Lithgow G J, White T M, Melov S, Johnson T E
Institute of Behavioral Genetics, Boulder, CO, USA.
Proc Natl Acad Sci U S A. 1995 Aug 1;92(16):7540-4. doi: 10.1073/pnas.92.16.7540.
We have discovered that three longevity mutants of the nematode Caenorhabditis elegans also exhibit increased intrinsic thermotolerance (Itt) as young adults. Mutation of the age-1 gene causes not only 65% longer life expectancy but also Itt. The Itt phenotype cosegregates with age-1. Long-lived spe-26 and daf-2 mutants also exhibit Itt. We investigated the relationship between increased thermotolerance and increased life-span by developing conditions for environmental induction of thermotolerance. Such pretreatments at sublethal temperatures induce significant increases in thermotolerance and small but statistically highly significant increases in life expectancy, consistent with a causal connection between these two traits. Thus, when an animal's resistance to stress is increased, by either genetic or environmental manipulation, we also observe an increase in life expectancy. These results suggest that ability to respond to stress limits the life expectancy of C. elegans and might do so in other metazoa as well.
我们发现，线虫秀丽隐杆线虫的三个长寿突变体在成虫早期也表现出内在耐热性（Itt）增强。age-1基因的突变不仅使预期寿命延长65%，还导致Itt增强。Itt表型与age-1基因共分离。长寿的spe-26和daf-2突变体也表现出Itt增强。我们通过开发环境诱导耐热性的条件，研究了耐热性增强与寿命延长之间的关系。在亚致死温度下进行这样的预处理可显著提高耐热性，并使预期寿命有小幅但在统计学上高度显著的增加，这与这两个性状之间的因果关系一致。因此，当通过基因或环境操纵提高动物对压力的抵抗力时，我们也会观察到预期寿命的增加。这些结果表明，应对压力的能力限制了秀丽隐杆线虫的预期寿命，在其他后生动物中可能也是如此。
