title: An inducer protein may control the timing of fate switching in a bipotential glial progenitor cell in rat optic nerve.
abstract: In rat optic nerve, oligodendrocytes and type-2 astrocytes develop from a common (O-2A) progenitor cell. The first oligodendrocytes differentiate at birth, while the first type-2 astrocytes differentiate in the second postnatal week. We previously showed that the timing of oligodendrocyte differentiation depends on an intrinsic clock in the O-2A progenitor cell. Here we provide evidence that the timing of type-2 astrocyte differentiation, by contrast, may depend on an inducing protein that appears late in the developing nerve. We show that extracts of 3- to 4-week-old, but not 1-week-old, rat optic nerve contain a protein (apparent Mr approximately 25,000) that induces O-2A progenitor cells in culture to express glial fibrillary acidic protein (GFAP), an astrocyte-specific marker in the rat central nervous system.
authors.affiliation: Department of Zoology and Cell Biology, University College London, UK.
authors.forename: S M
authors.initials: SM
authors.lastname: Hughes
authors.forename: M C
authors.initials: MC
authors.lastname: Raff
mesh_terms: D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development*; D005904:Glial Fibrillary Acidic Protein / Q000096:biosynthesis; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009900:Optic Nerve / Q000254:growth & development* / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013234:Stem Cells / Q000166:cytology*
chemical_list: D005904:Glial Fibrillary Acidic Protein; D009419:Nerve Tissue Proteins