THERMOTOLERANCE OF A LONG-LIVED MUTANT OF CAENORHABDITIS-ELEGANS

Age-synchronous cohorts of Caenorhabditis elegans were grown at 20 deg rees C, then stressed at 30 degrees C or 35 degrees C. Intrinsic therm otolerance of wild type and age-1 mutant strains was assessed by measu ring either progeny production or survival. in addition to increased l ife span (Age), mutation of age-1 results in a highly significant incr eased intrinsic thermotolerance (Itt) as measured by survival at 35 de grees C. Mean survival of ge strains is approximately 45% longer than that of non-Age strains for both sterile and nonsterile worms. Thermot olerance declines across the life span of both Age and non-Age strains , but In was observed at almost all ages. Unstressed age-1 animals sho wed a consistent and significant fertility deficit. Short thermal stre sses can cause a dramatic reduction in progeny production for both Age and non-Age genotypes. Mutants of age-1 showed a small but consistent increased thermotolerance as measured by fertility. We propose that t he enhanced ability of Age strains to cope with environmental stress m ay be mechanistically related to their lower age-specific mortality ra tes.