猪IGF2基因内含子3变异的遗传效应分析

采用错配PCR-RFLP技术鉴别了长白猪和大白猪纯种以及长白×大白猪杂交后代去势公猪胰岛素样生长因子2(IGF2)基因内含子3的3072位点变异, 分析了遗传来自父本不同等位基因个体间的相关性状差异及不同等位基因的遗传效应。结果表明: 在后代个体中, 与遗传父本G等位基因的G型个体相比, 遗传父本A等位基因的A型个体胸围和体躯指数分别增加了3.06% (P<0.05)和3.01% (P<0.05)。A型个体臀部膘厚、胸腰部膘厚和6～7肋膘厚比G型个体分别薄15.31% (P<0.01)、23.74% (P<0.01)和20.27% (P<0.05); 但A型个体肩部膘厚比G型个体厚7.97% (P<0.05)。A型个体比G型个体皮薄9.38% (P<0.01), 眼肌面积大22.58% (P<0.01), 活体瘦肉率高2.18% (P<0.01), 嫩度低17.32% (P<0.05)。A型个体的肌纤维横截面积和肌纤维直径比G型个体分别大32.70% (P<0.01)和15.38% (P<0.01), 而A型个体肌纤维密度比G型个体小20.03% (P<0.01)。结果提示, 猪IGF2基因内含子3的3072位点来自父源A等位基因有助于后代猪群的体骼发育粗壮, 并通过增加单个肌纤维面、眼肌面积和减少皮厚、背膘来影响猪整体肌肉含量和脂肪沉积的。

The genetic effects of IGF2 gene intron3 variance in pigs

A mispairing PCR-RFLP technique was applied in this study to determine the Insulin-like Growth Factor 2(IGF2) gene intron3 G3072A mutation in an outbred Landrace and Large White, and the gelded boars from Landrace x Large White cross. The difference of corresponding traits and the genetic effects of the boars inherited from parental A allele and inherited from parental G allele were analyzed. The results indicated that comparing with the boars inherited from parental G allele, the boars inherited from parental A allele increased significantly in the circumference 3.06% (P< 0.05) and index of body 3.01% (P< 0.05), respectively. The boars inherited from parental A allele had a significantly less average buttock fat thickness (15.31%, P< 0.01), thorax-waist fat thickness (23.74%, P< 0.01), skin thickness 9.38% (P< 0.01), fiber density (20.03%, P< 0.01) and had more less 6th-7th rib fat thickness (20.27%, P< 0.05), tendernce (17.32%, P< 0.05), and had more thick shoulder fat thickness (7.97%, P< 0.05), and had bigger the loin eye area (22.58%, P< 0.01) and fiber cross-sectional area (32.70%, P< 0.01) and fiber diameter (15.38%, P< 0.01) and lean meat (2.18%, P< 0.01) than the boars inherited from parental G allele. The results were suggested that the parental A allele has highly significant genetic effects in improving pig body development and carcass lean percent by increasing fiber diameter and the loin eye area, and decreasing the skin thickness and fat percent.