Research Paper Volume 15, Issue 21 pp 11720—11739

Figure 1. Schematic of the procedure used to establish long and short generation lines with consistent parental age at reproduction. Lines were established with short generation time (SG) or long generation time (LG) by maintaining the same parental age at reproduction for the next generation. For the reversal experiments, progeny of older parents were maintained for a certain number of long generations and then progeny were recovered at a younger age for several short generations. Using LG5.SG3 as an example, the progeny of the fifth long generation were recovered at a younger age for an additional three generations, and the progeny were then analyzed. The parental age for SG and LG lines was day 2 and day 4–5 of adulthood, respectively, for C. elegans (A), and day 2–6 and day 15–40 of adulthood, respectively, for D. melanogaster (B), depending on the genetic background.