Regulatory logic driving stable levels of defective proventriculus expression during terminal photoreceptor specification in flies

Jenny Yan, Caitlin Anderson, Kayla Viets, Sang Tran, Gregory Goldberg, Stephen Small, Robert J. Johnston

Research output: Contribution to journalArticle

Abstract

How differential levels of gene expression are controlled in postmitotic neurons is poorly understood. In the Drosophila retina, expression of the transcription factor Defective Proventriculus (Dve) at distinct cell type-specific levels is required for terminal differentiation of color- and motion-detecting photoreceptors. Here, we find that the activities of two cis-regulatory enhancers are coordinated to drive dve expression in the fly eye. Three transcription factors act on these enhancers to determine cell-type specificity. Negative autoregulation by Dve maintains expression from each enhancer at distinct homeostatic levels. One enhancer acts as an inducible backup (‘dark’ shadow enhancer) that is normally repressed but becomes active in the absence of the other enhancer. Thus, two enhancers integrate combinatorial transcription factor input, feedback and redundancy to generate cell type-specific levels of dve expression and stable photoreceptor fate. This regulatory logic may represent a general paradigm for how precise levels of gene expression are established and maintained in post-mitotic neurons.

Original languageEnglish (US)
Pages (from-to)844-855
Number of pages12
JournalDevelopment (Cambridge)
Volume144
Issue number5
DOIs
StatePublished - Mar 1 2017

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Keywords

  • Dark shadow enhancer
  • Defective proventriculus
  • Drosophila retina
  • Orthodenticle
  • Photoreceptor
  • Rhodopsin
  • Shadow enhancer
  • Spalt
  • Spineless

ASJC Scopus subject areas

  • Molecular Biology
  • Developmental Biology

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