Cloning and expression analysis of follicle-stimulating hormone and luteinizing hormone receptor during the reproductive cycle in Korean rockfish (Sebastes schlegeli)

Full-length cDNA sequences encoding the receptors for follicle-stimulating hormone (FSHR) and luteinizing hormone (LHR) were isolated from ovary of Korean rockfish (Sebastes schlegeli) using reverse transcription-polymerase chain reaction (PCR) and rapid amplification of cDNA ends procedures. The cDNA of the KrFSHR encodes a predicted protein of 703 amino acids that showed the greatest homology with European seabass (Dicentrarchus labrax) (78 %) and gilthead seabream (Sparus aurata) (73 %). The cDNA of the KrLHR encodes a predicted protein of 703 amino acids and exhibited the highest homology with European seabass (Dicentrarchus labrax) (79 %) and gilthead seabream (Sparus aurata) (76 %). Besides the gonads, expressions of GTHRs mRNA were also obtained in extra gonadal tissues. Seasonal changes in the gonads expression profiles of KrGTHRs mRNA were examined by quantitative real-time PCR, and the present results suggest that levels for KrFSHR mRNA increase during gonadal growth, whereas KrLHR shows high levels during the late gamete generation period. Our study provides molecular characterization of the GTHRs and expressions profile during reproductive cycles, reinforcing previous knowledge of GTHRs important role in the reproductive endocrine regulation of Korean rockfish.