Studies On The Genetics Polymorphism Of Myf-5 Gene And L-FABP Gene And The Association With Carcass And Meat Quality Traits In Pigs

The factors of myogenic detemination gene(MyoD) in growth of the skeleton muscleplays an important regulatory role, it can activate the muscle gene transcription andpromote myofibroblast differentiation. The fatty acid-binding proteins(FABPs) familyinvolved in the intracellular uptake of fatty acids, as well as triglyceride and phospholipidtransfer synthesis. This research analyzed the polymorphisms of porcine myogenicdetemination gene 5 (Myf-5) and liver fatty acid-binding protein (L-FABP) in 329individuals by PCR-SSCP method, and explored the genetic effect of Myf-5 and L-FABPto carcass and meat quality traits in different breeds. The breeds including Yanan pig, Dahepig, Dawu pig, Landrace×Yanan (Changya) pig, Duroc×(Landrace×Yorkshire) (DLY)pig,The main results are as follows:The fragments amplified of primer M1 in Myf-5 gene by gene sequencing and Myf-5reference sequence contrasting, detected a total of five point mutations. The 2335th C→A,the 2342th A→G and the 2370th G→A were situated in exon2, the 2395th C→T and the2425th A→G were situated in intron 2. The result analysis found that A allele was absentin Dahe pig; B allele was absent in Yorkshire pig; C allele gene was absent in Dahe pig; Dallele was absent in Yanan pig,Changya pig and DLY pig; the four allele gene existed inZang pig and PIC pig all. From all examination individuals, C allele in the four kinds ofallele had advantage most. Passing the associated analysis discovered the performancehigher lean meat rate, lower marble grade point of individuals with the genotype AB.Individuals with the genotype AC were minimum loin eye area, highest average backfatthickness, in the meantime the pH₂ valueses were lowest.The genotype BB contributed toimproving marble grade point, increasing IMF content.The genotype CC expressed for thevalue of improving the pH₂.The fragments amplified of primer M2 in Myf-5 gene detected a deletion and a pointmutation altogether, namely the 3387th A deletion and the 3502th A→C a mutation bygene sequencing results and Myf-5 reference sequence contrasting, these two sits were at 3exon. The result analysis found that Yorkshire pig only had H allele, rest pigs all examinetwo kinds of G, H allele. In all pigs, the H allele frequency in rest seven pigs was more than G allele frequency out of the Yanan pig, it could see a H allele share absoluteadvantage. By the least square analysis found that the genotype GH improved loin eye area,lowerd average backfat thickness, existed certain degree with lion area just related, withaverage backfat existed certain of negative related. The genotype GG contributed toincreasing IMF content in other meat quality traits.The fragments amplified of primer L2 in L-FABP gene by gene sequencing andL-FABP reference sequence contrasting,detected that the 2128th T→A mutation, the2145th G deletion and the 2158th A→G mutation. This three sites were situated in intron3 of L-FABP gene. The result analysis found that Dahe pig, Zang pig, Yorkshire pig, Dawupig, DLY pig, PIC pig were all detected R and T allele except Yanan pig and Changya pig,T allele which had more advantages than the R allele. By the associated analysis betweenL-FABP primer L2 genotype and the IM content found that the IMF content in the threegenotypes RR, RT, TT was not significant difference between the value of the IMF content.Carcass and meat quality traits with other analysis inferred TT genotype could increaseloin area and the average backfat thickness, and pH₂ larger.