Sex-specific Effects of the DAF-12 Steroid Receptor on Aging in Caenorhabditis elegans

摘要

Sex differences in longevity and aging are seen through-out the animal kingdom. These are likely to result, in part, from sexdifferences in endocrinology. In the nematode Caenorhabditis elegans,males are the longer-lived sex. Here we explore the possibility that sexdifferences in insulin/insulin-like growth factor 1 (IGF-1) and steroidendocrinology contribute to this sex difference in aging by studyingC. elegans populations in liquid culture. We report that in hermaphroditepopulations, mutational loss of the DAF-12 steroid receptor affected lifespan as in previous plate-culture studies: mutant longevity is suppressedin a weak daf-2insulin/IGF-1 receptor mutant but enhanced in a strongerdaf-2 mutant. However, in males, mutation of daf-12 had little effect onaging in either weak or strong daf-2 mutants. Moreover, while mutationof daf-12 marginally reduced life span in daf-2(+) hermaphrodites, asin plate-cultured populations, it did not in daf-2(+) males. These resultscould imply that in C. elegans, as in mammals, sex differences in steroidendocrinology contribute to sex differences in aging.