Faculty of Science, Ushimado Marine Institute (UMI), Okayama University, Ushimado, Setouchi 701-4303, Japan
Tropical Biosphere Research Center, Sesoko Station, University of the Ryukyus, 3422 Sesoko, Motobu, Okinawa 905-0227, Japan
Okinawa Churashima Foundation, 888 Ishikawa, Motobu, Okinawa 905-0206, Japan
Department of Biology, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan
Doublesex-mab 3-related transcription factor 1 (DMRT1) has been identified as the first conserved gene involved in the testicular differentiation of vertebrates. However, the precise role of DMRT1 in spermatogenesis has not been made clear. In this study, immunohistochemical method was used to observe DMRT1 protein localization in order to resolve cellular profile of DMRT1 in the adult testis of three-spot wrasse. DMRT1 protein was clearly and specifically localized in the Sertoli cells of all spermatogenic cells and epithelial cells comprising the efferent duct, but not in the germ cells. In addition, adult males were treated with aromatase inhibitor (AI) for investigating the role of estrogen on the transcription of DMRT1. AI treatment caused an increase in the levels of DMRT1 transcripts in the efferent duct region, concomitant with a decrease in spermatogonia and spermatocytes.