title: Ets transcription factor Pointed promotes the generation of intermediate neural progenitors in Drosophila larval brains.
abstract: Intermediate neural progenitor (INP) cells are transient amplifying neurogenic precursor cells generated from neural stem cells. Amplification of INPs significantly increases the number of neurons and glia produced from neural stem cells. In Drosophila larval brains, INPs are produced from type II neuroblasts (NBs, Drosophila neural stem cells), which lack the proneural protein Asense (Ase) but not from Ase-expressing type I NBs. To date, little is known about how Ase is suppressed in type II NBs and how the generation of INPs is controlled. Here we show that one isoform of the Ets transcription factor Pointed (Pnt), PntP1, is specifically expressed in type II NBs, immature INPs, and newly mature INPs in type II NB lineages. Partial loss of PntP1 in genetic mosaic clones or ectopic expression of the Pnt antagonist Yan, an Ets family transcriptional repressor, results in a reduction or elimination of INPs and ectopic expression of Ase in type II NBs. Conversely, ectopic expression of PntP1 in type I NBs suppresses Ase expression the NB and induces ectopic INP-like cells in a process that depends on the activity of the tumor suppressor Brain tumor. Our findings suggest that PntP1 is both necessary and sufficient for the suppression of Ase in type II NBs and the generation of INPs in Drosophila larval brains.
authors.affiliation: Department of Physiology, University of California, San Francisco, CA 94158, USA.
authors.forename: Sijun
authors.initials: S
authors.lastname: Zhu
authors.forename: Suzanne
authors.initials: S
authors.lastname: Barshow
authors.forename: Jill
authors.initials: J
authors.lastname: Wildonger
authors.forename: Lily Yeh
authors.initials: LY
authors.lastname: Jan
authors.forename: Yuh-Nung
authors.initials: YN
authors.lastname: Jan
mesh_terms: D000818:Animals; D001921:Brain / Q000196:embryology*; D019070:Cell Lineage; D003433:Crosses, Genetic; D004268:DNA-Binding Proteins / Q000378:metabolism / Q000502:physiology*; D004330:Drosophila / Q000196:embryology*; D029721:Drosophila Proteins / Q000378:metabolism / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D049452:Green Fluorescent Proteins / Q000378:metabolism; D007814:Larva / Q000378:metabolism*; D018613:Microscopy, Confocal / Q000379:methods; D009419:Nerve Tissue Proteins / Q000378:metabolism / Q000502:physiology*; D009457:Neuroglia / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism / Q000502:physiology*; D050783:Proto-Oncogene Proteins c-ets / Q000378:metabolism*; D034622:RNA Interference; D014157:Transcription Factors / Q000378:metabolism / Q000502:physiology*; D019076:Transgenes
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D009419:Nerve Tissue Proteins; D011518:Proto-Oncogene Proteins; D050783:Proto-Oncogene Proteins c-ets; D014157:Transcription Factors; C083884:pnt protein, Drosophila; D049452:Green Fluorescent Proteins