撒坝猪胰岛素样生长因子-Ⅰ基因多态性及其与部分生长性状的关联分析

摘要

The expression products of insulin-like growth factor- Ⅰ (IGF- Ⅰ ) gene play an important role in muscle growth of pigs. In this research, IGF- Ⅰ gene was chosen as candidate genes for growth traits of Saba pigs. The Hha Ⅰ polymorphism of the gene was investigated by using PCR-RFLP technology, and the relationship between the polymorphism and 12 growth traits was analyzed. The results showed that there was a higher degree of polymorphisms on IGF- Ⅰ gene in the population. AA, AB, BB genotypes of IGF- Ⅰ gene were detected in Saba pigs, which frequency were 0. 3473, 0. 5149, 0. 1378, respectively. The frequency of A and B were 0. 6048 and 0. 3952, respectively. The gene loci was in Hardy-Weinberg equilibration. The genetic variation of IGF Ⅰ gene of Saba pigs had significant influence on growth traits (P<0. 05 or P<0. 01). The favorable genotype of the body weight and the daily gains at different growth stages was AB genotype,and the favorable genotype of the body size traits at 6 months was BB genotype except partial traits was AB genotype. Combining with the previous results, it could be primarily deduced that IGF- Ⅰ gene was probably a major gene or a QTL linked gene that associated with growth traits in pigs.%胰岛素样生长因子-Ⅰ(insulin-like growth factor-Ⅰ,IGF-Ⅰ)基因的表达产物对猪肌肉的生长有着重要的调控作用.以IGF-Ⅰ基因作为撒坝猪生长性状的候选基因,运用PCR-RFLP技术对其HhaⅠ位点的多态性进行了检测,并对IGF-Ⅰ基因的多态性与12个阶段体重、日增重和体尺性状的关系进行了分析.结果表明,撒坝猪IGF-Ⅰ基因的多态性较为丰富,产生AA、AB和BB 3种基因型,其基因型频率分别是0.3473、0.5149、0.1378,等位基因A和B的频率分别是0.6048、0.3952,且该基因座位处于Hardy-Weinberg平衡状态,撒坝猪IGF-Ⅰ基因的遗传变异对其生长性状有着显著的影响(P＜0.05或P＜0.01),其中,不同阶段体重和日增重的增效基因型为AB基因型,180日龄体尺性状的增效基因型多为BB基因型(部分性状表现为AB基因型最高).结合前人的研究,初步推断IGF-Ⅰ基因可能是影响猪生长性状的一个主效基因或是一个与影响猪生长性状的数量性状座位(quantiative trait locus,QTL)连锁的基因.