Fig. 2.
Enterocyte p38 signaling promotes ISC proliferation via cytokine Upd3/Jak-Stat signaling. a Multiple stresses induce cytokine and JAK-STAT target gene expression. Mean relative mRNA with s.e.m. from n = 3 independent experiments of cytokine upd3 mRNA levels (one-way ANOVA: p < 0.0001; Dunnett’s: P.e. < 0.0001, Ecc15 = 0.0323, H2O2 = 0.4896, SDS = 0.0089, bleomycin = 0.409, heat shock = 0.0392) and JAK-STAT target, Socs36E, mRNA levels (one-way ANOVA: p = 0.0002; Dunnett’s: P.e. < 0.0001, Ecc15 < 0.0001, H2O2 = 0.3157, SDS < 0.0001, bleomycin < 0.0001, heat shock < 0.0001) determined by qPCR from stressed and unstressed w1118 midguts. b p38 signaling promotes cytokine induction upon P.e. infection. Mean relative mRNA with s.e.m. from n = 3 independent experiments of cytokine upd3 mRNA levels determined by qPCR from uninfected and infected midguts with p38b- (one-way ANOVA: p = 0.0223; one sample t test: p = 0.0452) and p38a + b-depleted (one-way ANOVA: p = 0.0202; one sample t test: p = 0.0421) in ECs for 7 days and control midguts (Myo1Ats). c Overexpression of MKK3/Licorne in ECs promotes cytokine expression. Mean relative mRNA with s.e.m. from n = 3 independent experiments of upd2 (one sample t test: p = 0.0488) and upd3 mRNA (one sample t test: p = 0.0467) levels determined by qPCR on midguts overexpressing Licorne for 1 day using EC-specific, Myo1Ats and control midguts (Myo1Ats). d–g p38 signaling in enterocytes promotes Stat activity upon P.e. infection. Increased 10x STAT-GFP is observed in P.e.-infected control midguts (e right, green) compared with uninfected control midguts (d right, green). Reduced 10x STAT-GFP is observed however in P.e.-infected midguts expressing p38a + bRNAi in ECs for 7 days (f right, green) compared with P.e.-infected control midguts. Quantified GFP levels are in g (n = 3 midguts from one experiment; unpaired t test; p = 0.0017). DNA is in blue. Scale bars in d–f are 50 μm. Representative images in d–g from three experiments. Source data are provided as a Source Data File