Life-span analysis of cco-1 hairpin transgenic animals. A. Wild-type worms allow import of dsRNA from surrounding tissues, but sid-1(qt9) mutant worm can not import dsRNA and RNAi knockdown is no longer systemic but is maintained locally within the tissue in which the dsRNA is produced (Winston et al., 2002). B. Intestine-specific knockdown of cco-1 results in life-span extension. sid-1(qt9)/rol-6 control (black line, mean 18.8 +/- 0.7 days), ges-1p∷cco-1hairpin (green line, 23.9 +/- 0.8 days, p<.0001). C. Body wall muscle knockdown of cco-1 does not significantly affect life span. sid-1(qt9)/rol-6 control (black line, mean 18.6 +/-0.5 days), myo-3p∷cco-1 hairpin (blue line, mean 16.6+/- 0.5 days, p=0.0574). D. Neuronal knockdown of cco-1 extends life span. sid-1(qt9)/rol-6 control (black line, 18.2 +/-0.2 days), rab-3p∷cco-1 hairpin (purple line, 21.7 +/- 0.5 days, p<.0001). E. Neuronal knockdown of cco-1 driven by the unc-119 promoter also extends life span. sid-1(qt9)/rol-6 control (black line, mean 19.8 +/-0.7days), unc-119p∷cco-1 hairpin (red line, mean 23.8 +/-0.8 days, p=.0001). Please see Table S1 for all statistical analyses and also Figure S1 and Movie S1 for additional experiments.