Cloning of FSH, LH and glycoprotein hormone subunits in pejerrey fish Odontesthes bonariensis. Expression profile and relationship with GnRHs expression and plasma sex steroid levels in male fish.

LEANDRO ANDRÉS MIRANDA; CARLOS STRÜSSMANN; LEONARDO GASTÓN GUILGUR; PABLO STROBL MAZZULLA; GUSTAVO MANUEL SOMOZA

JOURNAL OF FISH BIOLOGY

Blackwell Publishing

Año: 2007 vol. 71 p. 1571 - 1589

0022-1112

Three cDNAs encoding pejerrey (Odontesthes bonariensis) follicle stimulating hormone-â (FSH-â), luteinizing hormone-â (LH-â) and glycoprotein- á (GPH-á) subunits were cloned and characterized. Gene expression of these subunits was analyzed by real time PCR and compared to the brain gene expression of endogenous gonadotropin releasing hormones (GnRHs): salmon GnRH (GnRH-III), pejerrey GnRH (GnRH-I) and chiken GnRH-II (GnRH-II) and plasma sex steroid levels in adult males. The nucleotide sequences of the FSH-â, LH-â and GPH-á subunits are 466, 558 and 677 base pairs long, encoding for mature peptides of 102, 118, and 98 amino acids respectively. Maturing males had high expression of FSH-â and GPH-á subunits, and intermediate levels of LH-â when compared with running ripe and spent stages. These animals had the lowest plasma testosterone (T) and 11-ketosterone (11-KT) values as well as low expression of sGnRH, cGnRH-II and pjGnRH. Running ripe males had the lowest expression of FSH-â and the highest expression of LH-â and GPH-á subunits, and of the three GnRHs genes. At this stage, it was observed the highest values of T and 11-KT. Spent males showed low expression of the three gonadotropins (GtHs) subunits, sGnRH, pjGnRH, and low levels of T. At this stage, 11-KT levels and cGnRH-II expression showed a tendency to decrease but the values were not statistically significant (p<0·05) to running ripe stage. The present results would suggest that T and 11-KT modulate the expression of the FSH subunits. The expression of the anterior brain GnRH variants, sGnRH and pjGnRH is correlated with LH-â expression and reinforce the importance of the forebrain GnRH variants on the regulation of pituitary function.