Fig. 2.

H₂S increases lifespan in C. elegans. (A) Animals grown in H₂S live longer than untreated controls. The lifespan of animals was monitored in the same conditions in which they had developed. The mean lifespan of animals in H₂S was 22.6 ± 1.0 days (solid line; n = 80), compared with 13.0 ± 1.0 days for untreated controls in room air (dashed line; n = 40). Maximum lifespan also was increased. (B) Exposure to H₂S beginning as L4 does not increase lifespan. All animals were from populations grown in room air. The lifespan of animals moved into H₂S-containing environments at the beginning of the lifespan experiment (solid line) is 14.8 ± 0.3 days (n = 73), which is slightly shorter than controls that remained in house air (dashed line; mean lifespan 18.2 ± 0.4 days; n = 48). (C) Increased lifespan requires continuous exposure to H₂S. The lifespan of all animals was monitored in room air. The lifespan of animals raised in H₂S until L4 (solid line; 12.8 ± 0.7 days; n = 52) was indistinguishable from untreated controls (dashed line; 13.2 ± 0.7 days; n = 59). All lifespan experiments were performed at room temperature.