Abstract:

【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.

Key words: Laoshan dairy goat, diacylglycerol acyltransferase 1 gene, milk yield, fat rate, protein rate