RESUMO
Dietary restriction (DR) delays the onset of age-related deterioration and extends the life span in a variety of model organisms. In many species, age changes in mortality obey the Gompertz equation, which describes an exponential increase with age in age-specific mortality rate. Recently, this model has been used in fruitflies and rodents to investigate the mechanism by which DR reduces adult mortality. We report that food restriction imposed by axenic culture reduces the exponential increase of age-specific mortality of Caenorhabditis elegans. Furthermore, the life span appears largely independent of nutritional status during development, as shown by shifting worms to different food concentrations shortly before adulthood. When DR was exerted after reproduction, a smaller reduction in Gompertzian aging was seen. Thus, the demographic changes exerted by DR in C. elegans resemble those seen in rats, yet are different to those seen in Drosophila and mice.
