title: Molecular and functional characterization of Bemisia tabaci aquaporins reveals the water channel diversity of hemipteran insects.
abstract: The Middle East-Asia Minor 1 (MEAM1) whitefly, Bemisia tabaci (Gennadius) is an economically important pest of food, fiber, and ornamental crops. This pest has evolved a number of adaptations to overcome physiological challenges, including 1) the ability to regulate osmotic stress between gut lumen and hemolymph after imbibing large quantities of a low nitrogen, sugar-rich liquid diet; 2) the ability to avoid or prevent dehydration and desiccation, particularly during egg hatching and molting; and 3) to be adapted for survival at elevated temperatures. One superfamily of proteins involved in the maintenance of fluid homeostasis in many organisms includes the aquaporins, which are integral membrane channel proteins that aid in the rapid flux of water and other small solutes across biological membranes. Here, we show that B. tabaci has eight aquaporins (BtAqps), of which seven belong to the classical aquaporin 4-related grade of channels, including Bib, Drip, Prip, and Eglps and one that belongs to the unorthodox grade of aquaporin 12-like channels. B. tabaci has further expanded its repertoire of water channels through the expression of three BtDrip2 amino-terminal splice variants, while other hemipteran species express amino- or carboxyl-terminal isoforms of Drip, Prip, and Eglps. Each BtAqp has unique transcript expression profiles, cellular localization, and/or substrate preference. Our phylogenetic and functional data reveal that hemipteran insects lost the classical glp genes, but have compensated for this by duplicating the eglp genes early in their evolution to comprise at least three separate clades of glycerol transporters.
authors.affiliation: USDA-ARS, U.S. Arid Land Agricultural Research Center, Maricopa, AZ 85138, USA.
authors.forename: Evelien
authors.initials: E
authors.lastname: Van Ekert
authors.affiliation: Department of Biology, Bergen High Technology Centre, University of Bergen, 5020 Bergen, Norway; Institut de Recerca i Tecnologia Agroalimentaries (IRTA)-Institut de Ciencies del Mar, Consejo Superior de Investigaciones Cientificas (CSIC), 08003 Barcelona, Spain.
authors.forename: François
authors.initials: F
authors.lastname: Chauvigné
authors.affiliation: Department of Biology, Bergen High Technology Centre, University of Bergen, 5020 Bergen, Norway; Institute of Marine Research, Nordnes, 5817 Bergen, Norway.
authors.forename: Roderick Nigel
authors.initials: RN
authors.lastname: Finn
authors.affiliation: USDA-ARS, U.S. Arid Land Agricultural Research Center, Maricopa, AZ 85138, USA.
authors.forename: Lolita G
authors.initials: LG
authors.lastname: Mathew
authors.affiliation: USDA-ARS, U.S. Arid Land Agricultural Research Center, Maricopa, AZ 85138, USA.
authors.forename: J Joe
authors.initials: JJ
authors.lastname: Hull
authors.affiliation: Institut de Recerca i Tecnologia Agroalimentaries (IRTA)-Institut de Ciencies del Mar, Consejo Superior de Investigaciones Cientificas (CSIC), 08003 Barcelona, Spain.
authors.forename: Joan
authors.initials: J
authors.lastname: Cerdà
authors.affiliation: USDA-ARS, U.S. Arid Land Agricultural Research Center, Maricopa, AZ 85138, USA. Electronic address: jeff.fabrick@ars.usda.gov.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Fabrick
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D020346:Aquaporins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D005260:Female; D006430:Hemiptera / Q000235:genetics* / Q000378:metabolism; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D007814:Larva / Q000254:growth & development / Q000378:metabolism; D008297:Male; D010802:Phylogeny; D016415:Sequence Alignment
chemical_list: D020346:Aquaporins; D018076:DNA, Complementary; D019476:Insect Proteins
keywords: Aquaporin; Bemisia tabaci; Entomoglyceroporin; Major intrinsic protein family; Osmoregulation; Whitefly