Animals expressing sroIR1.Scer\UAS under the control of Scer\GAL42-286 complete embryogenesis, hatch normally and show no apparent morphological or behavioural defects until the second instar stage. The mutant larvae retain the second instar larva-type morphologies for both the mouth hooks and anterior spiracles even after 72 hours after egg laying. The mutant animals die as second instar larvae prior to 144 hours after egg laying.
Animals expressing sroIR1.Scer\UAS under the control of Scer\GAL42-286 and fed yeast paste containing 20-hydroxyecdysone or 5β-ketodiol often survive to the third larval instar stage, but feeding with cholesterol or 7-dehydrocholesterol does not rescue the second larval instar growth arrest phenotype of animals expressing sroIR1.Scer\UAS under the control of Scer\GAL42-286.