Figure 4. The lifespan extension induced by thymine depends on reproductive signals. (A–D) Lifespan analysis of (A) glp-1 (e2144), (B) daf-2 (e1370), (C) sir-2.1 (ok434), and (D) eat-2 (ad1116) animals treated with 2 mM thymine (red) and vehicle (black), on heat-inactivated E. coli OP50 (log-rank test). Lifespan values of replicated experiments are summarized in Supplementary Table 1. (E) The number of daily progeny and the total number of progeny of wild-type N2 worms treated with 2 mM thymine or vehicle. (F, G) DAPI-stained image of worm gonads. (H) Quantification of germline stem cells in wild-type N2 animals treated with 2 mM thymine or vehicle; n.s. not significant (Student’s t test). (I) Quantification of ORO staining. Mean ± SD.; n ≥ 30 per condition; P value was calculated using Student’s test; no significance is abbreviated as n.s. *p < 0.05, **p < 0.01, ***p < 0.001.