[Allozyme variation of lactate dehydrogenase (EC1.1.1.27) in a series of vertebrate animals].

An allozyme variation of loci-encoding lactate dehydrogenase was compared in different vertebrate classes. A lower level of heterozygosity in warm-blooded as compared to cold-blooded vertebrates was shown. The highest heterozygosity was revealed in anurous and caudate amphibians; the lowest, in birds and mammals. Fishes and reptiles exhibited an intermediate level of heterozygosity. In higher groups of vertebrates, differences in the electrophoretic mobilities between alleles decreased. A key aspect of this is a hiatus of these differences in fishes and mammals. On the basis of this analysis, the following conclusions may be drawn: (1) the rate of amino-acid substitutions in homologous proteins is unequal in distant phylogenetic lineages; (2) the level of heterozygosity is related to the average amount of electrophoretic allelic differences at the class level; (3) significant differences in variation pattern in the phylogenetic lineage of vertebrates is probably associated with the evolutionary features of the genomic organization of groups at different evolutionary levels.