title: Response of the calcifying coccolithophoreEmiliania huxleyito low pH/high pCO2: from physiology to molecular level.
abstract: The emergence of ocean acidification as a significant threat to calcifying organisms in marine ecosystems creates a pressing need to understand the physiological and molecular mechanisms by which calcification is affected by environmental parameters. We report here, for the first time, changes in gene expression induced by variations in pH/pCO2in the widespread and abundant coccolithophoreEmiliania huxleyi. Batch cultures were subjected to increased partial pressure of CO2(pCO2; i.e. decreased pH), and the changes in expression of four functional gene classes directly or indirectly related to calcification were investigated. Increased pCO2did not affect the calcification rate and only carbonic anhydrase transcripts exhibited a significant down-regulation. Our observation that elevated pCO2induces only limited changes in the transcription of several transporters of calcium and bicarbonate gives new significant elements to understand cellular mechanisms underlying the early response ofE. huxleyito CO2-driven ocean acidification.
authors.affiliation: INSU-CNRS, Laboratoire d'Océanographie de Villefranche, B.P. 28, 06234 Villefranche-sur-mer Cedex, France ; UPMC University of Paris 06, Observatoire Océanologique de Villefranche, 06230 Villefranche-sur-mer, France ; National Oceanography Centre, Southampton, University of Southampton Waterfront Campus, European Way, Southampton, SO14 3ZH UK.
authors.forename: Sophie
authors.initials: S
authors.lastname: Richier
authors.affiliation: INSU-CNRS, Laboratoire d'Océanographie de Villefranche, B.P. 28, 06234 Villefranche-sur-mer Cedex, France ; UPMC University of Paris 06, Observatoire Océanologique de Villefranche, 06230 Villefranche-sur-mer, France ; Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 140, 4400 AC Yerseke, The Netherlands.
authors.forename: Sarah
authors.initials: S
authors.lastname: Fiorini
authors.affiliation: INSU-CNRS, Laboratoire d'Océanographie de Villefranche, B.P. 28, 06234 Villefranche-sur-mer Cedex, France ; UPMC University of Paris 06, Observatoire Océanologique de Villefranche, 06230 Villefranche-sur-mer, France.
authors.forename: Marie-Emmanuelle
authors.initials: ME
authors.lastname: Kerros
authors.affiliation: Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Catolica de Chile, Alameda #340, Santiago, Chile.
authors.forename: Peter
authors.initials: P
authors.lastname: von Dassow
authors.affiliation: INSU-CNRS, Laboratoire d'Océanographie de Villefranche, B.P. 28, 06234 Villefranche-sur-mer Cedex, France ; UPMC University of Paris 06, Observatoire Océanologique de Villefranche, 06230 Villefranche-sur-mer, France.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Gattuso