We investigated the change mRNA expression of GtHs subunits (FSHβ, LHβ) in the pituitary, androgen receptor (AR), estrogen receptor (ERα) in gonad and histological observation of gonads in longthooth grouper Epinephelus bruneus by treatment Femara, an aromatase inhibitor (AI). Longtooth grouper (body weight 408±43.1 g; one year) cultured in Future Aquaculture Research Center, NFRDI were used in the experiments. The experiment was conducted for 12 weeks from 21 August 2013. Fish received intramuscular injection of AI at 5 mg/g BW dose in three times every 3 weeks. Fish were sampled pituitary and gonads at 3, 6, 12 weeks post-injection (n=50). The mRNA levels of FSH-β, LH-β in pituitary and AR, ERα mRNA in gonad were evaluated using qRT-PCR and qPCR. The histological change of gonads observed on light microscope. The gonads of control group contained most perinucleolus oocyte. At 3 to 6 weeks post-injection, the gonads of AI-treated group contained a few degenerated oocytes, spermatogonia and spermatocytes. At 12 weeks post-injection, gonads contained spermatids undergoing spermatogenesis. From 6 to 12 weeks post-injection, the expression level of GtHs subunits mRNA in pituitary was significantly higher than control group. The expression level of AR mRNA in gonad was higher than control group from 3 to 12 weeks post-injection. The expression level of ERα mRNA in gonad was lower than control group from 6 to 12 weeks post-injection. These results suggest that immature longtooth grouper with AI treatment induced masculinization via change of GtH subunits in pituitary, AR and ERα mRNA in gonad.

어류의 체내에서 성분화를 유도하는 물질이 성스테로이드호르몬(sex steroid hormone)이라는 사실이 잘 밝혀져 있으며, 성스테로이드 생합성 효소의 하나인 aromatase도 성분화에 직접적인 역할을 하는 것으로 알려져 있다. 본 연구에서는 유전적으로 암컷인 틸라피아 자어(larvae) 집단을 aromatase 저해제(aromatase inhibitor, AI)인 Fadrozole로 침지 처리하여 초기 발생단계 중 어느 시기에 aromatase가