title: Omics for aquatic ecotoxicology: control of extraneous variability to enhance the analysis of environmental effects.
abstract: There are multiple sources of biological and technical variation in a typical ecotoxicology study that may not be revealed by traditional endpoints but that become apparent in an omics dataset. As researchers increasingly apply omics technologies to environmental studies, it will be necessary to understand and control the main source(s) of variability to facilitate meaningful interpretation of such data. For instance, can variability in omics studies be addressed by changing the approach to study design and data analysis? Are there statistical methods that can be employed to correctly interpret omics data and make use of unattributed, inherent variability? The present study presents a review of experimental design and statistical considerations applicable to the use of omics methods in systems toxicology studies. In addition to highlighting potential sources that contribute to experimental variability, this review suggests strategies with which to reduce and/or control such variability so as to improve reliability, reproducibility, and ultimately the application of omics data for systems toxicology.
authors.affiliation: Emerging Methods Section, Aquatic Contaminants Research Division, Water Science & Technology Directorate, Environment Canada, Ontario, Canada.
authors.forename: Denina B D
authors.initials: DB
authors.lastname: Simmons
authors.affiliation: Axys Analytical Services, Sidney, British Columbia, Canada.
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Benskin
authors.affiliation: Axys Analytical Services, Sidney, British Columbia, Canada.
authors.forename: John R
authors.initials: JR
authors.lastname: Cosgrove
authors.affiliation: Department of Biology, University of Waterloo, Ontario, Canada.
authors.forename: Bernard P
authors.initials: BP
authors.lastname: Duncker
authors.affiliation: Ecosystems Research Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Athens, Georgia, USA.
authors.forename: Drew R
authors.initials: DR
authors.lastname: Ekman
authors.affiliation: Center for Environmental and Human Toxicology & Department of Physiological Sciences, University of Florida, Gainesville, Florida, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Martyniuk
authors.affiliation: Emerging Methods Section, Aquatic Contaminants Research Division, Water Science & Technology Directorate, Environment Canada, Ontario, Canada.
authors.forename: James P
authors.initials: JP
authors.lastname: Sherry
mesh_terms: D000818:Animals; D054750:Ecotoxicology; D005260:Female; D005399:Fishes / Q000502:physiology; D023281:Genomics; D008297:Male; D055432:Metabolomics; D040901:Proteomics; D012107:Research Design
keywords: Metabolomics; Proteomics; Systems toxicology; Transcriptomics; Variability