Figure 6

Lethality results from ubiquitous expression of UAS-rk RNAi. (A) Within standard food vials, Act5C>rk RNAi progeny all die before the end of the 3^rd larval stage. These larvae often exhibit the double vertical plates phenotype, indicative of failed larval ecdysis. New 3^rd instar mouthparts are labeled with the arrow; the 2^nd instar mouthparts which failed to shed are labeled with the arrowhead. (B) If Act5C>rk RNAi larvae are rescued from food vials and allowed to develop on grape juice agar plates, they progress to the pupal stage. Lethality is 100% during this stage, but the timing and phenotype are highly variable. Note the pale color and flattened shape of the puparia. All pupae are shown at the same scale, from the ventral side. (C) A second Act5C-GAL4 stock was also used, referred to here as Act5C(II). Although most Act5C(II)>rk RNAi progeny die as pupae (data not shown), adults occasionally eclose. Their wings never expand and their cuticle never tans. Panels A, B, and C are not shown at the same scale. (D) RT-PCR with pupal cDNA templates was performed to confirm that ubiquitous expression of UAS-rk RNAi knocks down rk transcript levels. Lanes 1 and 3: UAS-rk RNAi (control with no driver). Lanes 2 and 4: Act5C>rk RNAi. Open arrow: expected genomic band size for rk. Closed arrow: expected cDNA band size for rk. Note the absence of an appropriate sized rk cDNA band for Act5C>rk RNAi in lane 2. Feathered arrow: expected cDNA size for the positive control, RpS26.