Fig. 5

RIPS-1 protein abundance is strongly induced by RNAi of the hypoxia induction pathway genes. Control RNAi causes minimal induction of RIPS-1::GFP (a, f), and RNAi of the mitochondrial electron transport genes gas-1 (b) and cyc-1 (c) cause mild gut and hypodermal induction, while RNAi of transcription regulators mxl-3 (d) and skn-1 (e, arrowhead) causes mild gut-specific and embryo-specific induction, respectively. Strong gut and intestine induction were observed following RNAi with the hypoxia pathway-associated genes rhy-1 (g) and egl-9 (h) and induced in a gut-specific manner following vhl-1 RNAi (i). The transcription factor HIF-1 was shown to control RIPS-1 induction, as worms reared on control RNAi with 5 mM DTT treatment showed strong RIPS-1::GFP induction (j), while hif-1 RNAi alone (k) or followed by 5 mM DTT treatment (l) failed to induce RIPS-1::GFP. The RNAi of hypoxia pathway gene vhl-1 induced RIPS-1::GFP expression in the gut tissues (i, m), and this strong induction persisted following 5 mM DTT treatment (n). Bright-field images are shown inset; scale bars denote 0.5 mm. GFP quantification for conditions in a–d is shown in o, for f–i is shown in p, and for j, l, and n is shown in q. In o–q, red points with lines denote the mean and SEM, and p-values were determined from one-way ANOVA, followed by Dunnett’s test. NS, not significant, ***p < 0.001. Blue significance marks indicate the comparison of the RNAi groups to control RNAi (L4440)