Reproductive Activity of C. elegans Hermaphrodites

<p>(A), (C–E), (G), and (I) show average daily progeny production of live hermaphrodites. (B), (F), (H), and (J) show the percentage of live hermaphrodites producing progeny. The <i>daf-2</i> plot (H) does not end at zero percent because no <i>daf-2</i> hermaphrodites survived beyond day 12. Number of hermaphrodites at the start of the experiment is presented in <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.0030025#pgen-0030025-t001" target="_blank">Table 1</a>. Hermaphrodites were mated for days 1 and 2 to three wild-type (WT) males, except data labeled Self. Studies were conducted at 20 °C, except data labeled 15 °C and 25 °C. The mutant alleles were <i>isp-1(qm150</i>)<i>, clk-1(qm30</i>)<i>, eat-2(ad465), daf-2(e1370</i>)<i>,</i> and <i>daf-16(mu86</i>)<i>.</i> Wild-type hermaphrodites were exposed to 2 mg/ml ethosuximide (+ETH) from conception until death (I and J).</p

Reproductive Aging Is Independent of Early Progeny Production

<p>Wild-type (A), <i>spe-8(hc50)</i> (B), or <i>fog-2(q71)</i> (C) hermaphrodites were mated to wild-type (WT) males for 24–48 h starting with the day specified. Graphs show daily progeny production, and (D) shows the average total progeny production (+/−standard error) for days 1–7 and days 8–12. N, the number of animals examined. * and ** represent a <i>p</i>-value of 0.01−0.05 and <0.01, respectively, compared to the mated day 1 value of the same genotype. (E) A summary of the effects on early and late reproduction of an anticonvulsant drug, temperature, and mutations that affect mitochondrial function, caloric intake, and IGF signaling.</p

Reproductive Aging Contributes to the Ability of Animals to Generate the Optimal Progeny Number

<p>Hypothetical progeny production curves illustrate three mechanisms for controlling progeny number: the timing of the onset of progeny production (labeled 1), the level of steady-state progeny production (labeled 2), and the timing of cessation of progeny production or reproductive aging (labeled 3). Reproductive aging might be sculpted during evolution by selection for animals that generate the optimal number of progeny.</p