Genetic Polymorphisms and Genetic Effects of IGF2 Gene in Yak

Single nucleotide polymorphisms of the intron 2,7,8 of the Yak′s IGF2 gene were tested using PCR-SSCP.Genetic effects of the IGF2 gene on weight,stature,heart girth and body slanting length were analyzed.After compared by correlated series homology of bovine,sheep,human and pig used software of BioEdit.On the mainstay of the published DNA sequence(NW-001494548)of the bovine IGF2 gene,three pairs of primers were designed,and two polymorphisms,three genotypes were found in the PCR products amplified with intron7 and intron8 primers.C→T transition at 91 site of intron7,linked transition of G→C at 330 site and A→G at 358 site of intron8 was detected by sequencing the homozygotes.The results showed that:the genotype distribution of intron7 was meet the equilibrium of HardyWeinberg among the breeds of Datong Yak,Qinghai plateau Yak and Xinjiang Bazhou Yak.But it is not meet among Gannan Yak and Tianzhu White Yak.At intron8,it is not meet the equilibrium of Hardy-Weinberg only in Xinjiang Bazhou Yak.Using least square analysis,it was shown that individuals of AA and BB genotypes have significantly higher(P0.01)weight than BB genotype,but have no difference on the other growth traits,it was demonstrated that IGF2 gene have a mechanism of action to add weight without depending on skeletal growth.