Séminaire BOREA-AVIV : Evolutionary physiology of fish acid-base regulation avec Prof. Pung-Pung Hwang : jeudi 12 juillet 2018 au MNHN (Paris)

12 juil 2018

Le prochain séminaire du département AVIV « Adaptations du vivant » du Muséum national d’histoire naturelle  se tiendra :

Jeudi 12 juillet 2018 à 12h30 au MNHN, bâtiment de la Baleine, amphithéâtre Rouelle

Et accueillera : 

 Dr Pung-Pung Hwang, Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei, Taiwan

Titre du séminaire :  "Evolutionary physiology of fish acid-base regulation"

Stenohaline zebrafish expresses both H+-ATPase (HA) and Na+/H+ exchanger (NHE3) in the apical membrane of gill (or skin) acid-secreting ionocytes, and HA is the major player. The trait of HA as the major acid-secreting transporter appears to be conserved in limited fish species. Euryhaline medaka, similar to most of fish species, adopted NHE as the major acid-secreting transporter (the trait of NHE). NHE-mediated NH4+ excretion also plays a substantial role in the net acid excretion. The relative role of NH4+ excretion in the net acid excretion predominates over that of titratable acid (mainly, H+) in fish, and the difference between H+ secretion and NH4+ excretion is increasing following fish evolution. Mammalian kidney appears to present all these traits. 

Invité par Sylvie Dufour, UMR BOREA, Dpt Aviv