Temperature dependence of tumor formation in w1118 host flies after transplantation of third instar larval brain pieces of brat-RNAi knockdown using insc-Gal4 driver Temperature Time after Transplantation Percentage of Tumor Number of tumor-positive flies/total number of transplanted flies 29 oC 1 week 65% 13/20 2 weeks 83% 10/12 25 oC 1 week 42% 5/12 2 weeks 60% 6/10 18 oC 2 weeks 16% 2/12 3 weeks 16% 2/12 4 weeks 40% 4/10 5 weeks 78% 7/9

Table 2: brat-RNAi driven by insc-Gal4 in all brain neuroblasts results in an overproliferation, which results in tumor formation in host flies upon transplantation. The frequency of tumor formation at different time points (after transplantation) is recorded and displays a marked temperature dependence effect, with maximum frequency of tumor formation seen at 29°C, intermediate at 25°C and minimum at 18°C.