Movement as an index of vitality: comparing wild type and the age-1 mutant of Caenorhabditis elegans.

We have asked whether the mutant form of the age-1 gene, which lengthens the life span of the nematode Caenorhabditis elegans up to 70%, also affects the ability to move during this extended period of life. Both age-1 mutants and wild-type controls display a linear loss of movement as the nematodes age. age-1 mutant strains moved faster early in life when compared with non-Age strains and continued low rates of movement at older ages than did non-Age strains. Movement rates were not, in general, a good predictor of movement rates at any later age or of life span. Cumulative lifetime movements of individuals were highly correlated with, and thus a good predictor of, individual life span. These findings are similar to earlier studies of movement in long-lived recombinant-inbred strains of C. elegans and imply that the physiological process altered by the age-1 mutation results in increased health during later life as monitored by increased ability to move.