Expression of pic^{dsRNA.650.Scer\UAS} under the control of Scer\GAL4^Cg.PA leads to lethality during early larval stages.

Expression of DDB1^{dsRNA.650.Scer\UAS} under the control of Scer\GAL4^Act5C results in the formation of melanotic tumours. Most of the animals die at the third larval instar after a 1 to 2 day delay in development, although a few survive to the early pupal stage. About 70% of animals expressing DDB1^{dsRNA.650.Scer\UAS} under the control of Scer\GAL4^Act5C.PHb die by the third larval instar. The nuclei of fat body cells expressing DDB1^{dsRNA.650.Scer\UAS} under the control of Scer\GAL4^Cg.PA are abnormal in shape. Flies expressing one copy of DDB1^{dsRNA.650.Scer\UAS} under the control of one copy of Scer\GAL4^ey.PH have a severe rough eye phenotype, with irregular compound eyes and bristles and the eyes are smaller than normal. Flies expressing two copies of DDB1^{dsRNA.650.Scer\UAS} under the control of two copies of Scer\GAL4^ey.PH lack the head and die at the pupal stage. Eye imaginal discs of larvae expressing one copy of DDB1^{dsRNA.650.Scer\UAS} under the control of one copy of Scer\GAL4^ey.PH are smaller than control discs. No significant difference in BrdU incorporation in the region anterior to the morphogenetic furrow is seen between mutant and wild-type eye discs, however, the mutant discs show an extra S phase in some cells that are normally postmitotic. Apoptosis is significantly increased in the region posterior to the morphogenetic furrow in the mutant eye discs compared to wild type. Flies expressing DDB1^{dsRNA.650.Scer\UAS} under the control of Scer\GAL4^GMR.PS have normal eye morphology. The small eye phenotype caused by expression of one copy of DDB1^{dsRNA.650.Scer\UAS} under the control of one copy of Scer\GAL4^ey.PH is more severe if the flies are also carrying DDB1^EY01408.