Muscle type-specific effect of myostatin deficiency on myogenic regulatory factor expression in adult double-muscled Japanese Shorthorn cattle.
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.
Muroya
Susumu
S
Meat Protein Research Team, National Institute of Livestock and Grassland Science, Tsukuba, Ibaraki, Japan. muros@affrc.go.jp
Watanabe
Kouichi
K
Hayashi
Shinichiro
S
Miyake
Masato
M
Konashi
Shigeru
S
Sato
Youichi
Y
Takahashi
Manabu
M
Kawahata
Shigeki
S
Yoshikawa
Yoshisato
Y
Aso
Hisashi
H
Chikuni
Koichi
K
Yamaguchi
Takahiro
T
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
D018006:Myogenic Regulatory Factors; D055435:Myostatin