the present invention relates to a clk - 2 gene which has a function at the level of cellular physiology involved in developmental rate , telomere length and longevity , wherein clk - 2 mutations cause a longer life , an altered cellular metabolism and an altered telomere length relative to the wild type , wherein clk - 2 overexpression leads to telomere shortening . the present invention also relates to clk - 2 co - expressed gene which comprises a cex - 7 gene having the nucleotide sequence set forth in fig . 33 which codes for a cex - 7 protein having the amino acid sequence set forth in fig . 34 wherein said gene is located in the clk - 2 operon and said cex - 7 gene is transcriptionally co - expressed with clk - 2 gene present in said operon . the present invention also relates to a coq - 4 gene which has a function at the level of cellular physiology involved in the regulation of developmental rate and longevity , wherein coq - 4 mutations cause altered cellular metabolism and physiological relative to the wild type , wherein coq - 4 gene has the identifying characteristics of nucleotide sequence set forth in fig . 36 .