Genetic Polymorphism Of CAPN1 Gene And Correlation Analysis With Meat Quality Traits In China Red Steppe Cattle

In this study ,genetic polymorphism of Calpain (ICAPN1)gene's 6 sites in 40 China Red Steppe Cattle and its Crossed Herds(F1) was detected by SSCP ( polymerase chain reaction- Single Strand Conformation Polymorphism).Polymorphism fragments of CAPN1 gene were cloned and sequenced so as to ascertain variant location of mutational sites and base type. The correlativity between these polymorphism sites and cattle's meat quality traits was analysed with records of abatage determination, whose objective is that providing foundation of molecular biology for seed selection and selection about cattle's meat quality traits.The results based on PCR-SSCP revealed that six mutational sites were found in all China Red Steppe Cattle and its Crossed Herds (F1)population.Genetype frequencies of six sites all achieved balanced state of Hardy -Weinberg(P>0.05).The results of cloning and sequencing indicated that P1 sites polymorphism was dued to base mutation of C to G in position 947 (referring to NCBI accession number: AF252504). P2 is C to T in position 4685 (referring to NCBI accession number: AF248054).P3 is C to G in position 5709 (referring to NCBI accession number: AF252504).P4 is A to G in position 4558 (referring to NCBI accession number: AF248054).P5 is C to G in position 1324 (referring to NCBI accession number: AF248054).P6 is A to T in position 1324 (referring to NCBI accession number: AF252504).Correlativity between CAPN1 gene's genetic polymorphism and meat quality traits was analysed with SPSS 12.0 software.The results indicated P1 site had a significant influence on drip loss(P<0.05)。P2 ,P4 and P6 site had a extreme significant influence on shearing force (P<0.01)。P3 site had a significant influence on muscle fiber diameter(P<0.05)。P5 site had a extreme significant influence on marbling (P<0.05).It is important to note that the slaughter traits such as slaughter percentage, carcass weight, lean meat percentage and lean meat weight took on a significant difference statistically, but they were more affected by human factor and could not be taken as the rationale in this study.The length of intestine was measured more accurately and less effected by human, and was related to four sites, among which the individuals of different gene patterns corresponding to three sites were extremely different.CAPN1 was not identified special to the length of intestine, which has not been reported in domestic and abroad; intestine is the main digestion position, and its length is important for the animal growth, so whether CAPN1 effected on intestine is necessary for the future study.Based on this study, we conclud that the genotypic combination"aabbccddeeff"corresponding to the individuals with lower drip loss,minor muscle fiber diameter,better marbling score,less shearing force is the optimize genotypic combination.