Drosophila Grainyhead specifies late programmes of neural proliferation by regulating the mitotic activity and Hox-dependent apoptosis of neuroblasts.
The Drosophila central nervous system is generated by stem-cell-like progenitors called neuroblasts. Early in development, neuroblasts switch through a temporal series of transcription factors modulating neuronal fate according to the time of birth. At later stages, it is known that neuroblasts switch on expression of Grainyhead (Grh) and maintain it through many subsequent divisions. We report that the function of this conserved transcription factor is to specify the regionalised patterns of neurogenesis that are characteristic of postembryonic stages. In the thorax, Grh prolongs neural proliferation by maintaining a mitotically active neuroblast. In the abdomen, Grh terminates neural proliferation by regulating the competence of neuroblasts to undergo apoptosis in response to Abdominal-A expression. This study shows how a factor specific to late-stage neural progenitors can regulate the time at which neural proliferation stops, and identifies mechanisms linking it to the Hox axial patterning system.
Cenci
Caterina
C
Medical Research Council, National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK.
Gould
Alex P
AP
D000005:Abdomen / Q000196:embryology; D000818:Animals; D017209:Apoptosis / Q000235:genetics; D049109:Cell Proliferation; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology* / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D045888:Ganglion Cysts / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D008938:Mitosis; D009474:Neurons / Q000166:cytology* / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D009687:Nuclear Proteins; D014157:Transcription Factors; C066177:Ubx protein, Drosophila; C062330:grh protein, Drosophila; C066591:abd-A protein, Drosophila