胰岛素样生长因子Ⅰ基因第1内含子微卫星多态性对山西白猪体重和体尺性状的影响

试验检测了山西白猪174个个体胰岛素样生长因子-Ⅰ(insulin-like growth factor Ⅰ,IGF-Ⅰ)基因第1内含子以CA为核心重复序列的微卫星座位的多态性,并利用单变量动物模型分析了多态位点对山西白猪不同阶段体重和体尺性状的影响。结果表明,在该座位上,共检测到6个等位基因,分别为198、202、204、206、208和210 bp,表现出CA重复数较低的等位基因198和202 bp频率较高,分别为0.2759和0.2385;CA重复数较高的等位基因208 bp频率较低,为0.0747;共检测到12种基因型,纯合子频率较高,均大于0.010(208/208 bp类型除外);而杂合子个体频率都较低,为0.017。统计分析结果表明,IGF-Ⅰ基因型对山西白猪群体的初生重、断奶重、6月龄体重和体高、体长、胸围、背膘厚等性状有显著影响(P＜0.05)。204/204 bp基因型个体不同生长阶段体重高于其他类型个体,而6月龄活体背膘厚又显著低于其他类型个体,符合中国当前猪育种方向,在选育中应优先选留。

Association of CA Repeat Polymorphism at Intron 1 of Insulin-like Growth Factor Ⅰ Gene with Body Weight and Body Size in Shanxi White Pig

A total of 174 pigs from Shanxi White pig were used to investigate associations between the polymorphic(CA)n sequence repeat located at the first intron of the insulin-like growth factor(IGF-Ⅰ) gene and the traits of body weights at different growth stages and body sizes at six-month age by unvariate animal model.There were six alleles,which were 198,202,204,206,208 and 210 bp,were detected in Shanxi White population.The frequencies of alleles of 198 and 202 bp,with less CA repeat number,were 0.2759 and 0.2385,respectively,which were greater than those of alleles with more CA repeat number,such as the allele of 208 bp,whose frequency was 0.0747.Twelve genotypes were found in Shanxi White population,the frequencies of homozygotes were greater than 0.010 apart from 208/208 bp,and the frequencies of heterozygotes were 0.017.The associations of IGF-Ⅰ genotype with the traits of birth weight,weaning weight,body weight,body height,body length,chest girth,back fat thickness alive at six-month age were significant(P<0.05).Individuals with genotype of 204/204 bp has greater body weight and thinner back fat thickness than those of others,which was in accordance with the pig breeding direction in China,should be selected as boars or sows in the selection and breeding programme.