a, Germline-lacking worms (glp-1(e2141)) are long lived compared to wild-type (N2) strain at 20°C (N2 20°C mean ± s.e.m: 20.15 ± 0.40, glp-1 20°C: 26.90 ± 0.58, P<0.0001). In contrast, germline-lacking worms are short lived in comparison with wild-type worms at cold temperatures (N2 15°C: 29.01 ± 0.58, glp-1 15°C: 24.39 ± 0.56, P<0.0001; N2 10°C: 42.94 ± 1.05, glp-1 10°C: 33.95 ± 0.46, P<0.0001). b, Temperature reduction (15°C) extends lifespan of wild-type worms (N2 20°C mean ± s.e.m: 16.40 ± 0.60, N2 15°C: 26.73 ± 0.77, P<0.0001) but not glp-1 germline-lacking worms (glp-1 20°C: 21.59 ± 0.66, glp-1 15°C: 21.78 ± 0.60, P= 0.6396). Wild-type worms are long lived compared with glp-1 mutant worms at cold temperature (N2 15°C versus glp-1 15°C, P<0.0001). c, Temperature reduction extends lifespan of wild-type worms (N2 20°C mean ± s.e.m: 17.83 ± 0.58, N2 15°C: 26.81 ± 0.90, P<0.0001) but not glp-4(bn2) germline-lacking worms (glp-4 20°C: 16.44 ± 0.49, glp-4 15°C: 16.71 ± 0.45, P= 0.7379). Wild-type worms are long lived compared with glp-4 mutant worms at cold temperature (N2 15°C versus glp-4 15°C, P<0.0001). d, Temperature reduction extends lifespan of sterile fer-15(b26);fem-1(hc17) and fog-1(q250) mutant worms with a proliferating germ line. N2 20°C mean ± s.e.m: 18.17 ± 0.53 versus N2 15°C: 27.20 ± 0.67, P<0.0001; fer-15;fem-1 20°C: 21.42 ± 0.50 versus fer-15;fem-1 15°C: 28.46 ± 0.74, P<0.0001; fog-1 20°C: 19.62 ± 0.49 versus fog-1 15°C: 27.22 ± 0.70, P<0.0001. e, Temperature reduction (15°C) extends lifespan of sterile fog-2(q71) and spe-26(it112) mutant worms with a proliferating germ line. N2 20°C mean ± s.e.m: 17.01 ± 0.48 versus N2 15°C: 27.79 ± 0.60, P<0.0001; fog-2 20°C: 16.55 ± 0.46 versus fog-2 15°C: 27.94 ± 0.62, P<0.0001; spe-26 20°C: 17.51 ± 0.54 versus spe-26 15°C: 29.96 ± 0.67, P<0.0001. f, Wild-type larvae were raised at 25°C and then adult worms were shifted to the indicated temperatures. Exposure to low temperature (15°C) during adulthood is sufficient to extend longevity (P<0.0001). 25°C (development and adulthood) mean ± s.e.m: 13.38 ± 0.43, shifted to 20°C after development: 19.28 ± 0.44, shifted to 15°C after development: 29.07 ± 0.72, 15°C (development and adulthood): 29.89 ± 0.76. g, After development at 20°C, adult wild-type worms were shifted to the indicated temperatures. Exposure to low temperature during adulthood extends longevity (P<0.0001). 20°C (development and adulthood) mean ± s.e.m: 20.25 ± 0.44, shifted to 25°C after development: 13.66 ± 0.37, shifted to 15°C after development: 29.11 ± 0.53, 15°C (development and adulthood): 26.65 ± 0.70. P-values: two-sidedlog-rank test, n= 96 worms/condition. See Supplementary Data 3 for statistical analysis and replicate data of lifespan experiments.