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Osmoregulatory response to low salinities in the European sea bass embryos: a multi-site approach.
Osmoregulatory response to low salinities in the European sea bass embryos: a multi-site approach.
- Source :
-
Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology [J Comp Physiol B] 2013 Jan; Vol. 183 (1), pp. 83-97. Date of Electronic Publication: 2012 Jul 01. - Publication Year :
- 2013
-
Abstract
- Embryonic osmoregulation effected by embryonic ionocytes in the European sea bass Dicentrarchus labrax has been studied at several sites, including the yolk sac membrane, the first gill slits and the gut ionocytes. D. labrax embryos, spawned in seawater (SW) (39 ‰), were exposed to dilute seawater (DSW) (5 ‰) during 48 h, from stage 10 pairs of somites (10S) to hatching time (HT). Control embryos originating from the same spawn were maintained in SW. Both SW and DSW embryos were examined after 24- and 48-h exposure. Nanoosmometric measurements of the embryonic fluids osmolality suggest that late embryos are confronted with the variations in external salinity and that they were able to slightly regulate their osmolality. Immunolocalization of Na⁺/K⁺ ATPase, NKCC and CFTR has shown that DSW-exposed embryos can limit ion losses due to compensatory physiological mechanisms. CFTR and NKCC were not observed in DSW embryos in the yolk sac ionocytes and in the tegumentary ionocytes of the gill slits. The quantification of mRNA indicated that NKA, NKCC1 and CFTR transcript levels increased from stage 10S to stage HT. At stage HT, following 48 h of DSW- or SW-exposure, different responses were observed according to salinity. These results, when compared to those obtained in D. labrax juveniles and adults long-term exposed to fresh water (FW), show that in embryos the physiological response following a short-term DSW exposure is different. The mechanisms of hyper-osmoregulation observed in D. labrax embryos, although not fully efficient, allow their survival for several days in DSW.
- Subjects :
- Animals
Aquaculture
Bass physiology
Body Fluids chemistry
Cystic Fibrosis Transmembrane Conductance Regulator genetics
Cystic Fibrosis Transmembrane Conductance Regulator metabolism
Europe
Fish Proteins genetics
Fish Proteins metabolism
Gastrointestinal Tract embryology
Gastrointestinal Tract metabolism
Gills embryology
Gills metabolism
Mediterranean Sea
Protein Isoforms metabolism
RNA, Messenger metabolism
Sodium-Potassium-Chloride Symporters genetics
Sodium-Potassium-Chloride Symporters metabolism
Sodium-Potassium-Exchanging ATPase genetics
Sodium-Potassium-Exchanging ATPase metabolism
Somites embryology
Somites physiology
Yolk Sac embryology
Yolk Sac metabolism
Bass embryology
Gene Expression Regulation, Developmental
Salinity
Seawater
Water-Electrolyte Balance
Subjects
Details
- Language :
- English
- ISSN :
- 1432-136X
- Volume :
- 183
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology
- Publication Type :
- Academic Journal
- Accession number :
- 22752053
- Full Text :
- https://doi.org/10.1007/s00360-012-0687-2