Fig. 2. Loss of PTEN function rescues InR null mutations. (A) Pten2L117/Pten2L100 mutant larvae have increased PtdInsP3 levels. Data are presented as PtdInsP3:PtdInsP2 ratios and are standardized to the wild-type y w control. The experiment was performed twice with quantitatively similar results. (B) The Pten2L117/Pten2L100 mutant larva (top) is increased in size compared to the y w control. (C) Scanning electromicrograph (SEM) of a dorsal view of a y w control fly. Bar (above C) is 200 µm in all cases. (D) Loss of PTEN function (Pten2L117/Pten2L117) selectively in the head using the eyFlp system (Newsome et al., 2000) results in the overproliferation of the head. (E) Loss of InR function (InR327/InR327) selectively in the head using the eyFlp system results in a pinhead. (F) Concomitant loss of InR and PTEN function (Pten2L117/Pten2L117; InR327/InR327) in the head is sufficient to suppress the growth and proliferation defect associated with InR single mutants. (G) The 2nd instar lethality associated with the InR304/InR327 allelic combination is rescued to the pharate adult stage in the Pten2L117/Pten2L100; InR304/InR327 double mutant combination (left). (Right) A y w control. (H) The frequency of rescue to the pupal stage of InR304/InR327 (InR1) (n=15 crosses) and InR304/InR25 (InR2) (n=5 crosses) by the partial loss-of-function Pten2L117/Pten2L100 combination. ‘Expected’ denotes the expected Mendelian frequency for complete rescue to the pupal stage for the genotype: y w; Pten2L117/Pten2L100; InR304/InR327 from the cross (y w; Pten2L117; InR304/Cyo^TM6B x y w; Pten2L100; InR327/Cyo^TM6B).