Construct: Deletion of nucleotides 1 to 3464 leaving only the proline-rich C terminus, expressed from a heat inducible heat shock promoter and governed by a sev enhancer.
When introduced into a sev6/Y;SosJC2/+ background, 1% ommatidia have R7 cells as opposed to 17% for sev6/Y;SosJC2/+ with no transgene. In a sev6/+ background, 20% of ommatidia lack R7 cells (as opposed to 0% with no transgene).