Embryos expressing vri^1.Scer\UAS under the control of Scer\GAL4^pnr-MD237 have an atrophic dorsal epidermis and anterior hole and head defects. Expression of vri^1.Scer\UAS under the control of Scer\GAL4^vg.PM at 29^oC results in notching at the wing margin. Expression of vri^1.Scer\UAS under the control of Scer\GAL4^hs.PB results in atrophic or missing bristles on the adult cuticle. Expression of vri^1.Scer\UAS under the control of Scer\GAL4^ey.PH results in atrophy of the eye. A progressive reduction in the size of the eye, and a rough eye phenotype are seen according to the transgene used and the temperature. The ommatidia are disorganised with a globular aspect and interommatidial bristles are either duplicated or missing. In the most severe cases, all head structures derived from the eye-antennal disc are missing. Expression of vri^1.Scer\UAS under the control of Scer\GAL4^A9 results in a wing which is slightly reduced in size, enlarged cells (as shown by more widely spaced wing bristles) and a reduced L5 vein. Cells have multiple, abnormally oriented trichomes. Expression of vri^1.Scer\UAS under the control of Scer\GAL4^Bx-MS1096 results in increased apoptosis in the wing pouch region of the wing imaginal disc. Expression of vri^1.Scer\UAS under the control of Scer\GAL4^F4 results in salivary glands which are about one half normal size in third instar larvae. The nuclei are smaller than normal and are often pyknotic. Expression of vri^1.Scer\UAS under the control of Scer\GAL4^Act5C.PP in clones in the fat body results in small clones with smaller cells, indicating an inhibition of endoreplication.