The Structure and Function of Muscle

The control of meat quality traits constitutes an important target for any farm animal production, including cattle. Therefore, better understanding of the biochemical properties that drive muscle development and final outcomes constitutes one of the main challenging topics of animal production and meat science. Accordingly, this review has focused on skeletal muscle fibers in cattle and their relationships with beef qualities. It aimed to describe the chemical and structural properties of muscle fibers as well as a comprehensive review of their contractile and metabolic characteristics during the life of the animal. The existing methods for the classification of muscle fibers were reviewed, compared, and discussed. Then, the different stages of myogenesis in cattle were defined. The main factors regulating fetal and postnatal growth and the plasticity of muscle fibers were evidenced, especially the role of myostatin growth factor and the impact of nutritional factors. This review highlights that the knowledge about muscle fibers is paramount for a better understanding of how to control the muscle properties throughout the life of the animal for better management of the final eating qualities of beef. Accordingly, the associations between bovine muscle fibers and different meat eating qualities such as tenderness, pH decline, and color traits were further presented.

Muscle Fiber Properties in Cattle and Their Relationships with Meat Qualities: An Overview

Influence of oxidative damage to proteins on meat tenderness using a proteomics approach.

Recent advances in omic technologies for meat quality management.

Meta-proteomics for the discovery of protein biomarkers of beef tenderness: An overview of integrated studies

Hsp27—encoded by HspB1—is a member of the small heat shock proteins (sHsp, 12–43 kDa (kilodalton)) family. This protein is constitutively present in a wide variety of tissues and in many cell lines. The abundance of Hsp27 is highest in skeletal muscle, indicating a crucial role for muscle physiology. The protein identified as a beef tenderness biomarker was found at a crucial hub in a functional network involved in beef tenderness. The aim of this study was to analyze the proteins impacted by the targeted invalidation of HspB1 in the Tibialis anterior muscle of the mouse. Comparative proteomics using two-dimensional gel electrophoresis revealed 22 spots that were differentially abundant between HspB1-null mice and their controls that could be identified by mass spectrometry. Eighteen spots were more abundant in the muscle of the mutant mice, and four were less abundant. The proteins impacted by the absence of Hsp27 belonged mainly to calcium homeostasis (Srl and Calsq1), contraction (TnnT3), energy metabolism (Tpi1, Mdh1, PdhB, Ckm, Pygm, ApoA1) and the Hsp proteins family (HspA9). These data suggest a crucial role for these proteins in meat tenderization. The information gained by this study could also be helpful to predict the side effects of Hsp27 depletion in muscle development and pathologies linked to small Hsps.

/pdf/calcium-homeostasis-and-muscle-energy-metabolism-are-2ojg7gabvy.pdf

Calcium Homeostasis and Muscle Energy Metabolism Are Modified in HspB1-Null Mice

L'eleveur dispose d'un ensemble de leviers d'action pour modifier les caracteristiques des muscles des bovins determinantes pour la tendrete et la flaveur de leur viande qui ont ete decrites dans un premier article. Parmi ceux-ci figurent le choix du type genetique des animaux en fonction du type de production souhaite (veaux, genisses, boeufs, taurillons, etc.) et le choix du rythme de croissance et des apports nutritionnels (intensite et nature de ces apports). Les quelques exemples qui suivent soulignent l'importance de l'effet des facteurs de production sur les caracteristiques du muscle du bovin. Ainsi, le niveau et la nature de l'alimentation modifient l'expression de certains genes du metabolisme energetique dans les tissus, mais ces phenomenes sont tres differents entre les veaux preruminants et les bovins sevres. Chez le veau de boucherie, certaines sources de matieres grasses alimentaires ou un exces d'apport de glucides peuvent entrainer une infiltration lipidique du foie ou une resistance a l'insuline des tissus peripheriques, respectivement. Chez le taurillon ou le bouvillon, l'augmentation de l'âge des animaux au-dela de la puberte et la restriction alimentaire augmentent l'activite oxydative ou diminuent l'activite glycolytique des tissus musculaires. La croissance compensatrice (consecutive a une periode de realimentation apres une periode de restriction) semble globalement plutot favorable a la qualite de la viande. La conduite au pâturage renforce le metabolisme oxydatif des muscles et la flaveur de la viande. L'hypertrophie musculaire s'accompagne de teneurs en collagene total ou insoluble plus faibles dans le muscle et d'une proportion plus elevee de fibres rapides glycolytiques, facteurs favorables pour la tendrete, mais defavorables pour la flaveur. Toutefois, les modifications des caracteristiques musculaires sont souvent specifiques de chaque type de muscle. L'objectif des recherches est maintenant d'integrer l'ensemble de ces donnees dans une demarche de modelisation, afin de developper des outils d'aide a la decision pour mieux predire la composition du muscle a l'abattage et la qualite finale de la viande bovine qui en resulte.

Evolution des recherches sur le muscle des bovins et la qualité sensorielle de leur viande. II. Influence des facteurs d'élevage sur les caractéristiques musculaires

myogenesis can be characterized by five key stages during the foetal life. Thus, stages 60 and 110 days post conception (dpc) are witnesses of primary myoblasts and secondary myoblasts proliferation respectively. Stage 180 dpc shows the end of the proliferation step and is the point when the total number of muscle fibres is defined. The last third of bovine foetal life, encompassing 210 dpc and 260 dpc, is mainly characterised by a large metabolic and contractile differentiation step. If histological and biochemical experiments allowed the analysis of bovine myogenesis and allowed to display those stages, many questions remain about the proteomic mechanisms involved in the regulation of the: i) proliferation of the two myoblasts generations, ii) cellular transition proliferation/cellular alignment/fusion of the myoblasts in myotubes/ differentiation, iii) control of the total number of fibre. A proteomic approach, based on the analysis of the semitendinosus muscle from Charolais cattle at key stages, was leaded using a classical two-dimensional electrophoresis and mass spectrometry strategy. We investigate the in vivo proteome of bovine muscle during semitendinosus muscle ontogenesis. Gene Ontology is a modern in silico tool that allows the attribution of a biological function to a single gene or a single protein but it can be used to characterize the main biological function of a particular cluster (composed of several proteins). Analysis of common expression profile of proteins and the use of gene ontology enables us to show some already confirm results and, above all, enables us to find other tracks to investigate the muscular development of large mammals in order to answer our issues.

Description of in vivo bovine myogenesis using proteomic approach gives new insights for muscle development

Dans l'objectif de mettre en evidence de nouveaux marqueurs de tendrete de la viande bovine, une analyse proteomique a ete realisee sur le muscle Longissimus thoracis de deux lots extremes de dix animaux pour chacune des trois principales races a viande francaises Blonde d'Aquitaine, Charolaise, Limousine. La constitution des lots a ete faite sur la base d'un index combinant a la fois la note de tendrete estimee par analyse sensorielle et la valeur de la force de cisaillement (Warner-Bratzler). Ce choix a ete fait parmi trois mille trois cents jeunes bovins. Le nombre important d'animaux a permis de choisir les dix animaux de chaque lot toutes choses egales en termes de caracteristiques musculaires (fibres, collagene, lipides). Les proteines extraites des muscles des animaux des lots extremes 24 h apres abattage ont ete analysees par electrophorese bidimensionnelle et spectrometrie de masse. Les differences d'abondance entre spots permettent de retenir plusieurs proteines comme marqueurs potentiels de la tendrete. Ces marqueurs ne sont pas toujours les memes selon les races.

Brigitte Picard

Papers

Calcium Homeostasis and Muscle Energy Metabolism Are Modified in HspB1-Null Mice

Evolution des recherches sur le muscle des bovins et la qualité sensorielle de leur viande. II. Influence des facteurs d'élevage sur les caractéristiques musculaires

Description of in vivo bovine myogenesis using proteomic approach gives new insights for muscle development

Recherche de marqueurs de tendreté de la viande de jeunes bovins de races à viande par analyse protéomique

Bif-Beef : Un entrepôt de données sur la biologie du muscle pour prédire la qualité de la viande bovine