title: Isotopic ratio outlier analysis global metabolomics of Caenorhabditis elegans.
abstract: We demonstrate the global metabolic analysis of Caenorhabditis elegans stress responses using a mass-spectrometry-based technique called isotopic ratio outlier analysis (IROA). In an IROA protocol, control and experimental samples are isotopically labeled with 95 and 5% (13)C, and the two sample populations are mixed together for uniform extraction, sample preparation, and LC-MS analysis. This labeling strategy provides several advantages over conventional approaches: (1) compounds arising from biosynthesis are easily distinguished from artifacts, (2) errors from sample extraction and preparation are minimized because the control and experiment are combined into a single sample, (3) measurement of both the molecular weight and the exact number of carbon atoms in each molecule provides extremely accurate molecular formulas, and (4) relative concentrations of all metabolites are easily determined. A heat-shock perturbation was conducted on C. elegans to demonstrate this approach. We identified many compounds that significantly changed upon heat shock, including several from the purine metabolism pathway. The metabolomic response information by IROA may be interpreted in the context of a wealth of genetic and proteomic information available for C. elegans . Furthermore, the IROA protocol can be applied to any organism that can be isotopically labeled, making it a powerful new tool in a global metabolomics pipeline.
authors.affiliation: Department of Biochemistry & Molecular Biology, University of Florida, Gainesville, FL.
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Stupp
authors.affiliation: Department of Biochemistry & Molecular Biology, University of Florida, Gainesville, FL.
authors.forename: Chaevien S
authors.initials: CS
authors.lastname: Clendinen
authors.affiliation: Department of Biochemistry & Molecular Biology, University of Florida, Gainesville, FL.
authors.forename: Ramadan
authors.initials: R
authors.lastname: Ajredini
authors.affiliation: Thermo Fisher Scientific, Somerset, NJ.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Szewc
authors.affiliation: Department of Pathology, Immunology, and Laboratory Medicine, UF.|Southeast Center for Integrated Metabolomics, UF.
authors.forename: Timothy
authors.initials: T
authors.lastname: Garrett
authors.affiliation: Department of Chemistry, UF.
authors.forename: Robert F
authors.initials: RF
authors.lastname: Menger
authors.affiliation: Southeast Center for Integrated Metabolomics, UF.|Department of Chemistry, UF.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Yost
authors.affiliation: IROA Technologies, Ann Arbor, MI.
authors.forename: Chris
authors.initials: C
authors.lastname: Beecher
authors.affiliation: Department of Biochemistry & Molecular Biology, University of Florida, Gainesville, FL.|Southeast Center for Integrated Metabolomics, UF.
authors.forename: Arthur S
authors.initials: AS
authors.lastname: Edison
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000378:metabolism* / Q000502:physiology; D018869:Heat-Shock Response; D007553:Isotope Labeling; D013058:Mass Spectrometry / Q000379:methods*; D055432:Metabolomics / Q000379:methods*; D011687:Purines / Q000378:metabolism
chemical_list: D011687:Purines