FIGURE 6.

Drice and Dronc are essential for the survival of larvae lacking dS2P. A, virgin females homozygous for dS2P² were crossed to males heterozygous for dS2P¹. Parallel cultures were inoculated with 10 mg/plate of embryos on regular or supplemented medium (14:0 + 18:1). Larvae were scored on day 2 and day 4 AEL. A cross of dSREBP¹⁸⁹ heterozygotes served as a control for the efficacy of rescue. B, fly lines harboring mutations in both dS2P¹ or dS2P² and in drice^Δ1 were constructed as described under “Experimental Procedures.” Virgin females homozygous for dS2P² and heterozygous for drice^Δ1 were crossed to males heterozygous for dS2P¹ and drice^Δ1. The dS2P homozygous, drice^Δ1 heterozygous females were raised on medium supplemented with fatty acids to enable efficient recovery of these flies. Larvae homozygous or heterozygous for drice^Δ1 and wild type for dS2P survived equally well under all conditions tested in this experiment. C, crosses of flies doubly mutant for dS2P and dronc⁵¹ were conducted as described in B. Horizontal lines corresponding to the value for dSREBP¹⁸⁹ larvae under each condition are shown to facilitate comparison (black, supplemented medium; gray, unsupplemented medium). “+” indicates wild type, and “–” indicates null alleles as described above. Note that the values displayed are for whole populations rather than samples. * indicates p < 0.005 for day 2 compared with day 4. † indicates p < 0.005 for supplemented compared with unsupplemented medium. ‡ indicates p < 0.005 for dS2P transheterozygotes compared with dS2P; caspase larvae. A mean of 1057 larvae were scored for each cross and condition (range = 1446 to 751). The results shown are from a single experiment and are representative of three independent replications.