莱芜猪和沂蒙黑猪IGF-I基因的多态性及生长性状的关联性分析

Polymorphisms of IGF-I Gene and Its Correlations to Growth Traits in Laiwu and Yimeng Black Pigs

采用PCR-SSCP方法对莱芜猪(127头)和沂蒙黑猪(132头)的胰岛素样生长因子-I(IGF-I)基因exon3和exon4分别进行单核苷酸多态性分析.发现exon3上有多态性,且存在3种基因型(AA、AB、BB).统计结果表明,3种基因型在两品种中的分布不一致,差异极显著(P<0.01).固定效应模型分析结果表明,初生重、断奶重和6月龄重基因型间差异不显著(P>0.05).最小二乘分析结果表明,BB基因型与其它2种基因型比较有较大的初生重,同AA和AB型比较差异极显著(P<0.01),3种基因型在初生重的大小排列顺序为AA<AB<BB.因此,推测IGF-I基因对个体的初生重存在一定的影响,选择带有B等位基因的个体,有望提高个体的初生重.

Single nucleotide polymorphisms of 127 Laiwu pigs and 132 Yimeng black pigs at exon3 and exon4 of IGF-Ⅰ gene are tested by PCR-SSCP. One polymorphism is found at exon3, three genotypes exist （AA,AB,BB）. Results of Х^2 test show that frequencies of genotypes between two breeds differ significantly （P〈0.01）. Based on the fixed effect model, no significant difference exist on birth weight, weaning weight and 6-month body weight; Using least square analysis, individuals of the BB genotype has significantly higher （P〈0.01） birth weight than those of AA and AB genotypes, with the order being AA〈AB 〈BB. These results suggest that IGF-Ⅰ gene has significant effects on individual birth weight, and selection of the B allele is favored in terms of birth weight.