Restoration of the behavioral rates and lifespan in clk-1 mutant nematodes in response to exogenous coenzyme Q(10).

The clk-1 gene encodes demethoxyubiquinone mono-oxygenase that is necessary for the biosynthesis of coenzyme Q (CoQ), which is an electron transporter in the respiratory chain of mitochondria. Therefore, clk-1 mutant nematodes that have loss-of-function mutations in the clk-1 gene lack endogenous CoQ(9) and exhibit slowed behavioral rates and an extended lifespan compared with wild-type animals when they are fed standard bacteria containing endogenous CoQ(8). This finding suggests that clk-1 regulates behavioral rates and the lifespan through CoQ in nematodes; however, the effects of exogenous CoQ on the regulation of these biological processes have been incompletely evaluated. In this study, we found that adding 10 μM water-soluble CoQ(10) to the culture medium of clk-1 mutant nematodes that were fed a diet of standard bacteria restored the pharyngeal pumping, defecation and the lifespan to levels that were comparable to those of wild-type animals. The results indicate that both behavioral rates and lifespan are regulated by the clk-1 gene through the action of CoQ in nematodes.