陕北白绒山羊DGAT1基因外显子14多态性及其与部分生长和胴体性状的关系

Analysis on the polymorphisms in the exon 14 of DGAT1 gene and its relationship with some growth and carcass traits in Shaanbei white-cashmere goat

【目的】探讨陕北白绒山羊DGAT1基因的SNPs及其与部分生长、胴体性状的相关性,为陕北白绒山羊分子标记辅助选择提供理论依据。【方法】测定234只陕北白绒山羊的部分生长、胴体指标,利用PCR-SSCP技术分析其DGAT1基因外显子14的多态性及与生长和胴体性状的关系。【结果】该座位存在一个突变位点(G→A),此SNPs导致甘氨酸(G)突变为谷氨酸(E);该群体的该位点有1对等位基因A和B以及3种基因型AA、AB和BB,A基因为优势等位基因,AA型为优势基因型,群体处于Hardy-Weinberg非平衡状态;AA型与BB型之间、AB型与BB型之间均在断奶重、周岁重、胸围和管围4个性状上差异极显著(P<0.01),但AA型与AB型之间在此4个性状上差异不显著(P>0.05);3种基因型间在其他性状上差异均不显著(P>0.05);在初生重、周岁重和胸围上均表现为BB型>AA型>AB型,在断奶重、体高和管围上均表现为BB型>AB型>AA型。【结论】该基因的此突变位点与绒山羊育种指标具有一定的相关性,通过提高BB型的频率可望改善绒山羊的生长发育及胴体性状;DGAT1基因可作为陕北白绒山羊生长及胴体性状的候选基因,也可作为绒山羊肉用性能的分子标记。

[Objective] This research discussed the polymorphism in the exon 14 of DGAT1 gene and its relationship with some growth and carcass traits in Shaanbei White-Cashmere Goat in order to provide a theoretical foundation for their marker-assisted selection. [Method] The indexes of some growth and carcass traits for 234 Shaanbei White-Cashmere Goats were determined. PCR-SSCP technique was used to analyze the polymorphisms at the exonl4 of the DGAT1 gene and its relationship with some growth and carcass traits in Shaanbei White-Cashmere Goat. [Result] There was one mutation（G→A）which caused the glycine（G） into glutamic acid（E）;There were 2 alleles of A and B and 3 genotypes of AA, AB and BB in the locus of the population,and A was superior gene and AA was superior genotype, and the population was not at Hardy-Weinberg equilibration. There were significant differences between the genotype of AA and BB as well as between the genotype of AB and BB for the four traits of weaning weight, yearling weight,heart girth,circumference of cannon（P〈0.01）, but not between the genotypes of AA and AB for them,but no significant differences for other traits;The trend of ＂BB〉AA〉AB＂ was noted for three traits of birth weight,yearling weight, heart girth while the trend of ＂BB〉AB〉AA＂ was observed for three traits of weaning weight,wither height, circumference of cannon. [Conclusion]Some relation existed between the gene＇s mutation site and breeding index in the Shaanbei White-Cashmere Goat. It may improve some growth and carcass traits in the Shaanbei White-Cashmere Goat to raise the frequency of the genotype ＂BB＂. DGAT1 gene may be a candidate gene for growth and carcass traits in the Shaanbei white-cashmere goat and its polymorphism could be used as the molecular marker in cashmere goat breeding for meat traits.