Expression of Zzzz\ank1Scer\UAS.P\T.cDa using Scer\GAL4h-1J3 does not appear to affect embryonic and larval development, but larvae fail to pupate and die after an extended third instar larval life, which lasts up to three weeks. The size of the transgenic larvae expressing Zzzz\ank1Scer\UAS.P\T.cDa does not significantly differ from control larvae four days after egg deposition (AED). The transgenic larvae continue to feed and significantly increase in sized during their prolonged larval life, reaching at eighteen days AED the maximal length, while control animals pupated on day six AED.
Ecdysteroid biosynthesis is impaired in larvae expressing Scer\GAL4phm.PO>Zzzz\ank1Scer\UAS.P\T.cDa. Transgenic third instar larvae fed with 20-hydroxyecdysone (20E) just before the onset of the ecdysteroid peak occurring in the wild-type partially rescues the developmental arrest phenotype. All the mutant larvae pupate, but they fail to progress to the pharate stage.
Prothoracic glands (PGs) from control larvae are significantly larger than PGs from Scer\GAL4phm.PO>Zzzz\ank1Scer\UAS.P\T.cDa larvae. The size difference can be attributed to a reduction in cell number.
Expression of two copies of Zzzz\ank1Scer\UAS.P\T.cDa and one copy of Scer\GAL4nos.UTR.T:Hsim\VP16 causes ventralization of the eggshell, with defects in dorsal appendages. The eggs also appear short and rounded. In some eggs the dorsal appendages are fused at the base. The majority of eggs (65%) exhibit the most extreme ventralized phenotype with the complete loss of all appendage material.