摘要： 采用PCR-SSCP方法检测牦牛胰岛素样生长因子2(Insulin like growth factor2,IGF2)基因内含子2,7,8的多态性,并分析其对体重、体高、胸围和体斜长的遗传效应.用BioEdit软件对牛、羊、人、猪等相关序列同源性比对以后,主要依据牛(NW-00149448)DNA序列设计3对引物.结果在intron7和intron8引物扩增的片段上发现多态性,并对纯合子进行测序,发现intron7引物扩增片段91位存在C→T转换,intron8引物扩增片段存在330位G→C和38位A→G转换,且在该两对引物扩增产物均检测到3种基因型(AA、AB、BB).统计结果表明,intron7的3种基因型在大通牦牛、青海高原牦牛和新疆巴州牦牛群体中的分布处于平衡状态,而在甘南牦牛和天祝白牦牛群体中则处于极端不平衡状态.intron8的3种基因型仅在新疆牦牛群体中处于不平衡状态,最小二乘分析结果表明,AA和AB基因型同BB基因型相比有较大体重(P<0.01),但在体高、体长和胸围性状上AA与BB基因型均不显著,说明IGF2基因有不赖于骨骼增长而增加体重的作用机制.

关键词: IGF2, 内含子, 遗传多样性, 牦牛

Abstract: Single nucleotide polymorphisms of the intron 2,7,8 of the Yak′s IGF2 gene were tested using PCR-SS-CP.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 (NW2001494548)of the bovine IGF2 gene,three pairs of primers were designed,and two poly-morphisms,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 →Gat 358 site of intron8 was detected by sequencing the homozygotes.The results showed that :the genotype distribution of intron7 was meet the equilibriumof Hardy2Weinberg 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 ( P<0.01)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.

Key words: IGF2, Intron, Genetic polymorphisms, Yak

中图分类号: 

• S88.23