Understanding the mechanism of the dormant dauer formation of C. elegans: from genetics to biochemistry.

Dauer is a dormancy state that may occur at the end of developmental stage L1 or L2 of Caenorhabditis elegans when the environmental conditions are unfavorable (e.g., lack of food, high temperature, or overcrowding) for further growth. Dauer is a nonaging duration that does not affect the postdauer adult lifespan. Major molecular events would include the sensing of the environmental cues, the transduction of the signals into the cells, and the subsequent integration of the signals that result in the corresponding alteration of the metabolism and morphology of the organism. Genetics approach has been effectively used in identifying many of the so-called daf genes involved in dauer formation using C. elegans as the model. Nevertheless, biochemical studies at the protein and metabolic level has been lacking behind in understanding this important life phenomenon. This review focuses on the biochemical understanding so far achieved on dauer formation and dormancy in general, as well as important issues that need to be addressed in the future.