Fig. 6

Gain or loss of utx-1 expression in specific tissues induces lifespan extension. a Expression of GFP in transgenic lines was monitored to confirm tissue-specific expression. Top left panel: muscle cell expression of utx-1::gfp driven by the myo-3 promoter (white arrows); top right panel: epidermal expression driven by the dpy-7 promoter (white arrows); bottom left panel: neuronal expression driven by the rab-3 promoter (white arrows); bottom right panel: intestinal expression driven by the vha-6 promoter (white arrows). White dashed line is the outline of the worm in each case. b Lifespan assays were performed on transgenic animals overexpressing utx-1 in specific tissues. Lifespan extension was observed when utx-1 was overexpressed in neuronal and intestinal cells (****p < 0.0001 in both cases), but not in epidermal or muscle cells. c–f Lifespan assays were performed in animals subjected to tissue-specific knockdown of utx-1 by RNAi. In the case of muscle, epidermal and intestinal knockdown, the RNAi insensitive rde-1(ne219) mutant was used, rescued by muscle- (c), epidermal- (d) or intestinal-driven (f) rde-1, and animals subjected to utx-1 RNAi post-embryonically. For neuronal knockdown (e), sid-1 was expressed pan-neuronally in the RNAi-insensitive sid-1 mutant background, and utx-1 RNAi performed post-embryonically. Marked lifespan extension was seen in epidermal and neuronal knockdown (****p < 0.0001 in each case), slight lifespan extension was seen in intestinal knockdown (**p = 0.009) and no lifespan extension was associated with muscle-specific knockdown. EV, empty vector control (i.e. worms fed HT115 bacteria transformed with L4440 RNAi vector lacking a genomic insert) (see Additional file 13: Table S8 for the full statistical analysis of lifespan data, including repeats)