title: Cold acclimation wholly reorganizes the Drosophila melanogaster transcriptome and metabolome.
abstract: Cold tolerance is a key determinant of insect distribution and abundance, and thermal acclimation can strongly influence organismal stress tolerance phenotypes, particularly in small ectotherms like Drosophila. However, there is limited understanding of the molecular and biochemical mechanisms that confer such impressive plasticity. Here, we use high-throughput mRNA sequencing (RNA-seq) and liquid chromatography - mass spectrometry (LC-MS) to compare the transcriptomes and metabolomes of D. melanogaster acclimated as adults to warm (rearing) (21.5 °C) or cold conditions (6 °C). Cold acclimation improved cold tolerance and led to extensive biological reorganization: almost one third of the transcriptome and nearly half of the metabolome were differentially regulated. There was overlap in the metabolic pathways identified via transcriptomics and metabolomics, with proline and glutathione metabolism being the most strongly-supported metabolic pathways associated with increased cold tolerance. We discuss several new targets in the study of insect cold tolerance (e.g. dopamine signaling and Na(+)-driven transport), but many previously identified candidate genes and pathways (e.g. heat shock proteins, Ca(2+) signaling, and ROS detoxification) were also identified in the present study, and our results are thus consistent with and extend the current understanding of the mechanisms of insect chilling tolerance.
authors.affiliation: Department of Biology, University of Western Ontario, London, ON, Canada.
authors.forename: Heath A
authors.initials: HA
authors.lastname: MacMillan
authors.affiliation: Department of Chemistry and Biochemistry, Laurentian University, Sudbury, ON, Canada.
authors.forename: Jose M
authors.initials: JM
authors.lastname: Knee
authors.affiliation: Landcare Research, Auckland, New Zealand.|Allan Wilson Centre for Molecular Ecology and Evolution, Auckland, New Zealand.
authors.forename: Alice B
authors.initials: AB
authors.lastname: Dennis
authors.affiliation: Department of Biology, University of Western Ontario, London, ON, Canada.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Udaka
authors.affiliation: Department of Biology, University of Western Ontario, London, ON, Canada.
authors.forename: Katie E
authors.initials: KE
authors.lastname: Marshall
authors.affiliation: Department of Chemistry and Biochemistry, Laurentian University, Sudbury, ON, Canada.
authors.forename: Thomas J S
authors.initials: TJ
authors.lastname: Merritt
authors.affiliation: Department of Biology, University of Western Ontario, London, ON, Canada.
authors.forename: Brent J
authors.initials: BJ
authors.lastname: Sinclair
mesh_terms: D000064:Acclimatization / Q000235:genetics / Q000502:physiology*; D000818:Animals; D003080:Cold Temperature; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D005786:Gene Expression Regulation; D063990:Gene Ontology; D017344:Genes, Insect; D059014:High-Throughput Nucleotide Sequencing; D019476:Insect Proteins / Q000235:genetics / Q000502:physiology; D053858:Metabolic Networks and Pathways / Q000235:genetics; D055442:Metabolome; D008954:Models, Biological; D012333:RNA, Messenger / Q000096:biosynthesis; D000071436:Thermotolerance / Q000235:genetics; D059467:Transcriptome
chemical_list: D019476:Insect Proteins; D012333:RNA, Messenger