McCulloch Diana, Gems David
Cetre for Research on Ageing, Department of Biology, University College London, London WC1E 6BT, UK.
Ann N Y Acad Sci. 2007 Nov;1119:253-9. doi: 10.1196/annals.1404.018.
Sex differences in longevity and aging are seen throughout the animal kingdom. These are likely to result, in part, from sex differences in endocrinology. In the nematode Caenorhabditis elegans, males are the longer-lived sex. Here we explore the possibility that sex differences in insulin/insulin-like growth factor 1 (IGF-1) and steroid endocrinology contribute to this sex difference in aging by studying C. elegans populations in liquid culture. We report that in hermaphrodite populations, mutational loss of the DAF-12 steroid receptor affected life span as in previous plate-culture studies: mutant longevity is suppressed in a weak daf-2 insulin/IGF-1 receptor mutant but enhanced in a stronger daf-2 mutant. However, in males, mutation of daf-12 had little effect on aging in either weak or strong daf-2 mutants. Moreover, while mutation of daf-12 marginally reduced life span in daf-2(+) hermaphrodites, as in plate-cultured populations, it did not in daf-2(+) males. These results could imply that in C. elegans, as in mammals, sex differences in steroid endocrinology contribute to sex differences in aging.
寿命和衰老方面的性别差异在整个动物界都有体现。这些差异可能部分源于内分泌学上的性别差异。在秀丽隐杆线虫中，雄性是寿命较长的性别。在此，我们通过研究液体培养中的秀丽隐杆线虫群体，探讨胰岛素/胰岛素样生长因子1（IGF-1）和类固醇内分泌学方面的性别差异是否导致了衰老过程中的这种性别差异。我们报告称，在雌雄同体群体中，DAF-12类固醇受体的突变失活对寿命的影响与之前平板培养研究中的情况相同：在弱daf-2胰岛素/IGF-1受体突变体中，突变体的长寿受到抑制，但在强daf-2突变体中则得到增强。然而，在雄性中，daf-12突变对弱或强daf-2突变体的衰老影响很小。此外，虽然daf-12突变在daf-2(+)雌雄同体中略微缩短了寿命，如同平板培养群体中的情况，但在daf-2(+)雄性中却没有。这些结果可能意味着，在秀丽隐杆线虫中，如同在哺乳动物中一样，类固醇内分泌学上的性别差异导致了衰老方面的性别差异。
