The Analysis Of PPARα、 PPARγGene Polymorphisms In Bovine And Their Association With Growth Traits

Intramuscular fat content is one of the important factors affecting the quality of beef, it directly affects the meat tenderness and flavor. Peroxisome proliferator activated receptor PPARa and PPARy gene is related to the regulation of fat deposition in beef muscle. There is a correlation between bovine growth traits and fat deposition. In this study,6bovine populations Jiaxian red cattle, Luxi cattle, Nanyang cattle, Qinchuan cattle, Bohai cattle and Gaoyuan yak in Qinghai province, a total number of514head of cattle were choosed as experiment materials, investigating the genetic polymorphism of PPARa and PPARy gene, which impact on the bovine fat metabolism by PCR-RFLP combined with DNA sequencing method. And association analysis was carried out to evaluate the effects of genotypes of candidate genes on growth traits of Jiaxian cattle, Luxi cattle, Nanyang cattle and Qinchuan cattle, aiming to elucidate the relationship between genetic characterisitics and growth traits of Chinese cattle. The mainly results are showed as follows:1. SNPs detection of the bovine PPARa gene and the correlation analysis between growth traits.Three SNPs of the bovine PPARa gene were detected:the base transversion of A>G within the43334bp for inexon2, the base transversion of G>A within the24bp for inexon3and the base transversion of T>C within the326bp for exon8, respectively. In four cattle populations, Jiaxian red cattle, Nanyang cattle, Luxi cattle and Qinchuan cattle, the43334(A/G) and24(G/A) loci of the bovine PPARa gene were moderate polymorphism, while326(T/C) loci was low polymorphism. The association analysis result showed that43334(A/G) loci was associate with body length(BL), height at hip cross(HHC), abdominal circumference(AC) of Luxi cattle (P＜0.05).24(G/A)loci was associate with HHC, hucklebone width(HW), hip width(HBW) of Jiaxian red cattle, body height(HAW), BL, HHC, heart girth(HG), AC, body weight(BW)and beef performance index(BPI)of Luxi cattle, and HW(6month), BW(24month)and BL(24month)of Henan local cattle(P<0.05).326(T/C)loci was associate with BL(6month)of Henan local cattle(P<0.05). Through linkage disequilibrium analysis, the results showed that43334(A/G) and24(G/A) loci were in strong linkage disequilibrium, while43334(A/G) and326(T/C) loci,24(G/A) and326(T/C) loci were linked weakly or without linkage disequilibrium. In different populations, there are diverse in the haploid type distribution.2. SNPs detection of the bovine PPARy gene and the correlation analysis between growth traits.Three SNPs of the bovine PPARy gene were detected:the base transversion of C＞G within the56bp for inexon2, the base transversion of C>T within the20bp for exon7and the base transversion of T>C within the50bp fragment for exon7, respectively. In four local cattle populations, Jiaxian red cattle, Nanyang cattle, Luxi cattle and Qinchuan cattle, the59(C/G) loci of bovine PPARy gene were moderate polymorphism, while20(C/T) and50(T/C) loci was low polymorphism. The association analysis result showed that59(C/G)loci was associate with BW of Jiaxian red cattle and BL, AC, HBW, HW, HHC of Nanyang cattle(P<0.05).20(C/T) loci was associate with HAW and HHC of Jiaxian red cattle(P<0.05).50(T/C) loci was associate with HBW of Nanyang cattle, and HHC, BPI of Qinchuan cattle(P<0.05). Through linkage disequilibrium analysis, the result showed that it was linked weakly or without linkage disequilibrium between each other of59(C/G),20(C/T) and50(T/C). There are diverse in the haploid type distribution of different populations.