Figure 2.

Survivals of C. elegans wild-type strain CL2a, and two congenic lines derived from CL2a by introgression of the chromosome IV stP13–stP35 region from Bergerac-BO. SR700 and SR701 are independent congenic lineages generated by 20 generations of backcrossing, with marker-based selection of the Bergerac-BO allele for stP13, stP44, and stP35. Homozygotes for the introduced lsq4 region were ascertained, expanded, and used to measure survival at 20°C. (A) Survivals in liquid medium. (B) Survivals on solid agar medium. Protocols for nematode culture, scoring, and survival analysis are described in the “Materials and Methods” section. Each survival group was initiated with 56–70 worms at late L4, on two plates; after exclusion of censored losses, total numbers of natural deaths ranged from 50 to 65. Adult age is measured from the L4/adult molt; total age is the indicated “adult age” plus 2.5 days for all strains.