title: Transcriptional regulation of glial cell specification.
abstract: Neuronal differentiation relies on proneural factors that also integrate positional information and contribute to the specification of the neuronal type. The molecular pathway triggering glial specification is not understood yet. In Drosophila, all lateral glial precursors and glial-promoting activity have been identified, which provides us with a unique opportunity to dissect the regulatory pathways controlling glial differentiation and specification. Although glial lineages are very heterogeneous with respect to position, time of differentiation, and lineage tree, they all express and require two homologous genes, glial cell deficient/glial cell missing (glide/gcm) and glide2, that act in concert, with glide/gcm constituting the major glial-promoting factor. Here, we show that glial specification resides in glide/gcm transcriptional regulation. The glide/gcm promoter contains lineage-specific elements as well as quantitative and turmoil elements scattered throughout several kilobases. Interestingly, there is no correlation between a specific regulatory element and the type of glial lineage. Thus, the glial-promoting factor acts as a naive switch-on button that triggers gliogenesis in response to multiple pathways converging onto its promoter. Both negative and positive regulation are required to control glide/gcm expression, indicating that gliogenesis is actively repressed in some neural lineages.
authors.affiliation: Institut de Génétique et Biologie Moléculaire et Cellulaire, IGBMC/CNRS/ULP/INSERM - BP 10142 67404 Illkirch, c.u., de Strasbourg, France.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Ragone
authors.forename: Véronique
authors.initials: V
authors.lastname: Van De Bor
authors.forename: Sandro
authors.initials: S
authors.lastname: Sorrentino
authors.forename: Martial
authors.initials: M
authors.lastname: Kammerer
authors.forename: Anne
authors.initials: A
authors.lastname: Galy
authors.forename: Annette
authors.initials: A
authors.lastname: Schenck
authors.forename: Roberto
authors.initials: R
authors.lastname: Bernardoni
authors.forename: Alita A
authors.initials: AA
authors.lastname: Miller
authors.forename: Nivedita
authors.initials: N
authors.lastname: Roy
authors.forename: Angela
authors.initials: A
authors.lastname: Giangrande
mesh_terms: D000818:Animals; D001369:Axons / Q000473:pathology; D001483:Base Sequence; D015415:Biomarkers; D002454:Cell Differentiation; D019070:Cell Lineage; D002490:Central Nervous System / Q000166:cytology* / Q000196:embryology*; D004330:Drosophila / Q000196:embryology / Q000235:genetics*; D004625:Embryo, Nonmammalian; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect; D006720:Homozygote; D008959:Models, Neurological; D009154:Mutation; D009457:Neuroglia / Q000166:cytology*; D010641:Phenotype; D011401:Promoter Regions, Genetic; D013234:Stem Cells / Q000166:cytology; D013997:Time Factors; D014158:Transcription, Genetic; D019076:Transgenes
chemical_list: D015415:Biomarkers