Genetic polymorphism of dgat1 gene association with lactation traits in laoshan dairy goat | 崂山奶山羊DGAT1基因多态性及与泌乳性状的关系

Chinese. 【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600 bp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(P＜0.01),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。

English. 【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.