title: Changes in muscle fiber type and expression of mRNA of myosin heavy chain isoforms in porcine muscle during pre- and postnatal development.
abstract: The purpose of this study is to elucidate developmental changes in muscle fiber type in the pig during pre- and postnatal development. For this purpose, we performed a histochemical analysis for myosin adenosine triphosphatase activity to assess muscle fiber type and determined abundances of messenger RNA (mRNA) of myosin heavy chain (MHC) isoforms. Samples of Longissimus dorsi (LD) muscle were taken from fetuses on day 90 of the fetal stage. Further, samples of LD, Rhomboideus and Biceps femoris (B. femoris) muscles were taken from pigs when they were 1, 12, 26, 45 or 75 days old. Expression of MHC 2b mRNA in the LD and the B. femoris muscles rapidly and considerably increased from the late fetal stage to the early postnatal stage and this increase was associated with the development of type 2b fibers at least in the LD muscle. As shown by the rapid and considerable changes in expression of MHC 2b mRNA, it seems that a certain plasticity of muscle fiber type still remains in this developmental stage.
authors.affiliation: Animal Physiology and Nutrition Research Division, NARO Institute of Livestock and Grassland Science, Tsukuba, Ibaraki, Japan.|School of Veterinary Medicine, Azabu University, Sagamihara, Kanagawa, Japan.
authors.forename: Masaya
authors.initials: M
authors.lastname: Katsumata
authors.affiliation: Animal Physiology and Nutrition Research Division, NARO Institute of Livestock and Grassland Science, Tsukuba, Ibaraki, Japan.|Tokushima Prefectural Seibu Livestock Hygiene Center, Miyoshi, Tokushima, Japan.
authors.forename: Tomomi
authors.initials: T
authors.lastname: Yamaguchi
authors.affiliation: Animal Physiology and Nutrition Research Division, NARO Institute of Livestock and Grassland Science, Tsukuba, Ibaraki, Japan.
authors.forename: Aiko
authors.initials: A
authors.lastname: Ishida
authors.affiliation: Animal Physiology and Nutrition Research Division, NARO Institute of Livestock and Grassland Science, Tsukuba, Ibaraki, Japan.
authors.forename: Akane
authors.initials: A
authors.lastname: Ashihara
mesh_terms: D000818:Animals; D005260:Female; D015870:Gene Expression; D008297:Male; D018485:Muscle Fibers, Skeletal / Q000145:classification*; D018482:Muscle, Skeletal / Q000196:embryology* / Q000254:growth & development*; D018995:Myosin Heavy Chains / Q000235:genetics* / Q000378:metabolism*; D009218:Myosins / Q000378:metabolism; D011247:Pregnancy; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism*; D013552:Swine
chemical_list: D020033:Protein Isoforms; D012333:RNA, Messenger; D018995:Myosin Heavy Chains; D009218:Myosins
keywords: muscle fiber type; myosin heavy chain; pig