The dauer larva is a developmentally arrested, dispersal stage formed under conditions of overcrowding and limited food. Mutations in certain genes that cause inappropriate dauer larva formation can also result in extension of adult life span (Kenyon, et al., Nature 366:461, 1993; Larsen, et M., Genetics 139:1567, 1995). A temperature-sensitive daf-2 allele was used to determine when the wild type daf-2 gene functions in the adult. Results suggest that it functions to limit life span throughout adulthood and that the wild-type (limited) life span is not yet fixed in post-reproductive adults. A mechanism consistent with the apparent pliablity in the extension and the post-mitotic state of somatic cells of C. eleyans adults, would be an altered dauer-like physiology/metabolism under the control of DAF-2. The daf-12 mutation gives rise to a synergistic enhancement of the daf-2(e1370) longevity phenotype (2-fold) such that the daf-2(e1370); daf-12(m20) double mutant displays a nearly 4-fold increase of longevity in comparison to wild type animals (Larsen, et al., ibid.). Enhancement of daf-2(e1370) life span also occurs with elk-1 (Lakowski and ttekimi, Science 272:1010, 1996). Mutant daf-2(e1370) males have an extended life span that exceeds the mean and the maximum of both of these double mutants strains. However, these males barely move, unlike daf-2(m41), for which males and hermaphrodites are similarly long-lived. Sluggish movement alone is not sufficient to increase life span. Enhancement of daf-2(e1370) life span could also be a ruetabolic mechanism.
|Original language||English (US)|
|State||Published - Dec 1 1997|
ASJC Scopus subject areas
- Molecular Biology