Skeletal muscle proteomics in livestock production

B RIEFINGS IN FUNC TIONAL GENOMICS . VOL 9. NO 3. 259^278 doi:10.1093/bfgp/elq005 Skeletal muscle proteomics in livestock production Brigitte Picard, Ce¤cile Berri, Louis Lefaucheur, Caroline Molette, Thierry Sayd and ClaudiaTerlouw Advance Access publication date 21 March 2010 Abstract Keywords: proteomics; muscle; meat quality; myogenesis INTRODUCTION The term Proteome was used for the first time in 1994 by Marc Wilkins in Italy. Since then, the technique has evolved with increasing numbers of identified proteins and sequenced genomes. Proteomics allows the study of quantitative and qualitative variations in hundreds of proteins. It is complementary to transcriptomics as protein abundance is not the simple reflection of mRNA expression [1–3]. The development of proteomics was made possible by technical progress made in electrophoretic and chromatographic separations and subsequent mass spectrometer analysis. Proteomics can generate large data sets which can be analysed with high-throughput bioinformatic tools allowing identification of molecule interactions and analysis of molecular pathways, i.e. chains of chemical or physical interactions in which the product of one reaction becomes the reactant of the other. As the amount of information in pathway databases grows, efforts to rationalise this information increase and better definitions of molecular pathways emerge [4]. Proteome mapping has various constraints. For example, results depend on the pH gradient chosen at the start of the Corresponding author. Brigitte Picard, INRA, UR 1213, Herbivores, Theix, F-63122 St-Genès Champanelle, France. Tel.: þ33-4-73-62-40-56; Fax: þ33-4-73-62-46-39; E-mail: Brigitte Picard is a meat scientist. She obtained a PhD degree in Biochemistry in 1990 and is currently developing research on muscle growth and cattle meat quality. Ce¤cile Berri is a meat scientist. She obtained a PhD degree in Food Science in 1995 and is currently developing research on muscle growth and poultry meat quality. Louis Lefaucheur is a growth and muscle biology scientist. He obtained a PhD degree in Animal Production in 1985. His main research area is studying muscle growth, development and metabolism in relation to meat quality in pig. Caroline Molette is a muscle and meat scientist. She obtained her PhD in animal and meat science in 2004. She is currently developing research on muscle responses to stress. Thierry Sayd is a biochemist engineer and develops proteomic techniques applied to pig meat quality research. Claudia Terlouw obtained a PhD in Stress Physiology and Behaviour in 1993. She studies the causes and consequences of stress at slaughter, using behavioural, physiological, metabolic and proteomic indicators. INRA is the French National Agronomical Research Center; all the scientists/authors of this article carry out research on breeding systems and livestock for meat production ß The Author 2010. Published by Oxford University Press. All rights reserved. For permissions, please email: Proteomics allows studying large numbers of proteins, including their post-translational modifications. Proteomics has been, and still are, used in numerous studies on skeletal muscle. In this article, we focus on its use in the study of livestock muscle development and meat quality. Changes in protein profiles during myogenesis are described in cattle, pigs and fowl using comparative analyses across different ontogenetic stages. This approach allows a better understanding of the key stages of myogenesis and helps identifying processes that are similar or divergent between species. Genetic variability of muscle properties analysed by the study of hypertrophied cattle and sheep are discussed. Biological markers of meat quality, particularly tenderness in cattle, pigs and fowl are presented, including protein modifications during meat ageing in cattle, protein markers of PSE meat in turkeys and of post-mortem muscle metabolism in pigs. Finally, we discuss the interest of proteomics as a tool to understand better biochemical mechanisms underlying the effects of stress during the pre-slaughter period on meat quality traits. In conclusion, the study of proteomics in skeletal muscles allows generating large amounts of scientific knowledge that helps to improve our understanding of myogenesis and muscle growth and to control better meat quality. 260 Picard et al. MUSCLE ONTOGENESIS Meat is an important end product of livestock production. Muscle growth and intrinsic properties of the muscle determine at least in part the quantity and quality of the meat produced. Proteomics presents an interesting tool to increase our knowledge of muscle properties and how they develop during myogenesis. Many proteomic studies of myogenesis used in vitro models of C2C12 lines. For example, Tannu et al. [12] identified 653 proteins in myoblasts and 558 proteins in myotubes; 106 of these showed different abundance depending on the cell type. Proteins with a major role in differentiation were identified as mitogen activated protein kinase (MAPK), phosphorylated alpha 1 catalytic subunit isoform 1 (pAkt), protein kinase B (PKB), the kinase p38, phosphorylated extracellular regulated kinase (pERK), serine/threonine protein kinase (Akt2/PKB), IGF1 receptor and caspase 3. The analysis of the phosphoproteome showed that myoblast differentiation requires activity of numerous kinase proteins [13]. For example, proteins such as MAPK, Akt, c-Jun N-Terminal Protein Kinase 1 (JNK1) or cyclin dependant kinase 5 (CDK5) are essential for myogenesis. Phosphoproteins involved in neuronal differentiation such as stathmin and intracellular serine protease (LANP) also appeared to be important for myogenesis. Chan X’avia et al. [14] showed that moesin, fibronectin and pro-collagen migrate in the extracellular matrix (ECM) during differentiation and that other proteins such as serpin, pigment epithelium-derived factor (PEDF), annexin1 and galectin1 have an important role in cellular migration. These in vitro studies have been recently completed by in vivo analyses conducted in livestock animals such as cattle, pigs and chickens throughout myogenesis. In these species, the development of muscle fibres has been well described using histochemical and biochemical approaches [15]. To increase our understanding of mechanisms controlling myogenesis, changes of muscle proteome during foetal life were investigated at physiologically comparable stages in these three species (Figure 1). Proteomic analyses were carried out using 2DE as described by Bouley et al. [5] and mass spectrometry. The developmental stages studied correspond to: (i) proliferation of the first generation of myoblasts, (ii) proliferation of the second generation of myoblasts and differentiation of the first generation, (iii) end of proliferation of myoblasts and differentiation of myotubes (Total number of fibres (TNF) is fixed), (iv) contractile and metabolic maturation of myotubes (...truncated)