Isolating aging mutants: a novel method yields three strains of the nematode Caenorhabditis elegans with extended life spans

We designed a novel procedure for the isolation of mutant strains with sign ificantly increased life spans in the nematode Caenorhabditis elegans. This procedure involves using heat-shock to screen a large number of animals an d isolate a few which are more resistant to heat-shock stress. From the hea t-shock-resistant animals, three mutant strains, HG25, HG96, and HG246, all exhibiting increased life span, were isolated. One mutant strain (HG246) d evelops more slowly than the wild-type strain, N2. Two mutant strains, HG96 and HG246, exhibit lower fertility than the wild-type. Each of the three m utant strains has a normal appearance. Their locomotive behavior also appea rs normal; only HG246 shows slightly slower movement. Their feedings behavi or appears normal, and the males of HG25 and HG96 show normal mating behavi or. However, the males of HG246, either are defective in their mating abili ty or their sperm are defective. The results indicate that heat-shock can b e used as a means to facilitate the isolation of mutants which have longer Life expectancy. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved .