In vitro characterization of proliferation and differentiation of pig satellite cells.

Skeletal muscle contains various muscle fiber types exhibiting different contractile properties based on the myosin heavy chain (MyHC) isoform profile. Muscle fiber type composition is highly variable and influences growth performance and meat quality, but underlying mechanisms regulating fiber type composition remain poorly understood. The aim of the present work was to develop a model based on muscle satellite cell culture to further investigate the regulation of adult MyHC isoforms expression in pig skeletal muscle.

Differentially-expressed genes in pig Longissimus muscles with contrasting levels of fat, as identified by combined transcriptomic, reverse transcription PCR, and proteomic analyses.

Intramuscular fat content is important for many meat quality parameters. This work is aimed at identifying functional categories of genes associated with natural variation among individuals in intramuscular fat content to help the design of genetic schemes for high marbling potential. Taking advantage of the global nature of transcriptomic and proteomic technologies, 40 genes were identified as differently expressed between high fat and low fat pig Longissimus muscles at slaughter weight.

Early postnatal food intake alters myofiber maturation in pig skeletal muscle.

We examined the effects of undernutrition on muscle development during the first postnatal week in pigs. Eighteen piglets were subjected to three nutritional levels (300, 200 or 100 g/(kg body. d) of colostrum then milk) between birth and slaughter at 7 d of age.

New insights into muscle fiber types in the pig.

The accurate classification of skeletal muscle fiber types according to myosin heavy chain (MyHC) polymorphism remains a difficult task in the pig. Combined myofibrillar ATPase and metabolic enzyme histochemistry, in situ hybridization, and immunocytochemistry were performed on serial transverse sections of pig longissimus (L) and rhomboideus (R) muscles at 100 kg body weight to give a new insight into muscle fiber typing in the pig. Several monoclonal antibodies (MAbs) either specific for a single MyHC (I, IIa, or IIb) or of multiple MyHCs (IIa + IIx or I + IIx + IIb) were used.