Polymorphisms Of Some Functional Genes And Their Correlation To Carcass Traits And Meat Quality Performance In SuTai Pigs

Sutai pig is a new breed with high production performance. Eight genes with 15 loci were studied in this paper, using PCR-RFLPs for the purpose of retainment and improvement of production performance. The association between polymorphisms of candidate genes and carcass traits (carcass weight, back fat) and meat quality (marbling score, pH1, intramuscular fat, tenderness, water holding capacity and meat color values such as light, saturation, hue) were also analysed. Results showed as follows:Polymorphisms were found at the loci of candidate gene of IGF2, MC4R and 5′-H-FABP, and the population was Hardy-Weinberg disequilibrium (P<0.05) at these loci.Significant difference of meat quality was found between pigs with IGF1 and IGF2 genotypes. The favor genotype of IGF1 gene was not confirmed yet in this study. There was significant difference of IGF2 gene for the intramuscular value (P=0.040) and for the water holding capacity (P=0.009) between Bb and bb genotypes.There was no difference of each trait at the HSL locus between genotypes. For the MC4R locus, there was significant difference between DD and Dd genotypes for the A (P=0.031) and C value (P=0.028).There were only two genotypes (FF and Ff) on MspI loci in the second intron of MyoG gene and there was significant difference for the marbling score between FF and Ff genotypes (P=0.001). Three genotypes (GG, Gg, gg) of the MspI locus on the 3′-MyoG noncode region were detected in SuTai pigs, and significant difference was found between 3′- MyoG genotypes for marbling score, meat tenderness, A and C values.Polymorphisms were found on both sites of the second intron of H-FABP gene when emplified fragment (a length of 816 bp) was digested with MspI and HaeIII restriction endonucleases. Only one sample was found with HH genotype of the MspI restriction locus, and there was no significant difference between Hh and hh genotypes for each carcass and meat quality trait. Three genotypes of Haelll restriction loci were found (MM, Mm, mm) and there was significant difference (P=0.001) between MM and Mm genotypes for the water holding capacity (1.361 % and 1.049%, respectively). Results also showed that there was significant difference (P=0.021) between MM and mm genotypes for H (hue) values. A 693bp fragment located in the 3′-H-FABP gene was also amplified and digested by Hinfl restriction endonuclease in this paper. Results showed that there were three genotypes of water holding capacity and there was significant difference between NN genotype and Nn/nn genotypes.A 1.6kb fragment located in the sixth intron of CAST gene including MspI, HinfI and RsaI digesting loci was amplified and digested by endonuclease, individually. Results showed that there were polymorphisms for each digested locus. There were polymorphisms on MspI-RFLPs locus and significant difference was found between three genotypes (PP, Pp and pp) for pHI, meat tenderness, water holding capacity, A and C values. Only QQ and Qq genotypes were found on HinfI-RFLP locus and the values of Qq genotype were higher than these of QQ genotype for both carcass weight(P=0.046) and back fat(P=0.008) traits.