DISTRIBUTION OF CLONED PVUII REPEATED DNA -SEQUENCES OF PINK SALMON IN SALMONID GENOMES

After PvuII digestion of pink salmon DNA, fragments of ten different s izes ranging from 370 to 2450 bp were detected. They consisted of mode rate repetitive nucleotide sequences (1.5 kbp-4 x 10(4) copies) and in cluded 0.5-1.5% of genome. 370 bp-fragments of DNA were cloned in vect or M13. Southern blot hybridization of pink salmon DNA with two recomb inant clones indicated, that fragments generated after; PvuII digestio n represent two families of short repeats dispersed over the genome. D ot hybridization of four recombinant clones with total DNA pools from 15 species representing seven salmon and herring genera revealed the e volutionary conservatism of the cloned nucleotide sequences: DNA speci mens of the fish species studied hybridized with PvuII repeats to some extent. DNA hybridization levels from the same species with the four probes differed. Content of sequences homologous to PvuII repeats vari ed between species independently from their systematic position. The a nalysis of dot hybridization of four specimens of chum salmon and two specimens of masu salmon (fish were collected in different Far East po pulations) revealed intraspecies differences in individual genome cont ent of sequences homologous to PvuII repeats in pink salmon. For these two species, latitudinal dependence of the quantity of these sequence s was observed: it increased in fish genomes from south to north.