Baldal E A, Baktawar W, Brakefield P M, Zwaan B J
Institute of Biology, Leiden University, P.O. Box 9516, 2300 RA Leiden, The Netherlands.
Exp Gerontol. 2006 Nov;41(11):1126-35. doi: 10.1016/j.exger.2006.08.014. Epub 2006 Oct 24.
The laboratory has yielded many long-lived mutants of several model-organisms in the past few years. Many of the resulting claims for extended longevity have been nuanced or shown to be restricted to specific conditions, including environments and genetic backgrounds. Here, we test whether the long-lived mutant fruit fly methuselah (mth(1)) displays its apparent superiority in longevity and stress resistance in different environments, at different ages and in correlated traits. The results demonstrate that stress resistance at different times in life is not consistently higher in the mutant relative to its progenitor strain (w(1118)). Furthermore, the mth(1) genotype only leads to an increase in longevity in an environment where reproduction is not stimulated. Also, virgin and mated life span were compared and showed that mating negatively affects life span, especially in the mth(1) individuals. This reduced the life span enhancing effect of the mutation to zero. This apparent environment and mating dependent trade-off between longevity and reproduction supports the disposable soma theory of ageing. We conclude that these data can only provide limited information on natural variation. The data show the need to uncover the full complexity of variation in such traits in natural environments.
在过去几年里，该实验室培育出了多种模式生物的长寿突变体。许多关于这些突变体延长寿命的说法都较为微妙，或者已被证明仅限于特定条件，包括环境和遗传背景。在此，我们测试长寿突变体果蝇玛土撒拉（mth(1)）在不同环境、不同年龄以及相关性状方面，是否在寿命和抗逆性上表现出明显优势。结果表明，相对于其亲代菌株（w(1118)），突变体在生命不同阶段的抗逆性并非始终更高。此外，mth(1)基因型仅在不刺激繁殖的环境中才会使寿命延长。同时，对未交配和已交配果蝇的寿命进行了比较，结果显示交配会对寿命产生负面影响，尤其是对mth(1)个体。这使得突变对寿命的延长作用降至零。这种在寿命和繁殖之间明显的环境及交配依赖性权衡，支持了衰老的“废弃体细胞理论”。我们得出结论，这些数据仅能提供关于自然变异的有限信息。数据表明，有必要揭示自然环境中此类性状变异的全部复杂性。
