Tissue-specific ascaroside production in the nematode Caenorhabditis elegans

Abstract

Ascarosides are a family of small mols. used as signals in a variety of important behaviors in C. elegans and other nematodes; these include mate attraction, aggression, repulsion, and entry into dauer diapause under stressful conditions. Structurally, ascarosides are modular glycosides of the dideoxysugar ascarylose. Small structural changes in the fatty add moiety attached to the first position of the sugar as well as the addn. of other metabolically-derived components to the fourth position have been shown to elicit different behaviors. DAF-22, a thiolase responsible for the last step of peroxisomal beta-oxidn. of the ascaroside lipid side chain, is necessary for the prodn. of biol. active ascarosides and is normally expressed in the intestine, body wall muscle, and hypodermis of the worm. After transgenically rescuing the expression of DAF-22 in each tissue individually in a DAF-22 knockout background, HPLC-MS anal. revealed that all three tissues are capable of producing ascarosides, but in different quantities. Furthermore, the expression of DAF-22 in any of the three tissues rescues the ability of the worm to enter dauer diapause, but to varying degrees. By studying these site-specific activity relationships, we highlight the roles of multiple tissues in worm communication via ascarosides.