Polymorphisms of the Exon 5 in PRKAG3 Gene and Its Association with Meat Quality Traits of Xuanhe Pigs

PurposeThe aim of the present study was to investigate the polymorphisms of the exon 5 in protein kinase adenosine monophosphate gamma 3 subunit (PRKAG3) gene and its association with meat quality traits in Xuanhe pigs.

MethodThe single nucleotide polymorphisms (SNPs) within the exon 5 of PRKAG3 gene were detected by PCR product directed sequencing in 120 Xuanhe pigs, the effects of single- locus and multiple-loci combined genotypes of the identified SNPs on 6 meat quality traits were analyzed by using least square models.

ResultThree SNPs were identified within the exon 5 of PRKAG3 gene, which included 2 synonymous mutations (T579C, T580C) and 1 missense mutation (G595A), which were all in Hardy-Weinberg equilibrium. For the loci T579C, T580C and G595A, the highest frequency was presented for the genotypes TT, TT, GA and the alleles T, T, G, respectively. The genotypes TT and TC of T579C and T580C could significantly increase the marbling score (MS) (P<0.05) and decrease the water loss rate (WLR) (P<0.01), which presented as significant additive and additive-dominance effects (P<0.05 or P<0.01); pigs with genotype AA on locus G595A had the lowest WLR and the highest cooked rate (P<0.05), which presented as significant additive effects (P<0.05); the three-loci combined genotypes TTTTGG, TCTCGG and TTTTAA were the highest on MS and pH₁, and lowest on WLR (P<0.05 or P<0.01), respectively; but the genotype CCCCGG was the lowest on MS and pH₁, and highest on WLR (P<0.05 or P<0.01).

ConclusionThe present results further confirmed the polymorphisms in the exon 5 of PRKAG3 gene were significantly associated with the pork MS, pH and WLR in Xuanhe pigs, which the synergistic effects were presented for the genotype CC of T579C/T580C and the genotype GG of G595A on decreasing the meat quality.