Allozyme variation of lactate dehydrogenase (EC1.1.1.27) in vertebrate taxa

An allozyme variation of loci-encoding lactate dehydrogenase was compared i n different vertebrate classes, A lower level of heterozygosity in warm-blo oded as compared to cold-blooded vertebrates was shown, The highest heteroz ygosity was revealed in anurous and caudate amphibians; the lowest, in bird s and mammals, Fishes and reptiles exhibited an intermediate level of heter ozygosity, In higher groups of vertebrates, differences in the electrophore tic 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 substitu tions in homologous proteins is unequal in distant phylogenetic lineages; ( 2) the level of heterozygosity is related to the average amount of electrop horetic allelic differences at the class level; (3) significant differences in variation pattern in the phylogenetic lineage of vertebrates is probabl y associated with the evolutionary features of the genomic organization of groups at different evolutionary levels.