title: Plasticity of gene expression according to salinity in the testis of broodstock and F1 black-chinned tilapia, Sarotherodon melanotheron heudelotii.
abstract: The black-chinned tilapia Sarotherodon melanotheron heudelotii Rüppell 1852 (Teleostei, Cichlidae) displays remarkable acclimation capacities. When exposed to drastic changes of salinity, which can be the case in its natural habitat, it develops quick physiological responses and keeps reproducing. The present study focused on the physiological impact of salinity on male reproductive capacities, using gene expression as a proxy of acclimation process. Two series of experimental fish were investigated: the first one was composed of fish maintained in freshwater for several generations and newly acclimated to salinities of 35 and 70, whereas the second one consisted of the descendants of the latter born and were raised under their native salinity. Expression patterns of 43 candidate genes previously identified from the testes of wild males was investigated in the three salinities and two generations. Twenty of them showed significant expression differences between salinities, and their predicted function revealed that most of them are involved in the osmotic tolerance of sperm cells and/or in the maintenance of sperm motility. A high level of expression variation was evidenced, especially for fish maintained in freshwater. In spite of this, gene expression patterns allowed the differentiation between fish raised in freshwater and those maintained in hypersaline water in both generations. Altogether, the results presented here suggest that this high variability of expression is likely to ensure the reproductive success of this species under varying salinities.
authors.affiliation: Institut des Sciences de l'Evolution de Montpellier , UMR 226 IRD-CNRS-UM2, Montpellier , France.
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Avarre
authors.affiliation: Institut des Sciences de l'Evolution de Montpellier , UMR 226 IRD-CNRS-UM2, Montpellier , France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Guinand
authors.affiliation: Institut des Sciences de l'Evolution de Montpellier , UMR 226 IRD-CNRS-UM2, Montpellier , France.
authors.forename: Rémi
authors.initials: R
authors.lastname: Dugué
authors.affiliation: Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Research Institute of Fish Culture and Hydrobiology, University of South Bohemia in Ceske Budejovice , Vodňany , Czech Republic.
authors.forename: Jacky
authors.initials: J
authors.lastname: Cosson
authors.affiliation: Institut des Sciences de l'Evolution de Montpellier , UMR 226 IRD-CNRS-UM2, Montpellier , France.
authors.forename: Marc
authors.initials: M
authors.lastname: Legendre
authors.affiliation: Ecologie des Systèmes Marins Côtiers , UMR 5119 IRD-UM2-CNRS-IFREMER, Montpellier , France.
authors.forename: Jacques
authors.initials: J
authors.lastname: Panfili
authors.affiliation: Ecologie des Systèmes Marins Côtiers , UMR 5119 IRD-UM2-CNRS-IFREMER, Montpellier , France.
authors.forename: Jean-Dominique
authors.initials: JD
authors.lastname: Durand
keywords: Acclimation; Fish; Gene expression; Male reproduction; Salinity