Modulation of aging profiles in isogenic populations of Caenorhabditis elegans by bacteria causing different extrinsic mortality rates
Modulation of aging profiles in isogenic populations of Caenorhabditis elegans by bacteria causing different extrinsic mortality rates
复制标题
DOI：
10.1007/s10522-009-9228-0
复制
发表时间：
2010-02-01
期刊：
影响因子：
4.5
通讯作者：
Matic, Ivan
中科院分区：
文献类型：
--
作者：
Baeriswyl, Simon;Diard, Mederic;Matic, Ivan
据推测，寄生虫的存在导致高外源性死亡率可能会引发诱导加速宿主衰老。我们使用秀丽隐杆线虫线虫和不同大肠杆菌菌株的同基因群体测试了这一假设。当暴露于病原菌时，线虫的死亡率高达四倍，繁殖更早，产生更多的H2O2，并积累更多的自发荧光，而不是暴露于无害的菌株。我们还观察到，老年动物的死亡率增长速度较慢，这种现象被称为死亡减速。死亡率减速在死亡更快的人群中开始得更早，这可能是个体死亡倾向之间终身异质性的结果。综上所述，我们的研究结果强烈表明，病原体造成的高外在死亡率导致线虫的生活史特征，包括衰老和繁殖的调制。这可能是一种适应性反应，旨在最大化达尔文适应性。
It has been postulated that the presence of parasites causing high extrinsic mortality may trigger an inducible acceleration of the host aging. We tested this hypothesis using isogenic populations of Caenorhabditis elegans nematodes and different Escherichia coli strains. When exposed to pathogenic bacteria, nematodes showed up to fourfold higher mortality rates, reproduced earlier, produced more H2O2, and accumulated more autofluorescence, than when exposed to an innocuous strain. We also observed that mortality increased at a slower rate in old animals, a phenomenon known as mortality deceleration. Mortality deceleration started earlier in populations dying faster, likely as a consequence of lifelong heterogeneity between individual tendencies to die. Taken together, our results strongly suggest that the high extrinsic mortality imposed by the pathogens results in the modulation of nematodes' life-history traits, including aging and reproduction. This could be an adaptive response aiming at the maximization of Darwinian fitness.