Fig. 2.

AdoR is activated by adenosine released from polarity-deficient epithelial cells. a–d Ent2 overexpression (sal> ent2) activates TRE-dsRed in the wing disc. This is suppressed by expression of JNK^bskDN or silencing of AdoR. e–g AdoR overexpression (sal> AdoR) causes a very mild activation of TRE-dsRed on its own, but strongly enhances JNK activation caused by overexpression of Ent2. h CADO treatment increases expression of the JNK target gene dilp8 in explanted wild-type, but not in AdoR mutant discs. This effect is further enhanced by AdoR overexpression. Here, TNFR^grnd expression, measured by RT-qPCR, is shown as a control. Fold changes are relative to rp49, n ≥ 5. i–k AdoR overexpression leads to a strong enhancement of scrib-RNAi mediated activation of JNK signalling. l, m Silencing of various equilibrative adenosine transporter genes (ent1, ent2, ent3) by RNAi, reduction of Ent2 activity in a hypomorphic background, ent2^1/3 (l) or overexpression of AdoK (m) suppress scrib-RNAi mediated activation of JNK, whereas silencing of concentrative adenosine transporter (cnt1), ecto-nucleotidase NT5E-1 or NT5E-2 had no effect (l). Experimental RNAi lines in (l) were compared to ‘GFP-Ri’ for statistical analysis. Scale bars, 50 μm. In graphs, means are shown, and error bars represent ±SD; ****P < 0.0001, ^n.s.P ≥ 0.05, unpaired two-tailed Student’s t-test (males and females pooled together)