THE EFFECTS OF TEMPERATURE ON THE LONGEVITY OF A RADIATION-SENSITIVE MUTANT RAD-8 OF THE NEMATODE CAENORHABDITIS-ELEGANS

The effects of temperature on development and life span were examined in a radiation- and oxygen-hypersensitive mutant (rad-8) of the nematode Caenorhabditis elegans. At temperatures greater than 20 degrees C, the rad-8 mutant developed slightly slower and possessed a life span roughly equivalent to that of the wild type. At 16 degrees C, however, the mutant lived considerably longer than the wild type, with mean life spans of approximately 28 and 21 days, respectively. This lengthened life span was due to slower development. It was also dependent upon oxygen concentration, because the mean life spans of rad-8 and wild type were experimentally identical when reared at 16 degrees C in the presence of 5% rather than atmospheric oxygen. The rad-8 mutant represents an interesting paradox, as its life span can either be shortened or lengthened relative to the wild type, depending on temperature and oxygen concentration.