Worm Breeder's Gazette 10(2): 37
These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.
Mutations in the age-1 gene effect substantial (age-1 mutants live 40% longer than N2 at 20 C) extensions in life span (Friedman and Johnson, 1988, Genetics 118:7586). Because age-1 hermaphrodites also have reduced fertility (at 20 C, age-1 hermaphrodites produce about 50 self progeny), we are performing a series of mating experiments to find out if life extension in age-1 mutants directly results from low fertility. We have measured progeny production and life span in virgin and mated TJ412 [age-1;fer-15(b26ts)] hermaphrodites to determine if mean life span is reduced when mean progeny production is increased. Individual hermaphrodites were cultured first on agar to measure fertility, and then from 8 days until death in liquid microtiter wells to measure life span. Mean progeny production was increased five- to ten-fold in age-1 hermaphrodite by wild type (N2) male crosses. All trials showed significantly lower (P values 0.04, 0.002, <0.001) mean life span for age-1 hermaphrodites when mated to N2 males. Life spans for mated groups were 22, 14, and 16 days, respectively, compared to 31, 22, and 28 days for virgin age-1 hermaphrodites. In these experiments, age-1 hermaphrodites mated to N2 males had life spans indistinguishable from N2. Mated and virgin N2 hermaphrodites were compared to determine if mating itself has an effect on life span. N2 by N2 crosses increased total progeny about two-fold, but did not change life span of hermaphrodites in two trials. Mated N2 also showed significantly lowered life span in one trial. In one trial, TJ412 by TJ412 crosses increased total progeny more than three-fold and showed life span reduction (28 days for unmated; 25 days for mated) that was marginally significant (P value 0.05). TJ412 hermaphrodites mated by TJ412 males were significantly (P = 0.01) longer lived than N2 virgins (21 days). We are currently repeating the experiments with TJ412 and N2 males to find out if the apparent influence of male genotype on life span of mated age-1 hermaphrodites is real. We also are mating age-1 hermaphrodites with BA713 which contains fer-15(b26ts), a gene closely linked to age-1 and present in TJ412, to see if this sperm defect interacts with life span. Correlations between life span and total progeny production in T1412 hermaphrodites mated to N2 or TJ412 males tended to be negative, and repeats will firm up this observation.