Proteomic analysis of ovine muscle hypertrophy1

Abstract

Two-dimensional electrophoresis was used to investigate the effects of a QTL for muscle hypertrophy on sarcoplasmic protein expression in ovine muscles. In the Belgian Texel breed, the QTL for muscle hypertrophy is localized in the myostatin-encoding gene. Based on microsatellite markers flanking the myostatin gene, we compared the hypertrophied genotype with the normal genotype. The average age of the sheep was 3 mo. Among the 4 muscles studied, in the hypertrophied genotype only the vastus medialis was normal, whereas the semimembranosus, tensor fasciae latae, and LM were hypertrophied. In the hypertrophied genotype, these muscles showed upregulation of enzymes involved in glycolytic metabolism together with oxidative metabolism in LM. Certain chaperone proteins, including glutathione S-transferase-Pi, heat shock protein-27, and heat shock cognate-70, were also more highly expressed, probably due to increased use of energetic pathways. Expression of the iron transport protein transferrin was increased. Alpha-1-antitrypsin was the only protein showing a similar pattern of expression (i.e., less expressed) in all 4 muscles of the hypertrophied genotype. It is suggested that transferrin and alpha-1-antitrypsin may interact to reinforce myogenic proliferative signaling.

Proteomic profiling of bovine M. longissimus lumborum from Crossbred Aberdeen Angus and Belgian Blue sired steers varying in genetic merit for carcass weight1

“…Consistent with our results, Hamelin et al (2006) reported that muscle hypertrophy in the ovine is associated with an upregulation of enzymes involved in glycolytic metabolism together with oxidative metabolism in LM. They also showed that protein abundance of PGM1 and PGM2 was increased in rams with muscular hypertrophy compared with conventional genotypes (Hamelin et al, 2006). Muscular hypertrophy, or "double" muscling, occurs because of mutations in the myostatin coding sequence, resulting in the production of a truncated protein (McPherron et al, 1997).…”

“…The activity of PGM can be attributed to that of at least 2 closely related isoforms (PGM1 and PGM2) encoded by different genes (Oh and Hopper, 1990). Consistent with our results, Hamelin et al (2006) reported that muscle hypertrophy in the ovine is associated with an upregulation of enzymes involved in glycolytic metabolism together with oxidative metabolism in LM. They also showed that protein abundance of PGM1 and PGM2 was increased in rams with muscular hypertrophy compared with conventional genotypes (Hamelin et al, 2006).…”

“…Protein expression of skeletal muscle in both sheep (Hamelin et al, 2006) and cattle (Talamo et al, 2003;Bouley et al, 2004Bouley et al, , 2005 has been examined. To the knowledge of the authors, few data exist on the effect of either breed or genetic merit for carcass growth on global protein abundance in bovine muscle.…”

Expression of DNAJA1 in bovine muscles according to developmental age and management factors

“…More abundantly expressed Hsp (e.g. Hsp70 and Hsp27) in oxidative than glycolytic muscles (Locke et al, 1991;Hamelin et al, 2006;O'Neill et al, 2006) would play a crucial role in the protection of tissues against oxidative stress. It is therefore not surprising that the abundance of DNAJA1, a key partner of Hsp70, was higher in these muscles.…”

Application of gene expression studies in livestock production systems: a European perspective

“…In the same study, the proteome profiles demonstrated a shift towards a fast-twitch glycolytic muscle type in animals with a myostatin deletion. Accordingly, Hamelin et al (2006) examined the proteome profiles in four muscles of Texel sheep harbouring a QTL for muscle development and revealed 63 differential protein spots compared with Romanov sheep without myostatin mutation. Most of them could be related to the hypertrophic status of the muscle and the associated increased levels of glycolytic enzymes and lower capillary density, respectively.…”