Abstract:
Muscle fibre characteristics are not solely genetic in origin, but are influenced before birth with the prenatal environment contributing significantly to the potential growth of muscle. The main variable affecting the pre-natal environment is that of nutrition, via placental restriction, as mediated by maternal nutrition and/ or litter size. Myostatin is a negative regulator of myogenesis. Myostatin knockout mice display greater muscle mass (McPherron et al. 1997), while double-muscled cattle, which have a mutation in the myostatin protein (Kambadur et al. 1997), have double the number of muscle fibres of other breeds (Wegner et al. 2000). The aims of the present experiment were to examine a) the developmental expression of functional myostatin in fetal sheep, and b) the influence of maternal nutrition on myostatin expression.
