Meeting Abstract

P1.89A  Jan. 4  Ontogeny of kidney in the Persian Sturgeon, Acipenser persicus: Implication in osmoregulation KHODABANDEH, Saber; TAGHIZADEH, Zahra; ABTAHI, Behroz*; CHARMANTIER, Guy; CHARMANTIER-DAURES, Mireille; Univ. of Tarbiat Modarres, Tehran, IRAN; Univ. of Montpellier II, France; Univ. of Montpellier II, France

Mitochondria rich cells have been localized in the tegument, gill, digestive tract and kidney of fishes. They characterize by numerous mitochondria and Na+,K+-ATPase associated to basolateral membrane infoldings. In most teleost prelarvae, before gill emergence and mouth opening, immunolocalization of Na+,K+-ATPase showed a large number of ionocytes distributed on yolk sac, tegument of the head and the fins of prelarvae. In fish embryos and larvae, the primordial kidney is called the pronephros. Although several studies have described the successive ontogenetical stages of the fish pronephros, the timing of the onset of pronephric osmoregulatory function remains unknown for many species. In this study immumolocalization of Na+,K+-ATPase examined in the pronephros of newly hatched Persian Sturgeon, Acipenser persicus with immunofluorescence light microscopy by using a Mouse Monoclonal Antibody, IgGα5 raised against the α–subunit of the Chicken Na+,K+-ATPase and a Mouse Anti-fluorescein Antibody (FITC). Results showed that there is no immunofluorescence of Na+,K+-ATPase on the yolk sac, head and fins nor in the primordial digestive tract. The cells lining the pronephric ducts showed a well immunofluorescence of Na+,K+-ATPase on the basolateral sides. In conclusion, in the newly hatched prelarvae of the A. persicus , the renal systems appear as the main site of osmoregulation before gill emergence and mouth and anus opening, in contrast to the results of other studies on fish prelarvae, that the ionocytes present on yolk sac, digestive tract and gill slits. So at this stage primordial pronephros are the main osmoregulatory sites.