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  • 1
    Electronic Resource
    Electronic Resource
    Evolution of isozyme loci and their differential tissue expression (1978)
    Springer
    Journal of molecular evolution 12 (1978), S. 25-55 
    Details
    ISSN: 1432-1432
    Keywords: Isozymes ; Gene evolution ; Gene duplication ; Gene regulation ; Creatine kinase ; Fishes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The phylogeny of the creatine kinase (CK, EC 2.7.3.2) isozyme loci and their differential tissue expressions were determined for representatives of 65 families of vertebrates, with emphasis on the fishes. The transition from the single creatine kinase locus, characteristic of certain echinoderms, to the two creatine kinase loci which are orthologous to those present in all vertebrates, occurred early in the chordate line. The majority of pre-teleostean fishes possesses only these two CK loci (A and C). These loci are relatively generalized in their tissue expressions which are variable among species of primitive fishes. The third and fourth creatine kinase loci (B and D) arose separately in the ancestors of the bony fishes and appear to be the result of regional genome duplications. Concomitant with the increase in the number of isozyme loci has been an increase in the specificity of their tissue expression. In the advanced teleost fishes the four CK loci are differentially expressed in a characteristic manner. The A2 isozyme predominates in skeletal muscle, the B2 isozyme in eye and brain, the C2 isozyme in stomach muscle, and the D2 isozyme is found exclusively in testis. We propose a phylogeny of the creatine kinase genes in the lower chordates based on the time of appearance of new CK loci, the sequence in which the loci achieve a tissue restricted expression, and the immunochemical relatedness of the orthologous and paralogous gene products.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01732544
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  • 2
    Electronic Resource
    Electronic Resource
    Evolution of the differential regulation of duplicate genes after polyploidization (1979)
    Springer
    Journal of molecular evolution 12 (1979), S. 267-317 
    Details
    ISSN: 1432-1432
    Keywords: Isozymes ; Gene duplication and regulation ; Molecular and regulatory evolution ; Polyploidy Fish ; Teleosts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In the 50 million years since the polyploidization event that gave rise to the catostomid family of fishes the duplicate genes encoding isozymes have undergone different fates. Ample opportunity has been available for regulatory evolution of these duplicate genes. Approximately half the duplicate genes have lost their expressions during this time. Of the duplicate genes remaining, the majority have diverged to different extents in their expression within and among adult tissues. The pattern of divergence of duplicate gene expression is consistent with the accumulation of mutations at regulatory genes. The absence of a correlation of extent of divergence of gene expression with the level of genetic variability for isozymes at these loci is consistent with the view that the rates of regulatory gene and structural gene evolution are uncoupled. The magnitude of divergence of duplicate gene expressions varies among tissues, enzymes, and species. Little correlation was found with the extent of divergence of duplicate gene expression within a species and its degree of morphological “conservatism”, although species pairs which are increasingly taxonomically distant are less likely to share specific patterns of differential gene expression. Probable phylogenetic times of origin of several patterns of differential gene expression have been proposed. Some patterns of differential gene expression have evolved in recent evolutionary times and are specific to one or a few species, whereas at least one pattern of differential gene expression is present in nearly all species and probably arose soon after the polyploidization event. Multilocus isozymes, formed by polyploidization, provide a useful model system for studying the forces responsible for the maintenance of duplicate genes and the evolution of these once identical genes to new spatially and temporally specific patterns of regulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01732026
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  • 3
    Electronic Resource
    Electronic Resource
    Low levels of genetic heterozygosity in Hymenoptera (1975)
    [s.l.] : Nature Publishing Group
    Nature 257 (1975), S. 792-794 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Table 1 Allelic frequencies for enzyme loci resolved for seven species of solitary Hymenoptera Enzyme* locus 3 HBDH Stictia Carolina (Fabricius) 0.91 0.06 0.01 0.02 Chalybion californicum (Saussare) 0.28 0.64 0.08 Wasps Sceliphron caementanum (Dury) Scolia dubia dubia (Say) ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/257792a0
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  • 4
    Electronic Resource
    Electronic Resource
    Loss of duplicate gene expression after polyploidisation (1977)
    [s.l.] : Nature Publishing Group
    Nature 265 (1977), S. 258-260 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Theoretically, the most useful group of organisms for the analysis of gene loss after polyploidisation would be one which has undergone polyploidisation relatively recently (before complete diploidisation has taken place), yet not so recently that the enzymes encoded by the duplicate genes are ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/265258a0
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  • 5
    Electronic Resource
    Electronic Resource
    A phylogenetic analysis of the 18S ribosomal RNA sequence of the coelacanth Latimeria chalumnae (1991)
    Springer
    Environmental biology of fishes 32 (1991), S. 99-117 
    Details
    ISSN: 1573-5133
    Keywords: Molecular phylogeny ; Maximum parsimony ; Chondrichthyes ; Dipnoi ; Actinopterygii ; Tetrapoda ; Sarcopterygii
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Approximately 98% of the sequence of the 18S ribosomal RNA (rRNA) of the coelacanth Latimeria chalumnae was determined by a combination of direct RNA sequencing and sequencing of rRNA genes amplified by the polymerase chain reaction. This sequence was compared with 18S rRNA sequences of similar length from seven other vertebrate species, representing the taxa Petromyzontiformes, Holocephali, Elasmobranchii, Actinopterygii, Dipnoi, Amphibia, and Amniota, in order to determine the most likely sister group of the coelacanth. Maximum parsimony analysis of these sequences resulted in a single most parsimonious tree containing a number of anomalous relationships among these groups. A bootstrap analysis showed that none of the relationships in this tree was significantly supported at the 95% level, however. Addition of data from 15 other vertebrates (providing multiple representatives of most of the higher taxa) resulted in similar ambiguous groupings, as did a number of methods of editing the sites compared (designed to eliminate rapidly evolving positions). These results may be due to a relatively rapid radiation of the major lineages of osteichthyans, the resolution of which will require molecular information from a larger portion of the coelacanth genome.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00007447
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  • 6
    Electronic Resource
    Electronic Resource
    Evolution of five multilocus isozyme systems in the chordates (1984)
    Springer
    Genetica 52-53 (1984), S. 73-85 
    Details
    ISSN: 1573-6857
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00121817
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  • 7
    Electronic Resource
    Electronic Resource
    Synchronous allelic expression at the glucosephosphate isomerase A and B loci in interspecific sunfish hybrids (1976)
    Springer
    Biochemical genetics 14 (1976), S. 723-737 
    Details
    ISSN: 1573-4927
    Keywords: synchronous allelic expression ; glucosephosphate isomerase ; sunfish hybrids ; allelic isozymes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Allelic isozymes of glucosephosphate isomerase at the Gpi-A and -B loci were separated by starch gel electrophoresis in the warmouth (Lepomis gulosus) and green sunfish (L. cyanellus). The specific tissue distributions and developmental expressions of the GPI-A2, -AB, and -B2 isozymes were not different between these two species. The synchrony of allelic expression in normal intraspecific sunfish crosses was demonstrated by means of an electrophoretic variant at the Gpi-B locus. In embryos formed from warmouth × green sunfish hybrid crosses, the paternal GPI-A2 isozymes were first expressed at the same time in both reciprocal hybrids, at 21–25 hr after fertilization. The maternal and paternal GPI-B subunits were synchronously expressed in reciprocal hybrids just prior to hatching. The parental allelic isozymes at both loci showed codominant expression in all tissues of the mature F1 hybrids. These results are consistent with the absence of allelic asynchrony and inhibition in interspecific hybrids formed from more evolutionarily related species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00485337
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  • 8
    Electronic Resource
    Electronic Resource
    Duplicate gene expression in diploid and tetraploid loaches (Cypriniformes, Cobitidae) (1977)
    Springer
    Biochemical genetics 15 (1977), S. 1097-1112 
    Details
    ISSN: 1573-4927
    Keywords: duplicate gene expression ; tetraploid loaches ; duplicate loci, fish ; karotypes, fish ; isozymes, fish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Botia macracantha and B. modesta have been demonstrated to be tetraploid species on the basis of their karyotypes and on the basis of the expression of a number of isozymes encoded by duplicate loci. A rather low percentage of duplicate loci was detected by electrophoresis, compared to that for other tetraploid Cypriniformes. Several hypotheses have been advanced to account for the low levels of duplicate gene expression observed. Lastly, many of the duplicate loci have diverged to unique patterns of expressions in different tissues or different levels of activity within a single tissue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00484500
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  • 9
    Electronic Resource
    Electronic Resource
    Biochemical genetics of hybrid sunfish: Differential survival of heterozygotes (1974)
    Springer
    Biochemical genetics 11 (1974), S. 205-219 
    Details
    ISSN: 1573-4927
    Keywords: heterosis ; heterozygosity ; hybrids ; isozymes ; sunfish ; Centrarchidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Allelic segregation in reciprocal backcrosses involving the largemouth bass (Micropterus salmoides) and the F1 hybrid (largemouth bass × smallmouth bass, M. dolomieui) was investigated to determine the extent of euheterosis and luxuriance. The frequencies of allelic isozymes encoded in the lactate dehydrogenase E, malate dehydrogenase B, and isocitrate dehydrogenase loci were determined for reciprocal backcross progeny subjected to different selection pressures. The progeny of the backcross (male F1 × female largemouth bass) underwent a rapid loss of heterozygous individuals in a natural pond environment. When the offspring of this same mating were placed in artificial pools, where cannibalism is the main source of mortality, heterozygosity was advantageous. There was a marked correlation of increased heterozygosity at these enzyme loci with an increased growth rate. None of the above responses to selection was observed when the F1 hybrid served as the maternal parent in the reciprocal backcross. A maternal factor in the egg cytoplasm may influence the expression of heterosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00486056
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  • 10
    Electronic Resource
    Electronic Resource
    Genetic and molecular analysis of nonrandom dimer assembly of the creatine kinase isozymes of fishes (1978)
    Springer
    Biochemical genetics 16 (1978), S. 811-829 
    Details
    ISSN: 1573-4927
    Keywords: isozymes ; creatine kinase ; fishes ; dimer ; restricted assembly
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Species within many families of actinopterygian bony fishes (class Osteichthyes) have a two-banded allelic isozyme phenotype in individuals heterozygous at the creatine kinase A locus. This two-banded pattern is formed by the presence of the two homodimeric isozymes and the absence of the expected heterodimer. Sharks and amphibians have retained the ability to form all three allelic isozymes in individuals which are heterozygous. Reversible denaturation procedures were able to assemble the different allelic CK-A subunits within a species to form CK-A2 heterodimers. Furthermore, heterodimers were formed from different CK-A subunits from highly divergent species after this in vitro molecular hybridization process. It is concluded from these studies that the polypeptidebinding sites of creatine kinase are structurally conservative in most fishes and that the absence of a heterodimer in heterozygous individuals is not due to a structural incompatibility between the different A subunit types or to an instability of the heterodimer during electrophoresis. A temporal and/or spatial isolation of allelic CK-A subunit synthesis and assembly, within differentiated skeletal muscle, appears to have evolved in the actinopterygian bony fishes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00484738
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