Ectopic rough expression inhibits movement of the morphogenetic furrow. dpp expression is abolished (as assayed with a dpp-lacZ fusion gene). Clonal analysis shows that this effect is non-autonomous, ectopic rough inhibits a diffusible signal required for morphogenetic furrow movement.

Viability is reduced in heat shocked embryos and larvae multiply heat shocked in the second half of larval life. Adults derived from heat shocked third instar larvae have severe defects; a single heat shock in mid to late-third instar results in a prominent scar near the middle of the eye, a single heat shock in late third instar or prepupa results in a reduced eye with the anterior third of the retina missing, and multiple heat shocks during the third instar results in eyes almost completely devoid of facets, and with very few photoreceptor cells. ro^hs.PI can partially rescue the eye phenotype of ro^x63 flies.