Int. J. Dev. Biol. 45: S135 - S136 (2001)

Vol 45, Issue S1

The regulation of homothorax and the control of eye-head proportion in Drosophila

Published: 1 June 2001

J Bessa, F Casares

Inst Biol Mol & Celular, P-4150180 Oporto, Portugal

Abstract

In the fruit fly Drosophila melanogaster, eye and head grow up to a constant, species-specific, size proportion. Eye and head originate from the same pool of cells, so the correct number of cells must be allocated to one of either fate during development. Two signaling pathways are instrumental in this allocation: wingless (wg) promotes head while decapentaplegic (dpp) promotes eye. Key to understand how eye and head growth is coordinated is to find the genes these two antagonizing signaling pathways act upon. One of these genes seems to be the transcription factor homothorax (hth). In the absence of hth, the head capsule does not develop and ectopic eye tissue forms. Here we present data showing that wg and dpp signaling might be independently activating and repressing hth, respectively. The nuclear factor Dac is required for hth repression downstream of dpp.

Keywords

Disc