CHARACTERIZATION OF SECRETONEURIN VARIANTS IN PEJERREY (Odontesthes bonariensis).

DIEZ M; TOVAR MO; LÓPEZ GC; TRUDEAU VL; SOMOZA GM

Chascomús

Congreso; XVI Jornadas de la Asociación Argentinna de Biología; 2014

Secretoneurin   (SN)   is   a   well   conserved   peptide   from   sharks   to   mammals,   and   it   is   the product of the cleavage of the larger precursor Secretogranin II (also called Chromogranin C). Nevertheless a receptor for SN has not been found yet; SN has been proposed to be a new hormone. Also, in some teleost fish species two SN variants have been reported and called as SNa and SNb. In this context we attempted to characterize SN variants in pejerrey and   their   neuroanatomical   distribution   to   then   start   looking   for   their   function.   Consensus degenerated primers were designed after alignment of SNa and SNb forms in other teleost species and used on cDNAs obtained from pejerrey brains and pituitaries. Partial SNa and SNb sequences were obtained in both tissue extracts. Also pejerrey brains were treated for immunohistochemistry using a SN antiserum raised against goldfish SNa. SN- immunoreactive (SN-ir) cells were observed in pejerrey magnocellular and parvocellular cells of the preoptic nucleus with their projections ending at the neural lobe of the pituitary gland. Also, some SN-ir cells were observed in the pituitary gland, however up to the moment the nature of these cells is under study. In conclusion we report for the first time the presence of SN variants in pejerrey brain and pituitary to start studies on their physiological functions.