Gene expression changes governing extreme dehydration tolerance in an Antarctic insect

• Published in: Proceedings of the National Academy of Sciences
• Main Authors: Teets, Nicholas M., Peyton, Justin T., Colinet, Hervé, Renault, David, Kelley, Joanna L., Kawarasaki, Yuta, Lee, Richard E. Jr, Denlinger, David L.
• Other Authors: Entomology, Ohio State University, Ohio State University Columbus (OSU), Evolution, Ecology and Organismal Biology, Ecosystèmes, biodiversité, évolution Rennes (ECOBIO), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), Department of Genetics Stanford, Stanford Medicine, Stanford University-Stanford University, Zoology and Program in Ecology, Evolution and Environmental Biology, Miami University Ohio (MU), NSF OPP-ANT-0837613 and ANT-0837559; IPEV Program 136; SCAREB of Antarctic research program
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2012
• Subjects: environmental stress; physiological ecology; geo; envir; Antarctic; Arctic; The Antarctic; Antarc*; Antarctic midge; Antarctica; Belgica antarctica
• Online Access: https://doi.org/10.1073/pnas.1218661109; https://hal.archives-ouvertes.fr/hal-00801357

International audience Among terrestrial organisms, arthropods are especially susceptible to dehydration, given their small body size and high surface area to volume ratio. This challenge is particularly acute for polar arthropods that face near- constant desiccating conditions, as water is frozen and thus unavailable for much of the year. The molecular mechanisms that govern extreme dehydration tolerance in insects remain largely undefined. In this study, we used RNA sequencing to quantify transcriptional mechanisms of extreme dehydration tolerance in the Antarctic midge, Belgica antarctica, the world's southern most insect and only insect endemic to Antarctica. Larvae of B. antarctica are remarkably tolerant of dehydration, surviving losses up to 70% of their body water. Gene expression changes in response to dehydration indicated up-regulation of cellular recycling pathways including the ubiquitin-mediated proteasome and autophagy, with concurrent down-regulation of genes involved in general metabolism and ATP production. Metabolomics results revealed shifts in metabolite pools that correlated closely with changes in gene expression, indicating that coordinated changes in gene expression and metabolism are a critical component of the dehydration response. Finally, using comparative genomics, we compared our gene expression results with a transcriptomic dataset for the Arctic collembolan, Megaphorura arctica. Although B. antarctica and M. arctica are adapted to similar environments, our analysis indicated very little overlap in expression profiles between these two arthropods. Whereas several orthologous genes showed similar expression patterns, transcriptional changes were largely species specific, indicating these polar arthropods have developed distinct transcriptional mechanisms to cope with similar desiccating conditions. Utilisation du GC-MS de l'umr 6553 Ecobio; Aide technique de Vanessa Larvor