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. Author manuscript; available in PMC: 2020 Feb 19.
Published in final edited form as: Nat Metab. 2019 Aug 19;1(8):790–810. doi: 10.1038/s42255-019-0097-9

Figure 3. Thermosensory neurons regulate cold-induced longevity and GSC proliferation.

Figure 3

a, Lifespan of worms at 20°C shifted to lower temperature (15°C) at the indicated days (D). 20°C mean ± s.e.m: 20.72 ± 0.43, shifted to 15°C at D1: 29.85 ± 0.52 (P<0.0001), shifted to 15°C at D3: 29.86 ± 0.49 (P<0.0001), shifted to 15°C at D5: 27.75 ± 0.58 (P<0.0001), shifted to 15°C at D7: 26.92 ± 0.53 (P<0.0001), shifted to 15°C at D10: 23.26 ± 0.48 (P<0.0001). Cold-induced longevity decreases when worms are shifted to lower temperature at day 10 (D10 versus D1-7, P<0.0001). b, Lifespan of worms at 25°C shifted to 15°C at different days. 25°C mean ± s.e.m: 13.09 ± 0.35, shifted to 15°C at D1: 27.43 ± 0.60 (P<0.0001), shifted to 15°C at D3: 26.90 ± 0.80 (P<0.0001), shifted to 15°C at D5: 17.74 ± 0.68 (P<0.0001), shifted to 15°C at D7: 16.98 ± 0.62 (P<0.0001). Cold-induced longevity decreases when worms are shifted to lower temperature at day 5 (D5 versus D1-3, P<0.0001). Worms shifted to 15°C at either day 5 or day 7 exhibit a similar lifespan (P<0.2661). c, Percentage of BrdU-positive cells/total nuclei within the mitotic region (mean ± s.e.m., 25°C D5 and D9 (n=16 germ lines), shifted to 15°C at D1 or D5 (n=20), germ lines from 2 independent experiments). Worms were maintained at 25°C until BrdU analysis (D5 and D9) or shifted to 15°C at the indicated days before BrdU analysis at D9 of adulthood. NS= not significant (D5: WT versus trpa-1 (P=0.6091); WT vs trpa-1;pIL1::trpa-1 (P=0.5948). D9: WT vs trpa-1;pIL1::trpa-1 (P=0.2502). d, Transgenic expression of trpa-1 in IL1 neurons driven by aqp-6 promoter rescues the short-lived phenotype of trpa-1 mutants at 15°C. Wild-type mean ± s.e.m: 25.97 ± 0.73, trpa-1(ok999): 23.34 ± 0.72 (P=0.0127), trpa-1(ok999);pIL1::trpa-1: 27.70 ± 0.70 (P=0.4163). e, Expression of trpa-1 in IL1 neurons rescues low germline proliferation in trpa-1 mutant worms at 15°C. Graph represents the percentage of BrdU-positive cells/total nuclei in the indicated strains at day 5 and 9 of adulthood (mean ± s.e.m., 15 germ lines from 2 independent experiments). f, Specific AFD ablation by driving reconstituted caspase-3 under gcy-8 promoter reduces cold-induced longevity at 15°C (N2 wild-type mean ± s.e.m: 29.88 ± 0.58, pAFD::caspase-3: 25.61 ± 0.69, P= 0.0002). g, ttx-1(p767) mutant worms are short-lived at 15°C (N2 mean ± s.e.m: 27.05 ± 0.69, ttx-1(p767): 23.64 ± 0.54, P< 0.0001). h, ttx-1(oy29) mutant worms are short-lived at 15°C (N2 mean ± s.e.m: 26.81 ± 0.50, ttx-1(oy29): 22.49 ± 0.91, P= 0.0267). i, Percentage of BrdU-positive cells/total nuclei in the indicated strains at day 5 and 9 of adulthood (mean ± s.e.m., D5 (n=30 germ lines), D9 (n=15), germ lines from 3 independent experiments). In lifespan experiments, P-values: two-sided log-rank test, n= 96 worms/condition (see Supplementary Data 3 for statistical analysis and replicate data). In Figures 3c, 3e and 3i, statistical comparisons were made by two-tailed Student’s t-test for unpaired samples. P-value: *(P<0.05), **(P<0.01), ***(P<0.001), ****(P<0.0001).