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  • Evolution
  • Immunohistochemistry
  • Springer  (133)
  • Annual Reviews
  • Blackwell Publishing Ltd
  • 2020-2024  (1)
  • 2005-2009
  • 1980-1984  (132)
  • 1
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    Springer Nature | Springer
    Publication Date: 2024-04-05
    Description: This open access book offers the first comprehensive account of the pan-genome concept and its manifold implications. The realization that the genetic repertoire of a biological species always encompasses more than the genome of each individual is one of the earliest examples of big data in biology that opened biology to the unbounded. The study of genetic variation observed within a species challenges existing views and has profound consequences for our understanding of the fundamental mechanisms underpinning bacterial biology and evolution. The underlying rationale extends well beyond the initial prokaryotic focus to all kingdoms of life and evolves into similar concepts for metagenomes, phenomes and epigenomes. The book’s respective chapters address a range of topics, from the serendipitous emergence of the pan-genome concept and its impacts on the fields of microbiology, vaccinology and antimicrobial resistance, to the study of microbial communities, bioinformatic applications and mathematical models that tie in with complex systems and economic theory. Given its scope, the book will appeal to a broad readership interested in population dynamics, evolutionary biology and genomics.
    Keywords: Microbial Genetics and Genomics ; Evolutionary Biology ; Genetics and Population Dynamics ; Microbial Ecology ; Human Genetics ; Genetics and Genomics ; Comparative genomics ; Metagenomics ; Microbial Population Analysis ; Pangenome Profile ; Supra-Genome Analysis ; Adaptive Evolution ; Computational Tools ; Bioinformatic Genomics ; Core Dispensable Genome ; Selection, Recombination, Composition ; Acquired Resistance ; Bacterial Species Concept ; Genomic Diversity ; Bacterial Ecology, Microevolution ; Open Access ; Pan-metagenomics ; Pan-microbiomics ; Pan-epigenome ; Gene Transfer ; Pan-phenomes ; Microbiology (non-medical) ; Genetics (non-medical) ; Evolution ; Applied mathematics ; Ecological science, the Biosphere ; Medical genetics ; thema EDItEUR::P Mathematics and Science::PS Biology, life sciences::PSG Microbiology (non-medical) ; thema EDItEUR::P Mathematics and Science::PS Biology, life sciences::PSA Life sciences: general issues::PSAJ Evolution ; thema EDItEUR::P Mathematics and Science::PB Mathematics::PBW Applied mathematics ; thema EDItEUR::P Mathematics and Science::PS Biology, life sciences::PSA Life sciences: general issues::PSAF Ecological science, the Biosphere ; thema EDItEUR::M Medicine and Nursing::MF Pre-clinical medicine: basic sciences::MFN Medical genetics ; thema EDItEUR::P Mathematics and Science::PS Biology, life sciences::PSA Life sciences: general issues::PSAK Genetics (non-medical)
    Language: English
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  • 2
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    Acta biotheoretica 33 (1984), S. 35-50 
    ISSN: 1572-8358
    Keywords: Evolution ; falsification ; Darwinism ; philosophy of science
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In this paper we discuss the epistemological positions of evolution theories. A sharp distinction is made between the theory that species evolved from common ancestors along specified lines of descent (here called “the theory of common descent”), and the theories intended as causal explanations of evolution (e.g. Lamarck's and Darwin's theory). The theory of common descent permits a large number of predictions of new results that would be improbable without evolution. For instance, (a) phylogenetic trees have been validated now; (b) the observed order in fossils of new species discovered since Darwin's time could be predicted from the theory of common descent; (c) owing to the theory of common descent, the degrees of similarity and difference in newly discovered properties of more or less related species could be predicted. Such observations can be regarded as attempts to falsify the theory of common descent. We conclude that the theory of common descent is an easily-falsifiable & often-tested & still-not-falsified theory, which is the strongest predicate a theory in an empirical science can obtain. Theories intended as causal explanations of evolution can be falsified essentially, and Lamarck's theory has been falsified actually. Several elements of Darwin's theory have been modified or falsified: new versions of a theory of evolution by natural selection are now the leading scientific theories on evolution. We have argued that the theory of common descent and Darwinism are ordinary, falsifiable scientific theories.
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  • 3
    ISSN: 1432-0827
    Keywords: Anticollagen antibodies ; Collagen types ; Immunohistochemistry ; Ossified posterior longitudinal ligament
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Immunohistochemical localization of types I, II, and III collagen in the ossified posterior longitudinal ligament of the cervical spine was studied using type-specific anticollagen antibodies. In contrast to the normal ligament which contains both types I and III collagens, the ossified matrix, composed of lamellar bone, contains only type I collagen, except for Haversian canals where type III is located in the inner wall. In the transitional region of preossifying ligaments, types III and I are both present. Type II collagen is present in the hyperplastic matrix of the ligament, and cartilage-like cells surrounded by type II collagen are aligned along nonossified ligaments adjacent to the preossifying region. A possible mechanism of matrix transition during the ossification process is given attention.
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  • 4
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    Journal of molecular evolution 16 (1980), S. 149-150 
    ISSN: 1432-1432
    Keywords: Exons ; Evolution ; Heme-binding proteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary It is known that globin genes contain three exons with the middle exon coding for a four-helical supersecondary structure responsible for heme binding. Since this portion of the globin peptide chain can be structurally superimposed onto the cytochromec and cytochromeb 5 chains (Argos and Rossmann 1979), it can be inferred that the cytochromec gene will contain only one coding sequence while the cytochromeb 5 gene will be composed of three exons as found in the globin gene.
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  • 5
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    Journal of molecular evolution 16 (1980), S. 211-267 
    ISSN: 1432-1432
    Keywords: Nucleic acids ; Proteins ; Natural selection ; Genetics ; Nonrandom molecular divergence ; Nonrandom REH theory ; Evolution ; mRNA ; DNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary REH theory is extended by deriving the theoretical equations that permit one to analyze the nonrandom molecular divergence of homologous genes and proteins. The nonrandomicities considered are amino acid and base composition, the frequencies with which each of the four nucleotides is replaced by one of the other three, unequal usage of degenerate codons, distribution of fixed base replacements at the three nucleotide positions within codons, and distributions of fixed base replacements among codons. The latter two distributions turn out to dominate the accuracy of genetic distance estimates. The negative binomial density is used to allow for the unequal mutability of different codon sites, and the implications of its two limiting forms, the Poisson and geometric distributions, are considered. It is shown that the fixation intensity — the average number of base replacements per variable codon - is expressible as the simple product of two factors, the first describing the asymmetry of the distribution of base replacements over the gene and the second defining the ratio of the average probability that a codon will fix a mutation to the probability that it will not. Tables are given relating these features to experimentally observable quantities inα hemoglobin,β hemoglobin, myoglobin, cytochromec, and the parvalbumin group of proteins and to the structure of their corre-sponding genes or mRNAs. The principal results are (1) more accurate methods of estimating parameters of evolutionary interest from experimental gene and protein sequence data, and (2) the fact that change in gene and protein structure has been a much less efficient process than previously believed in the sense of requiring many more base replacements to effect a given structural change than earlier estimation procedures had indicated. This inefficiency is directly traceable to Darwinian selection for the nonrandom gene or protein structures necessary for biological function. The application of these methods is illustrated by detailed consideration of the rabbitα -andβ hemoglobin mRNAs and the proteins for which they code. It is found that these two genes are separated by about 425 fixed base replacements, which is a factor of two greater than earlier estimates. The replacements are distributed over approximately 114 codon sites that were free to accept base mutations during the divergence of these two genes.
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  • 6
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    Journal of molecular evolution 17 (1981), S. 31-42 
    ISSN: 1432-1432
    Keywords: Pea ; Mung bean ; Genome organization ; Evolution ; Amplification ; Repetitive DNA ; Single copy DNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Essentially all of the sequences in the pea (Pisum sativum) genome which reassociate with single copy kinetics at standard (Tm -25°C) criterion follow repetitive kinetics at lower temperatures (about Tm-35°C). Analysis of thermal stability profiles for presumptive single copy duplexes show that they contain substantial mismatch even when formed at standard criterion. Thus most of the sequences in the pea genome which are conventionally defined as “single copy” are actually “fossil repeats” — that is, they are members of extensively diverged (mutuated) and thus presumably ancient families of repeated sequences. Coding sequences as represented by a cDNA probe prepared from poly-somal poly(A) + mRNA reassociate with single copy kinetics regardless of criterion and do not form mismatched duplexes. The coding regions thus appear to be composed of true single copy sequences but they cannot represent more than a few percent of the pea genome. Ancient diverged repeats are present, but not a prominent feature of the smaller mung bean (Vigna radiata) genome. An extension of a simple evolutionary model is proposed in which these and other differences in genome organization are considered to reflect different rates of sequence amplification or genome turnover during evolution. The model accounts for some of the differences between typical plant and animal genomes.
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  • 7
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    Journal of molecular evolution 17 (1981), S. 368-376 
    ISSN: 1432-1432
    Keywords: Evolution ; Phylogeny ; Maximum likelihood ; Parsimony ; Estimation ; DNA sequences
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The application of maximum likelihood techniques to the estimation of evolutionary trees from nucleic acid sequence data is discussed. A computationally feasible method for finding such maximum likelihood estimates is developed, and a computer program is available. This method has advantages over the traditional parsimony algorithms, which can give misleading results if rates of evolution differ in different lineages. It also allows the testing of hypotheses about the constancy of evolutionary rates by likelihood ratio tests, and gives rough indication of the error of the estimate of the tree.
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  • 8
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    Journal of molecular evolution 18 (1981), S. 15-17 
    ISSN: 1432-1432
    Keywords: Amino acid code ; Evolution ; Primitive codes ; Mitochondria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Differences between mitochondrial codes and the universal code indicate that an evolutionary simplification has taken place, rather than a return to a more primitive code. However, these differences make it evident that the universal code is not the only code possible, and therefore earlier codes may have differed markedly from the previous code. The present universal code is probably a “frozen accident.” The change in CUN codons from leucine to threonine (Neurospora vs. yeast mitochondria) indicates that neutral or near-neutral changes occurred in the corresponding proteins when this code change took place, caused presumably by a mutation in a tRNA gene.
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  • 9
    ISSN: 1432-1432
    Keywords: Monomeric hemoglobins ; Dimeric hemoglobins ; Chironomus ; Antibodies ; Evolution ; Gene duplication
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The monomeric hemoglobins ofChironomus tentans andC. pallidivittatus have been isolated and separated into their respective components by gel chromatography on Sephadex G-75 and ion-exchange chromatography on DEAE-Sephacel. The amino acid compositions of the purified components are given. The sequence of the 30 N-terminal amino acid residues of one of the monomeric components (Hb I fromC. pallidivittatus) was determined and found to be identical in almost all of its parts with the monomeric hemoglobins ofC. thummi (CTT III and CTT IV). Antibodies against the monomeric hemoglobins Hb I and Hb IIc and the dimeric fraction were highly specific and no cross reaction between dimeric and monomeric hemoglobins could be demonstrated. The antibodies against the monomers crossreact with the monomeric hemoglobins CTT III and CTT IV ofC. thummi. Taken together with genetic data, the immunological results indicate that divergence of monomeric from dimeric forms was an early event in the evolution of the various hemoglobins inChironomus.
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  • 10
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    Journal of molecular evolution 19 (1982), S. 20-27 
    ISSN: 1432-1432
    Keywords: GU base pairing ; RNA replication ; Globular proteins ; Genetic code ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary It has previously been shown that the formation of GU base pairs in RNA copying processes leads to an accumulation of G and U in both strands of the replicating RNA, which results in a non-random distribution of base triplets. In the present paper, this distribution is calculated, and, using the χ2-test, a correlation between the distribution of triplets and the amino acid composition of the evolutionarily conservative interior regions of selected globular proteins is established. It is suggested that GU wobbling in early replication of RNA could have led to the observed amino acid composition of present-day protein interiors. If this hypothesis is correct, the GU wobbling must have been very extensive in the imprecisely replicating RNA, even reaching values close to the critical for stability of its double-helical structure. Implications of the hypothesis both for the evolution of the genetic code and of proteins are discussed.
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  • 11
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    Journal of molecular evolution 19 (1983), S. 203-213 
    ISSN: 1432-1432
    Keywords: Evolution ; Phylogenetic distribution ; Repetitive-dispersed DNAs ; Speciation ; Transposons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have examined the phylogenetic distribution of a spectrum ofDrosophila repetitive-dispersed DNAs ranging from structurally complex transposable elements to scrambled middle repetitive sequences. Our data suggest that unlike typical “genes” these DNAs are unstable components of the drosophilid genome. The unusual behavior of these repetitive-dispersed DNAs raises the possibility that this type of sequence may have an important role in the evolution of the family Drosophilidae.
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  • 12
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    Journal of molecular evolution 15 (1980), S. 149-159 
    ISSN: 1432-1432
    Keywords: Genes ; REH theory ; Genetic distance ; Evolution ; mRNA ; Nucleic acids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary It is shown how REH theory in conjunction with mRNA or gene sequence data can be used to obtain estimates of the fixation intensity, the number of varions, and the total mutations fixed between homologous pairs of nucleic acids. These estimates are more accurate than those that can be derived from amino acid sequence data. The method is illustrated forα andβ hemoglobin genes and these improved estimates are compared with those made from the amino acid sequences for which those genes code. Significant differences are found between the estimates made by these two methods. For theβ hemoglobin gene sequences examined here, the fixation intensity is some-what less than the protein data had suggested, and the number of rations is considerably greater. Depending on the gene sequences examined, between 62 and 83% of the codons appear able to fix mutations during the divergences considered. This reflects the constraints of natural selection on acceptable mutations. The total number of base replacements separating the genes for human, mouse, and rabbitβ hemoglobin varies from 61 to 105 depending on the pair examined. Rabbitα andβ hemoglobin are separated by at least 290 fixed mutations. For such distantly related sequences estimates made from protein and mRNA data differ less, reflecting the higher quality of information from the many observed changes in primary structure. The effects of nonrandom gene structure on these evolutionary estimates and the fact that various genetic events are not equiprobable are discussed.
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  • 13
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    Journal of molecular evolution 21 (1984), S. 54-57 
    ISSN: 1432-1432
    Keywords: Mitochondrion ; Cytochrome C ; Rhodospirillaceae ; Endosymbiosis ; rRNA ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The comparative morphology and pigmentation of protists suggest that those with tubular mitochondrial cristae belong to a different lineage than those with lamellar cristae and that the evolutionary divergence might have been very early. We propose that the difference in cristal morphology is the result of separate origins of the mitochondria from endosymbionts related to the Rhodospirillaceae (purple nonsulfur bacteria) but differing in the morphology of their internal membranes. Comparisons of the cytochromes c of protists and the Rhodospirillaceae and of 16s rRNA T1 oligonucleotide catalogs in the Rhodospirillaceae do not contradict, and in fact provide support for, the idea. More extensive evidence may be lacking simply because cytochromes c have been studied in very few protists with tubular mitochondrial cristae.
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  • 14
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    Journal of molecular evolution 21 (1984), S. 72-75 
    ISSN: 1432-1432
    Keywords: Heat ; Rates of copy error ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Heat induces a number of premutational lesions (for example, the deamination of cytosine to uracil) in DNA and RNA. These kinds of errors occur in resting as well as replicating polynucleotides. However, an increase in temperature also raises the probability of copying error occurring in nucleic acids because of increased thermal noise in the replicative machinery. In most modern genetic systems, the majority of heat-induced lesions are efficiently repaired. It follows that the importance of heat-induced error increases as the effectiveness of repair declines. We show in this paper that the error rate of enzymatic polynucleotide copying is expected to increase monotonically with temperature. We also explore the effects of temperature variations on the early evolution of biological information transmission mechanisms.
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  • 15
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    Journal of molecular evolution 17 (1981), S. 167-181 
    ISSN: 1432-1432
    Keywords: Evolution ; Genetics ; REH theory ; Mutations ; Natural selection ; Nucleic acids ; Proteins ; Paleogenetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have independently repeated the computer simulations on which Nei and Tateno (1978) base their criticism of REH theory and have extended the analysis to include mRNAs as well as proteins. The simulation data confirm the correctness of the REH method. The high average value of the fixation intensity μ2 found by Nei and Tateno is due to two factors: 1) they reported only the five replications in which μ2 was high, excluding the forty-five replications containing the more representative data;and 2) the lack of information, inherent to protein sequence data, about fixed mutations at the third nucleotide position within codons, as the values are lower when the estimate is made from the mRNAs that code for the proteins. REH values calculated from protein or nucleic acid data on the basis of the equiprobability of genetic events underestimate, not overestimate, the total fixed mutations. In REH theory the experimental data determine the estimate T2 of the time average number of codons that have been free to fix mutations during a given period of divergence. In the method of Nei and Tateno it is assumed, despite evidence to the contrary, that every amino acid position may fix a mutation. Under the latter assumption, the measure X2 of genetic divergence suggested by Nei and Tateno is not tenable: values of X2 for theα hemoglobin divergences are less than the minimum number of fixed substitutions known to have occurred. Within the context of REH theory, a paradox, first posed by Zuckerkandl, with respect to the high rate of covarion turnover and the nature of general function sites in proteins is resolved.
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  • 16
    ISSN: 1432-1432
    Keywords: Archaebacteria ; Taxonomy ; Evolution ; DNA ; 16S rRNA ; Hybridization ; Phylogeny ; Thermoproteales
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary DNAs from 16 species of archaebacteria including 6 novel isolates were hybridized with 16S rRNAs from 7 species representing different orders or groups of the urkingdom of archaebacteria. The yields, normalized for the number of genes perµg of DNA, and the temperature stabilities of all hybrids were determined and related to each other. A taxonomic tree constructed from such fractional stability data reveals the same major divisions as that derived from comparative cataloging of 16S rRNA sequences. The extreme halophiles appear however as a distinct order besides the three known divisions of methanogens. The methanogens, the halophiles andThermoplasma form one of two clearly recognizable branches of the archaebacterial urkingdom. The order represented bySulfolobus and the related novel orderThermoproteales form the other branch. Three novel genera,Thermoproteus, Desulfurococcus and the “stiff filaments” represent three families of this order. The extremely thermophilic methanogenMethanothermus fervidus belongs to theMethanobacteriales. SN1, a methanogen from Italy, appears as another species of the genusMethanococcus. Another novel methanogen, M3, represents a genus or family of the orderMethanomicrobiales.
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  • 17
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    Journal of molecular evolution 19 (1982), S. 80-86 
    ISSN: 1432-1432
    Keywords: Microtubules ; Tubulin ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Tubulin subunits have been isolated from a variety of protists and marine invertebrates. The sources were: sperm tails of a tunicate (Ciona intestinalis), an abalone (Haliotis rufescens) and a sea anemone (Tealia crassicornis), the gill cilia of a clam (Mercenaria mercenaria), the cilia of a ciliate (Tetrahymena pyriformis) and the cytoplasm of a slime mold (Physarum polycephalum). All the β-tubulins, as characterised by their electropherograms after limited proteolytic cleavage withStaphylococcus aureus protease, were fairly similar. In contrast, two markedly different peptide patterns were found for the α-tubulins of (a) metazoan axonemes and (b) protistan axonemes, plant axonemes and slime mold cytoplasm. Metazoan axonemal α-tubulin peptide patterns could be further divided into two similar but distinct subtypes which did not correlate with the taxonomic divisions of deuterostomia and protostomia, or to different tubulins within an axoneme, or to different tubulins of flagella and cilia. We have postulated that these small differences may be accounted for by a simple glutamicaspartic acid exchange at a particular position in the α-tubulin sequence. Identical peptide patterns were observed for sea urchin and sea anemone sperm tail tubulins, proving that the metazoan type of axonemal tubulin arose before the divergence of bilateral and radial symmetric organisms. The close similarity of the slime mold cytoplasmic α-tubulin peptide pattern to protistan and plant axonemal α-tubulin patterns suggests that the same type of tubulin might be used to form both axonemal and cytoplasmic types of microtubules in protists and plants. The large structural constraints imposed upon this tubulin molecule probably allowed very little change in its primary structure, thus explaining the similarity of tubulins from organisms which diverged at such an early time in eukaryote history. Duplication and modification of the tubulin gene may then have led to the development of specific axonemal and cytoplasmic microtubules during the evolution of the metazoa.
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  • 18
    ISSN: 1432-1432
    Keywords: Microbial phylogeny ; Evolution ; Aromatic biosynthesis ; Regulatory enzymes
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Abstract Pseudomonad bacterial are a phylogenetically diverse assemblage of species named within contemporary genera that includePseudomonas, Xanthomonas andAlcaligenes. Thus far, five distinct rRNA homology groups (Groups I through V) have been established by oligonucleotide cataloging and by rRNA/DNA hybridization. A pattern of enzymic features of aromatic amino acid biosynthesis (enzymological patterning) is conserved at the level of rRNA homology, five distinct and unambiguous patterns therefore existing in correspondence with the rRNA homology groups. We sorted 87 pseudomonad strains into Groups (and Subgroups) by aromatic pathway patterning. The reliability of this methodology was tested in a blind study using coded cultures of diverse pseudomonad organisms provided by American Type Culture Collection. Fourteen of 14 correct assignments were made at the Group level (the level of rRNA homology), and 12 of 14 correct assignments were made at the finer-tuned Subgroup levels. Many strains of unknown rRNA-homology affiliation had been placed into tentative rRNA groupings based upon enzymological patterning. Positive confirmation of such strains as members of the predicted rRNA homology groups was demonstrated by DNA/rRNA hybridization in nearly every case. It seems clear that the combination of these molecular approaches will make it feasible to deduce the evolution of biochemical-pathway construction and regulation in parallel with the emerging phylogenies of microbes housing these pathways.
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  • 19
    ISSN: 1432-1432
    Keywords: mtDNA ; Gene mapping ; Evolution ; Yeasts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Mapping of sequences specifying the large and small ribosomal RNAs and six polypeptides in the circular 23.7 kbp mitochondrial DNA ofSaccharomyces exiguus has shown that these genes have the same orientation and that a 5 gene cluster is common to this DNA and the 18.9 kbp mtDNA fromTorulopsis glabrata. Included in the preserved region are juxtaposed sequences specifying ATPase subunits 6 and 9 which have the same order and orientation as analogous genes in theEscherichia coli unc operon. The above data, together with knowledge that these two sequences are dispersed in larger yeast mtDNAs, leads us to suggest that larger forms are derived from a smaller ancestral molecule that would have had some resemblance to the mtDNAs ofS. exiguus andT. glabrata.
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    Journal of molecular evolution 19 (1983), S. 342-345 
    ISSN: 1432-1432
    Keywords: mtDNA ; Gene mapping ; Evolution ; Yeasts
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    Topics: Biology
    Notes: Summary Analysis of gene order and orientation in the circular 18.9 kbp mitochondrial DNA molecule ofTorulopsis glabrata has shown that the eight large genic sequences have the same orientation and that a five gene cluster which runs — cytochrome b, cytochrome oxidase subunit 1, ATPase subunits 6 and 9 and cytochrome oxidase subunit 2 — is common to this DNA andSaccharomyces exiguus mtDNA (see accompanying paper).
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  • 21
    ISSN: 1432-1432
    Keywords: Yeast ; E. coli ; tRNA ; rRNA ; Sequence homologies ; Evolution ; Origins ; Coding mechanism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Many tRNAs ofE. coli and yeast contain stretches whose base sequences are similar to those found in their respective rRNAs. The matches are too frequent and extensive to be attributed to coincidence. They are distributed without discernible pattern along and among the RNAs and between the two species. They occur in loops as well as in stems, among both conserved and non-conserved regions. Their distributions suggest that they reflect common ancestral origins rather than common functions, and that they represent true homologies.
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  • 22
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    Journal of molecular evolution 20 (1984), S. 128-134 
    ISSN: 1432-1432
    Keywords: Snake venom ; Neurotoxin ; Cytotoxin ; Evolution ; Circular dichroism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The amino acid sequences of the 139 homologous “short” neurotoxins, “long” neurotoxins and cytotoxins so far characterised from elapid snake venoms were compared on the basis of the amino acid deletion/insertion events that have occurred during evolution. Systematic grouping of the toxins according to similarity suggests that the short neurotoxins resemble the cytotoxins more closely than they do the long neurotoxins. The significance of this finding is discussed in relation to the methodology, the conformations of the toxins (as represented by circular dichroism spectra) and the outcome of the study that would have been obtained had more traditional methods been used. It appears probable that the cytotoxins evolved relatively recently from neurotoxic ancestors.
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  • 23
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    Journal of molecular evolution 18 (1982), S. 287-292 
    ISSN: 1432-1432
    Keywords: Evolution ; Endosymbiosis ; Gene transfer ; Transmembrane movement of proteins ; Receptors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In the origin of the mitochondrion and plastid, gene transfer from the ancestral endosymbiont to the host was proposed to be a crucial event. For this genic integration to proceed, products of transferred genes had to return to and enter the endosymbionts. The limiting event was the crossing of the barrier presented by the two semipermeable membranes bounding the proto-organelle. In this paper it is suggested that spontaneous transport allowed transferred gene encoded proteins to enter the endosymbionts before receptors evolved. The effects of these events, including the degeneration of the endosymbiont genome, are discussed. Although the presumed gene transfer had profound effects on the metabolic relationships between host and endosymbionts it probably cannot account for all examples of organelle/cytoplasmic isozyme pairs or the absence of amino acid synthetic enzymes in animal cells.
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    Journal of molecular evolution 16 (1980), S. 37-46 
    ISSN: 1432-1432
    Keywords: Evolution ; Drosophila ; Temperature ; Mitochondrial enzymes ; Kinetic properties
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    Notes: Summary The evolutionary behavior of two mitochondrial enzymes (L-glycerol 3-phosphate:cytochrome c oxidoreductase E.C.1.1.1.95,αGPO, and L-malate: NAD+ oxidoreductase, E.C.1.1.1.37, m-MDH) obtained from several temperate and tropicalDrosophila species was examined by comparing their catalytic properties, which related to temperature (Km-Ea-Q10-Thermostability). MitochondrialαGPO or m-MDH obtained either from temperate or from tropical species was found to exhibit similar catalytic properties while for both cytosolic enzymes, theαGPDH and s-MDH, Km patterns were similar among species from the same thermal habitat and different between thermal habitats. In combination with other observations reported in the literature these facts support the view that the function, and probably the structure, of mitochondrial enzymes are better conserved in evolution than those of the corresponding enzymes found in the cytosol. It is proposed that the relative invariance of the mitochondrial enzymes structure is probably linked to a necessary relative invariance of molecular interactions inside the mitochondrion.
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    Journal of molecular evolution 16 (1980), S. 73-94 
    ISSN: 1432-1432
    Keywords: Enzymes ; Evolution ; Gene regulation ; HawaiianDrosophila
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    Topics: Biology
    Notes: Summary The tissue and stage specificity of expression of five enzymes was examined by electrophoretic analysis of relative enzyme levels in extracts of 13 larval and adult tissues in 27 species of Hawaiian picture-wingedDrosophila. The developmentally regulated patterns of enzyme expression thus characterized were compared to a modal standard phenotype. About 30% of the pattern features analyzed differed significantly from the standard in one or more species. Many of these regulatory differences are essentially qualitative, with tissue specific differences in enzyme activity in excess of 100 fold for some species pairs. The adaptive significance of these pattern differences is unknown, but the results provide strong direct evidence for rapid evolution of new patterns of gene regulation in this group of organisms.
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  • 26
    ISSN: 1432-1432
    Keywords: Balbiani ring ; Repeat ; Evolution ; Repetitive DNA
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    Notes: Summary All known types of Balbiani ring (BR) gene consist of multiple, tandemly arranged, ca. 180 to 300-bp repeat units that can be divided into a constant region and a subrepeat region. The latter region includes short tandem subrepeats (SRs). Comparison of all available BR sequences using computer methods has enabled us (a) to define more precisely the constant and subrepeat regions, (b) to infer the evolutionary relationships among the various types of BR repeats, (c) to derive a consensus approximation of an ancestral sequence from a small segment of which the highly diverse present-day SRs may have originated, and (d) to detect an underlying substructure in the constant region, evident in the consensus but not in the present-day sequences and possibly corresponding to an original 39-bp DNA segment from which the extant, giant BR sequences may have evolved. We discuss the processes of reduplication, diversification, and homogenization within the hierarchically repetitive BR sequences as examples of how a simple DNA element may evolve into a diverse family of large, protein-coding genes.
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  • 27
    ISSN: 1432-1432
    Keywords: Evolution ; Gene family ; Balbiani ring genes ; Repetitive sequences ; Structural proteins ; Protein conformation ; Polymerization
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    Notes: Summary The large, repetitive Balbiani ring (BR) genes, BR 1, 2, and 6, inChironomus tentans originated from a short ancestral sequence and have all evolved according to analogous amplification schemes. We analyzed the structures of the BR-encoded secretory proteins and defined the parts that have been conserved during the evolutionary process. The BR products show striking similarities, with the BR 1 and BR 2 products being more similar to each other than to the BR 6 product. In the constant (C) region of the repeat units, 7 of the 30 amino acid residues are strictly conserved; 4 of these are the cysteine residues. The subrepeat (SR) regions of all the BR products are dominated by repeated tripeptide elements rich in proline and charged amino acid residues. Most of the amino acid replacements in both regions are conservative. Secondary structure predictions suggested that the C regions of the BR 1 and BR2 products have several elements of secondary structure: an α-helix, a β-strand, and one or two reverse turns, as in “globular structures.” The prediction for the C region of the BR 6 product is similar but lacks a β-strand. The predictions for the intervening SR regions appear less conclusive, but are clearly different from those for the C regions, and suggest regular structures not differing in their conformational elements. The SR regions evolved from an ancestor sequence similar to the C region; thus, the BR products seem to represent an example of evolution from one structure to two differently folded products. It is proposed that the alignment and polymerization of the long BR proteins could be promoted by the repetitive structure of the molecules, due to the possibility of forming disulfide bridges between half-cystine residues and electrostatic interactions between the charged residues of the SR regions. The divergence among the BR products is discussed in relation to possible functional differences among the members of the BR gene family.
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    Development genes and evolution 190 (1981), S. 127-131 
    ISSN: 1432-041X
    Keywords: Uteroglobin ; Radioimmunoassay ; Progesterone ; Osmotic minipumps ; Immunohistochemistry
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    Topics: Biology
    Notes: Summary This study was undertaken to determine whether the influx of progesterone into the uterine lumen of the rabbit, in the preimplantation period, is dependent onuteroglobin (UGL). Rabbits were ovariectomized and, three months later, treated with two defferent doses of progesterone. Purified UGL was injected into one uterine horn and, as a control,immunoglobulin G (IgG) was injected into the other. After four days, the animals were sacrificed their uteri flushed, and the progesterone content of the washes was determined by radioimmunoassay. Animals with the lower serum progesterone level (2.8 ng/ml) had a significantly different uterine horn progesterone content. The hormone accumulation in the horn containing UGL was 2.3 to 7.5 times higher than in the horn containing IgG. Animals with a higher serum progesterone level (7.2 ng/ml) showed no differences. The hormone content was equally high in both horns, presumably due to the synthesis of endogenous UGL being reactivated by the hormone treatment. The validity of these experiments as models for the events during early pregnancy and the physiological role of progesterone available inside the uterus are discussed.
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    Development genes and evolution 192 (1983), S. 337-346 
    ISSN: 1432-041X
    Keywords: Drosophila ; Gynandromorphs ; Genital disc ; Compartments ; Evolution
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    Topics: Biology
    Notes: Summary The genital imaginal disc ofDrosophila differentiates the terminalia, i.e. the genitalia and analia, of both sexes. It represents a composite anlage, containing a female genital primordium, a male genital primordium and an anal primordium. In normal males and females, only one of the two genital primordia differentiates; the other is developmentally repressed. Therefore, cell-lineage relationships between the male and female genital primordia can only be studied in sexual mosaics which differentiate female and male cells. We producedMinute (M)‖non-Minute(M+) gynandromorphs and selected those with sexually mosaic terminalia for a cell-lineage analysis. In these mosaics, either the male (XO) or female (XX) cells wereM + and thus had a growth advantage. The differential growth rates served as a tool to detect clonal restrictions. In control gynandromorphs (M +‖M +), the amount of female genitalia differentiated was largely independent of the amount of male genitalia present. In contrast, male and female anal structures, as a rule, added up to one full set. The same was true for the experimentalM‖M + gynandromorphs, but the contribution ofXX andXO cells to mosaic terminalia changed drastically due toM + cells competing successfully against the more slowly growingM cells. Specific subsamples ofM‖M + gynandromorphs showed thatM cells in a non-mosaic primordium are shielded from cell competition taking place in the neighbouring mosaic primordium. We conclude that the three primordia of the genital disc represent developmental compartments. In the genital primordia, even developmentally repressedM + cells compete successfully against developmentally activeM cells.
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  • 30
    ISSN: 1432-0983
    Keywords: Plastid DNA ; Cytochrome b6 gene ; Amino acid sequence ; Hydropathy ; Thylakoid membrane ; Transcript modification ; Evolution ; Spinach
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    Notes: Summary A 2.4 kilobase-pair segment of the spinach plastid chromosome carrying the genes for apocytochrome b6 and subunit 4 of the thylakoid membrane cytochrome b/f complex has been analysed by DNA sequencing and Northern blot analysis. The nucleotide sequence reveals two uninterrupted open reading frames of 211 and 139 triplets coding for two hydrophobic proteins of 23.7 kd (cytochrome b6) and 15.2 kd (subunit 4). The genes are located on the same strand and are separated from each other by 1018 untranslated base pairs. They map adjacent to the gene for the P680 chlorophyll α apoprotein of the photosystem II reaction center. The three genes appear to be under common transcriptional control and the transcripts post-transcriptionally modified. The deduced amino acid sequences of cytochrome b6 and subunit 4 both exhibit significant homology with published sequences from mitochondrial b cytochromes (42 kd) suggesting that these functionally equivalent polypeptides in photosynthetic and respiratory electron transport chains arose monophyletically.
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  • 31
    ISSN: 1432-072X
    Keywords: Glycogen ; Archaebacteria ; Thermoacidophiles ; Sulfolobus ; Thermoproteales ; Glucosyl transferase ; Evolution
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    Notes: Abstract Glycogen has been found in thermoacidophilic archaebacteria of the genera Sulfolobus, Thermoproteus, Desulfurococcus and Thermococcus. Thermoplasma acidophilum yielded a related, though less defined compound. Glycogen was identified by elementary analysis, infrared spectroscopy, the nature of the hydrolysis products, the iodine reaction, and the nature of the products of periodate oxydation and reduction. The average chain length was 7. From crude extracts of Sulfolobus and Thermoproteus complexes of glycogen with 4 respectively 2 proteins have been isolated by CsCl density gradient centrifugation. In either case, one of the proteins was identified as glucosyl transferase. The glucosyl transferase of Sulfolobus acidocaldarius strain B 12 utilizes UDP-glucose as well as ADP-glucose as substrates, with K m values of 0.42 and 0.2 mM respectively and turnover numbers of 4.6 and 5.2 per second respectively. In electron micrographs the isolated glycogen protein complex appears as scale like aggregates, whereas in cell sections amorphous bodies fill large portions of the cells.
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  • 32
    ISSN: 1432-072X
    Keywords: Superoxide dismutase ; Glutamine synthetase ; Evolution ; Marine bacteria ; Alcaligenes ; Alteromonas ; Deleya ; Oceanospirillum ; Pseudomonas
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    Notes: Abstract Evolutionary relationships among marine species assigned to the genera Alteromonas, Oceanospirillum, Pseudomonas, and Alcaligenes were determined by an immunological study of their Fe-containing superoxide dismutases (FeSOD) and glutamine synthetases (GS), two enzymes with differentially conserved amino acid sequences which are useful for determining intermediate and distant relationships, respectively. Five reference antisera were prepared against the FeSODs from Alteromonas macleodii, A. haloplanktis, Oceanospirillum commune, Pseudomonas stanieri, and Deleya pacifica. For GS, a previously prepared antiserum to the enzyme from Escherichia coli was employed. Amino acid sequence similarities for both enzymes were determined by the quantitative microcomplement fixation technique and the Ouchterlony double diffusion procedure. Six evolutionary groups were detected by FeSOD sequence similarities: three subgroups within the genus Alteromonas, the genera Oceanospirillum and Pseudomonas, and a new genus, Deleya (to accommodate marine Alcaligenes). Only four groupings were delineated by the GS data: the latter three genera and one group composed of all the species of Alteromonas. Evidence that all of these subgroups are derived from the evolutionary lineage defined by the purple sulfur photosynthetic bacteria is presented.
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  • 33
    ISSN: 1432-072X
    Keywords: Evolution ; Vibrio ; Photobacterium ; Alteromonas ; Aeromonas ; Marine bacteria ; Superoxide dismutase
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    Notes: Abstract The amino acid sequence divergence of superoxide dismutases (SODs) from 22 species and five groups of Vibrio, Photobacterium, and a number of related organisms was determined by means of the microcomplement fixation technique and the Ouchterlony double diffusion procedure. Five reference antisera were used which had been prepared against the purified SODs from V. alginolyticus, V. splendidus II, V. fischeri, V. cholerae, and P. leiognathi. With a few exceptions the results were in agreement with past studies of other informational molecules and provided a comprehensive overview of evolutionary relationships in Vibrio and Photobacterium. The genus Vibrio was found to consist of a major group of primarily marine species which included V. fischeri, V. logei, V. splendidus, V. pelagius, V. nereis, V. campbellii, V. harveyi, V. natriegens, V. alginolyticus, V. parahaemolyticus, V. proteolyticus, V. fluvialis, V. vulnificus, V. nigripulchritudo, and V. anguillarum. On the outskirts of this large and relatively heterogeneous group were the fresh water and estuarine species V. cholerae and V. metschnikovii as well as the marine species V. gazogenes. A considerable distance from Vibrio were the related species of Photobacterium: P. phosphoreum, P. leiognathi, and P. angustum. Both genera were distant from species of Aeromonas as well as from Plesiomonas shigelloides, Escherichia coli, and Alteromonas hanedai, a luminous strict aerobe. The agreement between these and previous studies of evolution of informational molecules in Vibrio and Photobacterium is best explained by vertical evolution (involving no genetic exchange between species) rather than by its opposite — horizontal evolution.
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    Journal of mathematical biology 11 (1981), S. 245-267 
    ISSN: 1432-1416
    Keywords: Population genetics ; Evolution ; Migration ; Geographical variation ; Habitat choice ; Polymorphism
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    Topics: Biology , Mathematics
    Notes: Abstract For a single autosomal locus with multiple alleles both an island and a multiple-niche model with discrete nonoverlapping generations are formulated for the maintenance of genetic variability. Both models incorporate viability selection in an arbitrary way and allow for genotypic differences in the pertinent migration structure. Random drift is ignored, and mating is at random. A global analysis is given for the island model in the neutral case. For a subdivided population, conditions are derived for the existence of a protected polymorphism, and the model is examined in some special two-niche cases. Of particular consideration is the loss of neutral alleles due solely to population regulation and genotype-dependent migration, and the possible existence of equilibrium clines without selection.
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    Journal of mathematical biology 14 (1982), S. 327-353 
    ISSN: 1432-1416
    Keywords: Evolution ; Molecular evolution ; Dynamical system ; Neo-Darwinian evolution ; Non-Darwinian evolution ; Neutral theory
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    Topics: Biology , Mathematics
    Notes: Abstract In order to understand generally how the biological evolution rate depends on relevant parameters such as mutation rate, intensity of selection pressure and its persistence time, the following mathematical model is proposed: dN n (t)/dt=(m n (t-μ)N n (t)+μN n-1(t) (n=0,1,2,3...), where N n (t) and m n (t) are respectively the number and Malthusian parameter of replicons with step number n in a population at time t and μ is the mutation rate, assumed to be a positive constant. The step number of each replicon is defined as either equal to or larger by one than that of its parent, the latter case occurring when and only when mutation has taken place. The average evolution rate defined by $$\upsilon _\infty \equiv {\text{ lim}}_{t \to \infty } \sum _{n = 0}^\infty nN_n (t)/t\sum _{n = 0}^\infty N_n (t)$$ is rigorously obtained for the case (i) m n (t)=m n is independent of t (constant fitness model), where m n is essentially periodic with respect to n, and for the case (ii) $$m_n (t) = {\text{ }}s( - 1)^{n + [1/\tau ]} $$ (periodic fitness model), together with the long time average m ∞ of the average Malthusian parameter $$\bar m \equiv \sum _{n = 0}^\infty m_n (t)N_n (t)/\sum _{n = 0}^\infty N_n (t)$$ . The biological meaning of the results is discussed, comparing them with the features of actual molecular evolution and with some results of computer simulation of the model for finite populations.
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    Journal of mathematical biology 19 (1984), S. 329-334 
    ISSN: 1432-1416
    Keywords: Evolution ; ESS ; games ; game dynamics ; n-person games ; strategies
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    Topics: Biology , Mathematics
    Notes: Abstract This note contains a generalization of the definition of an evolutionary stable strategy and of the corresponding game dynamics from 2-person to n-person games. This broader framework also allows modelling of several interacting populations or of populations containing different “types” of individuals, for example males and females.
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    Journal of mathematical biology 18 (1983), S. 13-23 
    ISSN: 1432-1416
    Keywords: Ecosystem ; Evolution ; Autonomous oscillations ; issipative structure ; Bifurcation
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    Topics: Biology , Mathematics
    Notes: Abstract The interrelation between autonomous oscillations in local systems and stable dissipative structures in spatially distributed systems is analyzed. Darwinian evolution in populations comprising the ecosystem is shown to be able to cause the qualitative rearrangements of dynamic modes and smooth appearance of oscillations in local systems. The same evolutionary mechanisms analyzed within bilocal systems, may lead to appearance of dissipative structures (both smooth and sharp).
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  • 38
    ISSN: 1432-1416
    Keywords: Evolution ; quantitative inheritance ; random matrix theory ; morphological integration
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    Topics: Biology , Mathematics
    Notes: Abstract A quantitative genetic model of “random pleiotropy” is introduced as reference model for detecting the kind and degree of organization in quantitative genetic variation. In this model the genetic dispersion matrix takes the form of G = BB T, where B is a general, real, Gaussian random matrix. The eigenvalue density of the corresponding ensemble of random matrices (ℰG) is considered. The first two moments are derived for variance-covariance matrices G as well as for correlation matrices R, and an approximate expression of the density function is given. The eigenvalue distribution of all empirical correlation matrices deviates from that of a random pleiotropy model by a very large leading eigenvalue associated with a “size factor”. However the frequency-distribution of the remaining eigenvalues shows only minor deviations in mammalian skeletal data. A prevalence of intermediate eigenvalues in insect data may be caused by the inclusion of many functionally unrelated characters. Hence two kinds of deviations from random organization have been found: a “mammal like” and an “insect like” organization. It is concluded that functionally related characters are on the average more tightly correlated than by chance (= “mammal like” organization), while functionally unrelated characters appear to be less correlated than by random pleiotropy (“insect like” organization).
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    Theoretical and applied genetics 68 (1984), S. 187-192 
    ISSN: 1432-2242
    Keywords: Vicia ; nuclear DNA ; Evolution ; Base sequence
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    Notes: Summary The composition of nuclear DNA in 3 Vicia species are compared. The species V. eriocarpa, V. johannis and V. melanops are from three separate subgeneric sections of Vicia and show a fourfold variation in their amounts of nuclear DNA. DNA melting experiments, buoyant density gradient analysis and Cot reassociation experiments show that the quantitiative change in nuclear DNA between the three species is achieved by changes in the amounts of both repetitive and nonrepetitive DNA sequences. It is suggested that while the increase in the repetitive fraction is achieved by the proliferation of repetitive base sequences the increase in the nonrepetitive fraction is due to the steady accretion of highly diverged base sequences resulting from mutations, deletions, insertions and base sequence rearrangements among families of repetitive sequences.
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    Theoretical and applied genetics 57 (1980), S. 225-232 
    ISSN: 1432-2242
    Keywords: Electrophoresis ; Proteins ; Leguminosae ; Taxonomy ; Evolution
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    Topics: Biology
    Notes: Summary Gel electrophoretic investigations were made on the seed albumins of several members of the family Papilionaceae. Relationships were found with taxa of a lower order i.e. between mutants, varieties and subspecies. More distantly related ones, for example species of the same genus or species of different genera, did not show similarities. Thus, it was concluded that the albumin banding pattern is only suitable for studying phylogenetic and taxonomic problems if the material under investigation is not too distantly related.
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    Theoretical and applied genetics 60 (1981), S. 65-70 
    ISSN: 1432-2242
    Keywords: Cross-incompatibility ; Solanum ; Reproductive barriers ; Introgression ; Evolution
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    Topics: Biology
    Notes: Summary Preliminary results from a large number of reciprocal crosses between the closely related sympatric species S. gourlayi Hawkes (2n=4x=48) and S. oplocense Hawkes (2n=6x=72) indicated that they are difficult to hybridize. Pollen-pistil incompatibility barriers were detected via fluorescent microscopy. The cross incompatibility reaction occurred at three sites in 6x×4x crosses; on the stigma, in the first one-third of the style, and in the first two-thirds of the style. In the reciprocal 4x×6x crosses the incompatibility reaction invariably occurred in the ovary. Backcrosses of interspecific pentaploid hybrids (that were occasionally formed) to both parental populations were fully compatible, partially compatible, and fully incompatible with three sites of cross-incompatibility reaction similar to those observed in 6x×4x crosses, respectively. Both polyploid species were found to be selfcompatible, whereas their F1 hybrids were found to be self-incompatible. An hypothesis based on interactions of dominant cross-incompatibility (CI) genes in pistils and dominant specific complementary genes in pollen grains is postulated to explain these observations. The cross-incompatibility system that appears to be operating in nature between 4x S. gourlayi and 6x S. oplocense provides a way for gene exchange between sympatric populations without threatening the identity of either species.
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    Theoretical and applied genetics 61 (1982), S. 73-79 
    ISSN: 1432-2242
    Keywords: Nicotiana ; Chloroplast DNA ; Restriction fragments ; Deletion ; Evolution
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    Topics: Biology
    Notes: Summary Nicotiana chloroplast genomes exhibit a high degree of diversity and a general similarity as revealed by restriction enzyme analysis. This property can be measured accurately by restriction enzymes which generate over 20 fragments. However, the restriction enzymes which generate a small number (about 10) of fragments are extremely useful not only in constructing the restriction maps but also in establishing the sequence of ct-DNA evolution. By using a single enzyme, Sma I, a elimination and sequential gain of its recognition sites during the course of ct-DNA evolution is clearly demonstrated. Thus, a sequence of ct-DNA evolution for many Nicotiana species is formulated. The observed changes are all clustered in one region to form a “hot spot” in the circular molecule of ct-DNA. The mechanisms involved for such alterations are mostly point mutations but inversion and deficiency are also indicated. Since there is a close correlation between the ct-DNA evolution and speciation in Nicotiana a high degree of cooperation and coordination betwen organellar and nuclear genomes is evident.
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    Theoretical and applied genetics 61 (1982), S. 161-169 
    ISSN: 1432-2242
    Keywords: Cultivated potato ; Evolution ; Parallel spindles ; 2n gametes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A high gene frequency for ps (parallel spindles) is expected in cultivated tetraploid potatoes, S. tuberosum Group Tuberosum, if 2n pollen produced by ancestral diploid plants which were psps was involved in the origin and evolution of the potato. Fifty-six North American cultivars (varieties and advanced selections) were pollinated by diploid clones, either W 5295.7 or W 5337.3 which are homozygous recessive for ps. The segregation ratios in regard to 2n pollen production in derived tetraploid progenies, from 4x×2x crosses, reveal the genotype of ps in the cultivars. Microsporogenesis of 2n pollen producing 4x progeny was observed to avoid an overestimation of the frequency of 2n pollen producing plants due to mechanisms other than parallel spindles. More than 50% of the 56 cultivars are simplex (Pspspsps), since in each of these cultivars about 50% of their progeny produced 2n pollen. The ps gene frequency in the 56 cultivars was estimated as high as 0.69. The high frequency of ps in the tetraploid cultivars clearly supports the hypothesis that 2n pollen produced by plants homozygous recessive for ps have been involved in the origin of cultivated tetraploid potatoes, since a higher frequency of ps in the tetraploid than in the ancestral diploid population can be expected from sexual polyploidization but not from somatic doubling. The importance of meiotic mutants such as ps for the successful evolution of polysomic polyploids is emphasized.
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    Theoretical and applied genetics 61 (1982), S. 305-314 
    ISSN: 1432-2242
    Keywords: Arachis ; Karyomorphology ; D2 analysis and genetic distance ; Evolution ; Crop improvement
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The chromosome complements of 12 taxa in section Arachis were karyotypically and meiotically analysed. In taxa with 2n=20 the arm ratio of the respective pair of chromosomes was taken as an independent quantitative character and statistically analysed by Mahalanobis D2. Two clusters were formed, one represented solely by A. batizocoi and the other consisting of the remaining 11 taxa. This grouping was confirmed by canonical analysis. In the larger group of species, A villosa and A. correntina were closely related karyotypically and on D2 distance, while A. cardenasii forms a distinct subgroup. A. cardenasii lacks the short “A” chromosome recorded in other species of this group, and A. batizocoi is no longer the only species to have a pair of chromosomes with a secondary constriction. The taxa with 2n=40, A. monticola and A. hypogaea, are karyotypically very similar, though there is a difference in the number of chromosome pairs with a secondary constriction. On the basis of karyomorphological affinity, especially in relation to marker chromosomes, A. cardenasii is probably one of the ancestors of the tetraploid species studied.
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    Theoretical and applied genetics 56 (1980), S. 11-15 
    ISSN: 1432-2242
    Keywords: Diploid pollen ; Evolution ; Sexual polyploidization ; Solanum ; Tuberosa ; Diplandroids
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    Topics: Biology
    Notes: Summary A group of wild, tuber-bearing species from Northwest Argentina, belonging to the series Tuberosa, Solarium spegazzini Bitt. (spg, 2n=2x=24), S. gourlayi Hawkes (grl, 2n=2x=24 and 2n=4x=48) and S. oplocense Hawkes (opl, 2n=6x=72), and Cuneolata, S. infundibuliforme Phil (ifd, 2n=2x=24), is being used to investigate the mode of origin of polyploids in the genus Solanum. 2n gametes have been detected in the diploid species ifd and spg and in a diploid race of grl, using cytological and breeding approaches. Twenty-two introductions of spg, 8 of grl and 26 of ifd have been tested for 2n pollen; 59%, 63% and 54% of them, respectively, had at least one 2n pollen producing plant. These introductions comprised 238, 76 and 235 plant respectively, of which 20, 16, and 32 plant produced 5% or more 2n pollen. The mechanism of 2n pollen formation was determined in several plant of 2x spg, 2x grl and 2x ifd. All of them were found to form diplandroids via parallel spindles. This mechanism, which gives meiotic products genetically equivalent to first division restitution gametes, is under control of the Mendelian recessive ps. The results suggest that the allele ps is widely distributed in natural populations of the three diploids, and that its frequency is very high. These species are seen as valuable material for population genetic studies, and for the eventual incorporation into a breeding scheme involving sexual polyploidization via 2n gametes.
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    Theoretical and applied genetics 57 (1980), S. 5-9 
    ISSN: 1432-2242
    Keywords: Endosperm ; Evolution ; Interspecific crosses ; Solanums ; 2n gametes
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    Topics: Biology
    Notes: Summary The endosperm has played a significant role in the evolution of angiosperms because of its physiological and genetic relationships to the embryo. One manifestation of this evolutionary role is its abnormal development in interploidy crosses. It is now established that the endosperm develops abnormally in interploidy-intraspecific crosses when the maternal: paternal genome ratio deviates from 2∶1 in the endosperm itself. We propose an Endosperm Balance Number (EBN) hypothesis to explain endosperm development in both interploidy-intraspecific and interspecific crosses. Each species is assigned an EBN on the basis of its crossing behavior to a standard species. It is the EBN which determines the effective ploidy in the endosperm of each species, and it is the EBNs which must be in a 2∶1, maternal:paternal ratio. The EBN of a species may be determined by a few genes rather than the whole genome. This hypothesis brings most intraspecific-interploidy and interspecific crossing data under a single concept with respect to endosperm function. The implications of this hypothesis to isolating mechanisms, 2n gametes, the evolution of disomic polyploids, and reciprocal differences in seed development are discussed.
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    Theoretical and applied genetics 58 (1980), S. 187-191 
    ISSN: 1432-2242
    Keywords: Conifers ; Deciduous tree ; Polyploidy ; Endoploidy ; Evolution ; Cytophotometry ; DNA content
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The DNA content of nuclei from meristematic root tip cells of five coniferous and one deciduous tree species and, for comparison, ofVicia faba was cytophotometrically determined. The DNA values of diploid nuclei fromGinkgo biloba are approximately a quarter lower than those fromVicia faba. The nuclear DNA values of the other tree species are merely a third to a ninth part of those ofVicia faba. In three tree species, as well as diploid, we have found nuclei of different polyploid level. The reliability of different cytochemical methods, which are used for determination of the nuclear DNA content, is critically analyzed. The DNA values of the investigated tree species are discussed in connection with the evolution of the DNA content in higher plants.
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  • 48
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    Theoretical and applied genetics 61 (1982), S. 91-95 
    ISSN: 1432-2242
    Keywords: Complement fractionation ; Excess sporads ; Diploid orchid species ; Phaius tribe ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Four out of 10 diploid orchid species showed “complement fractionation” a complex cytological phenomenon, hitherto reported only in polyploid plants. The manifestation of this phenomenon during meiosis is the formation of chromosome subgroups resulting eventually in cells with more than the usual four sporads; five or six being the optimum number in the investigated orchid species. No implications whatsoever can be deduced as to the genetic or genomic constitution of the end products. The presence of the phenomenon in these orchid species could perhaps indicate a polyploid ancestry or concealed hybridity. The operation of “complement fractionation”, however, could be interpreted as an alternative evolutionary pathway opposed to polyploidy.
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  • 49
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    Theoretical and applied genetics 63 (1982), S. 349-360 
    ISSN: 1432-2242
    Keywords: Chromosomes ; Nucleotides ; Evolution ; Polyploids ; Triticum ; Heterochromatin ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The nature of genome change during polyploid evolution was studied by analysing selected species within the tribe Triticeae. The levels of genome changes examined included structural alterations (translocations, inversions), heterochromatinization, and nucleotide sequence change in the rDNA regions. These analyses provided data for evaluating models of genome evolution in polyploids in the genus Triticum, postulated on the basis of chromosome pairing at metaphase I in interspecies hybrids. The significance of structural chromosome alterations with respect to reduced MI chromosome pairing in interspecific hybrids was assayed by determining the incidence of heterozygosity for translocations and paracentric inversions in the A and B genomes of T. timopheevii ssp. araraticum (referred to as T. araraticum) represented by two lines, 1760 and 2541, and T. aestivum cv. Chinese Spring. Line 1760 differed from Chinese Spring by translocations in chromosomes 1A, 3A, 4A, 6A, 7A, 3B, 4B, 7B and possibly 2B. Line 2541 differed from Chinese Spring by translocations in chromosomes 3A, 6A, 6B and possibly 2B. Line 1760 also differed from Chinese Spring by paracentric inversions in arms 1AL and 4AL whereas line 2541 differed by inversions in 1BL and 4AL (not all chromosomes arms were assayed). The incidence of structural changes in the A and B genomes did not coincide with the more extensive differentiation of the B genomes relative to the A genomes as reflected by chromosome pairing studies. To assay changing degrees of heterochromatinization among species of the genus Triticum, all the diploid and polyploid species were C-banded. No general agreement was observed between the amount of heterochromatin and the ability of the respective chromosomes to pair with chromosomes of the ancestral species. Marked changes in the amount of heterochromatin were found to have occurred during the evolution of some of the polyploids. The analysis of the rDNA region provided evidence for rapid “fixation” of new repeated sequences at two levels, namely, among the 130 bp repeated sequences of the spacer and at the level of the repeated arrays of the 9 kb rDNA units. These occurred both within a given rDNA region and between rDNA regions on nonhomologous chromosomes. The levels of change in the rDNA regions provided good precedent for expecting extensive nucleotide sequence changes associated with differentiation of Triticum genomes and these processes are argued to be the principal cause of genome differentiation as revealed by chromosome pairing studies.
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  • 50
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    Cell & tissue research 235 (1984), S. 703-705 
    ISSN: 1432-0878
    Keywords: Enterochromaffin cells ; Serotonin ; Immunohistochemistry ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The morphology of enterochromaffin (EC) cells in the human fundic mucosa was investigated at the lightmicroscopic level by means of the unlabeled peroxidase anti-peroxidase method, with the use of a highly specific anti-serotonin serum. EC-cells in the human fundic mucosa were sparsely distributed below the neck portion of the gland, but were found to be rather numerous in its lower half. Immunohistochemistry revealed marked pleomorphic and seemingly polynuclear EC-cells or cells with long, sometimes multipolar cytoplasmic processes. In addition, luminal contacts and contiguity between EC-cells, or interglandular connections were also encountered. The present immunohistochemical procedure permits, for the first time, a clear-cut morphological visualization of the entire population of EC-cells, and reveals the distinctive morphological features of these cells in the human fundic mucosa. These morphological findings imply that EC-cells in the fundic mucosa may be crucial in gastric function.
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  • 51
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    Cell & tissue research 237 (1984), S. 239-244 
    ISSN: 1432-0878
    Keywords: Islet A cell ; Catecholamine ; Combined microscopy ; Immunohistochemistry ; Fowl
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    Topics: Biology , Medicine
    Notes: Summary In an attempt to identify pancreatic islet cells emitting formaldehyde-induced fluorescence (FIF), the pancreatic islets of the domestic fowl were studied by combined fluorescence, ultrastructural, silver-impregnation and immunohistochemical methods in the same section or in consecutive semi-thin and ultra-thin sections. The results indicate that islet cells emitting intense FIF exhibit a strongly argyrophil reaction with the Grimelius' silver method and also immunohistochemical reaction with anti-glucagon serum, but not with anti-5-HT serum. Therefore, the fowl islet A cell, a peptide hormone-producing cell, stores simultaneously catecholamine as biogenic amine. The islet B and D cells did not display any FIF, any argyrophil reaction with the Grimelius' silver method, or any immunoreactivity with anti-glucagon or anti-5-HT sera. The fluorescent but non-argyrophil cells dispersed in the exocrine acinus may well be PP cells.
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  • 52
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    Keywords: Pineal complex (pineal and parapineal organs) ; Development, ontogenetic ; Photoreceptor cells ; Immunohistochemistry ; Serotonin (5-HT) ; Opsin ; Teleost (Gasterosteus aculeatus)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 5-hydroxytryptamine (5-HT, serotonin)- and opsin-immunoreactive sites were studied in the developing pineal complex of the stickleback, Gasterosteus aculeatus L., by use of light-microscopic indirect immunoperoxidase techniques. 5-HT immunoreactivity first occurs in the pineal organ at the age of 80 h after fertilization and appears to be localized in cells of the photoreceptor type. The outer segments of a few pineal photosensory cells exhibit opsin immunoreactivity at the age of 84 h after fertilization. The number of cells seems to increase until the pineal organ is completely developed. The increase in the number of 5-HT immunoreactive perikarya runs parallel in time to that of the opsinimmunoreactive outer segments. The cells of the parapineal organ show neither opsin nor 5-HT immunoreactivity. The retina of the embryonic stickleback does not display opsin immunoreactivity until after hatching, which takes place about 144 h after fertilization. These results suggest, in the three-spined stickleback, an earlier light-perception capacity for the developing pineal organ than for the retina.
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  • 53
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    Cell & tissue research 238 (1984), S. 421-423 
    ISSN: 1432-0878
    Keywords: Gut endocrine cells ; Ontogeny ; Immunohistochemistry ; Pancreatic polypeptide ; Insect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ontogeny of the endocrine cells of the gut of the cockroach Periplaneta americana was studied by immunohistochemistry. During embryogenesis, the midgut begins to be formed as an outgrowth of the foregut and hindgut invaginations. Gut endocrine cells with pancreatic polypeptide (PP)-like immunoreactivity begin to appear at the anterior and posterior ends of the forming midgut. These cells are restricted to the midgut epithelium, and no mitotic cells with PP-like immunoreactivity are observed. These results strongly suggest that the gut endocrine cells, at least those with PP-like immunoreactivity, are derived from precursor cells they have in common with other epithelial cells of the midgut.
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  • 54
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    Cell & tissue research 234 (1983), S. 519-531 
    ISSN: 1432-0878
    Keywords: Pineal organ ; Serotonin ; Immunohistochemistry ; Fluorescence histochemistry ; Sympathectomy ; Dog
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Monoamine (noradrenaline and serotonin)-containing nerve fibers distributed in the pineal organ of the dog were studied by means of histochemistry (formaldehyde-induced fluorescence) and immunohistochemistry (peroxidase-antiperoxidase-PAP method) with the use of a serotonin antiserum. With the fluorescence-histochemical technique a dense network of blue-green fluorescent fibers was demonstrated in the pineal organ. Most of these fibers formed a perivascular plexus and their branches penetrated into the intercellular spaces of the parenchymal cells. Since these fibers completely disappeared ten days after bilateral removal of the superior cervical ganglia, it was confirmed that they are noradrenergic post-ganglionic sympathetic nerve fibers. A few yellow-fluorescent fibers were detected in the proximal part of the organ after ganglionectomy. By the use of the PAP method, intensively immunoreactive parenchymal cells and nerve fibers were demonstrated. The distribution pattern of these fibers was similar to that of the fluorescent sympathetic fibers. After almost all immunopositive fibers had been abolished by sympathectomy, some serotonin-containing fibers remained. The latter could be traced back to a system of serotonin fibers in the epithalamic region. These findings suggest that 1) the sympathetic noradrenergic fibers in the pineal organ of the dog take up serotonin which is released from the pinealocytes, and 2) this organ receives a dual monoamine innervation via peripheral noradrenergic and central serotonergic nerve fibers.
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    Cell & tissue research 235 (1984), S. 497-502 
    ISSN: 1432-0878
    Keywords: Prolactin cell ; Mitosis ; Sex difference ; Aging ; Immunohistochemistry
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    Topics: Biology , Medicine
    Notes: Summary The anterior pituitary of colchicine-pretreated male and female rats from 20 days to 12 months of age was stained immunohistochemically with anti-rat prolactin serum. Immunoreactive mitotic cells were identified in all groups of rats. In adult female rats the mitotic index of prolactin cells was higher at oestrus than at other stages of the oestrus cycle and than that in male rats of comparable ages. If adult female rats were ovariectomized on the second day of dioestrus or on the day of proestrus, the mitotic indices at presumptive oestrus were less than those in sham-operated controls at oestrus. Estrogen administration to ovariectomized rats significantly elevated the mitotic index of prolactin cells at 48 h after the treatment. The mitotic indices of prolactin cells in female rats reached a peak at 60 days of age, and then decreased with age. In male rats the mitotic indices showed a steady decrease from the value at 20 days of age. A sex difference in the mitotic indices of prolactin cells was noted from 60 days to 12 months of age. The present results clearly demonstrate that differentiated prolactin cells can undergo mitosis and that a sex difference in the mitotic activity of prolactin cells is present during adult life.
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  • 56
    ISSN: 1432-0878
    Keywords: Hypothalamus ; Serotonin ; Neuroendocrine regulation ; Monkey (Macaca fuscata) ; Immunohistochemistry
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    Topics: Biology , Medicine
    Notes: Summary The distributional pattern of serotonin-containing nerve fibers in the hypothalamus of the monkey (Macaca fuscata) was analyzed with the use of the peroxidaseantiperoxidase method in conjunction with a highly sensitive and specific anti-serotonin serum. The highest concentrations of serotonin-immunoreactive varicose fibers were found in the nucleus praeopticus medialis, nucleus ventromedialis hypothalami, and the complex of mammillary nuclei (nucleus praemamillaris, supramamillaris, mamillaris medialis et lateralis). However, the nucleus suprachiasmaticus, where numerous serotoninergic fibers have been reported to occur in the rat, appeared to be almost devoid of these fibers. The infundibular stalk, and the intermediate and posterior lobes of the pituitary contained considerable numbers of immunoreactive fibers. The present study provides a morphological basis for possible clarification of the influence of serotoninergic projections on various neuroendocrine mechanisms in primates. Furthermore, an attempt was made to clarify the differences and similarities concerning the distributional patterns of serotoninergic nerve fibers within the monkey hypothalamus in contrast to the rat hypothalamus.
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  • 57
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    Cell & tissue research 236 (1984), S. 733-735 
    ISSN: 1432-0878
    Keywords: S-100 protein ; Adrenal medulla ; Sustentacular cells ; Human fetus ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Adrenal glands of human fetuses were investigated by means of an immunohistochemical method with the use of an anti-S-100 serum. S-100-immunoreactivity was recognized in sustentacular cells located among the chromaffin cells. A characteristic circular arrangement of the immunostained cells was found in the central region of the adrenal glands. It surrounded aggregations of non-argyrophilic, small, round cells, which were identified as the remaining sympathoblasts (primitive sympathetic cells).
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  • 58
    ISSN: 1432-0878
    Keywords: Immunohistochemistry ; Paraganglia ; Aging ; Catecholamines ; Catecholamine-synthesizing enzymes
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    Topics: Biology , Medicine
    Notes: Summary The catecholamine-synthesizing enzymes, tyrosine hydroxylase, dopamine-β-hydroxylase and phenylethanolamine-N-methyltransferase were examined by immunohistochemistry in hypertrophied paraganglia of aged male Fischer-344 rats. All paraganglionic cells reacted with antibodies against tyrosine hydroxylase. Dopamine β-hydroxylase was identified in most paraganglionic cells, indicating that they synthesized norepinephrine. A variable number of paraganglia were positive for phenylethanolamine-N-methyltransferase, which suggested that they synthesized epinephrine. The formaldehyde-induced fluorescence method demonstrated greenish-yellow fluorescence or yellowish-brown fluorescence. The intensity of the fluorescence was in the same range as in adrenal medullary cells. The observations indicate that paraganglia are capable of synthesizing epinephrine.
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  • 59
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    Cell & tissue research 232 (1983), S. 679-683 
    ISSN: 1432-0878
    Keywords: CRF-immunoreactive nerve fibers ; Circumventricular organs ; Immunohistochemistry ; Monkey, Macaca fuscata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The occurrence of CRF (corticotropin-releasing factor)-immunoreactive nerve fibers in the circumventricular organs of adult male monkeys, Macaca fuscata, was studied on serially sectioned brains, by means of the peroxidase-antiperoxidase technique in combination with a highly specific and sensitive CRF antiserum. CRF-containing nerve fibers were found in high concentrations in the infundibulum and, in addition, in small numbers in the posterior lobe, organum vasculosum laminae terminalis, subfornical organ, and area postrema; they were missing in the pineal body and the subcommissural organ. The CRF immunoreactive nerve fibers distributed in these organs were located in the proximity of the blood vessels.
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  • 60
    ISSN: 1432-0878
    Keywords: Thyrotropin releasing hormone ; Rana catesbeiana ; Hypothalamus ; Immunohistochemistry
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    Notes: Summary The distribution of immunoreactive thyrotropin-releasing hormone (TRH) in the forebrain and hypophysis of Rana catesbeiana was studied by means of specific radioimmunoassay and immunohistochemistry based on peroxidase-antiperoxidase (PAP) techniques. A relatively high concentration of immunoassayable TRH is present in the hypothalamus. Immunoreactive TRH cell bodies are found in the anterior part of the preoptic nucleus, the dorsal infundibular nucleus, the nucleus of diagonal band of Broca, and the medial part of the amygdala. Immunoreactive nerve terminals are observed in the neurohypophysis and the external layer of the median eminence, where the terminals are in close contact with the capillary loops of the hypophyseal portal vessels. The possible role of TRH in the frog brain is discussed.
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  • 61
    ISSN: 1432-0878
    Keywords: cGMP ; Calmodulin ; Immunohistochemistry ; Estrogen ; Cell growth regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cyclic guanosine 3′, 5′ monophosphate (cGMP), cGMP-dependent protein kinase, calmodulin and cyclic adenosine 3′, 5′ monophosphate (cAMP) were localized in the uterus of the immature rat by an indirect immunofluorescence technique. cGMP, cGMP-dependent protein kinase and calmodulin were detected predominantly along epithelial and myometrial plasma membranes and in the adjacent cytoplasm. In contrast, cAMP immunoreactive material was found principally in the cytoplasm of connective tissue. After administration of 17 β estradiol, similar time-dependent changes were observed in the localization of cGMP, cGMP-dependent protein kinase and calmodulin in all uterine cell types. For the three compounds, nucleolar-like distribution of the immunofluorescence appeared approximately 12 h after treatment. A more dispersed, reticular distribution of the nuclear fluorescent staining was observed 20–24 h after hormonal treatment. Estrogen did not affect the localization of cAMP. The simultaneous mobilization of cGMP, cGMP-dependent protein kinase and calmodulin towards the same nuclear loci suggests concerted roles for these three molecules in nuclear metabolic processes during the development of the uterotrophic action of estrogens.
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  • 62
    ISSN: 1432-0878
    Keywords: Immunohistochemistry ; Gastrointestinal endocrine cells ; Brain-gut peptides ; Small intestine ; Platypus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The relative frequencies of endocrine cells and peptidergic nerve elements in the proximal small intestine of the adult platypus were studied by immunohistochemistry. Six kinds of endocrine cells — serotonin (5-HT)-, somatostatin-, gastrin-, motilin-, cholecystokinin (CCK) and bovine pancreatic polypeptide (BPP)-immunoreactive cells — were identified in this study. These endocrine cells were found most frequently in the intestinal glands, in moderate numbers in the tubular ducts and were infrequent in the surface folds. 5-HT-immunoreactive cells were most numerous, somatostatin-, gastrin-, motilin and BPP-immunoreactive cells were moderately numerous, whereas CCK-immunoreactive cells were rare. Five kinds of neuropeptides: substance P, vasoactive intestinal polypeptide (VIP), gastrin releasing peptide (GRP), somatostatin and leuenkephalin, were detected in the intramural nerve elements. Substance P-, VIP and GRP-immunoreactive nerve fibers were found most frequently in the lamina propria mucosae of the surface folds. The relationships between the possible functions of the peptides and amine detected in this study as well as the characteristic structure of the digestive tract of the adult platypus are discussed.
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  • 63
    ISSN: 1432-0878
    Keywords: Neuropeptides ; Gut hormones ; Enteric nervous system ; Immunohistochemistry ; Elasmobranchs
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    Topics: Biology , Medicine
    Notes: Summary The presence of peptides and 5-hydroxytryptamine (5-HT) in neurons and endocrine cells in the gastrointestinal tract of the spiny dogfish, Squalus acanthias, was investigated by means of immunohisto-chemistry, and the distribution of catecholamines by use of the Falck-Hillarp fluorescence-histochemical technique. Bombesin-like immunore-activity was present in numerous nerves in all layers and all parts of the gut, and also in endocrine cells in the mucosa throughout the stomach, rectum and intestine. VIP-like immunoreactivity occurred in an abundance of nerve fibres and in nerve cell bodies in all parts of the gut except the oesophagus, while 5-HT-like immunoreactivity was found sparsely in nerve fibres and more frequently in endocrine cells throughout the gut. Gastrin/CCK-like immunoreactivity was present in numerous nerve fibres in the rectum, but only in scattered fibres in the other parts of the gut. Endocrine cells showing gastrin/CCK-like immunoreactivity were present in the intestine only. Somatostatin-like immunoreactivity occurred in both nerve fibres and endocrine cells of the stomach and intestine, but only in nerves in the rectum. Neurotensin-like immunoreactivity was confined to endocrine cells of the intestine. Falck-Hillarp fluorescence histochemistry revealed 5-HT in endocrine cells and catecholamines in nerve fibres (and possibly also in endocrine cells) throughout the gut. Bombesin-, VIP-, gastrin/CCK- and somatostatin-like immunoreactivities and catecholamine fluorescence were present in nerve fibres of the rectal gland and, with the exception of gastrin/CCK-like immunoreactivity, also in nerve bundles in the walls of the coeliac and mesenteric arteries. The findings of the present study form an anatomical basis for the assumption that several of the neuropeptides and amines could function as neurotransmitters or neuromodulators in the gut of Squalus.
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    Cell & tissue research 235 (1984), S. 657-661 
    ISSN: 1432-0878
    Keywords: Evolution ; Endocrine pancreas ; Regulatory peptides ; Snakes
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    Topics: Biology , Medicine
    Notes: Summary The pancreas from eleven species of snakes representing both advanced and primitive families has been investigated for the presence of eleven regulatory peptides reported to occur in the mammalian endocrine pancreas. Of the eleven peptides studied, insulin, pancreatic glucagon and somatostatin were present in endocrine cells within the islets of all the species investigated. The neuropeptide, vasoactive intestinal polypeptide, was located within nerve terminals innervating the islets in the Boidinae, Colubrinae, Elaphidae and Crotalidae but absent from the Natricinae investigated. No immunoreactivity was demonstrable with the antisera to substance P, met-enkephalin, C-terminal gastrin, bombesin, glicentin and gastric inhibitory polypeptide. Pancreatic polypeptide-like immunoreactivity was demonstrable only in the boid snakes and exclusively stained by a C-terminal specific antiserum.
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  • 65
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    Cell & tissue research 236 (1984), S. 99-105 
    ISSN: 1432-0878
    Keywords: Monoclonal antibodies ; Spermatozoa ; Surface antigens ; Reproductive organs ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Eleven monoclonal antibodies that recognize membrane determinants on spermatozoa of the carp Cyprinus carpio L. have been produced. Indirect immunofluorescence revealed that these determinants are uniformly distributed on the surface of head and midpiece. Most of them are also present on the outer membrane of precursor sperm cells. Although none of the monoclonal antibodies reacted with carp somatic tissue, five monoclonal antibodies were positive for surface membrane determinants of oogonia and early prophase oocytes in carp ovary. Preliminary analysis of the testis and ovary of three other species of fish showed that some carp determinants are shared with germ cells from Barbus conchonius, Clarias lazera, or Salmo gairdneri.
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  • 66
    ISSN: 1432-0878
    Keywords: Uterine epithelium ; Uterine proteins ; β-Glycoprotein ; Immunohistochemistry ; Rabbit
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    Notes: Summary Two antigens of the β-glycoprotein fraction from rabbit uterine secretion of the seventh day post coitum were purified firstly by gel filtration on Sephadex G 150, then either by ion exchange chromatography on DEAE Sephacel or chromatofocusing on PBE 94. By the use of a specific antiserum, raised in female sheep, two antigens with α 2- and β 2-mobility in agar gel electrophoresis could be demonstrated. Immunohistochemical staining of the uterine epithelium at the seventh and eighth day post coitum showed the antigens to be localized in a ciliated cell type of conspicuous shape, which is supposed to be the site of synthesis. Stain accumulated mainly in the apical part of the cell, but there were also small deposits around the nucleus.
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  • 67
    ISSN: 1432-0878
    Keywords: Pancreatic islets ; Adrenergic innervation ; Insulin secretion ; Chemical sympathectomy ; Adrenalectomy ; Fluorescence histochemistry ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Morphological changes in the adrenergic innervation of pancreatic islets after chemical sympathectomy by use of 6-hydroxydopamine and the influence of the sympatho-adrenal system on insulin secretion were investigated in the mouse and rat. Fluorescence histochemistry revealed a clear-cut reduction in the number of adrenergic nerve fibers in the pancreatic islets 2 days after administration of 6-hydroxydopamine; the reduction was more pronounced in the rat than in the mouse. In the rat, a partial regeneration was seen after 6 weeks. In the pancreas of the mouse, after administration of 6-hydroxydopamine, a severe damage of unmyelinated nerve fibers was revealed electron microscopically. However, no ultrastructural or immunohistochemical alterations could be demonstrated in the endocrine cells of the islets. 6-Hydroxydopamine induced a depression of basal plasma insulin concentrations in mice and an elevation in rats. Adrenalectomy depressed basal plasma insulin levels in mice. The α-adrenoceptor antagonist phentolamine enhanced insulin secretion in normal mice. The secretory response of insulin to phentolamine was diminished by chemical sympathectomy and almost abolished by adrenalectomy or the combination of chemical sympathectomy and adrenalectomy. Thus, the effect of phentolamine is probably mediated by liberated catecholamines. It is concluded that basal insulin secretion is partially regulated by the sympatho-adrenal system and that species differences exist in this respect. In addition, the results suggest that endogenous catecholamines have the ability to promote insulin secretion.
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  • 68
    ISSN: 1432-0878
    Keywords: Anterior pituitary ; Immunohistochemistry ; Thyrotrophs ; Postnatal development ; Classification of basophils
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The postnatal development of rat pituitary thyrotrophs was investigated immunohistochemically on days 1, 3, 5, 10, 15 and 25. Fetal thyrotrophs are strongly immunoreactive. In the postnatal period, however, weakly immunoreactive thyrotrophs increase in number to constitute clusters on days 3–5. The numbers and dimensions of the clusters reach a maximum on day 10. Thereafter the clusters break down to give rise to single, scattered neogenic thyrotrophs. Thyrotrophs in clusters on day 10 were investigated by electron microscopy in adjacent sections. They can be characterized as an immature type of basophil, according to the classification of Yoshimura et al. (1977): 1) Type I basophils, which are irregularly shaped with elongate processes, and characterized by rows of secretory granules about 100 nm in diameter. 2) Type I/II basophils, i.e., forms intermediate between Types I and II, containing less numerous secretory granules about 100–150 nm in diameter. Type II basophils which correspond to the classical thyrotrophs are not fully developed on day 10. Thus, most thyrotrophs develop from the clusters in the neonatal period. Such neogenic thyrotrophs retain the immature characteristics of Type I and I/II cells and may develop into Type II cells during subsequent maturation.
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  • 69
    ISSN: 1432-0878
    Keywords: Immunohistochemistry ; Human tonsil ; T-lymphocytes ; B-lymphocytes ; Quantitative morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary T-lymphocytes and B-lymphocytes are identified in tissue sections of human tonsils by applying the unlabelled antibody enzyme method. The epithelium of the tonsils contains a majority of immunoglobulin-positive cells and fewer T-lymphocytes. In the subepithelial zones, areas composed of B-cells predominate, however, regions containing T-lymphocytes are also present. The latter are mainly arranged in the lamina propria around high-endothelial venules and often include plasma cells containing immunoglobulin. Follicles containing germinal centres display a complex structure which changes during development. The lymphocytic cap consists of densely packed lymphocytes, labelled heavily by anti-IgM and anti-IGD, and of individual T-lymphocytes. Germinal centres show a framework of immunoglobulin-positive dendritic reticular cells; they contain some heavily labelled lymphoid cells and several cells weakly labelled by anti-IgM and anti-IgA, as well as a small number of T-lymphocytes. Furthermore, the total areas of T- and B-lymphocytes measured by planimetry may differ considerably between different tonsils. Especially total areas of germinal centres vary to a great extent. The quantitative data on amounts of T- and B-cells achieved by planimetry are comparable to those reported in cellular suspensions of tonsils.
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    Cell & tissue research 211 (1980), S. 241-250 
    ISSN: 1432-0878
    Keywords: Substance P-related peptides ; Immunohistochemistry ; Hypothalamus ; Amphibia (Triturus cristatus, Xenopus laevis, Rana esculenta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The occurrence of Substance P-(SP)-related peptides in the hypothalamus of three species of Amphibia (newt, clawed, toad, frog) was studied immunohistochemically employing the indirect immunofluorescence method or a double-step technique (indirect immunofluorescence followed by the peroxidase-antiperoxidase complex method). SP-like immunopositive fibers are seen throughout the hypothalamus. They are especially abundant in the preoptic area and in the outer zone of the median eminence, suggesting a role of SP-related peptides in the hypothalamo-hypophysial regulation in these animals. Some SP-like neurons are seen in the posterior hypothalamus and in the preoptic area. In the newt, such SP-like immunopositive neurons occur frequently in the preoptic periventricular grey.
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  • 71
    ISSN: 1432-0878
    Keywords: Neocortex ; Evolution ; Development ; Plasticity ; Visual system
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    Notes: Summary Recently discovered neocortical equivalents in anamniotes and certain patterns of interspecific variability in brain organization provide new insights into evolutionary and ontogenetic mechanisms of development. The new data suggest that nervous systems become more complex, not by one system invading another, but by a process of parcellation that involves the selective loss of connections of the newly formed daughter aggregates and subsystems. The parcellation process is reflected in the normal ontogenetic development of the CNS in a given species and can be manipulated, to a certain extent, by deprivation or surgically induced sprouting. The parcellation theory allows certain predictions about the range of variation of a given system at all levels of analysis including the cellular and aggregate levels. For example, the interspecific variability in organization of cortical columns, thalamic nuclei, cortical areas and tectal layers can be explained. The findings, summarized here, suggest that diffuse, undifferentiated systems existed in the beginning of vertebrate evolution and that during the evolution of complex behaviors, and analytical capacities related to these behaviors, a range of patterns of neural systems evolved that relate to these functions. One principle underlying the growth, differentiation and multiplication of neural systems appears to be the process of parcellation as defined by the theory.
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  • 72
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    Keywords: Heart, atrium ; Myoendocrine cells ; Cardiodilatin ; Peptide hormone ; Immunohistochemistry ; Pig
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    Topics: Biology , Medicine
    Notes: Summary A peptide hormone was extracted from the porcine right atrium following a bioassay for differential vaso-relaxant effects on smooth muscle strips from aorta and renal and inferior mesenteric arteries. The isolation procedure included several steps of gel-permeation and ion-exchange chromatography, and high performance liquid chromatography. During the isolation procedure, other peptides of smaller molecular weight were also found, which, in relation to cardiodilatin-126 (CDD-126), are shorter at their N-terminal. Among these, CDD-88 has also been isolated and characterizied, and has been established as a prominent member of the cardiac hormone family. The N-terminal and C-terminal segments of the 126 amino acid-containing molecule were synthesized and used to raise region-specific antibodies. The natural peptide was then localized within myoendocrine cells of the right atrium where specific atrial granules are located. Renal effects of cardiodilation were studied in conscious dogs and showed strong diuretic and natriuretic activities. According to our functional studies, cardiodilatin-126 and cardiodilatin-88 possess qualities of a significant hormone family regarding the regulation of extracellular fluid volume and blood pressure.
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    Cell & tissue research 209 (1980), S. 161-166 
    ISSN: 1432-0878
    Keywords: 1,25 (OH)2 vitamin D3 ; Thyrotropes ; Autoradiography ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the anterior pituitary of the rat, target cells of 1,25 (OH)2 vitamin D3 are identified as those that secrete thyroid stimulating hormone by means of a combined technique of thaw-mount autoradiography and immunohistochemistry. The results for the first time provide evidence that suggests a central effect of 1,25 (OH)2 vitamin D3 on the modulation of thyrotropin secretion in a manner similar to that of other steroid hormones at the level of the pituitary.
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  • 74
    ISSN: 1432-0878
    Keywords: Pituitary basophils ; Gonadotrophs ; LH Cells ; Immunohistochemistry ; Pars anterior ; Cell identification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Pituitaries from normal, young and adult male rats were fixed either in sublimate-formalin or in glutaraldehyde-osmium. In adjacent Paraplast sections, almost all the gonadotrophs were immunostained with both LH and FSH antisera. The rat LHβ and FSH antisera used were shown to be highly specific by the absorption test and by double antibody radioimmunoassay. Thin and thick adjacent Epon sections were prepared for EM and immunohistochemical examination. Cells stained with the rat LHβ antiserum were identified by LM, and then observed in detail by EM. On the basis of these observations we suggest that the LH cells are arranged in a sequence of basophils, i.e., Types II/III, III, III/IV and IV: Type II/III basophils are elongate with a cytoplasmic process and less vesiculated. They have morphological features of Type II (classical thyrotrophs) and also of Type III basophils. Type III basophils are oval in shape and moderately vesiculated. Both Types II/III and III basophils can be divided into two classes of cell characterized mainly by the existence of only small secretory granules (150–220 nm in diameter) (Type A) or by the coexistence of small and large (350–500 nm) (Type B). Type III/IV basophils are cells intermediate between types III and IV basophils, and moderately vesiculated with an abundance of secretory granules (150–300 nm in diameter). Type IV basophils are large, spherical or oval cells whose RER cisternae are conspicuously dilated; they contain less numerous secretory granules (150–300 nm in diameter). It is concluded that LH cells are not a single cell type, but include a wide range of subtypes.
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  • 75
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    Keywords: Melatonin ; Pineal gland ; Retina ; Harderian gland ; Immunohistochemistry
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    Topics: Biology , Medicine
    Notes: Summary The presence of melatonin is demonstrated in the pineal gland, the retina and the Harderian gland in some mammalian and non-mammalian vertebrates, using a specific fluorescence labelled antibody technique. Four different potent antibodies against melatonin have been used and compared. In the pineal gland of hamsters, mice, rats and snakes, specific fluorescence, mostly restricted to the cytoplasm of the cells, is detected in pinealocytes. Fluorescence is also detected in the pineal organ of fishes, tortoises and lizards, but it has not been possible, from cryostat sections of fresh tissue, to assert which kind of cell is reacting (photoreceptor cells or interstitial ependymal cells). In the retina, fluorescence is almost exclusively restricted to the outer nuclear layer. In the Harderian gland of mammals and reptiles, fluorescence is localized in the secretory cells of the alveoli and mostly restricted to the cytoplasm surrounding the nucleus. These results are discussed in relation to the concept of melatonin synthesis at extrapineal sites independent of pineal production.
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    Plant systematics and evolution 141 (1982), S. 143-152 
    ISSN: 1615-6110
    Keywords: Bacillariophyta ; Bacillariaceae ; Nitzschia ; Raphe Structure ; Systematics ; Evolution
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    Topics: Biology
    Notes: Abstract The use of the central raphe endings as a key character in the classification ofNitzschia is argued to be of doubtful validity. Some aspects of the evolution of the raphe are discussed in relation to variation in raphe structure within fibulate genera.
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    Plant systematics and evolution 144 (1984), S. 209-220 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Poaceae ; Triticum ; Elytrigia ; wheat ; Evolution ; genome ; karyotype
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    Topics: Biology
    Notes: Abstract The lengths of the A, B, and D genomes of common wheat,Triticum aestivum, were measured from the karyotype. Relative to the B genome, standardized as length 1.000, the lengths of the A and D genomes were 0.835 and 0.722, respectively. The lengths of the chromosome arms in the A and D genomes were then multiplied by the appropriate constants so that the total lengths of each genome also equalled 1.000. These calculations revealed that homoeologous chromosomes in wheat, with a few exceptions, have similar sizes and arm ratios. The arm lengths of the three homoeologues in each homoeologous group were then averaged. These average chromosomes turned out to be remarkably similar, in size and arm ratio, to their homoeologues in the E genome ofElytrigia elongata. This evidence and data on cross-compatibility and morphological characteristics suggested that the genusTriticum is a result of adaptive radiation from the perennial genusElytrigia, specifically from the complex of species possessing the E genome or one closely related to it.
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    Plant systematics and evolution 145 (1984), S. 203-222 
    ISSN: 1615-6110
    Keywords: Fabaceae ; Leguminosae ; Medicago ciliaris ; Medicago intertexta ; Medicago muricoleptis ; Medicago granadensis ; Evolution ; chromosomes ; Pleistocene glaciations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Karyotype and external morphological analyses were conducted onMedicago ciliaris, M. intertexta, M. muricoleptis andM. granadensis which comprise theIntertextae section of the genusMedicago. All species were found to have 2n = 16 chromosomes (= 2 ×), including one pair of satellite chromosomes in each respective complement. Karyotypic evolution in theIntertextae involves changes in absolute chromosome size and in centromeric and relative size symmetry. Numerical taxonomic analyses were conducted independently on 17 karyotypic features and on 16 features of external morphology. The results of the two sets of analyses proved comparable, withM. ciliaris andM. intertexta forming a fairly close pair, and the remaining two species appearing to have more distant relationships to each other and to the first pair. These observations are consistent with the infertility relationships and chorologies of the species. It is suggested thatM. muricoleptis andM. granadensis are derived from theM. ciliaris/intertexta species complex withM. granadensis arising fromM. muricoleptis, or these two species independently evolving from a common species complex. Chromosomal and numerical analyses suggest thatM. ciliaris is the most primitive andM. granadensis the most derived species of theIntertextae.
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    Protoplasma 112 (1982), S. 26-36 
    ISSN: 1615-6102
    Keywords: Aneilema ; Commelina ; Cytochemistry ; Evolution ; Papillae ; Pollination ; Secretion ; Stigmas ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The stigmas of species inAneilema andCommelina are trifid and comprise elongate papillae. Progressive degeneration of papular cells is observed in stigmas from open flowers and at anthesis papillae may be moribund and collapsed. Fluid emanating from the hollow style flows onto the surface through ruptures in the cuticle at the interpapillar junctions into the interstices at maturity. This secretion stains positively for protein. Stigmas are of the “wet” type. The cuticle overlying the papillar cells is ridged and at the final stages prior to flowering this cuticle becomes detached from the underlying cellulosic wall. The sub-cuticular space so formed is filled with secretion. InAneilema species detachment of cuticle is at the papillar tip and along the lateral walls. InCommelina species the anticlinal walls of adjacent papillae are strongly attached for much of their length and thus detachment of cuticle is restricted to the papillar tip. The cell wall at the tip in both genera may proliferate forming a rudimentary transfer-cell type wall. The secretion is considered to be produced by the papillar cells. It is PAS positive but fails to stain for protein and in both the light and electron microscopes appears heterogenous. Pollen attachment, hydration, germination and early tube growth are very rapid following self-pollination, the pollen tubes entering the neck of the style within ten minutes of attachment. A unique character combination involving pollen and stigmas in these genera indicates a monophyletic origin.
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    Plant systematics and evolution 138 (1981), S. 9-22 
    ISSN: 1615-6110
    Keywords: Boraginaceae ; Echium ; Evolution ; anatomy ; paedomorphosis ; pachycauls ; tracheary elements ; wood rays ; stem anatomy ; Macaronesian flora
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The endemic Macaronesian members of the genusEchium (Boraginaceae) were examined anatomically to elucidate their relationships. Vessel length to breadth ratio was used as the initial guide to the relative primitive or derived nature of each taxon. Together with other features (e.g. trichome structure) it was possible to establish the phylogenetic pathways within this recently evolved relict group (Fig. 1).
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    Environmental biology of fishes 6 (1981), S. 201-202 
    ISSN: 1573-5133
    Keywords: Mouth brooding ; Breeding behaviour ; Pelagic lifestyle ; Courtship ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Haplochromis chrysonotus, a semipelagic shoaling cichlid from Lake Malawi, has been observed spawning in open water up to ten metres above the substratum. It is suggested that open water spawning without the establishment of a substratum-based territory eliminates competition with other species for breeding space and that it may be a stage in the evolution of a totally pelagic mode of life.
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    Environmental biology of fishes 6 (1981), S. 357-360 
    ISSN: 1573-5133
    Keywords: Behaviour ; Esterase ; Evolution ; Genetics ; Isozymes ; Stock structure ; Schools ; Starch gel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Heterogeneous gene frequencies of Est-1 across groups ofNotropis cornutus provide evidence of behaviourally imposed restrictions on stock structuring. Positive fixation indices (F1S = 0.056 and F1T = 0.085) were reflected by a deficiency of heterozygotes for pooled groups. The degree of subdivision ofN. cornutus stocks cannot be evaluated with the present evidence. but it is likely that their schooling behaviour is associated with significant genotypic structuring of the species.
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    Environmental biology of fishes 9 (1983), S. 87-101 
    ISSN: 1573-5133
    Keywords: Feeding habits ; Lepidophagy ; Evolution ; Behavior ; Predation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Scale-eating is known for several unrelated fish groups, but few data are available on the habits of most species. General habits and feeding behavior of some lepidophagous characoids are presented and compared to other scale-eating species. The diversity of morphology, habits, and behavior of scale-eating fishes is great, and few patterns are shared by the specialized scale-eaters. Except for modified teeth, no morphological characteristic permits identifying a fish as a specialized lepidophage. Hunting tactics consist mainly of ambush, stalking, or disguise (aggressive mimicry). Scale-removal may be accomplished by a jarring strike with the snout, generally directed at the prey's flank, or by biting or rasping. The mode of scale-removal seems to reflect primarily the disposition of the jaws and the teeth. Scales are swallowed directly if taken in the mouth; if not, they are gathered as they sink, or picked up from the bottom. Scale-eating is probably a size-limited habit. Specialized scale-eaters rarely exceed 200 mm, most ranging near 120 mm. Some species eat scales only when young; most take other food items in addition to scales. Scale-eating habits probably arose from trophic or social behaviors. These are not mutually exclusive and, indeed, may have acted together during the evolution of lepidophagy. Suggested trophic origins include scraping epilithic algae, modified piscivory, and necrophagy. Social origins include intra- and interspecific aggressive behavior during feeding.
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    Environmental biology of fishes 9 (1983), S. 277-287 
    ISSN: 1573-5133
    Keywords: Freshwater adaptation ; Heavy metals ; Heterochrony ; Landlocked ; Larval period ; Migration ; Ontogeny ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Growth parameters for anadromous alewives,Alosa pseudoharengus (Clupeidae) from two Gulf of Maine watersheds are described. Fish from Damariscotta Lake are typical of other coastal anadromous stocks whereas fish from Walker Pond are dwarfs. The dwarf stock has a life history pattern intermediate between that of fully landlocked and typical anadromous stocks. The dwarfs are anadromous but their young remain in freshwater approximately 16 months, compared to the 2 to 4 months typical of anadromous stocks. This prolonged period of freshwater residence includes a greatly extended larval period and a reduced growth rate. The data suggest that the principal adaptive interval in alewife life history occurs during early ontogeny and that variations in larval development may be the basis for the evolution of fully landlocked stocks from anadromous ancestors.
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    Plant and soil 82 (1984), S. 337-357 
    ISSN: 1573-5036
    Keywords: Evolution ; Grain legumes ; Induced mutations ; Mutation breeding ; Symbiotic nitrogen fixation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Grain legumes are an important group of crop plants. They provide an essential source of protein food for many developing countries, but their production has gone down in favour of more profitable crops like cereals. Therefore, genetic improvement of grain legumes is urgently needed. The primary aim of grain legume breeding must be the increase of production through adaptation to more advanced cropping schemes and reduction of crop losses. Symbiotic nitrogen fixation as developed by natural evolution does not always seem to be compatible with the needed substantial increase in yield: It is not supplying sufficient nitrogen and supplementation by fertilizer is rather uneconomic. By genetic manipulation of the plant's regulatory system nitrogen fixation may become more effective and tolerant to high soil nitrogen levels. Through a number of mutation breeding projects in different countries involving all important grain legume species it has been proven that mutation induction is a good tool for supplementing the genetic variation available from natural evolution and from selection by man. High-yielding cultivars have been developed from induced mutants, which eventually also possess a more efficient nitrogen fixation capacity.
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    Environmental biology of fishes 10 (1984), S. 3-14 
    ISSN: 1573-5133
    Keywords: Mormyriforms ; Gymnotiforms ; Communication ; Spawning cues ; Circannual cycles ; Evolution
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    Environmental biology of fishes 10 (1984), S. 111-116 
    ISSN: 1573-5133
    Keywords: Branchial canopy ; Evolution ; Interbranchial septum ; Isurus oxyrinchus ; Passive gill ventilation ; Prionace glauca ; Ram gill ventilation ; Secondary lamellae ; Sphyrna zygaena
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Gill filaments of one highly active and two less active shark species exhibit a conservative morphological scheme including such features as branchial canopies, marginal lamellar projections, and enlarged, discrete outer marginal lamellar channels and lateral lamellar sinuses. The specific spatial orientation of the secondary lamellae respective to one another, the gill filaments, and the interbranchial septa create what appears as one-way interfilament water channels, suggesting the presence of an efficient branchial countercurrent system. It is proposed that the fortified structure of shark gills allows many shark species to ventilate passively without having evolved gill filament modifications as apparently did some highly active teleosts. This in turn may have expedited the evolution of lamnid shark species through pre-adaptation to a swift oceanic lifestyle.
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  • 88
    ISSN: 1573-5133
    Keywords: Cichlid ; Ecology ; Behavior ; Evolution ; Tropics ; Polymorphism ; Central America ; Lake Malawi ; Africa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Cichlasoma citrinellum is a polymorphic species whose individual coloration varies from the dark grey markings typical of the species to yellow, orange, and red. In Lake Jiloá, Nicaragua the depth distribution of these latter, nongrey, golden morphs shows dramatic seasonal variation. In the height of the dry season in February over 50% of the gold morphs occur above 9 m, but as the breeding season approaches they migrate deeper such that less than 7% of the gold population occurs above 9 m at the onset of the breeding season. During the rainy season when breeding occurs most of the gold morphs occur below 15 m. It appears that gold morphs ‘voluntarily’ move into deeper water to breed rather than being aggressively forced deeper by larger, territorial grey morphs as was implied in an earlier paper (McKaye & Barlow 1976). Since the morphs of this species assortatively mate and select different habitats in which to breed, future sympatric splitting of this species is possible. Likely examples of sympatric speciation and of incipient speciation in the family Cichlidae are discussed.
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    Cell & tissue research 228 (1983), S. 297-311 
    ISSN: 1432-0878
    Keywords: Serotonin ; Supraependymal axons ; Circumventricular organs ; Forebrain ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of supraependymal nerve fibers (SEF) containing serotonin (5-HT) was investigated immunohistochemically in the forebrain of the guinea pig. The highest densities of immunoreactive axons were found in the pars centralis and the inferior horn of the lateral ventricle and also in the superior part of the third ventricle. Because of the special development of the choroid plexus in these ventricular regions, it is suggested that 5-HT SEF might be involved in the regulation of the composition of the cerebrospinal fluid. The ependyma lining the circumventricular organs located in the forebrain, was not observed to receive a significant 5-HT-SEF innervation. In the pituitary gland, a loose but constant network of 5-HT axons, resembling those which course in the anterobasal hypothalamus, arcuate nucleus and internal layer of the median eminence, was observed in the neural lobe. In the epiphysis, immunoreactive 5-HT was detected in all pinealocytes (the entire cell was filled with reaction product) and in fibers running between them.
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    Cell & tissue research 229 (1983), S. 411-422 
    ISSN: 1432-0878
    Keywords: Substance P ; Neuropeptides ; Immunohistochemistry ; Vascular smooth muscle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Substance P-immunoreactive nerve fibres were localized by the indirect immunohistochemical method in the adventitia and the adventitial-medial border of large peripheral arteries and veins of the rat. Arteries showed a richer substance P-containing innervation than veins. The superior mesenteric artery was densely innervated, whereas no substance P-containing fibres were found around the carotid artery. Substance P produced a vasoconstriction of the veins, but was basically without effect on arteries, although with the carotid artery a dose-dependent relaxation was observed. The absence of a correlation between the degree of innervation of the blood vessels and their responsiveness to exogenous substance P suggests that these nerves do not subserve a vasomotor function. The depletion of substance P immunoreactivity from nerves in arteries and veins by capsaicin suggests that substance P-containing vascular nerves are primarily sensory in nature.
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  • 91
    ISSN: 1432-0878
    Keywords: CRF ; Oxytocin ; Vasopressin ; Immunohistochemistry ; Median eminence ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Conspicuous differences in the distributional pattern of nerve fibers containing corticotropin-releasing factor (CRF) or posterior lobe hormones, respectively, were shown in the median eminence of the adult male rat by means of immunoperoxidase histochemistry, with the use of anti-CRF, anti-oxytocin, and anti-vasopressin sera. In the rostral and central divisions of the median eminence, a high concentration of CRF-immunoreactive nerve fibers was found in the median portion of the external layer; these fibers terminated on the capillary loops of the hypophysial portal system. In the caudal division of the median eminence, the CRF-immunoreactive nerve fibers were located in the median to paramedian portions of the external layer. Numerous oxytocin- and vasopressin-immunoreactive nerve fibers were observed evenly distributed throughout the internal layer of the median eminence. In the external layer, a small number of the oxytocin- and vasopressin-containing nerve fibers was found around the capillary loops, particularly in the median to paramedian portions. The distributional patterns of the CRF and the posterior lobe hormones in the hypothalamo-hypophysial system and their functional interrelationship are discussed.
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    Cell & tissue research 230 (1983), S. 517-525 
    ISSN: 1432-0878
    Keywords: Substance P ; Olfactory mucosa ; Nerve ; Capsaicin ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Location and distribution of nerve fibers immunoreactive to substance P were studied in the mouse olfactory mucosa. A moderately dense plexus of fibers is present at the interface of the olfactory epithelium and the connective tissue of the lamina propria. In addition, many immunoreactive nerve fibers are noted in close association with Bowman's glands and blood vessels in the lamina propria. However, such fibers were not observed in olfactory epithelium proper nor in the fila olfactoria. Substance-P-immunoreactivity is almost totally abolished by treatment of animals with capsaicin, an agent known to deplete substance P from primary sensory neurons. It is suggested that the substance-P-immunoreactive fibers are of sensory origin, with their perikarya most likely located in the trigeminal ganglia. Functionally, they might influence local blood flow and/or the secretion of Bowman's glands.
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    Cell & tissue research 234 (1983), S. 237-248 
    ISSN: 1432-0878
    Keywords: Serotonin ; Vasopressin ; Immunohistochemistry ; Suprachiasmatic nucleus ; Mammals (rat, hamster, cat, Macaca fuscata)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of serotonin- and vasopressin immunoreactivities in the suprachiasmatic nucleus (SCN) of four mammalian species was studied with the use of the modified peroxidase-antiperoxidase (PAP) method and antisera to serotonin and vasopressin. In the SCN of the rat, hamster and cat, we noted a large number of serotoninimmunoreactive nerve fibers particularly in the ventral area, where these fibers containing small varicosities (less than 1μm in diameter) formed a dense plexus. In the monkey (Macaca fuscata), however, only few serotonin-containing fibers were evident throughout the SCN. Vasopressin-immunoreactive somata and fibers were distributed in large numbers in the SCN of the rat, hamster, cat and monkey, especially in the dorsal nuclear area. Regional and species-related differences of serotonin- and vasopressin distribution in the SCN were elucidated; possible functional differences between the ventral and dorsal areas of the SCN are discussed.
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  • 94
    ISSN: 1432-0878
    Keywords: Serotonin fibers ; Spinal cord ; Immunohistochemistry ; Monkey (Macaca fuscata)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A modified procedure of PAP-immunohistochemistry with the use of a rabbit antiserum against serotonin was applied to investigate the pattern of serotonin-containing nerve fibers in the spinal cord of the monkey, Macaca fuscata. The majority of descending serotonin fibers in the white matter is located immediately below the pia mater in the ventrolateral funiculi. Lamina I and the outer zone of lamina II are supplied with numerous serotonin fibers. In the intermediate gray, two prominent bundles composed of longitudinal fibers, i.e., lateral and medial longitudinal serotonin bundles, were recognized at the lateral column and in the vicinity of the central canal, respectively. The motoneurons of the anterior horn are encompassed by fine networks of serotonin fibers and terminals. The results obtained from studies with the monkey spinal cord closely resemble those characteristic of the dog spinal cord as presented in a previous paper, except for portions of the lumbar level. In segments L3–L4, intercalated cell groups between the medial and lateral motor nuclei receive particularly rich inputs of serotonin fibers in the same manner as the neurons of the nucleus intermediolateralis. This peculiar finding may suggest the presence of a specialized nucleus in the anterior column of the simian and also human spinal cord.
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  • 95
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    Cell & tissue research 229 (1983), S. 155-174 
    ISSN: 1432-0878
    Keywords: Pituitary ; Tammar wallaby ; Marsupialia ; Ultrastructure ; Immunohistochemistry ; Cell types
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An immunohistochemical, light- and electron-microscopial study was made of the pars distalis in adult tammar wallabies (Macropus eugenii). The pars distalis of this marsupial mammal was divided into three regions, based on the distribution of cell types within the gland. Somatotropic, mammotropic, luteotropic, folliculotropic, corticotropic and thyrotropic cells were identified on the basis of their immunohistochemistry, cytology and ultrastructure. Non-granulated (folliculo-stellate) cells, identified in electron micrographs, were found throughout the pars distalis. Somatotropic cells were predominant in the posterior pars distalis in all animals examined. In the single male specimen and in the non-lactating females examined, small numbers of apparently inactive mammotropic cells were scattered throughout the pars distalis; the same cell type was apparently active and present in considerable numbers in lactating females. Only one morphological type of gonadotropic cell was evident; these cells were scattered throughout the pars distalis, but in largest numbers in the median region. Small numbers of thyrotropic cells were found, most commonly in the anterior pars distalis. Corticotrops were also observed in moderate numbers, predominantly in the anterior regions of the pars distalis.
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  • 96
    ISSN: 1432-0878
    Keywords: CRF neurons ; Hypothalamus ; Immunohistochemistry ; PAP ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A specific rabbit anti-CRF serum and the immunoperoxidase technique were used to show that CRF-containing neurons are mainly distributed in the paraventricular and supraoptic nuclei of the rat hypothalamus. In addition, immunoreactive neurons are scattered in other hypothalamic regions. These neurons are 20–30 μm in diameter. From the present and previous investigations it may be concluded that the hypothalamic magnocellular nuclei, i.e., paraventricular and supraoptic, and other hypothalamic accessory nuclei, are the producing sites not only for vasopressin and oxytocin, but also for corticotropin-releasing factor.
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  • 97
    ISSN: 1432-0878
    Keywords: Somatostatin ; Luliberin (LRF) ; Postnatal development (rat) ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary By means of light-microscopic immunohistochemistry the perikarya of the luliberin-(LRF-) and somatostatin systems of neonate rats were found to be in differing stages of development. At a time point when the LRF-producing neurons had obviously attained their final shape and size, the somatostatin-immunoreactive perikarya were still in a postnatal phase of maturation. Whereas the number of the latter perikarya increases with advancing age, the number of LRF-immunoreactive perikarya decreases significantly from postnatal day 7 onward. Both peptide-hormone systems do not project concomitantly and to the same extent to their principal neurohemal regions in the organum vasculosum laminae terminalis (OVLT) and the median eminence (ME). In all presently studied stages of development, despite considerable individual variations in one age group, among the components of the LRFsystem the OVLT displays a more intense immunoreactivity than the ME. The somatostatin system, however, projects to the OVLT with a conspicuous temporal delay compared to the ME, and, furthermore, in the OVLT the pattern of immunoreactivity characteristic of adult rats is not yet attained at postnatal day 21. Evidence for differences in the immunoreactivity between male and female animals was restricted to the LRF-system. Finally, the results obtained on the stria terminalis speak in favour of the fact that the long-range extrahypothalamic projections of the somatostatin system also undergo postnatal maturation. In the stria terminalis, somatostatin-immunoreactive fibers can be demonstrated initially on postnatal day 7. They attain their full immunoreactivity on postnatal day 21. Furthermore, in the bed nucleus of the stria terminalis an intermittent cytoplasmic immunoreactivity is observed, which is limited to the animals of postnatal day 7 and disappears completely during the further course of development.
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  • 98
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    Parasitology research 63 (1980), S. 65-70 
    ISSN: 1432-1955
    Keywords: Chromosome ; Cytology ; Proteocephalid ; Cestode ; Gametogenesis ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The diploid chromosome number of the proteocephalid cestodeAcanthotaenia multitesticulata is reported for the first time to be fourteen from mitotic as well as meiotic stages of gametogenesis. A chiasma frequency of 2.42 was found. Variation in chromosome numbers in cestodes with reference to this parasite is discussed from an evolutionary point of view.
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  • 99
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    Cell & tissue research 205 (1980), S. 187-198 
    ISSN: 1432-0878
    Keywords: Pancreatic polypeptide (PP) ; Glucagon ; Pancreatic islet ; Xiphophorus helleri ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé L'étude immunohistochimique de l'îlot pancréatique du poisson téléostéen Xiphophorus helleri, à l'aide de sérums anti-polypeptide pancréatique (PP) et anti-glucagon a permis de montrer que deux populations cellulaires distinctes sont responsables de la sécrétion de ces hormones. L'observation comparée de coupes sériées, ultrafines et semifines, traitées par la technique immunohistochimique, a démontré que les cellules à PP correspondent aux cellules qui avaient été précédemment définies, dans cette espèce, comme “cellules A2 à grains ronds” et que les cellules sécrétrices de glucagon sont les “cellules A2 à grains cristallins”. L'hypothèse de l'existence de deux catégories de cellules à glucagon chez les téléostéens est abandonnée.
    Notes: Summary Correlative immunohistochemical and electron microscopical studies on the pancreatic islet of the teleost fish Xiphophorus helleri using antibodies to pancreatic polypeptide (PP) and glucagon show that separate cell types are responsible for the production of these peptides. The PP-cells correspond to the previously described “A2-cells with round granules”, while the “A2-cells with crystalline granules” are the true glucagon cells. An earlier suggestion that there are two types of glucagon cells in teleost islets is therefore withdrawn.
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  • 100
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    Cell & tissue research 205 (1980), S. 327-331 
    ISSN: 1432-0878
    Keywords: Somatostatin ; Cortical cells and fibers ; Immunohistochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Using light microscopic immunohistochemistry, somatostatinpositive structures were observed in the cortex of the rat. These structures, including cells and fibers, are widely distributed in all cortical laminae and are also found in the basal ganglia. The positive results were obtained exclusively in two groups of animals sacrificed during two different months of two subsequent years. The reason for this variability in the immunocytochemical stainability of cortical structures remains enigmatic.
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