Fig. 4.

O-GlcNAc cycling mutants affect aging and the stress response. The absence of O-GlcNAc modifications in ogt-1(ok430) resulted in shorter lifespan in (A) wild-type and (B) daf-2(e1370) animals. In contrast, an overabundance of O-GlcNAc modification in oga-1(ok1207) mutants had a negligible effect on wild-type lifespan (A), but extended lifespan of daf-2(e1370) animals in a daf-16-independent manner (B and C). Data are from individual representative trials; all results are presented in Dataset S5. Number of animals scored: (A) control, n = 88; ok1207, n = 83; ok430, n = 86; ok430;ok1207, n = 72; (B) control, n = 101; ok1207, n = 101; ok430, n = 95; ok430; ok1207, n = 102; (C) daf-2 daf-16 RNAi, control n = 54; ok1207, n = 59; daf-16(mu86);daf-2, control n = 88; ok1207, n = 76. Experiment in A was performed at 25 °C; similar results were obtained at 20 °C; B and C were performed at 20 °C. Animals in A and B were grown on OP50 food source; animals in C were grown on HT115 bacteria. (D) Neither mutant significantly affected daf-2 fertility at either the semipermissive (22.5 °C) or the restrictive (25 °C) temperature. Error bars represent SD for three independent experiments; P > 0.3. (E) The absence of the O-GlcNAc modification in ogt-1(ok430) decreased resistance to UV stress, whereas the abundance in oga-1(ok1207) increased stress resistance. Young adult hermaphrodites were exposed to 23 mJ of UV radiation and were followed for 3 days to determine the fraction surviving. (F) A large pool of DAF-16:GFP accumulates in the nucleus in ogt-1(ok430) L1 hermaphrodites (Left) without stress induction. In contrast, wild-type animals have very little DAF-16::GFP in the nucleus (Inset). Upon heat challenge at 37 °C for 10 min, nuclear DAF-16::GFP was detected in 100% of N2, ogt-1(ok430), and oga-1(ok1207) animals (Table S4). Quantitation of the fraction of animals with nuclear DAF-16::GFP in the absence of stress (Right).