Biochemical Genetics, Vol. 29, Nos. 7/8, 1991 Isolation of Caenorhabditis elegans Mutants Lacking Alcohol Dehydrogenase Activity Valerie M. Wiiliamson, 1'2 Manyuan Long, 1 and George Theodoris 1 Received 5 Jan. 1991--Final2 Apr. 1991 Alcohol dehydrogenase (ADH) and the genes encoding this enzyme have been studied intensively in a broad range of organisms. Little, however, has been reported on ADH in the free-living nematode Caenorhabditis elegans. Extracts of wild-type C. elegans contain ADH activity and display a single band of activity on a native polyacrylamide gel, Reaction rate for alcohol oxidation is more rapid with higher molecular weight alcohols as substrate than with ethanol. Primary alcohols are preferred to secondary alcohols. C. elegans is sensitive to allyl alcohol, a compound that has been used to select for ADH-null mutants of several organisms. Allyl alcohol-resistant mutant strains were selected from ethylmethanesulfonate (EMS)-mutagenized nematode populations. ADH activ- ity was measured in extracts from eight of these strains and was found to be low or nondetectable. These results forrn a basis for molecular and genetic character- ization of ADH expression in C. elegans. KEY WORDS: alcoholdehydrogenase;allylalcohol selection;ADH- mutants; Caenorhabditis elegans. INTRODUCTION Alcohol dehydrogenase (ADH; EC 1.1.1.1) catalyzes the reversible oxida- tion of ethanol to acetaldehyde coupled with reduction of NAD +. The proteins and genes encoding ADH have been intensively studied in a broad range of organisms including yeast, maize, horse, and fruit flies (Ciriacy, 1975; Williamson et al., 1980; Williamson and Paquin, 1987; Freeling and Birchler, 1981; Jornvall et al., 1987; O'Donnell et al., 1975; Goldberg et al., Department of Nematology,University of California, Davis,California95616. 2 To whomcorrespondenceshouldbe addressed. 313 0006-2928/91/0800-0313506.50/0 © 1991 Plenum PuNishing Corporation