title: Changes in muscle-fiber properties of the murine digastric muscle before and after weaning.
abstract: The digastric muscle is one of the suprahyoid muscles and consists of the anterior and posterior bellies. Because muscle fiber alignments in these two bellies are different, the functional roles are said to be different. Since the digastric muscle relates to mastication, its functions may change markedly before and after weaning, but many details remain unknown. The aim of this study was to clarify changes in muscle fiber properties of the anterior and posterior bellies of the digastric muscle in mice before and after weaning. Expressions of myosin heavy chain (MyHC) isoforms were assessed at the protein and transcriptional levels. Expression of the MyHC-2b isoform, an isoform displaying fast, strong contraction, was greater in the anterior belly than in the posterior belly after weaning. This suggests that, in mice, the anterior belly of the digastric muscle needs to move rapidly anteroposteriorly for mastication, compared with the posterior belly.
authors.affiliation: Department of Anatomy, Tokyo Dental College, Chiba-City, Chiba 261-8502, Japan. ohkubo@tdc.ac.jp
authors.forename: Koji
authors.initials: K
authors.lastname: Okubo
authors.forename: Shinichi
authors.initials: S
authors.lastname: Abe
authors.forename: Akinobu
authors.initials: A
authors.lastname: Usami
authors.forename: Hiroko
authors.initials: H
authors.lastname: Agematsu
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nakamura
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Hashimoto
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Ide
mesh_terms: D000818:Animals; D005786:Gene Expression Regulation; D051379:Mice; D008813:Mice, Inbred ICR; D018485:Muscle Fibers, Skeletal / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D018995:Myosin Heavy Chains / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D014886:Weaning
chemical_list: D012333:RNA, Messenger; D018995:Myosin Heavy Chains