Osmoregulatory response to low salinities in the European sea bass embryos: a multi-site approach - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Journal of Comparative Physiology B Année : 2013

Osmoregulatory response to low salinities in the European sea bass embryos: a multi-site approach

Elliott Sucre
  • Fonction : Auteur
Maryline Bossus
  • Fonction : Auteur
Charlotte Bodinier
  • Fonction : Auteur
Guy Charmantier
  • Fonction : Auteur
Mireille Charmantier-Daures
  • Fonction : Auteur
Patricia Cucchi
  • Fonction : Auteur

Résumé

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 aEuro degrees), were exposed to dilute seawater (DSW) (5 aEuro degrees) 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.

Dates et versions

hal-04499302 , version 1 (11-03-2024)

Identifiants

Citer

Elliott Sucre, Maryline Bossus, Charlotte Bodinier, Viviane Boulo, Guy Charmantier, et al.. Osmoregulatory response to low salinities in the European sea bass embryos: a multi-site approach. Journal of Comparative Physiology B, 2013, 183 (1), pp.83-97. ⟨10.1007/s00360-012-0687-2⟩. ⟨hal-04499302⟩
0 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More