Caenorhabditis elegans 2007: the premier model for the study of aging.

This is the 25th anniversary of the discovery of extended longevity mutants in Caenorhabditis elegans. About one hundred papers describing results from studies on C. elegans in aging research appeared this year. Many themes were pursued including dietary restriction, daf-9 action, the role of proteolysis and autophagy, and the continued search for more Age mutants. I use the word "modulate" not "regulate" so as to be consistent with the evolutionary theory of aging, which is also consistent with the empirical findings of all extended longevity (Age) mutants. These Age mutants universally result from deficits in known physiologic systems, rather than in some process designed to kill the animal in old age.