Figure 2. Feeding defects in itpr^sv35/ug3 can be rescued by UASitpr⁺ expression in Dilp2GAL4 and DdcGAL4 domains.

(A, C) At 60 hrs and 108 hrs AEL, itpr^sv35/ug3 have much less red food in their guts in comparison to UASitpr⁺/+;DdcGAL4/+;itpr^sv35/ug3, UASitpr⁺/+;Dilp2GAL4/+; itpr^sv35/ug3 and wild-type larvae. (B, D) Spectrophotometric quantification of homogenates from larvae fed yeast paste containing a red dye. Control, Dilp2GAL4 or DdcGAL4 rescued larvae ingest significantly more dye than itpr^sv35/ug3 (itpr mutant) larvae at 60 hrs AEL (*p<0.05; Student's t-test) and at 108 hrs AEL (*p<0.005; Student's t-test). The following number of larvae (n) in batches (N) were assayed for each genotype: At 60 hrs AEL: n = 95 or more, N = 4 for all genotypes; at 108 hrs AEL: for UASitpr⁺/+;itpr^{sv35/ ug3} L3 n = 46, N = 3; L2 n = 87, N = 3; for all other genotypes n = 100, N = 4 or more. Quantification of cell number in salivary glands from larvae at 60 hrs AEL stained with DAPI to visualize nuclei. itpr^sv35/ug3 (itpr mutant) in (E) and wild-type are shown in (F). No significant difference (G) was observed in the number of nuclei in itpr mutant and wild-type salivary glands. n = 10 salivary glands for each genotype. RT-PCR analysis (H) and quantitative real-time PCR analysis (I, J) revealed significant up-regulation of transcript levels of d4E-BP and dLipase-3 in itpr^sv35/ug3 at 60 hrs AEL that can be significantly rescued by Dilp2GAL4 or DdcGAL4 driven expression of UASitpr⁺ (*p<0.005; Student's t-test). Real-time PCR analysis was repeated three times with independently isolated RNA samples for each genotype. Results are expressed as mean±SEM.