The Notch pathway regulates the Second Mitotic Wave cell cycle independently of bHLH proteins

Abhishek Bhattacharya, Ke Li, Manon Quiquand, Gerard Rimesso, Nicholas E. Baker

Research output: Contribution to journalArticle

1 Scopus citations

Abstract

Notch regulates both neurogenesis and cell cycle activity to coordinate precursor cell generation in the differentiating Drosophila eye. Mosaic analysis with mitotic clones mutant for Notch components was used to identify the pathway of Notch signaling that regulates the cell cycle in the Second Mitotic Wave. Although S phase entry depends on Notch signaling and on the transcription factor Su(H), the transcriptional co-activator Mam and the bHLH repressor genes of the E(spl)-Complex were not essential, although these are Su(H) coactivators and targets during the regulation of neurogenesis. The Second Mitotic Wave showed little dependence on ubiquitin ligases neuralized or mindbomb, and although the ligand Delta is required non-autonomously, partial cell cycle activity occurred in the absence of known Notch ligands. We found that myc was not essential for the Second Mitotic Wave. The Second Mitotic Wave did not require the HLH protein Extra macrochaetae, and the bHLH protein Daughterless was required only cell-nonautonomously. Similar cell cycle phenotypes for Daughterless and Atonal were consistent with requirement for neuronal differentiation to stimulate Delta expression, affecting Notch activity in the Second Mitotic Wave indirectly. Therefore Notch signaling acts to regulate the Second Mitotic Wave without activating bHLH gene targets.

Original languageEnglish (US)
Pages (from-to)309-320
Number of pages12
JournalDevelopmental Biology
Volume431
Issue number2
DOIs
Publication statusPublished - Nov 15 2017

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Keywords

  • Cell proliferation
  • Developmental genetics
  • Drosophila eye
  • Notch signaling
  • Second Mitotic Wave

ASJC Scopus subject areas

  • Molecular Biology
  • Developmental Biology
  • Cell Biology

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