The Association Analysis Of SNPs Of The OB Gene And SCD1 Gene On The Muscular Fatty Acid Content In Yak

OB and SCD1 genes are two major genes affected fat metabolism in mammals, and their association analyses with muscle fatty acid in yak have not been reported. In this study, the association analyses between SNPs in the OB and SCD1 genes and the fatty acid content of intramuscular fat in yak were studied using PCR-HRMA technology, and Gannan, Datong and Tianzhu yaks were choosed as experimental materials. The resualts are as follows:(1) In OB gene of Gannan, Datong and Tianzhu yaks, 11 genetical polymorphic sites, which were 12034 T→A, 12038 T→C, 12108 C→T, 12146 A→G, 12168 A→T, 14107 T→C, 14459 C→T, 15720 A→T, 15726-15725 inserting an adenine base, 15729 A→G and 16149 T→C, were found, among these sites, 12034 and 12038 sites were located in intron 1, 12108, 12146 and 12168 sites were located in exon 2, 14107 site was located in exon 3, 14459 C→T, 15720 A→T, 15725-15726 inserting adenine base, 15729 A→G and 16149 T→C sites were located in 3 '-flanking sequence region. After analysis, we found that the allele C in polymorphic site of 12108 C→T could increase the C18 index (+0.025; P <0.008), MUFA content (+1.013%; P <0.08) and C18: 1n- 9 (+1.41%; P <0.07), decrease C18: 0 content (-1.19; P <0.01) and all the short-chain saturated fatty acids content; and this effect was higher than that of the allele C of SCD1 gene. And we also found that the affect of the allele T of the polymorphic site 12168 A→T on C14:1 content (+0.021%; P <0.04) and the C14 index (+0.009; P <0.004) was significant. The corresponding amino acid were changed from serine to cysteine, thus we can speculate that the cysteine corresponding to T allele of the gene can change the enzyme activity of leptin and different leptin subtypes may have different biological activities.(2) In OB genes of Datong yaks, two polymorphic sites were detected, which are 14459 C→T and 16149 T→C located in located in 3 '-flanking sequence region of OB gene.(3) In OB genes of Tianzhu yaks, three polymorphic sites were detected, which were 14459 C→T, 16149 T→C and 16730 T→G located in 3 '-flanking sequence region.(4) In SCD1 genes of Gannan, Datong and Tianzhu yaks, the polymorphic site 10329T→C was detected in each group. And the content of MUFA was higher in the carcass carried C allele than that carried T allele in this polymorphic site.(5) All of the polymorphic sites, 12034 T→A, 14459 C→T and 16149 T→C in Gannan yaks and 14459 C→T and 16149 T→C in Datong and Tianzhu yaks in the OB gene, had an impact on the total fat content. Because the polymorphic site 12034 T→A is located in intron 1, we can speculate that intron 1 of the OB gene may take part in the regulation of it's own transcription. In this study, we obtained thirteen-point DNA markers with the yak traits related to the fatty acid content of intramuscular fat, which may be importantfor yak genetic resources protection, development and utilization, as well as DNA markers in marker-assisted selection and breeding in yak meat quality.