title: Developmental regulation of M-cadherin in the terminal differentiation of skeletal myoblasts.
abstract: Cadherins form a large family of membrane glycoproteins which mediate homophilic calcium-dependent cell adhesion. They are thought to mediate the initial calcium-dependent cell adhesion which precedes the plasma membrane fusion of skeletal myoblasts. Two cadherin subtypes are known to be expressed in mammalian skeletal myoblasts: muscle cadherin (M-cadherin) and neural cadherin (N-cadherin). In the present study we demonstrate that 1) the expression of M- and N-cadherin is differentially regulated during myoblast differentiation in vitro, 2) the expression of M-cadherin but not N-cadherin is inhibited by 5-bromo-2'-deoxyuridine (BUdR), an agent which selectively inhibits skeletal myoblast differentiation, and 3) fusion and differentiation-competent rat L6 myoblasts do not express detectable levels of N-cadherin mRNA. In vivo, M-cadherin mRNA was detectable exclusively in skeletal muscle. M-cadherin mRNA levels peaked during the secondary myogenic wave in rat hindlimb muscle, becoming barely detectable in 1-week-old and adult rats. These observations indicate that M-cadherin is unique in two ways: It is the first cadherin to be included in the family of skeletal muscle-specific genes, and it shows peak levels of expression in developing skeletal muscle tissue. Taken together, these results suggest that M-cadherin plays an important role in skeletal myogenesis.
authors.affiliation: Department of Biology, McGill University, Montréal, Québec, Canada.
authors.forename: Y
authors.initials: Y
authors.lastname: Pouliot
authors.forename: M
authors.initials: M
authors.lastname: Gravel
authors.forename: P C
authors.initials: PC
authors.lastname: Holland
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development / Q000378:metabolism*; D001483:Base Sequence; D001973:Bromodeoxyuridine / Q000494:pharmacology; D015820:Cadherins / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation; D002460:Cell Line; D051379:Mice; D008969:Molecular Sequence Data; D024510:Muscle Development; D018482:Muscle, Skeletal / Q000166:cytology* / Q000254:growth & development; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D015820:Cadherins; D012333:RNA, Messenger; C070896:M-cadherin; D001973:Bromodeoxyuridine