C. elegans clk-2, a gene that limits life span, encodes a telomere length regulator similar to yeast telomere binding protein Tel2p

An important quest in modern biology is to identify genes involved in aging . Model organisms such as the nematode Caenorhabditis elegans are particula rly useful in this regard. The C. elegans genome has been sequenced [1], an d single gene mutations that extend adult life span have been identified [2 ]. Among these longevity-controlling loci are four apparently unrelated gen es that belong to the clk family [3-5]. In mammals, telomere length and str ucture can influence cellular, and possibly organismal, aging [6]. Here, we show that clk-2 encodes a regulator of telomere length in C. elegans.