Study On The Function Of CAPN1 Gene And CASP9 Gene In Bovine Skeletal Muscle Formation

The quality characteristics of beef is affected by the type and characteristics of muscle fiber diameter,but with the livestock and poultry growing,the increase of diameter of muscle fiber and muscle fiber type transformation has been constantly changing.It is developmentally regulated in skeletal muscle satellite cells.The study found that CAPN1 gene and CASP9 gene are two important genes which are closely associated with skeletal muscle growth and development.It is a new research direction of meat quality to study the candidate genes of skeletal muscle satellite cells in order to improve the meat quality.(1)In this study,we successfully isolated and extracted bovine primary skeletal muscle satellite cells by two step digestion with both of 0.1% collagenase type I and0.25% trypsin.Meanwhile,it have cultured skeletal muscle satellite cells in vitro by drawing cell growth curve showed that the cell growth in good condition and also carried on the purification,cryopreservation and recovery as well as the corresponding differentiation.At last,it turned out that it had high cell purity in the batches to 3-4generation and after subculture,the biological characteristics of cultured cells were stable.(2)In this study,the bovine skeletal muscle satellite cells were successfully identified by immunocytochemistry staining techniques and the surface markers of bovine skeletal muscle satellite cells were positive expression,which was consistent with the expression characteristics of the markers.According to the result of the gel electrophoresis about the brightness,it indicated that after the subculture,bovine skeletal muscle satellite cells can still have amplification characteristics of cultured skeletal muscle satellite cells in vitro through reverse transcription PCR detection technology.(3)The research found that the CAPN1 and CAPN3 members of the calpain system and the CASP3,CASP7 and CASP9 are members of caspase system can be both expressed in bovine skeletal muscle satellite cells.With the proliferation and differentiation of bovine skeletal muscle satellite cells,the expression of them are in change,which indicates that CAPN1 gene and the CASP9 gene play an indispensable role in the process of muscle together.At the same time,we found no correlation between expression of CAPN1 gene and CASP9 gene in the skeletal muscle satellitecells in skeletal muscle tissue and the expression of the situation.Therefore,we think the skeletal muscle satellite cell development process and the process of muscle tissue tenderization after slaughter is not relevant and the changes of expression in these genes can not reflect the changes in muscle tissues.(4)This study was determined by analysis of Luxi cattle tissue sections of different ages of the muscle fiber diameter with tissue slice technique.The results showed that with the age of Luxi cattle increasing,the muscle fiber diameter is also significant growth.Meanwhile,analyze the expression of CAPN1 and CASP9 with using the real-time quantitative PCR of different ages in Luxi cattle longissimus muscle in mRNA as well as the diameter of muscle fiber.The results showed that there was a significant negative correlation between the expression of CAPN1 gene and the diameter of muscle fiber.The expression of CASP9 gene mRNA was positively correlated with the diameter of muscle fiber,but not significant in the expression of mRNA.In this study,we established a method about isolation and purification of bovine skeletal muscle satellite cells and amplification system of bovine skeletal muscle satellite cells in vitro.It obtained the expression of CAPN1 gene and CASP9 gene in the process of growth and development of bovine muscle and the change trend of mRNA gene.At the same time,it also obtained the relationship between the expression of CAPN1 gen,CASP9 gene m RNA and the diameter of muscle fiber.In conclusion,those can provide important data support for elucidating the molecular mechanism of the growth,development of bovine skeletal muscle and the regulatory mechanism of the candidate genes in theory.