Fig. 1.

Autophagic activity is elevated at low temperature in C. elegans. a Representative images of autophagosomes (GFP::LGG-1 puncta) in the seam cells and intestinal cells of day 1 worms grown at 15, 20, and 25 °C for 24 h, respectively. The arrow denotes a representative autophagosome. The numbers of GFP::LGG-1 puncta were counted. These results are means ± SD of three independent experiments (n = 30–35 worms per experiment). ***P < 0.001, 15 °C versus 20 °C; ns, not significant. Scale bars: seam cells, 10 μm; intestinal cells, 20 μm. b The ratio of PE-GFP-LGG-1 to GFP-LGG-1 was measured by western blotting in worms. The blot shown here is typical of three independent experiments. These results are means ± SD (n = 3). P < 0.01, 15 °C versus 20 °C. c, d Quantification of GFP::LGG-1 puncta. After 1-day growth at 15, 20, and 25 °C for 24 h, adult worms were injected with 50 mM BafA or DMSO. Two hours after injection, GFP::LGG-1 puncta were quantified in seam cells (c) and intestinal cells (d), respectively. These results are means ± SD of three independent experiments (n = 30–35 worms per experiment). **P < 0.01; ***P < 0.001, 15 °C (+BafA) versus 15 °C (-BafA); ***P < 0.001, 15 °C (-BafA) versus 20 °C (-BafA). Scale bars: seam cells, 10 μm; intestinal cells, 20 μm. e The expression of SQST-1::GFP in adult worms. The right panel shows quantification of GFP levels. These results are means ± SD of three independent experiments (n = 50–55 worms per experiment). *P < 0.05, 15 °C versus 20 °C. Scale bars: 50 μm. f The levels of SQST-1::GFP were measured by western blotting. The blot shown here is typical of three independent experiments. These results are means ± SD (n = 3). P < 0.01, 15 °C versus 20 °C. P-values throughout were calculated using a one-way ANOVA followed by a Student-Newman-Keuls test