Mitotic G2-arrest is required for neural cell fate determination in Drosophila.
In the wing discs of Drosophila, the mecanosensory precursor cells are singled out from clusters of cells blocked at the G2 phase of the cell cycle. This mitotic quiescence and the selection of the precursors are under strict spatio-temporal control. We forced G2 cells to enter mitosis by overexpression of string, the Drosophila homologue of the cdc25 gene. Premature entrance in the cell cycle is associated to a loss of precursor cells. Precursors are lost consecutively to a transcriptional down-regulation of the determinant proneural achaete/scute genes. This down-regulation results from an over-activation of the Enhancer of Split genes, known as effectors of the Notch signalling pathway. We conclude that exit from the cell cycle is required for proper neural cell fate determination.
Nègre
Nicolas
N
Institut de Génétique Humaine, CNRS, 141 rue de la cardonille, 34396 Cedex 5, Montpellier, France.
Ghysen
Alain
A
Martinez
Anne Marie
AM
D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D018797:Cell Cycle Proteins; D002454:Cell Differentiation / Q000502:physiology; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004330:Drosophila / Q000166:cytology / Q000235:genetics* / Q000254:growth & development; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D016195:G2 Phase / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D007814:Larva; D008938:Mitosis; D009420:Nervous System / Q000166:cytology* / Q000254:growth & development; D009474:Neurons / Q000166:cytology*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism; D017027:Protein Tyrosine Phosphatases; D016601:RNA-Binding Proteins; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014921:Wings, Animal / Q000002:abnormalities / Q000166:cytology / Q000254:growth & development / Q000378:metabolism
D051792:Basic Helix-Loop-Helix Proteins; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D009687:Nuclear Proteins; D010749:Phosphoprotein Phosphatases; D017027:Protein Tyrosine Phosphatases; D016601:RNA-Binding Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; C121960:E(spl)m7-HLH protein, Drosophila; C402387:Spen protein, Drosophila; C089199:ac protein, Drosophila; C089197:sc protein, Drosophila; C059217:stg protein, Drosophila