title: Escargot and Scratch regulate neural commitment by antagonizing Notch activity in Drosophila sensory organs.
abstract: During Notch (N)-mediated binary cell fate decisions, cells adopt two different fates according to the levels of N pathway activation: an Noff-dependent or an Non-dependent fate. How cells maintain these N activity levels over time remains largely unknown. We address this question in the cell lineage that gives rise to the Drosophila mechanosensory organs. In this lineage a primary precursor cell undergoes a stereotyped sequence of oriented asymmetric cell divisions and transits through two neural precursor states before acquiring a neuron identity. Using a combination of genetic and cell biology strategies, we show that Escargot and Scratch, two transcription factors belonging to the Snail superfamily, maintain Noff neural commitment by directly blocking the transcription of N target genes. We propose that Snail factors act by displacing proneural transcription activators from DNA binding sites. As such, Snail factors maintain the Noff state in neural precursor cells by buffering any ectopic variation in the level of N activity. Since Escargot and Scratch orthologs are present in other precursor cells, our findings are fundamental for understanding precursor cell fate acquisition in other systems.
authors.affiliation: CNRS, UMR 7622, Laboratoire de Biologie du Développement, IBPS, Paris F-75005, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Ramat
authors.affiliation: Sorbonne Universités, UPMC Université Paris 06, UMR7622, Laboratoire de Biologie du Développement, Paris F-75005, France.
authors.forename: Agnès
authors.initials: A
authors.lastname: Audibert
authors.affiliation: Sorbonne Universités, UPMC Université Paris 06, UMR7622, Laboratoire de Biologie du Développement, Paris F-75005, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Louvet-Vallée
authors.affiliation: CNRS, UMR 7622, Laboratoire de Biologie du Développement, IBPS, Paris F-75005, France.
authors.forename: Françoise
authors.initials: F
authors.lastname: Simon
authors.affiliation: CNRS, UMR 7622, Laboratoire de Biologie du Développement, IBPS, Paris F-75005, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Fichelson
authors.affiliation: CNRS, UMR 7622, Laboratoire de Biologie du Développement, IBPS, Paris F-75005, France michel.gho@upmc.fr.
authors.forename: Michel
authors.identifier: 0000-0001-9198-5754
authors.initials: M
authors.lastname: Gho
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology; D004330:Drosophila / Q000166:cytology* / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D008297:Male; D058953:Neural Stem Cells / Q000166:cytology / Q000378:metabolism; D051880:Receptors, Notch / Q000235:genetics / Q000378:metabolism*; D000071250:Snail Family Transcription Factors / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D029721:Drosophila Proteins; D051880:Receptors, Notch; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors; C467520:esg protein, Drosophila; C096141:scrt protein, Drosophila
keywords: Bristle lineage; E(spl) genes; Neural cell commitment; Notch pathway; Snail factors; Transcription repression