Cloning, functional characterization, and expression of a gonadotropin receptor cDNA in the ovary and testis of amago salmon (Oncorhynchus rhodurus)

A gonadotropin receptor was cloned from amago salmon (Oncorhynchus rhodurus ) ovarian follicles. This receptor (sGTH-R) belongs to the glycoprotein hor mone receptor family with a large extracellular and seven-transmembrane dom ains. Its sequence homology is highest with mammalian LH receptors, Phyloge netic analysis reveals that sGTH-R is grouped with mammalian and chicken FS H and LH receptors, but not with mammalian TSH receptors. sGTH-R is express ed dominantly in the ovary and testis. Functional characterization examined with transiently transfected mammalian cells revealed increased intracellu lar cAMP level when exposed to mammalian and fish gonadotropins; the most p otent hormone was salmon GTH II. These results indicate that the cloned cDN A encodes a functional amago salmon GTH receptor protein. (C) 1999 Academic Press.