Comparative demography of isogenic populations of Caenorhabditis elegans

Demographic characteristics of the bacterial-feeding nematode Caenorhabditi s elegans were determined in two long-lived mutant strains, TJ1052 (age-1), CB4876 (clk-1), and a wild-type strain, N2. Within each strain, there was little correlation between longevity and reproduction for individuals that lived longer than 10 days. Long-lived mutant strains produced fewer eggs th an the wild type. Mean total life spans were 13.2 days for the wild type, 2 1.9 days for age-1, and 15.8 days for clk-1; maximum life spans were 24 day s for the wild type, 47 days for age-1, and 32 days for clk-1. Differences in total life span resulted primarily from longer post-reproductive surviva l. The mean post-reproductive life spans were longer than the wild type by 183% in age-1 and 60% in clk-1. We conclude that (i) post-reproductive surv ival is not correlated with egg production within isogenic populations of C . elegans, and (ii) the relationship between reproduction and longevity dif fers among isogenic populations with specific longevity genes. (C) 2001 Els evier Science Inc. All rights reserved.