(F, G) The eyeless promoter directs the flipase recombinase during eye development. Flipase allows recombination on the right arm of the second chromosome and eventually leads to an adult eye (F) that is homozygous for the wild-type allele of DHR3. (G) Homozygosity for a DHR3K243X mutation results in a decrease in the size of the adult eye. A dotted yellow line surrounding the control eye in (F) has been copied and pasted on the mutant eyes (G); insets are higher magnification images of ommatidia showing misorientation of bristles. 