A Novel Genetic Polymorphism and Its Genetic Effects of Porcine Myogenin Gene in Intron 1 / 中国生物化学与分子生物学报

ABSTRACT

Single-nucleotide polymorphisms of the MyoG gene were tested using PCR-SSCP from 73 Landrace pigs, 68 Large White pigs, 57 Yimeng pigs and 83 Laiwu pigs. The effects of the MyoG gene on the birth weight, the average daily gain, the meat tenderness, and the backfat thickness were also analyzed. On the basis of the DNA sequence (M14331) of the porcine MyoG gene, primers were designed to amplify MyoG gene. One polymorphism was found in the amplified region of intron 1, in which two alleles ( A, and B) and three genotypes (AA, AB, and BB ) were examined. A G→ C transition was detected at 2 943 locus by sequencing the homozygotes. The results show that ( 1 ) The Large White breed differed significantly ( P ＜0.05) in genotype distribution from the Landrace, the Laiwu and the Yimeng breeds;and the Laiwu breed differed significantly( P ＜ 0.05) in genotype distribution from the Landrace and the Yimeng breeds; whereas no significant differences( P ＞ 0.05) were found in genotype distribution between the Landrace and the Yimeng breeds. (2) On the basis of the fixed effect model, significant differences ( P ＜ 0.05) were found in the birth weight and the tenderness among the different MyoG genotypes, whereas no significant differences ( P ＞ 0.05)existed in the average daily gain and the backfat thickness. (3) Using least square analysis, it was seen that significant differences ( P ＜ 0.05) exist in the meat tenderness between the individuals of the BB genotypes and those of the AA genotypes; and significant differences ( P ＜ 0.05 ) were found in the backfat thickness compared the pigs of the AA genotypes with the pigs of the AB, BB genotypes. These results suggest that the MyoG genotype has significant effects on the meat quality, the growth rate, and the backfat thickness,therefore MyoG gene can be used in marker-assisted selection to improve meat quality and growth rate, and to accelerate the breeding progress.