IGF-Ⅰ基因第3外显子多态性对山西白猪生长性状的影响

Effect of the Polymorphism at Exon 3 of Insulin-like Growth Factor Ⅰ(IGF-Ⅰ) Gene onthe Growth Traits of Shanxi White Pig

胰岛素样生长因子Ⅰ(IGF-Ⅰ)是动物生长发育和代谢的主要调节因子,是生长激素启动生长活性的主要介导者。采用PCR-SSCP技术检测了山西白猪群体IGF-Ⅰ基因第3外显子的多态性,共检测到3个等位基因A、B、C,形成了AA、AB、AC、BB、BC和CC6种基因型。A等位基因的频率较高,为0.549,等位基因B和C的频率较低,分别为0.173和0.278。就基因型频率的分布来看,纯合子AA型、杂合子AB和AC型频率较高,分别为0.230、0.204和0.434,其他类型频率较低,均低于10%。利用最小二乘法分析了突变位点对山西白猪初生重、断奶重、6月龄体重和体高、体长、胸围、背膘厚等性状的影响。结果表明,该突变位点对6月龄猪的体高有显著影响(P<0.05),BC型个体的6月龄体高显著低于其他类型个体(P<0.05),而对其他性状的影响不显著(P>0.05)。

Insulin-like growth factor I （IGF- I ）is the main regulatory factor for animal growth ,development and metabolism ,and it is the main mediator that the growth hormones activate the growth activity. The polymorphism at the exon 3 of IGF- I gene in Shanxi White Pig population was detected by PCR-SSCP. Three alleles ofA ,B and C were detected and six genotypes ofAA ,AB,A C, BB,BC and CC were found. The frequency of allele A was higher （0.549）than those of alleles of B and C,which were 0.173 and 0.278 respectively. In the case of genotype distribution, the frequencies of homozygote A A, heterozygote A B and A C （0.230,0.204, and 0.434 respectively ） were higher than those of other genotypes （less than ! 0% ）. The effects of mutation site on the birth weight, weaning weight and body weight, body height, body length, chest girth, back-fat thickness at the age of six months of Shanxi White Pig were analyzed by using the least square method. The results showed that the mutation site had significant influences on the body height of six-month pigs （P〈0.05）and the body height of six-month pigs with BC genotype was significant shorter than other genotypes （P〈0.05）. But the mutation site had no significant effect on other traits （P 〉0.05 ）.