Temporal transcription factors and their targets schedule the end of neural proliferation in Drosophila.
The timing mechanisms responsible for terminating cell proliferation toward the end of development remain unclear. In the Drosophila CNS, individual progenitors called neuroblasts are known to express a series of transcription factors endowing daughter neurons with different temporal identities. Here we show that Castor and Seven-Up, members of this temporal series, regulate key events in many different neuroblast lineages during late neurogenesis. First, they schedule a switch in the cell size and identity of neurons involving the targets Chinmo and Broad Complex. Second, they regulate the time at which neuroblasts undergo Prospero-dependent cell-cycle exit or Reaper/Hid/Grim-dependent apoptosis. Both types of progenitor termination require the combined action of a late phase of the temporal series and indirect feedforward via Castor targets such as Grainyhead and Dichaete. These studies identify the timing mechanism ending CNS proliferation and reveal how aging progenitors transduce bursts of transcription factors into long-lasting changes in cell proliferation and cell identity.
MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK.
Cédric
C
Maurange
Louise
L
Cheng
Alex P
AP
Gould
D000818:Animals; D017209:Apoptosis; D002453:Cell Cycle; D002454:Cell Differentiation; D049109:Cell Proliferation; D048429:Cell Size; D004268:DNA-Binding Proteins / Q000378:metabolism; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology*; D018507:Gene Expression Regulation, Developmental; D006609:High Mobility Group Proteins / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009474:Neurons / Q000166:cytology*; D011987:Receptors, Steroid / Q000378:metabolism; D055747:SOX Transcription Factors; D013234:Stem Cells / Q000166:cytology*; D014157:Transcription Factors / Q000378:metabolism*
C515167:Chinmo protein, Drosophila; C103073:D protein, Drosophila; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D006609:High Mobility Group Proteins; D009419:Nerve Tissue Proteins; D011987:Receptors, Steroid; D055747:SOX Transcription Factors; D014157:Transcription Factors; C110593:cas protein, Drosophila; C062330:grh protein, Drosophila; C094295:svp protein, Drosophila