Fig. 5.

Autophagy in the epidermis is involved in lifespan extension at low temperature. a–c Epidermal-specific knockdown of bec-1 (a), let-512 (b), and epg-1 (c) by RNAi significantly reduced the lifespan of worms at 15 °C. P < 0.01 versus EV. d–f Intestinal-specific knockdown of bec-1 (d), let-512 (e), and epg-1 (f) by RNAi did not influence the lifespan of worms at 15 °C. P > 0.05 versus EV. P-values (a–f) were calculated using log-rank test. See Supplementary Data 1 for details. g The relative collagen levels in 8-day-old worms at 15 °C were markedly higher than those at 20 °C. Inhibition of autophagy by bec-1 RNAi significantly reduced the collagen levels in 8-day-old worms at 15 °C. The data are expressed as percent of control (the value of 1-day-old worms at 20 °C). These results are means ± SD (n = 3). *P < 0.05, 8-day-old worms with EV at 15 °C versus 8-day-old worms with EV at 20 °C, or 8-day-old worms with bec-1 RNAi at 15 °C. ns, not significant. P-values (g) were calculated using a one-way ANOVA followed by a Student-Newman-Keuls test