Myostatin mRNA expression and its association with body weight and carcass traits in Yunnan Wuding chicken.

Myostatin (MSTN) is expressed in the myotome and developing skeletal muscles, and acts to regulate the number of muscle fibers. Wuding chicken large body, developed muscle, high disease resistance, and tender, delicious meat, and are not selected for fast growth. Broiler chickens (Avian broiler) are selected for fast growth and have a large body size and high muscle mass. Here, 240 one-day-old chickens (120 Wuding chickens and 120 broilers) were examined. Twenty chickens from each breed were sacrificed at days 1, 30, 60, 90, 120, and 150. Breast and leg muscle samples were collected within 20 min of sacrifice to investigate the effects of MSTN gene expression on growth performance and carcass traits. Body weight, carcass traits, and skeletal muscle mass in Wuding chickens were significantly (P < 0.05) lower than those in broiler chickens at all time points. Breast muscle MSTN mRNA was lower in Wuding chickens than in broilers before day 30 (P < 0.05). After day 30, breast muscle MSTN expression was higher in Wuding chicken than in broilers (P < 0.05). Leg muscle MSTN mRNA expression was higher in Wuding chicken than in broilers at all ages except for day 60 (P < 0.05). Correlation analysis revealed that breast muscle MSTN expression has a greater effect in slow growing Wuding chickens than in the fast growing broilers. In contract, leg muscle MSTN mRNA level has a greater effect in broilers than in Wuding chickens. MSTN regulates growth performance and carcass traits in chickens.

Comparison and analysis of Wuding and avian chicken skeletal muscle satellite cells.

Chicken skeletal muscle satellite cells are located between the basement membrane and the sarcolemma of mature muscle fibers. Avian broilers have been genetically selected based on their high growth velocity and large muscle mass. The Wuding chicken is a famous local chicken in Yunnan Province that undergoes non-selection breeding and is slow growing. In this study, we aimed to explore differences in the proliferation and differentiation properties of satellite cells isolated from the two chicken breeds. Using immunofluorescence, hematoxylin-eosin staining and real-time polymerase chain reaction analysis, we analyzed the in vitro characteristics of proliferating and differentiating satellite cells isolated from the two chicken breeds. The growth curve of satellite cells was S-shaped, and cells from Wuding chickens entered the logarithmic phase and plateau phase 1 day later than those from Avian chicken. The results also showed that the two skeletal muscle satellite cell lines were positive for Pax7, MyoD and IGF-1. The expression of Pax7 followed a downward trend, whereas that of MyoD and IGF-1 first increased and subsequently decreased in cells isolated from the two chickens. These data indicated that the skeletal muscle satellite cells of Avian chicken grow and differentiate faster than did those of Wuding chickens. We suggest that the methods of breeding selection applied to these breeds regulate the characteristics of skeletal muscle satellite cells to influence muscle growth.