photoreceptor cell & axon | somatic clone
Mosaic animals in which the retina is homozygous for sd-216 (generated using the "EGUF/hid" system) have normal external eye morphology but show defects in a phototaxis assay. The electroretinogram of mosaic animals in which the retina is homozygous for sd-216 has defective on/off transients. The projection pattern of the photoreceptor axons is grossly abnormal in these animals and the medulla and lamina are grossly abnormal, with the medulla being about 90o from its normal position relative to the lamina. Hemizygotes die as embryos/first instar larvae and homozygotes die as embryos.