Guangxi Four Local Chicken Breeds And Love Dial Acres (AA) Chicken’s Muscle Fiber Characteristics And Calpain I Gene And Calpastatin Gene Expression Comparative Study

The calpain system is a kind of rate-limiting enzyme, which mainly control muscle fiber degradation and muscle protein degradation, closely related to the myo fibers growth and the change of post-mortem. The calpain system is mainly include calpain and calpastatin. Calpain is a kind of neutral calcium dependency on a cysteine protease, which exist in myofibril Z disk and near the muscle endoplasmic reticulum, calpain playing an important role of both in the muscle protein degradation of living tissues and the change of post-mortem. Calpastatin is a kind of endogenous protease inhibitor. when animal after slaughtered, calpastatin can inhibit the activity and of calpain and depress the hydrolyzation of protein, thus affecting the muscle growth and the change of tenderness.To explore the expression differences of calpain I gene and calpastatin gene between local and external varieties chicken. In this research, Cen xi classical chicken, Liang feng chicken, East Ian black-bone chicken, Ju dong chicken and A A chicken were used as test material. Using slicing technology to observe the difference of the fiber density of each species chicken breast muscle and leg muscle. Besides using semi-quantitative RT-PCR method to detect the expression quantity of CAPNI genes in different varieties of chicken and tissues. The results as followed.(1) the muscle fiber density of AA chicken is minimum than other chickens among five varieties chicken, but muscle fiber diameter is the largest(P<0.05).(2) The muscle fiber diameter of Cen xi classical chicken was lager than the other three local groups,and the muscle fiber density was lower than the other three local groups(P<0.05).Ju dong chicken and Hang feng chicken has no significant differently between muscle fiber diameter and density of muscle fiber(P>0.05). The muscle density of East Lan black-bone chicken was the most largest.and muscle fiber diameter was the lowest.(3) In the cock, The CAPNI expression level in AA chicken was the lowest, There was no significantly difference in Cen xi classical chicken, East Lan black-bone chicken, liang feng chicken and Ju dong chicken (P>0.05),but higher than AA chicken. CAPNI gene expression difference level In breast muscle and leg muscle tissue have the same trend. In contrast, In the hen, The CAPNI expression level in Cen xi classical chicken, East Lan black-bone chicken and Ju dong chicken have no significant difference,both of them were higher than Liang feng chicken and AA chicken (P<0.05), and AA chicken was the lowest(P<0.05). The expression level of CAST gene and CAPNI gene are completely comtrary. the expression level of CAST gene in AA chicken was the highest, and the other four species chicken were no signitificantly different(P<0.05), all of them lower than AA chicken. CAST gene expression difference level In hock breast muscle and leg muscle tissue both have the same trend. The CAST gene expression level in Cen xi classical chicken, East Lan black-bone chicken and Ju dong chicken have no significant difference, both of them were lower than Liang feng chicken and AA chicken(P<0.05),and AA chicken was the highest(P<0.05).(4) The difference between tissues, In liver tissue, The CAPNIgene and CAST gene expression level in AA chicken was the lowest, there was no significantly difference in Cen xi classical chicken, East Lan black-bone chicken, liang feng chicken and Ju dong chicken (P>0.05),but higher than AA chicken(P<0.05). and the muscle tissue has higher expression level than liver Among Liang feng cock, donglan black-bone cock, judong cock and AA cock, CAST gene has higer expression level in the leg muscle than breast muscle. From the result above, conclusion can be achieved:Guangxi local chickens muscle fiber diameter and density significantly different with AA chickens,and the expression level of CAPNI genes and CAST gene in Guangxi local chicken in muscle tissue was significantly difference with AA chickens (P<0.05). Initially speculated that CAPNI gene and CAST gene can be used as the major gene of chicken tenderness.