title: Embryonic development of glial cells and myelin in the shark, Chiloscyllium punctatum.
abstract: Glial cells are responsible for a wide range of functions in the nervous system of vertebrates. The myelinated nervous systems of extant elasmobranchs have the longest independent history of all gnathostomes. Much is known about the development of glia in other jawed vertebrates, but research in elasmobranchs is just beginning to reveal the mechanisms guiding neurodevelopment. This study examines the development of glial cells in the bamboo shark, Chiloscyllium punctatum, by identifying the expression pattern of several classic glial and myelin proteins. We show for the first time that glial development in the bamboo shark (C. punctamum) embryo follows closely the one observed in other vertebrates and that neural development seems to proceed at a faster rate in the PNS than in the CNS. In addition, we observed more myelinated tracts in the PNS than in the CNS, and as early as stage 32, suggesting that the ontogeny of myelin in sharks is closer to osteichthyans than agnathans.
authors.affiliation: California State University Northridge, Biology Dept., 91330, USA.
authors.forename: Lisa
authors.initials: L
authors.lastname: Rotenstein
authors.forename: Anthony
authors.initials: A
authors.lastname: Milanes
authors.forename: Marilyn
authors.initials: M
authors.lastname: Juarez
authors.forename: Michelle
authors.initials: M
authors.lastname: Reyes
authors.forename: Maria Elena
authors.initials: ME
authors.lastname: de Bellard
mesh_terms: D000818:Animals; D002490:Central Nervous System / Q000196:embryology; D004625:Embryo, Nonmammalian / Q000378:metabolism; D020869:Gene Expression Profiling; D009186:Myelin Sheath / Q000235:genetics / Q000378:metabolism*; D009457:Neuroglia / Q000378:metabolism*; D017933:Peripheral Nervous System / Q000196:embryology*; D012754:Sharks / Q000196:embryology*