HOME HELP CONTACT US SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Varsamos, S. Articles by Spanings-Pierrot, C. Search for Related Content PubMed PubMed Citation Articles by Varsamos, S. Articles by Spanings-Pierrot, C.

Adaptation Ecophysiologique et Ontogenèse, UMR 5171, GPIA, Université Montpellier II, Place Eugène Bataillon, CC092, 34095 Montpellier Cedex 05, France
¹ IGH/UPR, CNRS 1142, 141 rue de la Cardonille, 34396 Montpellier Cedex 05, France
² Department of Animal Physiology, Faculty of Science, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands

(Requests for offprints should be addressed to S Varsamos; Email: varsamos{at}univ-montp2.fr)

The mRNA expression of pituitary prolactin (prl), growth hormone (gh), somatolactin (sl), proopiomelanocortin (pomc), and gonadotropins (gthI and gthII) was quantified by real-time PCR, in sea bass, Dicentrarchus labrax, adapted for 1 month to seawater (SW) or freshwater (FW). In addition, IGF-I (igfI) mRNA expression in liver and branchial Na⁺/K⁺-ATPase activity were determined. L17 ribosomal protein (rpL17) and elongation factor 1 (ef1) were validated as reference genes in real-time PCR in the experimental context. The real-time PCR assays were validated for the different hormone genes considered. Expression of pituitary pomc, gthI, gthII, gh, and liver igfI was not significantly different between FW and SW fish. Pituitary prlwas 4.5-foldhigher in FWthan in SW, whereas pituitary sl was 1.8-fold higher in SW- compared with FW-adapted fish. Gill Na⁺/K⁺-ATPase specific activity was 2.3-fold higher in FW sea bass compared with SW fish. Plasma cortisol levels were 6.5-fold lower in SW- than in FW-adapted specimens. The results are discussed in relation to the osmoregulatory strategy of this euryhaline SW species, which displays features that do not fit present models based on salmonids and FWeuryhaline teleosts.