Genetic Polymorphisms Of Bovine A-FABP Gene And Relationships With Beef Performance Traits In Qinchuan Cattle

As a member of FABPs gene family, A-FABP gene played a critical role in fatty metabolism which can transport fatty acid through cytoplasm, enhancing the content of fatty acid inside cells. Its mutations were associated with fatty deposition and IMF in swine and chicken. In this study, PCR-SSCP and DNA sequencing methods were employed to screen the genetic variation within bovine A-FABP gene in 594 bovine, these species were Qinchuan Cattle, Jiaxian red Cattle, Xia'nan Cattle, Luxi Cattle and Nanyang Cattle. Furthermore , the associations beef performance of Qinchuan Cattle were statisticed.In order to find a probable major QTL that affects marbling and moisture content or tightly links to it and to establish the theory of a candidate molecular marker for the beef cattle breeding.1. A sequence of 1441bp from 5'flanking region of A-FABP gene was sequenced, The sequencing results showed only one SNP, namely -389(T/C), then the genotypes of five native cattle breeds in China were invested by PCR-SSCP. The SNP was detected in each group and devided into three genotypes: AA,AB,BB.χ2 test indicated that this polymorphism site met Hardy-Weinberg equilibrium(P>0.05)in five native cattle breeds. The study of relationships with some beef performance traits in Qinchuan cattle showed slaughter weight, carcass weight, moisture content of genotype AB were significantly lower than that individuals with genotype AA and BB respectively(P>0.05), but no significant differences between AA and BB. The marbling of genotype BB was very significantly better than that individuals with genotype AB(P<0.01)and significantly better than that individuals with genotype AA(P<0.05), but no significant differences between AB and AA.2. the results revealed a mutation: 2989A>G in exon2, the mutation of 2989A>G was proved to be a missense mutation: ATC (Ile) > GTC (Val). The SNP was detected in each group and devided into three genotypes: EE,EF,FF. Moreover, The associations with beef performance traits of 101 Qinchuan Cattle showed: the individuals with genotype EE were very significantly better than individuals with genotype EF and FF on the Dressing percentage and Water holding capacity (P<0.01); and there was a significant effect on the Carcass length, Loin muscle area and Meat tenderness (P<0.05). 3.the results revealed a mutation: 3711G>C in exon3, The SNP was detected in each group and devided into three genotypes: RR,RH,HH. Moreover, The associations with beef performance traits of 101 Qinchuan Cattle showed: At the SNP marker of 3711G>C in exon2 there was a significant effect on the Loin muscle area (P<0.05), there were no significant effect on other traits.4. the results revealed a mutation: 5060C>T in 3'flanking region, The SNP was detected in each group and devided into three genotypes: CC,CD,DD.At the SNP marker of 5060C>T in 3'flanking region there was a significant effect on the Carcass chest depth (P<0.05).