogeny. Indeed, all orders investigated, with the exception of Pholidota, seem to share a common ancestor. The compositional patterns of the megachiropteran and of Myomorpha may be derived from the general pattern or have independent origins.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02407344
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    Compartmentalized isozyme genes and the origin of introns (1990)
    Springer
    Journal of molecular evolution 31 (1990), S. 205-210 
    Details
    ISSN: 1432-1432
    Keywords: Isozyme ; Intron ; Phylogenetic tree ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Both the mouse cytosolic malate dehydrogenase gene and its mitochondrial counterpart contain eight introns, of which two are present at identical positions between the isozyme genes. The probability that the two intron positions coincide by chance between the two genes has been shown to be significantly small (=1.3×10−3), suggesting that the conservation of the intron positions has a biological significance. On the basis of a rooted phylogenetic tree inferred from a comparison of these isozymes and lactate dehydrogenases, we have shown that the origins of the conserved introns are very old, possibly going back to a date before the divergence of eubacteria, archaebacteria, and eukaryotes. In the aspartate aminotransferase isozyme genes, five of the introns are at identical places. The origins of the five conserved introns, however, are not obvious at present. It remains possible that some or all of the conserved introns have evolved after the divergence of eubacteria and eukaryotes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02109497
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    Prokaryotic and eukaryotic pyridoxal-dependent decarboxylases are homologous (1990)
    Springer
    Journal of molecular evolution 31 (1990), S. 325-329 
    Details
    ISSN: 1432-1432
    Keywords: PLP-dependent decarboxylase ; Evolution ; Profile analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A database search has revealed significant and extensive sequence similarities among prokaryotic and eukaryotic pyridoxal phosphate (PLP)-dependent decarboxylases, includingDrosophila glutamic acid decarboxylase (GAD) and bacterial histidine decarboxylase (HDC). Based on these findings, the sequences of seven PLP-dependent decarboxylases from five different organisms have been aligned to derive a consensus sequence for this family of enzymes. In addition, quantitative methods have been employed to calculate the relative evolutionary distances between pairs of the decarboxylases comprising this family. The multiple sequence analysis together with the quantitative results strongly suggest an ancient and common origin for all PLP-dependent decarboxylases. This analysis also indicates that prokaryotic and eukaryotic HDC activities evolved independently. Finally, a sensitive search algorithm (PROFILE) was unable to detect additional members of this decarboxylase family in protein sequence databases.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02101126
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    Cloning and characterization of the platypus mitochondrial genome (1994)
    Springer
    Journal of molecular evolution 39 (1994), S. 200-205 
    Details
    ISSN: 1432-1432
    Keywords: Evolution ; Monotreme ; Platypus ; mtDNA ; tRNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The vertebrate mitochondrial genome is highly conserved in size and gene content. Among the chordates there appears to be one basic gene arrangement, but rearrangements in the mitochondrial gene order of the avian lineages have indicated that the mitochondrial genome may be more variable than once thought. Different gene orders in marsupials and eutherian mammals leave the ancestral mammalian order in some doubt. We have investigated the mitochondrial gene order in the platypus (Ornithorhynchus anatinus), a representative of the third major group of mammals, to determine which mitochondrial gene arrangement is ancestral in mammals. We have found that the platypus mtDNA conforms to the basic chordate gene arrangement, common to fish, amphibians, and eutherian mammals, indicating that this arrangement was the original mammalian arrangement, and that the unusual rearrangements observed in the avians and marsupials are probably lineage-specific.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00163808
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    Regulatory DNA sequence conserved in the course of BK virus evolution (1990)
    Springer
    Journal of molecular evolution 31 (1990), S. 485-492 
    Details
    ISSN: 1432-1432
    Keywords: BK virus ; Strains ; Regulatory region ; Late region ; Nucleotide sequence ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Within the genome of human polyomavirus BK (BKV), there exists a noncoding regulatory region toward the late region side of the origin of DNA replication. In most BKV strains isolated by viral culture, this regulatory region contains tandem repeats varying in size. Recently. however, several laboratories isolated new BKV strains (designated as archetypal strains) lacking such repeat sequences. To examine the genetic relationship between archetypal strains, a phylogenetic tree was constructed for seven BKV strains, including three archetypal strains, from DNA sequence data on the late genes, those for leader protein (agnoprotein), and those for structural proteins (VP1, VP2, and VP3). For three strains data previously reported were used, whereas for the others sequences were determined in this study. From total numbers of nucleotide substitutions in each pair of strains, a phylogenetic tree was constructed by the unweighted pair-group method. The phylogenetic tree obtained reveals that BKV strains containing the archetypal regulatory region do not constitute a cluster of closely related strains and that these strains, together with those carrying the major part of the archetypal regulatory region, are widespread in the BKV population. This finding suggests that the basic structure of the archetypal regulatory region has been conserved in the course of BKV evolution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02102075
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    Interspecific sequence comparison of the muscle-myosin heavy-chain genes from Drosophila hydei and Drosophila melanogaster (1994)
    Springer
    Journal of molecular evolution 39 (1994), S. 357-368 
    Details
    ISSN: 1432-1432
    Keywords: Drosophila ; Muscle-myosin heavy-chain gene ; Alternative exons ; Synonymous substitutions ; Amino acid substitutions ; Evolution ; Testis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The muscle-myosin heavy-chain (mMHC) gene of Drosophila hydei has been sequenced completely (size 23.3 kb). The sequence comparison with the D. melanogaster mMHC gene revealed that the exonintron pattern is identical. The protein coding regions show a high degree of conservation (97%). The alternatively spliced exons (3a-b, 7a-d, 9a-c, 11a-e, and 15a-b) display more variations in the number of nonsynonymous and synonymous substitutions than the common exons (2, 4, 5, 6, 8, 10, 12, 13, 14, 16, 17, and 19). The base composition at synonymous sites of fourfold degenerate codons (third position) is not biased in the alternative exons. In the common exons there exists a bias for C and against A. These findings imply that the alternative exons of the Drosophila mMHC gene evolve at a different, in several cases higher, rate than the common ones. The 5′ splice junctions and 5′ and 3′ untranslated regions show a high level of similarity, indicating a functional constraint on these sequences. The intron regions vary considerably in length within one species, but the corresponding introns are very similar in length between the two species and all contain stretches of sequence similarity. A particular example is the first intron, which contains multiple regions of similarity. In the conserved regions of intron 12 (head-tail border) sequences were found which have the potential to direct another smaller mMHC transcript.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00160268
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    An analysis of retroposition in plants based on a family of SINEs from Brassica napus (1994)
    Springer
    Journal of molecular evolution 39 (1994), S. 378-386 
    Details
    ISSN: 1432-1432
    Keywords: CpG dinucleotides ; Evolution ; Repetitive sequences ; Reverse transcriptase ; S1Bn retroposons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The identification of a family of SINE retroposons dispersed in the genome of oilseed rape Brassica napus has provided the basis for an evolutionary analysis of retroposition in plants. The repetitive elements (called S1Bn) are 170 by long and occupy roughly 500 loci by haploid genome. They present characteristic features of SINE retroposons such as a 3′ terminal A-rich region, two conserved polymerase III motifs (box A and B), flanking direct repeats of variable sizes, and a primary and secondary sequence homology to several tRNA species. A consensus sequence was made from the alignment of 34 members of the family. The retroposon population was divided into five subfamilies based on several correlated sets of mutations from the consensus. These precise separations in subfamilies based on “diagnostic” mutations and the random distribution of mutations observed inside each subfamily are consistent with the master sequence model proposed for the dispersion of mammalian retroposons. An independent analysis of each subfamily provides strong evidence for the coexpression of at least three subfamily master sequences (SMS). In contrast to mammalian retroposition, diagnostic positions are not shared between SMS. We therefore propose that SMS were all derived from a general master sequence (GMS) and independently activated for retroposition after a variable period of random drift. Possible models for plant retroposition are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00160270
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    The evolution of the thrombospondin gene family (1993)
    Springer
    Journal of molecular evolution 36 (1993), S. 509-516 
    Details
    ISSN: 1432-1432
    Keywords: Thrombospondin ; Evolution ; Adhesive glycoproteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Thrombospondin-1 is an adhesive glycoprotein that is involved in cellular attachment, spreading, migration, and proliferation. To date, four genes have been identified that encode for the members of the thrombospondin gene family. These four genes are homologous to each other in the EGF-like (type 2) repeats, the calcium-binding (type 3) motifs, and the COOH-terminal. The latter has been reported to be a cell-binding domain in thrombospondin-1. Phylogenetic trees have been constructed from the multisequence alignment of thrombospondin sequences from human, mouse, chicken, and frog. Two different algorithms generate comparable results in terms of the topology and the branch lengths. The analysis indicates that an early form of the thrombospondin gene duplicated about 925 million years ago. The gene duplication that produced the thrombospondin-1 and -2 branches of the family is predicted to have occurred 583 million years ago, whereas the gene duplication that produced the thrombospondin-3 and -4 branches of the family is predicted to have occurred 644 million years ago. These results indicate that the members of the thrombospondin gene family have existed throughout the evolution of the animal kingdom and thus probably participate in functions that are common to most of its members.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00556355
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    The compositional patterns of the avian genomes and their evolutionary implications (1993)
    Springer
    Journal of molecular evolution 37 (1993), S. 544-551 
    Details
    ISSN: 1432-1432
    Keywords: Isochores ; DNA ; Coding sequences ; Birds ; Mammals ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The compositional distributions of large (main-band) DNA fragments from eight birds belonging to eight different orders (including both paleognathous and neognathous species) are very broad and extremely close to each other. These findings, which are paralleled by the compositional similarity of homologous coding sequences and their codon positions, support the idea that birds are a monophyletic group. The compositional distribution of third-codon positions of genes from chicken, the only avian species for which a relatively large number of coding sequences is known, is very broad and bimodal, the minor GC-richer peak reaching 100% GC. The very high compositional heterogeneity of avian genomes is accompanied (as in the case of mammalian genomes) by a very high speciation rate compared to cold-blooded vertebrates which are characterized by genomes that are much less heterogeneous. The higher GC levels attained by avian compared to mammalian genomes might be correlated with the higher body temperature (41–43°C) of birds compared to mammals (37°C). A comparison of GC levels of coding sequences and codon positions from man and chicken revealed very close average GC levels and standard deviations. Homologous coding sequences and codon positions from man and chicken showed a surprisingly high degree of compositional similarity which was, however, higher for GC-poor than for GC-rich sequences. This indicates that GC-poor isochores of warm-blooded vertebrates reflect the composition of the isochores of the genome of the common reptilian ancestor of mammals and birds, which underwent only a small compositional change at the transition from cold- to warm-blooded vertebrates. In contrast, the GC-rich isochores of birds and mammals are the result of large compositional changes at the same evolutionary transition, where were in part different in the two classes of warm-blooded vertebrates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00160434
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    Evolution of regulatory genes and patterns: Relationships to evolutionary rates and to metabolic functions (1993)
    Springer
    Journal of molecular evolution 37 (1993), S. 590-599 
    Details
    ISSN: 1432-1432
    Keywords: Evolution ; Gene regulation ; Drosophila ; Adaptation ; Enzymes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In an effort to understand the forces shaping evolution of regulatory genes and patterns, we have compared data on interspecific differences in enzyme expression patterns among the rapidly evolving Hawaiian picture-winged Drosophila to similar data on the more conservative virilis species group. Divergence of regulatory patterns is significantly more common in the former group, but cause and effect are difficult to discern. Random fixation of regulatory variants in small populations and/or during speciation may be somewhat more likely than divergence driven by selection. Within the picture-winged group, we also have compared enzymes that fulfill different metabolic roles. There are highly significant differences between individual enzymes, but no obvious correlations to functional categories.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00182745
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    The sequence and expression pattern of the Calliphora erythrocephala yolk protein A and B genes (1994)
    Springer
    Journal of molecular evolution 38 (1994), S. 336-351 
    Details
    ISSN: 1432-1432
    Keywords: Yolk protein genes ; Vitellogenesis ; Calliphora ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The yolk protein genes (yps) are expressed in a temporal, tissue- and sex-specific fashion in Drosophila melanogaster. Here we report the sequence of two related genes in Calliphora erythrocephala. The predicted Calliphora yolk protein (YP) sequences are well conserved, especially at the C-terminal end when compared to those of D. melanogaster and Ceratitis capitata. Database searches with the Calliphora yolk protein B (CeYPB) sequence identify the vertebrate lipase similarity reported for the YPs of Drosophila and Ceratitis. Moreover, sequences with identity to divalent ion-binding sites were observed, which colocalized with putative tyrosine sulfation sites. Calliphora oogenesis differs from Drosophila in that it is cyclic in response to a meat feed. The Calliphora yp genes are expressed in the follicle cells of the egg chamber during vitellogenesis, as shown by in situ hybridization, and the yp message levels correlate with YP synthesis. The synthesis of the yp transcripts in ovaries of Calliphora occurs in the same pattern as that for ovarian transcripts in Drosophila. In the carcass, yp transcript levels are correlated with the production of a batch of eggs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00163151
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    Molecular phylogenies based on ribosomal protein L11, L1, L10, and L12 sequences (1994)
    Springer
    Journal of molecular evolution 38 (1994), S. 405-419 
    Details
    ISSN: 1432-1432
    Keywords: Molecular phylogeny ; Universal tree ; Ribosomal proteins ; Evolution ; Archaebacteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Available sequences that correspond to the E. coli ribosomal proteins L11, L1, L10, and L12 from eubacteria, archaebacteria, and eukaryotes have been aligned. The alignments were analyzed qualitatively for shared structural features and for conservation of deletions or insertions. The alignments were further subjected to quantitative phylogenetic analysis, and the amino acid identity between selected pairs of sequences was calculated. In general, eubacteria, archaebacteria, and eukaryotes each form coherent and well-resolved nonoverlapping phylogenetic domains. The degree of diversity of the four proteins between the three groups is not uniform. For L11, the eubacterial and archaebacterial proteins are very similar whereas the eukaryotic L11 is clearly less similar. In contrast, in the case of the L12 proteins and to a lesser extent the L10 proteins, the archaebacterial and eukaryotic proteins are similar whereas the eubacterial proteins are different. The eukaryotic L1 equivalent protein has yet to be identified. If the root of the universal tree is near or within the eubacterial domain, our ribosomal protein-based phylogenies indicate that archaebacteria are monophyletic. The eukaryotic lineage appears to originate either near or within the archaebacterial domain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00163157
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    Phylogeny and physiology of Drosophila opsins (1994)
    Springer
    Journal of molecular evolution 38 (1994), S. 250-262 
    Details
    ISSN: 1432-1432
    Keywords: Opsin ; Visual pigments ; Gene family ; Evolution ; Phylogeny ; Spectral sensitivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Phylogenetic and physiological methods were used to study the evolution of the opsin gene family in Drosophila. A phylogeny based on DNA sequences from 13 opsin genes including representatives from the two major subgenera of Drosophila shows six major, well-supported clades: The “blue opsin” clade includes all of the Rhl and Rh2 genes and is separated into two distinct subclades of Rhl sequences and Rh2 sequences; the ultraviolet opsin clade includes all Rh3 and Rh4 genes and bifurcates into separate Rh3 and Rh4 clades. The duplications that generated this gene family most likely took place before the evolution of the subgenera Drosophila and Sophophora and their component species groups. Numerous changes have occurred in these genes since the duplications, including the loss and/or gain of introns in the different genes and even within the Rhl and Rh4 clades. Despite these changes, the spectral sensitivity of each of the opsins has remained remarkably fixed in a sample of four species representing two species groups in each of the two subgenera. All of the strains that were investigated had R1-6 (Rhl) spectral sensitivity curves that peaked at or near 480 nm, R7 (Rh3 and Rh4) peaks in the ultraviolet range, and ocellar (Rh2) peaks near 420 nm. Each of the four gene clades on the phylogeny exhibits very conservative patterns of amino acid replacement in domains of the protein thought to influence spectral sen sitivity, reflecting strong constraints on the spectrum of light visible to Drosophila.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00176087
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    Investigation of the human Rh blood group system in nonhuman primates and other species with serologic and Southern blot analysis (1994)
    Springer
    Journal of molecular evolution 39 (1994), S. 87-92 
    Details
    ISSN: 1432-1432
    Keywords: Rh blood group ; Evolution ; Rh antibodies ; Restriction fragments ; Primates ; Chimpanzee ; Gorilla ; New World monkey ; Old World monkey
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract To investigate the evolution of the Rh blood-group system in anthropoid apes, New and Old World monkeys, and nonprimate animals, serologic typing of erythrocytes from these species with antibodies specific for the human Rh blood-group antigens was performed. In addition, genomic DNA from these animals was analyzed on Southern blots with a human Rh-specific cDNA. Consistent with earlier reports, serologic results showed that gorilla and chimpanzee erythrocytes had epitopes recognized by human Rh D and c antisera, and gibbon erythrocytes were recognized by the c antisera. Surprisingly, some Old and New World monkeys also expressed a Rh c epitope on their erythrocytes. No erythrocytes from the nonprimate animals reacted specifically with any of the human Rh antisera. Southern blot analysis with a human Rh-specific cDNA probe detected Rh-related sequences in anthropoid apes, all New and Old World monkeys, and in most nonprimate animals tested. Although some Rh-related restriction fragments were conserved across species lines in primates, the Rh locus was more polymorphic in chimpanzees and gorillas than in humans. In addition, restriction fragments segregating with the presence of the D antigen in humans were present in the primate species that expressed the D antigen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00178253
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    Mycotoxin formation in HY-320 wheat during granary storage at 15 and 19% moisture content (1990)
    Springer
    Mycopathologia 111 (1990), S. 181-189 
    Details
    ISSN: 1573-0832
    Keywords: mycotoxin ; ochratoxin ; Penicillium ; storage ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Eleven-kilogram parcels of HY-320 wheat, a cultivar of the new Canada Prairie Spring class, were kept at 15 and 19% initial moisture contents (IMC) in simulated storage in a Manitoba farm granary for 60 weeks to determine biotic and abiotic changes and mycotoxin production. Ochratoxin A reached a maximum of 0.24 ppm by week 20 in the 19% IMC wheat, but was absent in the 15% IMC wheat; no other mycotoxins were detected. Temperature, moisture content, O2 and CO2 levels, fat acidity values, seed germination, microfloral incidence and abundance, and the presence of other mycotoxins were monitored. Principal component analysis of all variables showed that the first principal components accounted for 32–41% of the system variability, and contained the ochratoxin A variable. Ochratoxin A was produced in moist grain that had decreased seed germination andAltermaria activity, and high fungal activity byPenicillium andAspergillus versicolor. Compared to other stored cereals previously studied, HY-320 wheat would be ranked in a low-risk category for mycotoxin formation, based on the ochratoxin A levels observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02282802
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    Effect of the incubation conditions on the production of patulin by Penicillium griseofulvum isolated from wheat (1991)
    Springer
    Mycopathologia 115 (1991), S. 163-168 
    Details
    ISSN: 1573-0832
    Keywords: Penicillium griseofulvum ; patulin ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Sixty-four wheat samples from Spanish flour factories were screened for patulin and patulin-producing moulds. None of them was found to contain any patulin, whereas samples experimentally contaminated with this toxin proved it to be highly unstable. On the other hand, Penicillium griseofulvum was the only in vitro patulin-producing species found (19 samples). Mould growth in the samples was investigated by using yeast-sucrose medium (YES) and high-performance liquid chromatography (HPLC) to measure the amounts of toxin produced during 40 day's incubation at 20 and 28°C. The highest yield rate of patulin was obtained between the 20th and 30th day of incubation; such a rate, however, was very low throughout the vigorous growth phase, during the first 20 days of incubation. The more appropriate temperature for incubation and patulin production was 28 °C. We also investigated the influence of other incubation conditions in the yield and found stationary dark cultures to be more efficient that shaken or fermentation cultures in YES medium. The best patulin yield achieved was 11.9 mg in the culture broth and 6.3 mg in the mycelium from 100 ml of medium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00462220
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    Heritability of locomotor performance and its correlates in a natural population (1990)
    Springer
    Cellular and molecular life sciences 46 (1990), S. 530-533 
    Details
    ISSN: 1420-9071
    Keywords: Evolution ; genetics ; heritability ; locomotion ; physiology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Locomotor capacities and their physiological bases are thought to be of considerable selective importance in natural populations. Within this functional complex, organismal performance traits (e.g., speed, stamina) are expected to be of more direct selective importance than their suborganismal determinants (e.g., heart size). Quantitative genetics theory predicts that traits of greater selective importance should generally have lower heritabilities at equilibrium. Contrary to these expectations, we report that organismal performance traits had the highest heritabilities in a natural population of garter snakes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01954257
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    Effect of feeding cereal-legume diets to rats on in vitro absorption of45Ca (1990)
    Springer
    Cellular and molecular life sciences 46 (1990), S. 1016-1017 
    Details
    ISSN: 1420-9071
    Keywords: In vitro absorption ; calcium ; wheat ; Bengal gram
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The in vitro absorption of calcium from the duodenum was significantly less in a group of rats fed on a wheat diet than in a group fed a wheat and Bengal gram (70∶30) diet.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01940659
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    Role of ooplasmic segregation in mammalian development (1994)
    Springer
    Development genes and evolution 203 (1994), S. 199-204 
    Details
    ISSN: 1432-041X
    Keywords: Cell differentiation ; Cytoplasm ; Micromanipulation ; Mouse embryo ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A new micromanipulation technique permitted the scrambling of the zygote cytoplasm. Such interference had no effect on preimplantation development, and when zygotes with scrambled cytoplasm were transfered to the pseudopregnant females, normal and fertile mice were born. This demonstrates that no morphogenetic factors are prelocalized in the egg cytoplasm. Cleavage characteristics of mouse embryos provide the evidence that zygote cytoplasm does not define any determinate type of cleavage. We conclude that the mechanism of ooplasmic segregation is not used in the mouse (and presumably mammalian) development. It is suggested that the turning point in the evolution of mammalian embryogenesis was the transition to the intrauterine development, that started the process leading among other changes, to the loss of the ooplasmic morphogenetic determinants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00636335
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    Phenotypic plasticity and nutrition in a phytophagous insect: consequences of colonizing a new host (1994)
    Springer
    Oecologia 100 (1994), S. 379-385 
    Details
    ISSN: 1432-1939
    Keywords: Tephritidae ; Phenotypic plasticity ; Phytophagous insects ; Evolution ; Selection regime
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The European rose-hip fruit fly Rhagoletis alternata (Diptera, Tephritidae) infests hips of Rosa species. This fly includes R. rugosa, an Asian species now cultivated all over Europe, in its host range. Differences in size and biomass of hips between the ancestral host R. canina and the new host translate into better growth, shorter larval development of larvae within hips of R. rugosa and larger body size and fertility of flies which developing in the new host. In turn this causes different interactions with other organisms of the food-web centred on the host plant. The importance of nutrition and phenotypic plasticity is twofold: they generate a considerable part of life-history diversity within a species and reinforce differences in the ecological context of the ancestral and new host.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00317858
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    A segment of rye chromosome 1 enhances growth and embryogenesis of calli derived from immature embryos of wheat (1991)
    Springer
    Plant cell reports 10 (1991), S. 148-151 
    Details
    ISSN: 1432-203X
    Keywords: wheat ; rye ; embryogenesis ; growth ; tissue culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The influence of the short arm of rye chromosome 1 (1RS) from Secale cereale var. Imperial on the growth and differentiation of callus cultures from wheat Triticum aestivum var. Chinese Spring immature embryos was analysed. This chromosome arm was found to stimulate both embryogenesis and the rate of growth of calli. Recombinant lines carrying segments of 1RS were used to delineate the regions of 1RS responsible for the tissue culture effects. The enhancement of embryogenesis and the stimulation of growth were shown to be associated with two distinct genetic regions of the chromosome arm; the former is located between the centromere and the Sec 1 locus, while the latter is situated in the immediate vicinity of the Sec 1 locus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00232047
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    Neighbour specificity between Lolium perenne and Trifolium repens from a natural pasture (1992)
    Springer
    Oecologia 91 (1992), S. 404-409 
    Details
    ISSN: 1432-1939
    Keywords: Trifolium repens ; Lolium perenne ; Competition ; Coadaptation ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Five genotypes of Trifolium repens and Lolium perenne were collected as neighbouring pairs along a fertility gradient in a natural pasture. After vegetative multiplication, the 25 possible combinations of Lolium genotype x Trifolium genotype were planted in the greenhouse in order to investigate competition between the genotypes. The comparison of the five combinations whose individual components had been neighbours with the combinations of genotypes that had not coexisted before disclosed no difference in total biomass production over 7 months. However, the yield of Trifolium increased when grown with the Lolium genotype which had been its natural neighbour, while the latter showed a decrease in yield. This neighbour specificity existed even when carryover effects from the sampling site had been eliminated (preconditioning period of 18 months) and when native Rhizobium strains were not present (inoculation with a non-native strain). The complex pattern of neighbour specificity with time indicated the importance of environmental conditions for its outcome. These results are a further confirmation of positive effects on the growth of Trifolium repens when grown together with its natural neighbour. They are discussed in the context of coexistence and coevolution
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00317630
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    Fisheries as a large-scale experiment on life-history evolution: disentangling phenotypic and genetic effects in changes in maturation and reproduction of North Sea plaice, Pleuronectes platessa L. (1993)
    Springer
    Oecologia 96 (1993), S. 391-401 
    Details
    ISSN: 1432-1939
    Keywords: Plaice ; Life-history ; Evolution ; Maturation ; Reproduction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This paper attempts to interpret the observed changes in reproductive strategy of female North Sea plaice since 1900 in the light of possible genetical selection exerted by the fisheries. Somatic growth of juvenile plaice increased between the 1950s and the 1980s, probably as a response to an increase in food availability. Adult growth rate was constant, except during a period of increased population abundance when somatic growth decreased. Both length (L mat) and age at first sexual maturity decreased since 1990. No firm evidence was obtained for a change in total reproductive investment, although size-specific fecundity was reduced in the period of increased population abundance, suggesting a trade-off between egg numbers and egg size. Analysis of the phenotypic response of maturation to an increase in juvenile growth suggested that only a part of the decrease in L mat could be ascribed to the observed increase in juvenile growth. The unexplained part of the change in L mat corresponded with the predicted change due to genetical selection by the fisheries. This supported the hypothesis that fishing caused a genetical change in L mat, although an unequivocal interpretation is not possible from a descriptive study.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00317510
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    Modelling the nutritional ecology of ungulate herbivores: evolution of body size and competitive interactions (1992)
    Springer
    Oecologia 89 (1992), S. 428-434 
    Details
    ISSN: 1432-1939
    Keywords: Ruminant ; Hindgut fermenter ; Nutritional ecology ; Evolution ; Body size
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A simulation model is used to quantify relationships between diet quality, digestive processes and body weight in ungulate herbivores. Retention time of food in the digestive tract is shown by regression to scale with W0.27, and to be longer in ruminants than in hindgut fermenters. Allometric relationships between whole gut mean retention time (MRT, h) and weight (W) were: MRT=9.4 W0.255 (r 2=0.80) for hindgut fermenters and MRT=15.3 W0.251 (r 2=0.76) in ruminants. Longer retention of ingesta by large-bodied ruminants and hindgut fermenters increases digestive efficiency relative to small animals and permits them to survive on lower-quality foods. Compared with ruminants, hindgut fermenters' faster throughput is an advantage which outweighs their lower digestive efficiency, particularly on poor quality foods, provided that food resources are not limiting. This suggests that the predominance of ruminants in the middle range of body weights results from their more efficient use of scarce resources under conditions of resource depletion. Considering only physical limitations on intake, the model shows that the allometric coefficient which scales energy intake to body mass is 0.88 in ruminants and 0.82 in hindgut fermenters. The advantages of large body size are countered by disadvantages where food quantity is limited, and we suggest that the upper limit to ungulate body size is determined by the ability to extract nutrients from feeding niches during the nadir of the seasonal cycle of resource quality and abundance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00317422
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    Pollen mitosis in the slipper orchid Cypripedium fasciculatum (1994)
    Springer
    Sexual plant reproduction 7 (1994), S. 87-94 
    Details
    ISSN: 1432-2145
    Keywords: Evolution ; Microtubules ; Polarity Pollen ; Mitosis ; Orchids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Pollen mitosis in the slipper orchid Cypripedium fasciculatum was studied using correlated methods of immunofluorescence and transmission electron microscopy. Unlike the more highly evolved orchids, the cypripedioid orchids shed pollen as monosulcate monads. Prior to pollen mitosis, the microspore nucleus migrates to a proximal position opposite the aperture, as is typical of monocotyledons. There is no distinct generative pole microtubule system (GPMS) like that recently reported in development of pollen polarity in the vandoid moth orchid Phalaenopsis. Instead, microtubules in early prophase are concentrated around the nucleus and extend into the cytoplasm toward the future generative pole. Once the nucleus has migrated to the continuous surface opposite the aperture, microtubules surround the nucleus evenly and show no tendency to be more concentrated in the generative domain. The mitotic spindle, which develops from the perinuclear microtubules, is asymmetrically placed in the microspore and is cone-shaped. The generative pole is broad and closely appressed to the continuous spore surface, while the vegetative pole is pointed and located in the interior of the microspore. As the chromosomes move poleward, microtubules proliferate in the interzone and a phragmoplast develops. The phragmoplast expands in a hemispherical path beyond the interzone following an array of microtubules that radiates from the generative nucleus. Data from this study indicate that evolution of pollen in orchids includes a shift in location of the generative cell from proximal to distal and the evolution of a GPMS, in addition in the well-known trend toward increased pollen aggregation and loss of exine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00230576
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    Sequences of two rbcS cDNA clones of Batophora oerstedii: structural and evolutionary considerations (1991)
    Springer
    Current genetics 20 (1991), S. 173-175 
    Details
    ISSN: 1432-0983
    Keywords: Batophora ; Small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (SSU) ; rbcS cDNA sequence ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Two cDNA clones for the small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (SSU) of Batophora oerstedii were isolated and sequenced. One clone contains the coding information for the complete SSU precursor protein. As in two other species of Dasycladaceae (Acetabularia mediterranea and A. cliftonii), the rbcS cDNA sequences of B. oerstedii display the codons TAA or TAG, which seem to code for glutamine, in the reading frame. The amino acid substitution rate for the SSU protein was calculated to be 0.35–0.41 amino acids per 109 years per site based on the substitutions observed in the SSU amino acid sequences of Acetabularia and Batophora.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00312782
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    Sequence analysis of the glyceraldehyde-3-phosphate dehydrogenase genes from the basidiomycetes Schizophyllum commune, Phanerochaete chrysosporium and Agaricus bisporus (1992)
    Springer
    Current genetics 22 (1992), S. 447-454 
    Details
    ISSN: 1432-0983
    Keywords: Glyceraldehyde-3-phosphate dehydrogenase (GPD) ; Basiodiomycete ; Sequence ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract GPD genes encoding glyceraldehyde-3-phosphate dehydrogenase were isolated from the homobasidiomycetes Schizophyllum commune, Phanerochaete chrysosporium and Agaricus bisporus. All three species contain one transcriptionally active GPD gene, but A. bisporus also contains an inactive GPD gene (tandemly linked to the active gene). These genes contain 5–9 introns located at conserved positions, differing (except in one case) from intron positions in ascomycetous GPD genes. The predicted amino-acid sequences of the proteins encoded by the three active GPD genes are highly homologous. A comparison with protein sequences from filamentous ascomycetes shows a clear distinction, whereas the GPD genes from ascomycetous yeasts are quite distinct from both the filamentous ascomycetes and basidiomycetes. Promoter regions of ascomycetous GPD genes do not correspond to those of the GPD genes of basidiomycetes which may (partly) explain poor expression in basidiomycetes of introduced genes driven by an ascomycete GPD promoter.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00326409
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    Comparative analysis of a recombining-repeat-sequence family in the mitochondrial genomes of wheat (Triticum aestivum L.) and rye (Secale cereale L.) (1993)
    Springer
    Current genetics 23 (1993), S. 255-264 
    Details
    ISSN: 1432-0983
    Keywords: Triticum aestivum ; Secale cerele ; Ribosomal RNA genes ; Mitochondrial DNA ; Recombining-repeats ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The mitochondrial genomes of wheat and rye each contain a three-member family of recombining repeat peat sequences (the “18S/5S repeat”) that encode genes for 18S and 5S rRNAs (rrn18 and rrn5) and tRNAfMet (trnfM). Here we present, for wheat and rye, the sequence and boundaries of the “common sequence unit” (CSU) that is shared between all three repeat copies in each species. The wheat CSU is 4,429 base-pairs long and contains (in addition to trnfM, rrn18 and rrn5) a putative promoter, three tRNA-like elements (“t-elements”), and part of a pseudogene (“ψatpA c”) that is homologous to chloroplast atpA, which encodes the α subunit of chloroplast F1 ATPase. The rye CSU is somewhat smaller (2,855 base pairs) but contains much the same genic and other sequence elements as its wheat counterpart, except that two of the three t-elements as well as ψatpA c are found in only one of the three downstream flanks of the 18S/5S repeat, outside the CSU boundaries. In interpreting the seuuence data in terms of the evolutionary history of the 18S/5S-repeat family of wheat and rye, we conclude that (1) the wheat-rye form of the 18S/5S repeat most likely originated between 3 and 14 million years ago, in a lineage that gave rise to wheat and rye but not to barley, oasts, rice or maize; (2) the close linkage (1-bp apart) between trnfM and rrn18 is similarly limited in its taxonomic distribution to the wheat/rye lineage; (3) the trnfM-rrn18 pair arose via a single mutation that inserted a sequence block containing trnfM immediately upstream of rrn18; and (4) the presence of a putative promoter upstream of rrn18 in all wheat and rye repeats is consistent with all three repeat copies being transcriptionally active. We discuss these conclusions in the light of the possible functional significance of recombining-repeats in plant mitochondrial genomes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00351504
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    psbD sequences of Bumilleriopsis filiformis (Heterokontophyta, Xanthophyceae) and Porphyridium purpureum (Rhodophyta, Bangiophycidae): evidence for polyphyletic origins of plastids (1993)
    Springer
    Current genetics 24 (1993), S. 437-442 
    Details
    ISSN: 1432-0983
    Keywords: Evolution ; Algae ; Plastid ; Endocytobiosis ; Molecular clock ; psbD
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The nucleotide sequences of the plastidal psbD genes of Bumilleriopsis filiformis and Porphyridium purpureum (encoding the D2 protein of photosystem II) are reported in this paper. The Bumilleriopsis sequence clusters together with Porphyridium when a most parsimonious protein tree of D2 sequences is constructed. A composite D1/D2 protein-similarity network reveals that neither the three red algal sequences nor the two heterokontophyte sequences (Bumilleriopsis, xanthophytes and Ectocarpus, phaeophytes) group together. Therefore, the Heterokontophyta and Rhodophyta may be heterogeneous groups. Instead, it emerges that the D1/D2 proteins of Porphyridium and Bumilleriopsis clearly form a tight cluster. D1 and D2 proteins apparently do not provide a reliable molecular clock. These results fit into hypotheses proposing a polyphyletic origin for complex plastids, even among the supposedly “natural” group of heterokontophytes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00351854
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    Comparative analysis of the mitochondrial genomes of Chlamydomonas eugametos and Chlamydomonas moewusii (1992)
    Springer
    Current genetics 21 (1992), S. 197-202 
    Details
    ISSN: 1432-0983
    Keywords: Chlamydomonas ; Gene mapping ; Mitochondrial genome ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We report the cloning and physical mapping of the mitochondrial genome of Chlamydomonas eugametos together with a comparison of the overall sequence structure of this DNA with the mitochondrial genome of Chlamydomonas moewusii, its closely related and interfertile relative. The C. eugametos mitochondrial DNA (mtDNA) has a 24 kb circular map and is thus 2 kb larger than the 22 kb circular mitochondrial genome of C. moewusii. Restriction mapping and heterologous fragment hybridization experiments indicate that the C. eugametos and C. moewusii mtDNAs are colinear. Nine cross-hybridizing restriction fragments common to the C. eugametos and C. moewusii mtDNAs, and spanning the entirety of these genomes, show length differences between homologous fragments which vary from 0.1 to 2.3 kb. A 600 bp subfragment of C. moewusii mtDNA, within one of these conserved fragments, showed no hybridization with the C. eugametos mtDNA. Of the 73 restriction sites identified in the C. eugametos and C. moewusii mtDNAs, five are specific to C. moewusii, eight are specific to C. eugametos and 30 are common to both species. Hybridization experiments with gene probes derived from protein-coding and ribosomal RNA-coding regions of wheat and Chlamydomonas reinhardtii mtDNAs support the view that the small and large subunit ribosomal RNA-coding regions of the C. eugametos and C. moewusii mtDNAs are interrupted and interspersed with each other and with protein-coding regions, as are the ribosomal RNA-coding regions of C. reinhardtii mtDNA; however, the specific arrangement of these coding elements in the C. eugametos and C. moewusii mtDNAs appears different from that of C. reinhardtii mtDNA.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00336841
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    Structure and expression of a plastid-encoded groEL homologous heat-shock gene in a thermophilic unicellular red alga (1992)
    Springer
    Current genetics 21 (1992), S. 521-525 
    Details
    ISSN: 1432-0983
    Keywords: Chaperonin ; Evolution ; Heat shock ; Plastid ; Red algae ; Rubisco-subunit binding protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A gene homologous to the E. coli groEL locus was identified on the plastid genome of the unicellular red alga Cyanidium caldarium strain 14-1-1 (synonym: Galdieria sulphuraria). The complete nucleotide sequence was determined and compared to bacterial-and nuclear-encoded counterparts of higher plants. At the amino-acid level the C. caldarium gene shows 70% homology to the corresponding gene of the cyanobacterium Synechococcus and 52% homology to nuclear-encoded counterparts of higher plants, respectively. Northern and Western blot experiments were used to investigate the dependence of the transcript-and protein-level on culture temperature and heat shock.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00351663
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    Three unexpected cases of refracting superposition eyes in crustaceans (1990)
    Springer
    Journal of comparative physiology 167 (1990), S. 71-78 
    Details
    ISSN: 1432-1351
    Keywords: Compound eye ; Optics ; Crustacea ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Compound eyes of the decapod shrimp Gennadas, the hermit crab Dardanus, and the syncarid crustacean Anaspides are studied histologically and with optical experiments. The results demonstrate that these three crustaceans all have refracting superposition eyes. The conclusion is based on the following observations: 1. There is a wide clear-zone, which allows for a superposition image to be formed. 2. Dark-adapted eyes display a large eye-glow, and the ommatidia are not optically isolated. 3. The crystalline cones have the shape typical for refracting superposition eyes, and they contain the required lens-cylinder gradient of refractive index. Euphausiids and mysids were previously thought to be the only crustaceans with refracting superposition eyes, whereas the species investigated here were assumed to have reflecting superposition eyes (decapod shrimps) or apposition eyes (hermit crabs and syncarids). The present findings increase more than twofold the number of crustacean groups that are known to have developed refracting superposition optics. It also provides insight into the evolutionary mechanisms that may have led to the development of this type of imaging optics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00192407
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    Contribution of abdominal commissures in the bilateral coordination of the hindlegs during stridulation in the grasshopper Chorthippus dorsatus (1991)
    Springer
    Journal of comparative physiology 169 (1991), S. 191-200 
    Details
    ISSN: 1432-1351
    Keywords: Insect ; Behaviour ; Pattern generation ; Grasshopper ; Stridulation ; Bilateral coordination ; Abdominal ganglia ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Stridulation of grasshoppers is controlled by hemisegmental pattern generator subunits which probably are restricted to the metathoracic ganglion complex (TG3-complex). The coordination of left and right pattern generator subunits depends on commissures of the TG3-complex (Ronacher 1989). The coordination of the stridulatory movements was studied in Chorthippus dorsatus males with partial mediosagittal incisions in the TG3-complex. Animals bearing anterior incisions in the TG3-complex, by which all commissures of the metathoracic neuromere and the first abdominal neuromere were transected, were still able to produce bilaterally coordinated species-specific stridulatory movements. Commissures of the T3- and A1-neuromere, thus, are not necessary, and the A2-, A3-commissures are sufficient for this coordination (Figs. 3, 4). Animals with partial posterior incisions, extending until A1, had deficits in their stridulation pattern; the coordination between the hindlegs was impaired though not completely lost (Fig. 6). This is discussed in view of the structure of ‘stridulation interneurons’ identified in a related grasshopper species (Omocestus viridulus). These results indicate an unexpected substantial contribution of the abdominal neuromeres A2 and A3 to the control of stridulatory movements. This constitutes an interesting parallel to the flight control system of locusts where interneurons located in the first 3 abdominal neuromeres also appear to contribute to the flight pattern generator (Robertson et al. 1982).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00215866
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    Evolutionary relationship of some stalked and budding bacteria (genera Caulobacter, “Hyphobacter”, Hyphomonas and Hyphomicrobium) as studied by the new integral taxonomical method (1990)
    Springer
    Archives of microbiology 153 (1990), S. 123-128 
    Details
    ISSN: 1432-072X
    Keywords: Oligotrophic bacteria ; Caulobacter ; “Hyphobacter” ; Hyphomonas ; Hyphomicrobium ; Antibiotic sensitivity ; Evolution ; Fatty acids ; Lipids ; Taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A new approach was developed for the determination of taxonomic and evolutional relationships among four genera of oligotrophic bacteria. The main idea of this approach is the algorithmized integrative analysis of the morphological and physiological specificity of these bacteria, their 5S rRNA sequences, fatty acid and lipid composition of their membranes, as well as their sensitivity to a large variety of antibiotics. It was shown that the genera Caulobacter and Hyphomonas are closely related to each other, but they are both distant from Hyphomicrobium species. The new genus, “Hyphobacter”, is placed between Caulobacter and Hyphomonas. Taxonomic heterogeneity was found to exist within the genera Caulobacter and Hyphomicrobium. Evolutional pathways from Caulobacter to Hyphomicrobium are proposed on the basis of the present data. No correlations were found between the cell morphology of the organisms and their geno-and chemotaxonomy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00247808
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    Sequence divergence of the murB and rrfB genes from Escherichia coli and Salmonella typhimurium (1994)
    Springer
    Archives of microbiology 161 (1994), S. 501-507 
    Details
    ISSN: 1432-072X
    Keywords: Escherichia coli ; Salmonella typhimurium ; murB ; rrfB ; Repetitive extragenic palindrome ; Evolution ; Mutation rate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The murB gene of Salmonella typhimurium was cloned and found to be 75% and 82% identical to the DNA and protein sequences, respectively, of the same gene in Escherichia coli. These identities are among the lowest recorded between the two bacteria. Nevertheless, wild-type S. typhimurium murB complemented the known temperature-sensitive E. coli mutant, and wild-type E. coli murB complemented three temperature-sensitive mutants of S. typhimurium. The 5S rRNA gene, rrfB, and the region between murB and rrfB were also cloned and sequenced. The rrfB gene of S. typhimurium differs from rrfB of E. coli in only 2 of 120 nt, but the region between murB and rrfB has diverged greatly and includes a sequence that elosely resembles a repetitive extragenic palindrome of the type normally associated with E. coli. Previous comparisons of gene divergence have suggested that the chromosomal mutation rate is lower in the vicinity of the origin of replication. However, the S. typhimurium murB gene, located 6 map minutes from the origin of replication, is highly substituted at synonymous sites and the sequence between murB and rrfB is significantly modified as well. Thus, murB is an exception to the general observation that genes near the origin of replication show less divergence than do genes elsewhere in the bacterial chromosome.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307771
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    Fervidobacterium islandicum sp. nov., a new extremely thermophilic eubacterium belonging to the “Thermotogales” (1990)
    Springer
    Archives of microbiology 154 (1990), S. 105-111 
    Details
    ISSN: 1432-072X
    Keywords: Eubacterium ; Thermophile ; Evolution ; Fervidobacterium ; Lipids ; Thermotoga
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract An extremely thermophilic anaerobic fermentative eubacterium growing at temperatures between 50 and 80°C (opt.: 65°C) was isolated from an Icelandic hot spring. The cells were Gram-negative motile rods, about 1.8 μm in length, and 0.6 μm in width occurring singly and in pairs. About 50% of the cells formed large spheroids at one end similar to Fervidobacterium nodosum. The new isolate H 21 differed from Fervidobacterium nodosum by a 6 mol % higher GC-content of its DNA (41 mol %), its ability to grow on cellulose, and insignificant DNA homology. The lipids of isolate H 21 were similar to that of members of “Thermotogales”. 16S rRNA sequencing of isolate H 21 and Fervidobacterium nodosum indicated (a) that isolate H 21 represents a new species of the genus Fervidobacterium which we name Fervidobacterium islandicum and (b) that the genus Fervidobacterium belongs to the “Thermotogales” branch.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00423318
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    Chemical marker from silk ofYponomeuta cagnagellus (1990)
    Springer
    Journal of chemical ecology 16 (1990), S. 2203-2216 
    Details
    ISSN: 1573-1561
    Keywords: Yponomeuta cagnagellus ; caterpillars ; Lepidoptera ; Yponomeutidae ; trail following ; chemical marker ; trail pheromone ; stability ; pheromone secretory site
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Trail following in lepidopterous larvae is often attributed to chemical markers, but only a few clear-cut examples are found in the literature. In this paper evidence is presented for a chemical basis of the trail following behaviour ofYponomeuta cagnagellus. (Lepidoptera: Yponomeutidae) The marker is shown to be very persistent under laboratory conditions and is water soluble. Several possible secretory sites were investigated, and it is concluded that the marker is probably secreted together with the silk from the labial gland. Problems associated with the demonstration of trail markers in caterpillars are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01026931
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    Allelochemicals in soil from no-tillage versus conventional-tillage wheat (Triticum aestivum) fields (1990)
    Springer
    Journal of chemical ecology 16 (1990), S. 2277-2289 
    Details
    ISSN: 1573-1561
    Keywords: Allelochemicals ; no-tillage ; conventional-tillage ; soils ; wheat ; Triticum aestivum ; mass spectrometry ; Petri-dish bioassay ; fatty acids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Putative allelochemicals found in the soil of no-tillage and conventional-tillage wheat plots near Stillwater, Oklahoma, were obtained by a mild alkaline aqueous extraction procedure, bioassayed to determine their biological activity, purified, and analyzed with a capillary gas chromatography-mass spectrometry-data analysis system. The most significant inhibition was found in bioassays of extracts from soil collected immediately after harvest in June, July, and August. No-tillage soils produced significant inhibition during the rest of the year also. Mass spectrometry showed fatty acids as the most abundant compounds. However, when bioassayed authentic samples of the five free fatty acids showed no significant biological activity toward wheat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01026937
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    Allelopathic activity in wheat-conventional and wheat-no-till soils: Development of soil extract bioassays (1992)
    Springer
    Journal of chemical ecology 18 (1992), S. 2191-2221 
    Details
    ISSN: 1573-1561
    Keywords: Cover crops ; wheat ; Triticum aestivum ; soybean ; Glycine max ; soil extracts ; germination bioassays ; phenolic acids ; hydroxamic acids ; allelopathy ; slope analysis ; ivy-leaved morning glory ; Ipomoea hederacea ; crimson clover ; Trifolium incarnalum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The primary objective of this research was to determine if soil extracts could be used directly in bioassays for the detection of allelopathic activity. Here we describe: (1) a way to estimate levels of allelopathic compounds in soil; (2) how pH, solute potential, and/or ion content of extracts may modify the action of allelopathic compounds on germination and radicle and hypocotyl length of crimson clover (Trifolium incarnatum L.) and ivyleaved morning glory (Ipomoea hederacea L. Jacquin.); and (3) how biological activity of soil extracts may be determined. A water-autoclave extraction procedure was chosen over the immediate-water and 5-hr EDTA extraction procedures, because the autoclave procedure was effective in extracting solution and reversibly bound ferulic acid as well as phenolic acids from wheat debris. The resulting soil extracts were used directly in germination bioassays. A mixture of phenolic acids similar to that obtained from wheat-no-till soils did not affect germination of clover or morning glory and radicle and hypocotyl length of morning glory. The mixture did, however, reduce radicle and hypocotyl length of clover. Individual phenolic acids also did not inhibit germination, but did reduce radicle and hypocotyl length of both species. 6-MBOA (6-methoxy-2,3-benzoxazolinone), a conversion product of 2-o-glucosyl-7-methoxy-1,4-benzoxazin-3-one, a hydroxamic acid in living wheat plants, inhibited germination and radicle and hypocotyl length of clover and morning glory. 6-MBOA, however, was not detected in wheat debris, stubble, or soil extracts. Total phenolic acids (FC) in extracts were determined with Folin and Ciocalteu's phenol reagent. Levels of FC in wheat-conventionaltill soil extracts were not related to germination or radicle and hypocotyl length of either species. Levels of FC in wheat-no-till soil extracts were also not related to germination of clover or morning glory, but were inversely related to radicle and hypocotyl length of clover and morning glory. FC values, solute potential, and acidity of wheat-no-till soil extracts appeared to be independent (additive) in action on clover radicle and hypocotyl length. Radicle and hypocotyl length of clover was inversely related to increasing FC and solute potential and directly related to decreasing acidity. Biological activity of extracts was determined best from slopes of radicle and hypocotyl length obtained from bioassays of extract dilutions. Thus, data derived from the water-autoclave extraction procedure, FC analysis, and slope analysis for extract activity in conjunction with data on extract pH and solute potential can be used to estimate allelopathic activity of wheat-no-till soils
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00984946
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    Nucleotide sequence of a cDNA coding for the barley seed protein CMa: an inhibitor of insect α-amylase (1992)
    Springer
    Plant molecular biology 18 (1992), S. 423-427 
    Details
    ISSN: 1573-5028
    Keywords: Hordeum vulgare L. ; CM protein ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The primary structure of the insect α-amylase inhibitor CMa of barley seeds was deduced from a full-length cDNA clone pc43F6. Analysis of RNA from barley endosperm shows high levels 15 and 20 days after flowering. The cDNA predicts an amino acid sequence of 119 residues preceded by a signal peptide of 25 amino acids. Ala and Leu account for 55% of the signal peptide. CMa is 60–85% identical with α-amylase inhibitors of wheat, but shows less than 50% identity to trypsin inhibitors of barley and wheat. The 10 Cys residues are located in identical positions compared to the cereal inhibitor family with a Pro-X-Cys motif present in all.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00034972
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    Homologues of wheat ubiquitin-conjugating enzymes - TaUBC1 and TaUBC4 are encoded by small multigene families in Arabidopsis thaliana (1994)
    Springer
    Plant molecular biology 24 (1994), S. 651-661 
    Details
    ISSN: 1573-5028
    Keywords: protein degradation ; ubiquitin conjugating enzymes ; DNA repair ; N-end recognition ; wheat ; Arabidopsis thaliana
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Covalent attachment of ubiquitin to other cellular proteins has been implicated in a multitude of diverse physiological processes in eukaryotes including selective protein degradation. This attachment is carried out by a multi-enzyme pathway consisting of three classes of enzymes: ubiquitin-activating enzymes (E1s), ubiquitin-conjugating enzymes (E2s), and ubiquitin-protein ligases (E3s). E2s accept activated ubiquitin from E1 and conjugate it to target proteins with or without the participation of specific E3s. Previously, we have isolated wheat cDNAs encoding 16 and 23 kDa E2s, TaUBC1 and TaUBC4, respectively. TaUBC1 shows structural homology to the yeast RAD6 E2 that is essential for DNA repair whereas TaUBC4 is related to the yeast ScUBC8 E2, both of which effectively conjugate ubiquitin to histones in vitro but as yet are without a known in vivo function. Here, we report the isolation of genomic and cDNA homologues of these genes from Arabidopsis thaliana. In Arabidopsis, both of these E2s are encoded by three member gene families. Members of the AtUBC1 gene family, comprising AtUBC1, 2 and 3, encode 150–152 amino acid proteins that are 83–99% identical to each other and TaUBC1 and contain four introns that are conserved with respect to position. Members of the AtUBC4 gene family, comprising AtUBC4, 5 and 6, encode 187–191 amino acid proteins that are 73–88% identical to each other and TaUBC4 and contain five introns that are conserved with respect to position. In contrast, AtUBC1-3 gene products are only 31–36% identical to those derived from AtUBC4-6. mRNA for each family was detected in Arabidopsis roots, leaves, stems, and flowers indicating that members of each family are expressed in most if not all tissues.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00023561
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    Analysis of the gibberellin-responsive promoter of a cathepsin B-like gene from wheat (1992)
    Springer
    Plant molecular biology 20 (1992), S. 849-856 
    Details
    ISSN: 1573-5028
    Keywords: GA regulation ; thiol-protease promoter ; wheat ; aleurone ; particle gun
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A wheat gene (A121) encoding a protein with sequence similarity to mammalian cathepsin B is regulated by gibberellic acid (GA) in aleurone layers of germinating grains. To analyse the mechanism of A121 regulation, its promoter was fused to the β-glucuronidase reporter gene (GUS) and introduced by micro-projectile bombardment into aleurone layers of oat. With 2.3 kb of promoter sequence, the GUS expression was enhanced by GA treatment. This effect was reversed by abscisic acid (ABA). This result showed for A121, like the α-amylase genes, that the regulation by GA and ABA was at the level of transcription. The GA responsiveness of the promoter was retained with as little as 276 bp of promoter sequence. Sequence comparison with a GA responsive promoter of an α-amylase gene identified the conserved element GCAACGGCAACGATGG which is required intact for full expression of both promoters. However, there was no identifiable similarity in the cathepsin-like promoter with the GA-responsive element of α-amylase promoters with the consensus sequence TAACAAA, suggesting that GA affects more than one mechanism of transcriptional control.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00027156
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    Sequence analysis of WIS-2-1A, a retrotransposon-like element from wheat (1992)
    Springer
    Plant molecular biology 20 (1992), S. 991-995 
    Details
    ISSN: 1573-5028
    Keywords: retrotransposon-like element ; sequence analysis ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract WIS-2-1A, a 8624 bp insertion in the Glu-1A-2 locus of chromosome 1A of wheat, consists of two 1755 bp long terminal repeats enclosing a 5114 bp internal region. No long open reading frames could be found, but inspection of the predicted amino acid sequence showed regions with homology to retrotransposon structures, including a methionine tRNA initiator binding site, a nucleotide binding domain, a protease, an integrase and a polymerase. DNA replication errors have resulted in frame-shifts in the protein coding region, suggesting that retrotransposition of WIS-2-1A, if it occurs, must be mediated by trans-acting factors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00027169
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    Destabilization of pea lectin by substitution of a single amino acid in a surface loop (1993)
    Springer
    Plant molecular biology 22 (1993), S. 1039-1046 
    Details
    ISSN: 1573-5028
    Keywords: antinutritional factor ; pea lectin ; site-directed mutagenesis ; stability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Legume lectins are considered to be antinutritional factors (ANF) in the animal feeding industry. Inactivation of ANF is an important element in processing of food. In our study on the stability ofPisum sativum L. lectin (PSL), a conserved hydrophobic amino acid (Val103) in a surface loop was replaced with alanine. The mutant lectin, PSL V103A, showed a decrease in unfolding temperature (T m ) by some 10 °C in comparison with wild-type (wt) PSL, and the denaturation energy (ΔH) is only about 55% of that of wt PSL. Replacement of an adjacent amino acid (Phe104) with alanine did not result in a significant difference in stability in comparison with wt PSL. Both mutations did not change the sugarbinding properties of the lectin, as compared with wt PSL and with PSL from pea seeds, at ambient temperatures. The double mutant, PSL V103A/F104A, was produced inEscherichia coli, but could not be isolated in an active (i.e. sugar-binding) form. Interestingly, the mutation in PSL V103A reversibly affected sugar-binding at 37 °C, as judged from haemagglutination assays. These results open the possibility of production of lectins that are activein planta at ambient temperatures, but are inactive and possibly non-toxic at 37 °C in the intestines of mammals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00028976
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    Single-seed PCR of LMW glutenin genes to distinguish between durum wheat cultivars with good and poor technological properties (1993)
    Springer
    Plant molecular biology 22 (1993), S. 1173-1176 
    Details
    ISSN: 1573-5028
    Keywords: polymerase chain reaction ; LMW glutenin genes ; wheat ; quality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Polymerase chain reaction (PCR) was used to amplify low-molecular-weight (LMW) glutenin sequences from genomic DNA extracted from a single germinating seed of several durum wheat genotypes. Electrophoretic analysis of PCR reactions showed the presence of amplified products characteristic of durum wheat cultivars with good and poor technological properties. This PCR-based approach is proposed as a very efficient and safe alternative to standard procedures for selecting durum wheat genotypes with good qualitative characteristics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00028988
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    In vitro processing of transcripts containing novel tRNA-like sequences (‘t-elements’) encoded by wheat mitochondrial DNA (1990)
    Springer
    Plant molecular biology 15 (1990), S. 551-559 
    Details
    ISSN: 1573-5028
    Keywords: tRNA-like sequences ; t-elements ; RNA processing ; mitochondria ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have recently described the properties of a wheat mitochondrial extract that is able to process, accurately and efficiently, artificial transcripts containing wheat mitochondrial tRNA sequences, with the production of mature tRNAs (P.J. Hanic-Joyce and M.W. Gray, J. Biol. Chem., in press). Such processing involves 5′-endonucleolytic, 3′-endonucleolytic, and TRNA nucleotidyltransferase activities. Here we show that this system also acts on transcripts containing sequences corresponding to an unusual class of short repeats (‘t-elements’) in wheat mtDNA. These repeats are theoretically capable of assuming a tRNA-like secondary structure, although stable transcripts corresponding to them are not detectable in vivo. We find that t-element sequences are processed with the same specificity and with comparable efficiency as are authentic tRNA sequences. Because known t-elements are located close to and in the same transcriptional orientation as active genes (18S-5S, 26S, tRNAPro) in wheat mtDNA, our results raise the question of whether t-elements play a role in gene expression in wheat mitochondria.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00017830
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    Characterization of members of a pseudogene subfamily of the wheat α-gliadin storage protein genes (1991)
    Springer
    Plant molecular biology 16 (1991), S. 335-337 
    Details
    ISSN: 1573-5028
    Keywords: Triticum ; wheat ; endosperm ; gliadin ; pseudogene ; duplication ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00020565
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    Wheat ubiquitin gene exhibits a conserved protein coding region and a diverged 3′ non-coding region (1991)
    Springer
    Plant molecular biology 16 (1991), S. 907-908 
    Details
    ISSN: 1573-5028
    Keywords: ubiquitin ; wheat ; heat shock protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00015082
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    Site-directed mutagenesis and expression inEscherichia coli of WMAI-1, a wheat monomeric inhibitor of insect α-amylase (1991)
    Springer
    Plant molecular biology 17 (1991), S. 1005-1011 
    Details
    ISSN: 1573-5028
    Keywords: α-amylase inhibitor ; expression inE. coli ; glycosylation versus activity ; insect α-amylase ; mutagenesis ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The wheat monomeric inhibitor WMAI-1 (syn. 0.28) produced inEscherichia coli using the pT7-7 expression ventor has the correct N-terminal sequence and the same electrophoretic mobility and specific activity towards the α-amylase from the insectTenebrio molitor as the native WMAI-1 isolated from wheat. This confirms that the native inhibitor is not glycosylated and contradicts claims that a putative glycosyl moiety was essential for inhibition. Thirteen mutants have been obtained at six different sites. Substitution of the highly conserved N-terminal S by the sequence ARIRAR increased the pre-incubation time required for maximum activity. A similar result was obtained by insertion of GPRLPW after position 4, while insertion of EPRAPW at the same position rendered the inhibitor inactive. The substitution D/EGPRL and insertions DGP or D, at position 58, produced complete inactivation. All other mutations had only minor effects on activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00037140
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    A Triticum aestivum cDNA clone encoding a low-molecular-weight heat shock protein (1991)
    Springer
    Plant molecular biology 17 (1991), S. 273-275 
    Details
    ISSN: 1573-5028
    Keywords: Tahsp17.3 ; low-molecular-weight HSP ; Triticum aestivum L. ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00039504
    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...