Biomaterial Database

Myosin heavy chain isoform content and energy metabolism can be uncoupled in pig skeletal muscle. 2009

S K Park, and A M Gunawan, and T L Scheffler, and A L Grant, and D E Gerrard

Department of Animal Sciences, Purdue University, West Lafayette, IN 47907, USA.

Genetic selection for improved growth and overall meatiness has resulted in the occurrence of 2 major mutations in pigs, the Rendement Napole (RN) and Halothane (Hal) gene mutations. At the tissue level, these mutations influence energy metabolism in skeletal muscle and muscle fiber type composition, yet also influence total body composition. The RN mutation affects the adenosine monophosphate-activated protein kinase gamma subunit and results in increased glycogen deposition in the muscle, whereas the Hal mutation alters sarcoplasmic calcium release mechanisms and results in altered energy metabolism. From a meat quality standpoint, these mutations independently influence the extent and rate of muscle energy metabolism postmortem, respectively. Even though these mutations alter overall muscle energy metabolism and histochemically derived muscle fiber type independently, their effects have not been yet fully elucidated in respect to myosin heavy chain (MyHC) isoform content and those enzymes responsible for defining energetics of the tissue. Therefore, the objective of this study was to determine the collective effects of the RN and Hal genes on genes and gene products associated with different muscle fiber types in pig skeletal muscle. To overcome potential pitfalls associated with traditional muscle fiber typing, real-time PCR, gel electrophoresis, and Western blotting were used to evaluate MyHC composition and several energy-related gene expressions in muscles from wild-type, RN, Hal, and Hal-RN mutant pigs. The MyHC mRNA levels displayed sequential transitions from IIb to IIx and IIa in pigs bearing the RN mutation. In addition, our results showed MyHC protein isoform abundance is correlated with mRNA level supporting the hypothesis that MyHC genes are transcriptionally controlled. However, transcript abundance of genes involved in energy metabolism, including lactate dehydrogenase, citrate synthase, glycogen synthase, and peroxisome proliferator-activated receptor alpha, was not different between genotypes. These data show that the RN and Hal gene mutations alter muscle fiber type composition and suggest that muscle fiber energy metabolism and speed of contraction, the 2 determinants of muscle fiber type, can be uncoupled.

UI	MeSH Term	Description	Entries
D001835	Body Weight	The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.	Body Weights,Weight, Body,Weights, Body
D004734	Energy Metabolism	The chemical reactions involved in the production and utilization of various forms of energy in cells.	Bioenergetics,Energy Expenditure,Bioenergetic,Energy Expenditures,Energy Metabolisms,Expenditure, Energy,Expenditures, Energy,Metabolism, Energy,Metabolisms, Energy
D005786	Gene Expression Regulation	Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.	Gene Action Regulation,Regulation of Gene Expression,Expression Regulation, Gene,Regulation, Gene Action,Regulation, Gene Expression
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013552	Swine	Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).	Phacochoerus,Pigs,Suidae,Warthogs,Wart Hogs,Hog, Wart,Hogs, Wart,Wart Hog
D018482	Muscle, Skeletal	A subtype of striated muscle, attached by TENDONS to the SKELETON. Skeletal muscles are innervated and their movement can be consciously controlled. They are also called voluntary muscles.	Anterior Tibial Muscle,Gastrocnemius Muscle,Muscle, Voluntary,Plantaris Muscle,Skeletal Muscle,Soleus Muscle,Muscle, Anterior Tibial,Muscle, Gastrocnemius,Muscle, Plantaris,Muscle, Soleus,Muscles, Skeletal,Muscles, Voluntary,Skeletal Muscles,Tibial Muscle, Anterior,Voluntary Muscle,Voluntary Muscles
D018995	Myosin Heavy Chains	The larger subunits of MYOSINS. The heavy chains have a molecular weight of about 230 kDa and each heavy chain is usually associated with a dissimilar pair of MYOSIN LIGHT CHAINS. The heavy chains possess actin-binding and ATPase activity.	Myosin Heavy Chain,Heavy Chain, Myosin,Heavy Chains, Myosin
D020033	Protein Isoforms	Different forms of a protein that may be produced from different GENES, or from the same gene by ALTERNATIVE SPLICING.	Isoform,Isoforms,Protein Isoform,Protein Splice Variant,Splice Variants, Protein,Protein Splice Variants,Isoform, Protein,Isoforms, Protein,Splice Variant, Protein,Variant, Protein Splice,Variants, Protein Splice