Regulation of myostatin expression is associated with growth and muscle development in commercial broiler and DMC muscle

Abstract

Myostatin is a negative regulator of skeletal muscle growth. Muscle tissue is the largest tissue in the body and influences body growth. Commercial Avian broiler chickens are selected for high growth rate and muscularity. Daweishan mini chickens are a slow growing small-sized chicken breed. We investigated the relations between muscle (breast and leg) myostatin mRNA expression and body and muscle growth. Twenty chickens per breed were slaughtered at 0, 30, 60, 90, 120, and 150 days of age. Body and muscle weights were higher at all times in Avian chickens. Breast muscle myostatin expression was higher in Avian chickens than in Daweishan mini chickens at day 30. Myostatin expression peaked at day 60 in Daweishan mini chickens and expression remained higher in breast muscle. Daweishan mini chickens myostatin expression correlated positively with carcass weight, breast and leg muscle weight from day 0 to 60, and correlated negatively with body weight from day 90 to 150, while myostatin expression in Avian chickens was negatively correlated with carcass and muscle weight from day 90 to 150. The results suggest that myostatin expression is related to regulation of body growth and muscle development, with two different regulatory mechanisms that switch between days 30 and 60.

Keywords: Commercial broiler chicken; Daweishan mini chicken; Growth rate; Muscle weight; Myostatin; mRNA expression.

Fig. 1

Daily growth rate (a) and body weight (b) of the ABC and the DMC. Data are in grams

Fig. 2

Developmental changes in commercial AB (ABC) and DMC (DMC) from birth to 150 days of age. a, c, e Measured weights (g) of carcass, breast muscle, and leg muscle, respectively; b, d, f calculated percentages of dressing, breast muscle, and leg muscle, respectively. The dressing percentage was the carcass weight divided by the body weight. The muscle percentages were calculated by dividing muscle weight by carcass weight. All measurements differed between ABC and DMC at all time points except for breast muscle percentage (d) at birth (0 days) and leg muscle percentage at day 0, 30, 60, and 120

Fig. 3

Myostatin expression of the breast muscle of DMC (BM-DMC) and commercial AB (BM-ABC), and the leg muscle of DMC (LM-DMC) and commercial AB (LM-ABC) at 0, 30, 60, 90, 120, and 150 days of age. Data are expressed as the mean ratio ± SE of specific myostatin mRNA:18S rRNA for each time point from the two breeds. Myostatin expression differences (P < 0.05) were evaluated between time points within each breed (lower case letters) and between the two breeds for each time point (*)