Fig. 2. Ice is required for normal pupal development. (A) The percent viability to adulthood for wandering third instar larvae of several different genotypes is shown: wild type, Ice¹, Ice^+2.4; Ice¹, dcp-1^Prev1 and dcp-1^Prev1; Ice1. (B-G) Paraffin sections of pupae aged 24 hours after puparium formation (apf). (B) In control pupae, salivary glands and larval muscle have both disappeared and the larval mid-gut has degenerated, as previously described (Lee and Baehrecke, 2001). (C) Seventy-three percent of Ice¹ pupae develop normally. By 24 hours apf, only a few remaining small degraded fragments of salivary glands and larval muscles are observed and the mid-gut is normal. (D) Twenty-seven percent of Ice¹ pupae were arrested in development. Of those that arrested, one-third did not undergo head eversion and arrested prior to the commencement of salivary gland cell death. The remaining pupae appear to have arrested 1 or 2 hours after head eversion, and thus the salivary glands and larval muscle are not degraded, and the larval gut has failed to condense properly. Ice¹ pupae have abnormal masses in the head (C,E), wing and leg discs (C,F), and abdomen (G). Arrows indicate abnormal masses; arrowheads indicate muscle; red circles are placed around salivary glands, salivary gland fragments and regions where degraded salivary glands would be if they had failed to die. Animals homozygous for Ice¹ lack zygotic but not maternal Ice. Scale bars: 200 µm in B-D; 40 µm in E-G.