title: Ontogeny of osmoregulation in the Pacific blue shrimp, Litopenaeus stylirostris (Decapoda, Penaeidae): Deciphering the role of the Na(+)/K(+)-ATPase.
abstract: The role of the main ion transporting enzyme Na+/K+-ATPase in osmoregulation processes was investigated in Litopenaeus stylirostris. The development and localization of the osmoregulation sites were studied during ontogenesis by immunodetection of Na(+)K(+)-ATPase using monoclonal antibodies and transmission electron microscopy (TEM). Osmoregulation sites were identified as the pleurae and branchiostegites in the zoeae and mysis stages. In the subsequent post-metamorphic stages the osmoregulatory function was mainly located in the epipodites and branchiostegites and osmotic regulation was later detected in the gills. The presence of ionocytes and microvilli in these tissues confirmed their role in ionic processes. The complete open reading frame of the mRNA coding for the α-subunit of Na+K+-ATPase was characterized in L. stylirostris. The resulting 3092-bp cDNA (LsNKA) encodes a putative 1011-amino-acid protein with a predicted molecular mass of 112.3kDa. The inferred amino acid sequence revealed that the putative protein possesses the main structural characteristics of the Na+K+-ATPase α-subunits. Quantitative RT-PCR analyses indicated that LsNKA transcripts did not significantly vary between the different developmental stages. The number of transcripts was about 2.5-fold higher in the epipodites and gills than in any other tissues tested in juveniles. A reverse genetic approach was finally implemented to study the role of LsNKA in vivo. Knockdown of LsNKA expression by gene-specific dsRNA injection led to an increase of shrimp mortality following an abrupt salinity change compared to control animals. These data strongly suggest that LsNKA plays an important role in osmoregulation when the shrimp are challenged by changing salinities.
authors.affiliation: Lagon, Environnement et Aquaculture Durable, Ifremer, Boulouparis, Nouvelle-Calédonie, France. Electronic address: dominique.pham@ifremer.fr.
authors.forename: Dominique
authors.initials: D
authors.lastname: Pham
authors.affiliation: Université de Montpellier, Adaptation Ecophysiologique et Ontogenèse, UMR 9190, Marbec, UM, CNRS, IRD, Ifremer, Place Eugène Bataillon, CC 092, 34095 Montpellier Cedex 05, France.
authors.forename: Guy
authors.initials: G
authors.lastname: Charmantier
authors.affiliation: Lagon, Environnement et Aquaculture Durable, Ifremer, Boulouparis, Nouvelle-Calédonie, France; Université de Montpellier, Adaptation Ecophysiologique et Ontogenèse, UMR 9190, Marbec, UM, CNRS, IRD, Ifremer, Place Eugène Bataillon, CC 092, 34095 Montpellier Cedex 05, France.
authors.forename: Viviane
authors.initials: V
authors.lastname: Boulo
authors.affiliation: Lagon, Environnement et Aquaculture Durable, Ifremer, Boulouparis, Nouvelle-Calédonie, France.
authors.forename: Nelly
authors.initials: N
authors.lastname: Wabete
authors.affiliation: Lagon, Environnement et Aquaculture Durable, Ifremer, Boulouparis, Nouvelle-Calédonie, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Ansquer
authors.affiliation: Lagon, Environnement et Aquaculture Durable, Ifremer, Boulouparis, Nouvelle-Calédonie, France.
authors.forename: Clément
authors.initials: C
authors.lastname: Dauga
authors.affiliation: Université de Montpellier, Adaptation Ecophysiologique et Ontogenèse, UMR 9190, Marbec, UM, CNRS, IRD, Ifremer, Place Eugène Bataillon, CC 092, 34095 Montpellier Cedex 05, France.
authors.forename: Evelyse
authors.initials: E
authors.lastname: Grousset
authors.affiliation: Ifremer, Unite Physiologie Fonctionnelle des Organismes Marins, ZI de la Pointe du Diable, CS 10070, F-29280 Plouzane, France; Sorbonne Universités, UPMC Paris 06, CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688 Roscoff cedex, France. Electronic address: ylabreuche@sb-roscoff.fr.
authors.forename: Yannick
authors.initials: Y
authors.lastname: Labreuche
authors.affiliation: Université de Montpellier, Adaptation Ecophysiologique et Ontogenèse, UMR 9190, Marbec, UM, CNRS, IRD, Ifremer, Place Eugène Bataillon, CC 092, 34095 Montpellier Cedex 05, France.
authors.forename: Mireille
authors.initials: M
authors.lastname: Charmantier-Daures
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D064587:Osmoregulation; D033561:Penaeidae / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism; D021381:Protein Transport; D000254:Sodium-Potassium-Exchanging ATPase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D018076:DNA, Complementary; D000254:Sodium-Potassium-Exchanging ATPase
keywords: Litopenaeus stylirostris; Na(+/)K(+)-ATPase; Ontogeny; Osmoregulation; Penaeid; RNA interference