Figure 1. Tissue stress promotes ISC tumor initiation.

(a) System to independently express transgenes in ECs with Myo1A^ts and subsequently initiate ISC- derived tumors by heat shock- induced Flp-FRT mediated recombination.

(b) Mean number of tumors per midgut with s.e.m. 14 days (18°C) after tumor induction following GFP (n=20 midguts), JNKK (hep) (n=12 midguts, Mann-Whitney: p=0.0203) or activated JNKK (hep^Act) (n=10 midguts, Mann-Whitney: p=0.0002) expression in ECs with Myo1A^ts for 5 days (29°C). Midguts pooled from 2 independent experiments.

(c) Mean percent of flies with tumors with s.e.m. from n=3 independent experiments 14 days (18°C) after tumor induction following GFP, JNKK (hep) or activated JNKK (hep^Act) (paired t-test: p=0.0076) expression in ECs with Myo1A^ts for 5 days (29°C).

(d) Cells per neur^IF65/− tumor with mean (red line) and s.e.m. 14 days (18°C) after tumor induction following GFP (n=13 tumors pooled from 20 midguts), JNKK (hep) (n=31 tumors pooled from 12 midguts) or activated JNKK (hep^Act) (n=77 tumors pooled from 10 midguts) expression in ECs with Myo1A^ts for 5 days (29°C). Midguts pooled from 2 independent experiments.

(e) Mean percent of flies with tumors with s.e.m. from n=3 independent experiments in flies expressing GFP and N^RNAi or N^RNAi, Cyclin E (CycE) and cdc25/string (stg) (paired t-test: p= 0.0185) with esg^ts (weak) for 3 days.

(f) Mean percent of flies with tumors with s.e.m. from n=3 independent experiments after being fed food alone, P.e. containing food (paired t-test: p=0.0034), sucrose alone or P.e. containing sucrose (paired t- test: p=0.0007) for 1 day prior to tumor induction by expressing N^RNAi with esg^ts (weak) for 3 days (food alone).