Clones homozygous for Chi^45F autonomously form ectopic eye tissue in the ventral head capsule. In addition to producing ectopic eye differentiation, Chi^45F mutant clones result in head cuticle defects, including abnormal clustering of sensory vibrissae on the ventral head, malformation of the rostral membrane separating the antennae, and asymmetric placement of the ocelli on the dorsal head. In the most extreme cases, the vibrissae, antennae and maxillary palps are absent. Although the size of the endogenous eye is sometimes reduced, ommatidial differentiation appear normal.

When Chi^45F mutant cells form almost the entire eye-antennal disc in a Minute background, abnormal growth is sometimes observed at the dorsal margin, but ectopic photoreceptor differentiation still occurs only in an outgrowth arising from the ventral border between the eye and antennal discs. This outgrowth appear to behave as an independent eye field.

Expression of Scer\GAL4^αTub84B.PL>Chi^{FL.Scer\UAS.T:Hsap\MYC} completely prevents ectopic photoreceptor differentiation within Chi^45F mutant clones, although it has no effect when expressed in wild-type eye discs.

Chi^45F mutant clones expressing Scer\GAL4^αTub84B.PL>Chi^{ΔLID.Scer\UAS.T:Hsap\MYC} still differentiate ectopic photoreceptors in the ventral anterior eye disc.

Chi^45F mutant clones expressing Scer\GAL4^αTub84B.PL>Chi^{ΔDD.Scer\UAS.T:Hsap\MYC} still differentiate ectopic photoreceptors in the ventral anterior eye disc.