title: SAGE surveys C. elegans carbohydrate metabolism: evidence for an anaerobic shift in the long-lived dauer larva.
abstract: The dauer larva, a non-feeding and developmentally arrested stage of the free-living nematode Caenorhabditis elegans, is morphologically and physiologically specialized for survival and dispersal during adverse growth conditions. The ability of dauer larvae to live several times longer than the continuous developmental life span has been attributed in part to a repressed metabolism. We used serial analysis of gene expression (SAGE) profiles from dauer larvae and mixed growing stages to compare expression patterns for genes with known or predicted roles in glycolysis, gluconeogenesis, glycogen metabolism, the Krebs and glyoxylate cycles, and selected fermentation pathways. Ratios of mixed:dauer transcripts indicated non-dauer enrichment that was consistent with previously determined adult:dauer enzyme activity ratios for hexokinase (glycolysis), phosphoenolpyruvate carboxykinase and fructose 1,6-bisphosphatase (gluconeogenesis), isocitrate dehydrogenase (NADP-dependent), and isocitrate lyase-malate synthase (glyoxylate cycle). Transcripts for the majority of Krebs cycle components were not differentially represented in the two profiles. Transcript abundance for pyruvate kinase, alcohol dehydrogenase, a putative cytosolic fumarate reductase, two pyruvate dehydrogenase components, and a succinyl CoA synthetase alpha subunit implied that anaerobic pathways were upregulated in dauer larvae. Generation of nutritive fermentation byproducts and the moderation of oxidative damage are potential benefits of a hypoxic dauer interior.
authors.affiliation: Division of Biological Sciences and Molecular Biology Program, 311 Tucker Hall, University of Missouri, Columbia, MO 65211, USA.
authors.forename: Suzan J
authors.initials: SJ
authors.lastname: Holt
authors.forename: Donald L
authors.initials: DL
authors.lastname: Riddle
mesh_terms: D000438:Alcohols / Q000378:metabolism; D000693:Anaerobiosis; D000818:Animals; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D050260:Carbohydrate Metabolism; D002952:Citric Acid Cycle / Q000235:genetics; D004734:Energy Metabolism / Q000235:genetics*; D005285:Fermentation / Q000235:genetics; D020869:Gene Expression Profiling; D005943:Gluconeogenesis / Q000235:genetics; D006003:Glycogen / Q000378:metabolism; D006019:Glycolysis / Q000235:genetics; D006038:Glyoxylates / Q000378:metabolism; D000860:Hypoxia / Q000235:genetics / Q000378:metabolism; D007814:Larva / Q000235:genetics / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011768:Pyruvate Dehydrogenase Complex / Q000235:genetics / Q000378:metabolism; D013385:Succinate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D019802:Succinic Acid / Q000378:metabolism
chemical_list: D000438:Alcohols; D006038:Glyoxylates; D011768:Pyruvate Dehydrogenase Complex; D006003:Glycogen; D019802:Succinic Acid; D013385:Succinate Dehydrogenase; C031150:glyoxylic acid