title: olig1 Expression identifies developing oligodendrocytes in zebrafish and requires hedgehog and notch signaling.
abstract: Myelin, the isolating sheath around large diameter axons, is formed in the central nervous system (CNS) by oligodendrocytes. We isolated the zebrafish ortholog of olig1, a bHLH transcription factor, and describe the origin and development of oligodendrocytes in the zebrafish brain. Olig1:mem-eGFP transgenic animals demonstrate the highly dynamic nature of oligodendrocyte membrane processes, providing a tool for studying in vivo oligodendrocyte development. Formation of oligodendrocytes and initiation of olig1 expression are under the control of long-range hedgehog and notch signaling while maintenance of olig1 expression only depends on hedgehog. Over-expression of olig1 did not affect myelin formation in the brain and combined over-expression of olig1 and olig2 could not rescue loss of hedgehog signaling, indicating that critical factors other than olig1 and olig2 are necessary. Lastly, knockdown of Olig1 in an Olig2-sensitized background did result in defects in CNS myelination, indicating a functional overlap between Olig1 and Olig2 proteins.
authors.affiliation: Developmental and Molecular Pathways, Novartis Institutes for Biomedical Research, Cambridge, Massachusetts 02139, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Schebesta
authors.forename: Fabrizio C
authors.initials: FC
authors.lastname: Serluca
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D001921:Brain / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D002454:Cell Differentiation; D017124:Conserved Sequence; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D053823:Hedgehog Proteins / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D009836:Oligodendroglia / Q000166:cytology* / Q000378:metabolism*; D010802:Phylogeny; D011401:Promoter Regions, Genetic / Q000235:genetics; D051880:Receptors, Notch / Q000378:metabolism*; D016415:Sequence Alignment; D015398:Signal Transduction; D013116:Spinal Cord / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015027:Zebrafish / Q000196:embryology* / Q000235:genetics / Q000378:metabolism*; D029961:Zebrafish Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D053823:Hedgehog Proteins; D051880:Receptors, Notch; D014157:Transcription Factors; D029961:Zebrafish Proteins; C540919:olig1 protein, zebrafish