[Expression of the paternal genes for lactate dehydrogenase, glutamate dehydrogenase and acetylcholinesterase in the development of hybrid fish between species from the families of Cobitidae and Cyprinidae].

The time of expression of the paternal genes of glutamate dehydrogenase (GDH), lactate dehydrogenase (LDH) and acetylcholine esterase (AChE) was investigated in the development of fish hybrids. The species which differed by the thermostability of homologous enzymes were selected as parental pairs. The appearance of differences in the thermostability of homologous enzymes between the hybrids and the maternal species suggested the beginning of paternal enzyme synthesis in the hybrid embryos. Differences in the AChE thermostability appeared simultaneously with the enzyme activity at the stage of first muscle contractions (35 hrs of development), differences in the mitochondrial GDH thermostability appeared at the stage of hatching (50-60 hrs) and those in the LDH thermostability 12-17 days after hatching. The total activity of AChE and GDH sharply increased during the period of the paternal enzyme appearance whereas the activity of LDH suffered practically no changes. Differences in the AChE thermostability between the hybrids and the maternal species are the same for both the total AChE (in supernatant, 15,000 gX10 min.) and the solubilised AChE (in supernatant, 130,000 gX60 min.). AChE of the parental species and the hybrids have the same electrophoretic mobility. The differences in the thermostability of enzymes are preserved following the electrophoresis in polyacrilamide gel.