Figure 2.

Exogenous dafachronic acid (DA) extended the lifespan of wild type (WT) worms at elevated temperatures in a daf-12-, daf-16-, and hsf-1-dependent manner. (A−C) Exogenous DA supplemented only during adulthood extended the lifespan of WT worms cultured at 25° (B) and 28° (C), but not at 20° (A). (D) WT day-1 adults exhibited weak or strong nuclear accumulation of DAF-16::GFP (indicated by arrows) 12 hr after a temperature shift from 20° to 25° or 28°. (E−J) The lifespan extension effect of DA at 25° and 28° required daf-12 (E, H), daf-16 (F, I), and hsf-1 (G, J). Δ4-DA was not tested in the lifespan assays at 28° nor in the lifespan assay of the hsf-1 mutant at 25°.