1 research outputs found
Lines is required for normal operation of Wingless, Hedgehog and Notch pathways during wing development
The regulatory Lines/Drumstick/Bowl gene network is implicated in the
integration of patterning information at several stages during development.
Here, we show that during Drosophila wing development, Lines prevents
Bowl accumulation in the wing primordium, confining its expression to the
peripodial epithelium. In cells that lack lines or over-expressing
Drumstick, Bowl stabilization is responsible for alterations such as dramatic
overgrowths and cell identity changes in the proximodistal patterning owing to
aberrant responses to signaling pathways. The complex phenotypes are explained
by Bowl repressing the Wingless pathway, the earliest effect seen. In
addition, Bowl sequesters the general co-repressor Groucho from repressor
complexes functioning in the Notch pathway and in Hedgehog expression, leading
to ectopic activity of their targets. Supporting this model, elimination of
the Groucho interaction domain in Bowl prevents the activation of the Notch
and Hedgehog pathways, although not the repression of the Wingless pathway.
Similarly, the effects of ectopic Bowl are partially rescued by co-expression
of either Hairless or Master of thickveins, co-repressors that act with
Groucho in the Notch and Hedgehog pathways, respectively. We conclude that by
preventing Bowl accumulation in the wing, primordial Lines permits the correct
balance of nuclear co-repressors that control the activity of the Wingless,
Notch and Hedgehog pathways