Prolactin and growth hormone gene polymorphisms in chicken lines of Ukrainian selection

Prolactin and growth hormone gene polymorphisms were studied in two Ukrainian meat-egglaying (G-2) and egg-laying (A) chicken lines. Polymorphism was revealed by the presence of an insertion in the prolactin promoter, by single nucleotide polymorphism (SNP, C to T transition at position −2402) of the prolactin gene, and in the first intron of the growth hormone gene. The frequency of alleles I and D in chicken line G-2 was 0.135 and 0.865; in chicken line A, 0.730 and 0.270; that of alleles C and T, 0.155, 0.845 and 0.745, 0.255; that of alleles A, B, and C, 0.435, 0.395, 0.170 and 0.670, 0.160, 0.170, respectively. It is shown that an increased frequency of alleles I, C, and A in line A corresponds to egg-laying hens.