Figure 1. Two types of corpse in ageing C. elegans populations.

(a) Positive correlation between pharyngeal pathology on day 7 of adulthood and age at death. (n=16). (b) Corpses with an enlarged or atrophied pharynx. For comparison, the pharynx of a healthy 10-day-old adult worm is shown. The posterior bulb is outlined. Scale bar, 40 μm. (c) Age distribution of P and p deaths. y Axis shows cross-sectional area of pharynxes on the day of death (n=179). Dotted lines represent the size of a healthy pharynx on day 10 (mean±s.d.). (d) Survival curves of all worms (black) or with P and p deaths resolved (red and blue, respectively). Data compiled from 11 independent trials (n=622). An additional single large trial (n=587) was also performed (Supplementary Fig. 3e). (e) Age changes in pharyngeal size in individual worms. Early deaths (mostly pre-day 15) are preceded by a dramatic increase in pharyngeal size. The pharynxes of the remaining worms gradually decrease in size until death (n=29). (f) Mean pumping rate of worms that die with P. Day 0, first day of swelling. Worms show a major reduction in pumping rate immediately before pharyngeal swelling. Data are mean±s.e.m. (Trials: 1, n=17). (g) Segmented linear regression analysis on log mortality rate of wild-type survival under standard conditions (data as in d, X₀=11). The slopes before and after day 11 are significantly different (slope test P=2.81 × 10⁻⁹). (h) Mortality deconvolution of wild-type survival (data as in d). Age-specific mortality rates of the whole population (black) or with P and p deaths resolved (red and blue, respectively).