age-1(
hx546) is a recessive mutant allele in Caenorhabditis elegans that results in an increase in mean life span averaging 40% and in maximal life span averaging 60% at 20C; at 25C
age-1(
hx546) averages a 65% increase in mean life span (25.3 days vs. 15.0 days) and a 110% increase in maximum life span (46.2 days vs. 22.0 days for wild-type hermaphrodites). Mutant males also show extended life spans.
age-1(
hx546) is associated with a 75% decrease in hermaphrodite self-fertility as compared to the
age-1+ allele at 20C. Using two novel strategies for following the segregation of
age-1, we present evidence that longer life results from a mutation in a single gene that increases the probability of survival at all chronological ages. The long-life and reduced-fertility phenotypes cosegregate and are tightly linked to
fer-15, a locus on linkage group II.
age-1(
hx546) does not affect the timing of larval molts, the length of embryogenesis, food uptake, movement, or behavior in any way tested. Although
age-1(
hx546) lowers hermaphrodite self-fertility, it does not markedly affect the length of the reproductive period with all the increase in life expenctancy due to an increase in the length of postreproductive life. In so far as we are aware, this mutant in
age-1 is the only instance of a well-characterized genetic locus in which the mutant form results in lengthened life. It is likely that the action of
age-1 in lengthening life results not from eliminating a programmed aging function but rather from reduced hermaphrodite self-fertility or from some other unknown metabolic or physiologic alteration.