A NOVEL POLYMORPHISM WITHIN INTRON B OF GROWTH HORMONE GENE (GH2) OF THE RAINBOW TROUT, ONCORHYNCHUS MYKISS

摘要

Nucleotide composition of both growth hormone variants of rainbow trout {Oncorhynchus mykiss) has been strongly preserved evolutionally what might suggest that any change within these sequences can have an influence on the functioning of the somatotropic axis. A 121 bp fragment that contained nearly the entire B intron was amplified by the polymerase chain reaction. PCR products were bidirectionally sequenced. PCR products were digested by Tail according to manufacturer's instructions and resulting DNA was subjected to electrophoresis. An analysis of the gene fragment for growth hormone 2 showed the presence of SNP, easily identifiable by means of digestion with Tail restriction enzyme. Statistical analysis confirmed that homozygous GH~(BB) fish were the longest (31.77 cm) and the heaviest (404.70 g) and were statistically significantly different (P s 0.05) from heterozygous GH~(AB) fish. Mean length of Gff~(AA) homozygous fish was insignificantly lower (30.06 cm) with mean body weight of 339.12 gthan homozygotes GH~(BB).