Dietary restriction enhances germline stem cell maintenance.

Dietary restriction (DR) increases lifespan in species ranging from yeast to primates, maintaining tissues in a youthful state and delaying reproductive senescence. However, little is known about the mechanisms by which this occurs. Here we demonstrate that, concurrent with extending lifespan, DR attenuates the age-related decline in male germline stem cell (GSC) number in Drosophila. These data support a model whereby DR enhances maintenance of GSCs to extend the reproductive period of animals subjected to adverse nutritional conditions. This represents the first example of DR maintaining an adult stem cell pool and suggests a potential mechanism by which DR might delay aging in the tissues of higher organisms.