Fig. 4.

Protein and mRNA expression of myostatin, TLL-1 and TLL-2 in cold-trained and exercise-trained house sparrows. Relative mRNA expression from qRT-PCR for Myostatin and its metalloproteinase activators TLL1 and TLL2 in pectoralis for cold- (A) and exercise-trained (B) sparrows relative to control birds. Relative protein levels from western blot for both unprocessed latent and active forms of myostatin (MSTN) for cold- (C) and exercise-trained (D) sparrows relative to control birds. *P<0.05.