Expanded and fat regulate growth and differentiation in the Drosophila eye through multiple signaling pathways

David M. Tyler, Nicholas E. Baker

Research output: Contribution to journalArticle

84 Scopus citations


Mutations in the expanded gene act as hyperplastic tumor suppressors, interfere with cell competition and elevate Dpp signaling. Unlike Dpp overexpression, ex causes few patterning defects. Our data suggest that patterning effects are partly masked by antagonistic roles of other signaling pathways that are also activated. ex causes proliferation of cells in the posterior eye disc that are normally postmitotic. ex mutations elevate Wg signaling, but Dpp signaling antagonizes patterning effects of Wg. By contrast, if Dpp signaling is blocked in ex mutant cells, the elevated Wg signaling preserves an immature developmental state and prevents retinal differentiation. An effect of ex mutations on vesicle transport is suggested by evidence for altered sterol distribution. Mutations in ft show effects on proliferation, Wg signaling and sterols very similar to those of ex mutations. During disc growth, ex was largely epistatic to ft, and the Warts pathway mutation hippo largely epistatic to ex. Our data suggest that ft and ex act partially through the Warts pathway.

Original languageEnglish (US)
Pages (from-to)187-201
Number of pages15
JournalDevelopmental Biology
Issue number1
Publication statusPublished - May 1 2007



  • Dpp
  • Drosophila eye
  • Expanded
  • Fat
  • Growth
  • Hippo
  • Proliferation
  • Signaling
  • Sterol trafficking
  • Warts
  • Wingless

ASJC Scopus subject areas

  • Molecular Biology
  • Developmental Biology
  • Cell Biology

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