Figure 1

Identification of a spontaneous E. coli mutant that extends lifespan. A) Survival curves of rrf-3(pk1426); daf-2(m577) animals at 25°C on the control strain (n = 201): HT115(DE3) containing the empty vector L4440 and a strain, containing the plasmid for the ugt-27 gene, that caused a 50% increase in lifespan (n = 92, P = < 0.0001). B) Survival of rrf-3 (25°C) on the mutant strain from which the ugt-27 has been lost (n = 68) compared with the control strain in which the L4440 empty vector has been lost (n = 62). Increase in lifespan = 49.6% (P = < 0.0001). C) Position of the IS1 transposon insertion at position 1777116 on the E. coli K12 W3110 chromosome [44] (diagram based on EcoCyc.org [45]). As the insertion is at nucleotide 717 of the aroD open reading frame, the allele is designated aroD717::IS1. D) The lifespan effect of the mutant bacteria is rescued by the plasmid containing aroD. glp-4(bn2) animals were raised on the aroD mutant until L4 (15°C) and then transferred to the aroD mutant + pMMB67EH vector (n = 126), aroD mutant + pMMB67EH plasmid containing aroD region (n = 85), wild type bacteria + vector (n = 126) (25°C). E) Worms maintained on the aroD deletion mutant from the Keio collection (n = 128) show an extended lifespan compared to wild type (n = 131). P = < 0.001.