ARS | Publication request: STEROID METABOLISM AND FUNCTION IN C. ELEGANS

Submitted to: Abstracts of the Korean C. elegans Conference
Publication Type: Abstract Only
Publication Acceptance Date: January 31, 2005
Publication Date: January 31, 2005
Citation: Chitwood, David, J. Steroid Metabolism and Function in C. elegans. 12th Korean C. elegans Conference Abstracts. 2005.

Technical Abstract: Nematodes possess a nutritional requirement for sterol because of their inability to biosynthesize sterols de novo. Consequently, parasitic nematodes must obtain sterols from their hosts and then metabolize them to sterols better suited to nematode growth, development and reproduction. We have performed several investigations utilizing Caenorhabditis elegans as a model organism for studying sterol biochemistry in plant-parasitic nematodes. This species can reproduce on a large variety of sterols lacking methyl groups at the 4-position and possessing a trans-A/B ring system and an intact, nonhydroxylated side chain. Radiotracer experiments indicated that C. elegans can remove the methyl or ethyl substituents present at the C-24 position of the sterol side chain; C-24 alkyl groups are typical of plant sterols but are usually absent in animals. This dealkylation process can be inhibited by 25-azacoprostane, and proteomic analysis of 25-azacoprostane-treated C. elegans revealed that the inhibitor induces reductions in the levels of several proteins. Additionally, C. elegans can perform several metabolic transformations upon the sterol nucleus, such as double bond introduction, removal, or isomerization. The ability of C. elegans and other nematodes to introduce a methyl group at C-4 of the sterol nucleus is unique to nematodes. Evidence for the role of steroids as hormones in nematodes will be discussed.