title: Sexual dimorphism is associated with decreased expression of processed myostatin in males.
abstract: Myostatin inhibits skeletal muscle development. Therefore, we sought to determine whether larger body and muscle mass in male mice was associated with lower mRNA and protein expression of myostatin compared with females. Ten male and ten female mice of the C57 strain were killed at 16-18 wk of age, and their biceps femoris, gastrocnemius, and quadriceps femoris muscles were collected. Body and muscle masses were 40% heavier (P < 0.001) in males than in females. Northern analysis showed no difference in mRNA between males and females. In contrast, Western analysis showed that processed myostatin (26 kDa) was 40-60% lower (P < 0.001) in males compared with females. These data show first that decreased processed myostatin is a posttranscriptional and posttranslational event and, second, that decreased abundance of processed myostatin is associated with increased body mass and skeletal muscle mass in male compared with female mice.
authors.affiliation: Animal Genomics, AgResearch Ltd., Ruakura Agricultural Centre, Hamilton 2001, New Zealand. chris.mcmahon@agresearch.co.nz
authors.forename: Christopher D
authors.initials: CD
authors.lastname: McMahon
authors.forename: Ljiljana
authors.initials: L
authors.lastname: Popovic
authors.forename: Ferenc
authors.initials: F
authors.lastname: Jeanplong
authors.forename: Jenny M
authors.initials: JM
authors.lastname: Oldham
authors.forename: Sonnie P
authors.initials: SP
authors.lastname: Kirk
authors.forename: Claire C
authors.initials: CC
authors.lastname: Osepchook
authors.forename: Karen W Y
authors.initials: KW
authors.lastname: Wong
authors.forename: Mridula
authors.initials: M
authors.lastname: Sharma
authors.forename: Ravi
authors.initials: R
authors.lastname: Kambadur
authors.forename: John J
authors.initials: JJ
authors.lastname: Bass
mesh_terms: D000367:Age Factors; D000818:Animals; D005260:Female; D018507:Gene Expression Regulation, Developmental; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000254:growth & development / Q000502:physiology*; D055435:Myostatin; D009929:Organ Size; D012333:RNA, Messenger / Q000032:analysis; D012727:Sex Characteristics; D016212:Transforming Growth Factor beta / Q000235:genetics*
chemical_list: C525912:Mstn protein, mouse; D055435:Myostatin; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta