Molecular cloning and expression analysis of estrogen receptor betas (ERβl and ERβ2) during gonad development in the Korean rockfish, Sebastes schlegeli

Estrogen receptors (ER) play a crucial role in mediation of estrogen activities. Here we report the isolation and expression analysis of ER beta 1 and ER beta 2 from ovary Korean rockfish (Sebastes schlegeli). were isolated using reverse transcription-polymerase chain reaction (PCR) and rapid amplification of cDNA ends procedures. The cDNA of this study, ER beta 1 (588 amino acids) and ER beta 2 (659 amino acids) were identified using reverse-transcriptase PCR (RT-PCR) and rapid amplification of cDNA ends procedures. Structural analysis showed both ER beta s contain six typical nuclear receptor-characteristic domains. Phylogenetic analysis indicated that Korean rockfish ER beta s were highly conserved among teleost RT-PCR confirmed that the ER beta s were widely distributed in both gonads and extra gonadal tissues. Further, we analyzed the expression patterns of male and female S. schlegeli during the reproductive cycle using quantitative real-time PCR (qRT-PCR). The results showed that the highest expression levels were observed in testis at immature sperm stage for both of KrER beta 1 and KrER beta 2. For female, the expressions of KrER beta 1 and KrER beta 2 were significantly higher in the ovary at the early-oocyte stage. Cloning these two ER beta subtypes in the Korean rockfish, together with the information on expression levels in adult fish has given us the foundation to investigate their possible role in brain-pituitary-gonad neuroendocrine axis in future studies. (C) 2013 Elsevier B.V. All rights reserved.