The methionine cycle is required for the longevity effect of glycine in <i>C</i>. <i>elegans</i>.

(A) The lifespan analysis of N2 worms fed control diet (UV-killed E. coli OP50) or 500 μM glycine diet showing that 500 μM glycine supplementation significantly promotes lifespan (p (B and C) Lifespan analysis of the mutant metr-1(ok521) worms or (B) sams-1(ok3033) worms (C) supplemented with 500 μM glycine diet compared to their corresponding mutant worms fed control diet (UV-killed E. coli OP50). Comparisons of survival curves were performed by log-rank tests. See S1 Table for lifespan statistics.