title: Muscle type-specific effect of myostatin deficiency on myogenic regulatory factor expression in adult double-muscled Japanese Shorthorn cattle.
abstract: To clarify muscle type-specific effect of myostatin on myogenic regulatory factors (MRFs), we examined mRNA expression of MRFs in five skeletal muscles of normal (NM) and myostatin-deficient double-muscled (DM) adult Japanese Shorthorn cattle by quantitative reverse-transcribed PCR. Among the four MRFs, namely, Myf5, MyoD, myogenin, and MRF4, MyoD expression was different among the muscles of the DM cattle (P < 0.01) but not of the NM cattle. Meanwhile, MyoD expression was significantly elevated only in masseter (MS) muscle in the DM cattle due to the myostatin deficiency (P < 0.05). Myf5 and MRF4 expression in semitendinosus (ST) was higher in the DM than in the NM cattle (P < 0.05). According to analysis of myosin heavy chain (MyHC) isoform expression, more MyHC-2x and -2a and less -slow isoforms were expressed in the longissimus and ST muscles compared to the MS muscle in both cattle (P < 0.05), but no significant difference in MyHC expression was observed between the NM and DM cattle. Taken together, myostatin has influences on Myf5 and MRF4 expression in faster-type muscles and on MyoD expression in slower-type muscles, suggesting a possible muscle type-specific effect of myostatin in skeletal muscle growth and maintenance.
authors.affiliation: Meat Protein Research Team, National Institute of Livestock and Grassland Science, Tsukuba, Ibaraki, Japan. muros@affrc.go.jp
authors.forename: Susumu
authors.initials: S
authors.lastname: Muroya
authors.forename: Kouichi
authors.initials: K
authors.lastname: Watanabe
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Hayashi
authors.forename: Masato
authors.initials: M
authors.lastname: Miyake
authors.forename: Shigeru
authors.initials: S
authors.lastname: Konashi
authors.forename: Youichi
authors.initials: Y
authors.lastname: Sato
authors.forename: Manabu
authors.initials: M
authors.lastname: Takahashi
authors.forename: Shigeki
authors.initials: S
authors.lastname: Kawahata
authors.forename: Yoshisato
authors.initials: Y
authors.lastname: Yoshikawa
authors.forename: Hisashi
authors.initials: H
authors.lastname: Aso
authors.forename: Koichi
authors.initials: K
authors.lastname: Chikuni
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yamaguchi
mesh_terms: D000818:Animals; D002417:Cattle / Q000502:physiology*; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000737:chemistry*; D018006:Myogenic Regulatory Factors / Q000032:analysis* / Q000235:genetics; D055435:Myostatin / Q000172:deficiency* / Q000502:physiology
chemical_list: D018006:Myogenic Regulatory Factors; D055435:Myostatin