Absolute transcript abundance of genes involved in muscle growth in <i>Pectoralis major</i> muscle of fast- and medium-growing chickens at different ages.

The genes include (a) insulin-like growth factor 1 (IGF1), (b) myogenic differentiation 1 (MYOD1), (c) myogenic factor 5 (MYF5) and (d) myostatin (MSTN). Markers and error bars depict mean value and standard deviation (n = 5). Upper case letters indicate significant differences among medium-growing chickens. Asterisks and sharps indicate significant differences between the two strains at the same age. #p<0.1, *p<0.05, **p<0.01.