DETERMINATION OF LIFE-SPAN IN CAENORHABDITIS-ELEGANS BY 4 CLOCK GENES

The nematode worm Caenorhabditis elegans is a model system for the stu dy of the genetic basis of aging. Maternal-effect mutations in four ge nes-clk-1, clk-2, clk-3, and gro-1-interact genetically to determine b oth the duration of development and life-span. Analysis of the phenoty pes of these mutants suggests the existence of a general physiological clock in the worm. Mutations in certain genes involved in dauer forma tion (an alternative larval stage induced by adverse conditions in whi ch development is arrested) can also extend life-span, but the life ex tension of Clock mutants appears to be independent of these genes. The daf-2(e1370) clk-1(e2519) worms, which carry life-span-extending muta tions from two different pathways, live nearly five times as long as w ild-type worms.