MC4R基因主效位点在中外猪种中的遗传多样性及其与生长肥育性状的关联性分析

Polymorphisms of the MC4R Causative Mutation in Chinese and Western Pig Breeds and Its Effects on Growth and Fatness Traits

采用PCR-TaqI-RFLP技术,检测了9个中国地方猪种、3个外来猪种和1个培育猪种的612个个体及白色杜洛克×二花脸资源家系418头F2个体在MC4R基因D298N主效位点的遗传变异,统计分析了MC4R基因型与日增重、腹脂率及肩、胸、腰、臀部膘厚等生长肥育性状的关联性。结果表明:(1)G等位基因在中国地方猪种、长白和杜洛克中呈高频分布,而大白和南昌白猪具有高频率的A等位基因;(2)GG基因型个体的胸、腰、臀部膘厚较AA基因型和AG基因型个体厚,GG基因型个体的240日龄重、至240日龄平均日增重大于AA基因型个体,GG基因型个体的腹脂率高于AA基因型个体,差异显著。试验结果进一步验证了MC4R基因对猪生长肥育性状的影响效应。

Six hundred and twelve individuals from 9 Chinese indigenous pig breeds, 3 Western commercial breeds and 1 cultivated breed and four hundred and eighteen F2 animals from a White Duroc × Erhualian resource population were genotyped at the MC4R Asp298Asn locus using PCR-TaqI-RFLP. Association analysis were performed to evaluate the correlation of the MC4R polymorphisms with several growth and carcass traits including weights at 210 days and 240 days, the average daily gain from birth to 240 days, the backfat thickness at shoulder, the last rib, 6-7^th rib and hip joint, and the percentage of abdominal fat. The results show that （1） the high frequencies of the G allele were observed in the tested Chinese indigenous pig breeds, Landrace and Duroc, while the high frequencies of the A allele were present in Large White and Nanchang White pigs; （2） MC4R Asp298Asn substitution was significantly associated with the growth and carcass traits in the White Duroc × Erhua the GG genotype were fatter and faster-growing anima Our result further convinced that MC4R had significant ian F2 population, and individuals having s compared with AA and AG individuals. effects on the growth and fatness traits in pigs.