Expression of NICN.Scer\UAS driven by Scer\GAL4ey.PH in a ey2 background, produced flies with reduced eyes. About 15% of these flies had both a reduced original and a reduced ectopic eye. In addition, ectopic antennae were seen in about 1/4 of these flies.
Ectopic eyes are still produced if OptixScer\UAS.cSa is expressed under the control of Scer\GAL4dpp.blk1 in an ey2 background. The efficiency of occurrence of ectopic eyes is not changed from when OptixScer\UAS.cSa is expressed under the control of Scer\GAL4dpp.blk1 in a wild-type background, but the frequency of induction of extra ocelli is increased.
Ectopic eyes are not produced when eyaScer\UAS.cPa and soScer\UAS.cPa are coexpressed under the control of Scer\GAL4dpp.blk1 in an ey2 background, although growth alterations and patches of red pigment cells on the legs are still seen.
In the presence of Opt mutations, ey2 flies exhibit protrusions of wing tissue from the region of the eye; development is normal at 17oC, but homeotic transformation is observed at 29oC; the temperature-sensitive period is during the second larval instar. Protrusions from the anterior portion of the eye have the triple row of bristles characteristic of the anterior wing margin; the fronto-orbital region of the head produces bristles with bracts characteristic of the costa in the proximal wing.
In ey2 mutant eye-antennal discs that contain clones of cells expressing BacA\p35Scer\UAS.cHa under the control of Scer\GAL4Act5C.PI, either no endogenous eyes form, or a partial eye forms (as scored by expression of gl) in the ventral region.
In ey2/ey2 BacA\p35Scer\UAS.cHa; Scer\GAL4ey.PH third instar larvae, the eye portion of the eye-antennal disc is replaced by a duplication of the antennal half of the disc. The resulting adults have an extra antenna in place of each eye. This ectopic antenna phenotype is suppressed by eyScer\UAS.ΔPD, which does not rescue eye development. In contrast eyScer\UAS.ΔHD can both rescue eye development and suppress ectopic antenna formation, although this suppression is incompletely penetrant for both aspects of the phenotype.