Protein Expression in Pig Species Longissimus dorsi Muscles among Different Breeds and Growth Stages

Abstract

When proteins extracted from longissimus dorsi muscles of Landrace and Berkshire at the finishing stage were compared by 2-DE, the Landrace demonstrated a quantitative increase in proteins related to slow skeletal muscle function, such as serum albumin precursor, troponin T (slow skeletal muscle; sTnT) and myoglobin. In contrast, the Berkshire exhibited comparatively elevated enzymes involved in metabolic pathways, fast skeletal muscle function, and energy production, such as heat shock 27-kDa protein (HSP27)-1, TnT (fast skeletal muscle; fTnT), muscle creatine kinase, phosphoglucomutase 1 (PGM1), triosephosphate isomerase (Tpi1) and adenylate kinase isoenzyme 1 (AK1). When compared to growing Berkshire, finishing Berkshire showed increased levels of aldehyde dehydrogenase 1 family, member L1 (ALDHL1), and muscle creatine kinase. In contrast, the growing Berkshire muscle had elevated levels of HSP27-1, sTnT, fTnT, serum albumin precursor, PGM1, AK1, and Tpi 1 as compared to the finishing Berkshire. The Landrace longissimus dorsi muscle may be composed of slower skeletal muscle, whereas Berkshire is composed of a faster skeletal muscle. The uniquely elevated quantities of proteins involved in skeletal muscle function, energy metabolism, and cytoskeleton function in the growing Berkshire indicate that these factors support growth and maintenance during the growing stage when compared with the finishing Berkshire.