Study On The Growth And Development Of The High Meat Quality Chicken HS1 And The Expression Of The Genes Regulating Skeletal Muscle Fibers Growth

The growth and development of skeletal muscle fiber has definitely pertinence with the meat quality, especially diameter of muscle fiber and density of muscle fiber. The number of fibers has confirmed in chicken embryos and in the growth process of muscle fiber. The family of Pax and MRFs play a critical role in cell proliferation and differentiation.1GF-1 has definitely pertinence with cell hypertrophy. They are considered to be the candidate genes of influencing the muscle characteristics.In this study, histology characteristics of muscle and development pattern of muscle fiber were studied in the random samples from high qualitymeat-type chicken HS1 and arbor acre (AA) broiler and analysis the differences between them. Analysis the expression of MyoD、MyoG、IGF-1、Pax3 and Pax7 genes in chest muscle and leg muscle of HS1 and AA by RQ-PCR and the differences between them. The main results were as follows:1. The results of growth rule of HS1 and AA showed that the live weight, chest and leg muscle weights of HS 1 were significantly lower than AA (P<0.05). Analysis on phenotypic value of characteristics of chest muscle and leg muscle fiber of HS1 and AA showed that, the chest and leg muscle fiber diameter of AA and HS1 increased gradually with the increasing age, which was contrary with the density. The breast and leg muscle fiber diameter in AA was bigger than HS1 on the 49th,70th days (P< 0.05), which was contrary with the density.2. The expression patterns of IGF-1、MyoD、MyoG、Pax3 and Pax7 were not all the same in both the chest and leg muscle of AA and HS1. the expression trend of IGF-1 in both the chest and leg muscle of AA and HS1 was the same, which was increased before the reduction. To MyoD, its expression quantity in chest muscle was increased first, and then decreased, while it was reducing with the increasing age in leg muscle. The variation of MyoG in both chest and leg muscle of AA and HSl chest muscle were the same, which showed an up-down trend. The variation of MyoG in both chest and leg muscle of AA and HSl chest muscle were the same, which showed an up-down trend. The variation of Pax3 expression in breast and leg muscle in AA was the same, which showed a "down-up-down" trend. Pax7 gene expression in AA and HSl were in the same law.They were also showing a "down-up-down " trend.The expression of IGF-1、MyoD、MyoG in AA chest and leg muscle was significantly more than that in HS1 (P<0.05).The expression of most of all gens in both the chest and leg muscle of AA and HS1 was the most on the 7th and 28th day.3. Through the correlation among various genes, body weight, chest muscle weight, leg muscle weight and the muscle fiber diameter, the results showed that the expression quantity of IGF-1 in chest muscle of HS1 was significantly related to body weight, chest muscle weight and muscle fiber diameter (P<0.05). MyoD expression in AA chest, leg muscles and HS1 leg muscles were significantly negatively correlated to body weight, muscle weight, leg muscle weight, muscle fiber diameter (P<0.05), MyoD expression in HS1 chest was significantly negatively correlated to body weight and chest muscle (P< 0.05). MyoD expression in AA chest, leg muscles and HS1 leg muscles were significantly negatively correlated to body weight, chest muscle weight, leg muscle weight, muscle fiber diameter (P<0.05). MyoD expression in HS1 chest was significantly negatively correlated to body weight, chest muscle weight (P<0.05). Pax3 expression in AA chest was significantly negatively correlated to chest muscle weight (P<0.05). Pax3 expression in HS1 chest was significantly negatively correlated to body weight, chest muscle weight, muscle fiber diameter (P<0.05). In the correlation analysis between Pax7 expression in AA chest, leg muscles and HS1 chest, Pax7 expression was significantly negatively correlated to body weight, chest muscle weight, leg muscle weight and muscle fiber diameter (P< 0.05).