崂山奶山羊DGAT1基因多态性及与泌乳性状的关系

【目的】探讨崂山奶山羊DGAT1基因与泌乳性状的关系。【方法】以175只崂山奶山羊泌乳母羊为试验群体,利用PCR-SSCP方法和候选基因直接测序法检测DGAT1-P1(包含第8外显子)、DGAT1-P2(5’调控区内)、DGAT1-P3和DGAT1-P4位点在该群体中的多态性,并采用最小二乘方法分析DGAT1-P4位点多态性与泌乳性状之间的关联效应。【结果】崂山奶山羊DGAT1-P1和DGAT1-P2位点不存在多态性。对崂山奶山羊高乳脂率和低乳脂率个体的DGAT1-P3位点核苷酸序列比对,发现在序列600bp处即DAGT1-P4位点上存在着A→G的单核苷酸替换,对乳脂率有显著影响(P0.01),其中AA基因型为崂山奶山羊乳脂率性状最有利的基因型,A等位基因对乳脂率性状有正效应。【结论】在崂山奶山羊中发现候选基因DGAT1存在多态性,且对乳脂率性状有显著效应,为开展崂山奶山羊的标记辅助选择提供了依据。

Genetic Polymorphism of DGAT1 Gene Association with Lactation Traits in Laoshan Dairy Goat

【Objective】 The present study was aimed to research the association of DGAT1 candidate gene with milk raits in Laoshan dairy goat. 【Method】 Diacylglycerol acyltransferase 1 (DGAT1) is a microsomal enzyme that catalyzes the final and only committed step in the synthesis of triglycerides. PCR-single strand conformation polymorphism (PCR-SSCP) assay was used to diagnose polymorphisms of DGAT1-P1(including exon 5), DGAT1-P2 (containing 5′ control region) and DGAT1-P4 loci in dairy goat populations (containing 175 individuals). Polymorphism of DGAT1-P3 locus was analyzed by direct sequencing of candidate gene, and least square method was performed to evaluate the association of DGAT1-P4 site with milk traits. 【Result】 No polymorphism was found in DGAT1-P1 and DGAT1-P2 sites. A mutation from A to G at 600 bp of DGAT1-P3 was found by means of comparative between DNAs in high fat rate and low fat rate goats. One A→G single nucleotide polymorphism was identified at DAGT1-P4 site, which had a significant effect on the fat rate (P＜0.01), and the genotype AA was the most favorable one, the alleles A had a positive effect on fat rate. 【Conclusion】 Results from this study show that the candidate gene DGAT1 has a diversity in Laoshan dairy goat and a significant effect on milk fat rate trait, so they could provide valuable genetic markers for marker-assisted selection of Laoshan dairy goat.