Bidirectional Sex Change Induced by Sex Steroid Implantation in the Hermaphrodite Fish, Pseudolabrus sieboldi
Article first published online: 27 AUG 2012
Copyright © 2012 Wiley Periodicals, Inc.
Journal of Experimental Zoology Part A: Ecological Genetics and Physiology
Volume 317, Issue 9, pages 552–560, November 2012
How to Cite
2012. Bidirectional sex change induced by sex steroid implantation in the hermaphrodite fish, Pseudolabrus sieboldi. J. Exp. Zool. 317A:552–560., , , , , , .
- Issue published online: 10 OCT 2012
- Article first published online: 27 AUG 2012
- Manuscript Accepted: 1 JUL 2012
- Manuscript Revised: 9 JUN 2012
- Manuscript Received: 28 DEC 2011
- JSPS Research Fellowship for Young Scientists
Sex steroids have been suggested to be involved in gonadal sex change in hermaphrodite fish. Aromatase, the enzyme that catalyzes the conversion of androgens into estrogens, is a principal enzyme regulating gonadal sex. However, the detailed functions of each steroid hormone remain to be evaluated. Recent studies have demonstrated that estradiol-17β (E2) is synthesized via estrone (E1) in some hermaphrodite species. On the other hand, 11-ketotestosterone (11KT) is produced in the testis via testosterone (T). In this study, we hypothesized that E1 and T are also involved in the sex change as precursors for E2 and 11KT, respectively. We implanted females of the wrasse, Pseudolabrus sieboldi, with T and 11KT, and males with E1 and E2, by use of sustained-release capsules. In females, testicular tissues and body color change were observed after androgen administration, in which 11KT was more effective than T. In contrast, after estrogen administration, the gonads of males contained oocytes. In females, the administration of T and 11KT resulted in reduced serum E2 levels. Conversely, serum 11KT levels decreased in the E1- and E2-treated males. Thus, we successfully induced bidirectional sex change in the gonad by estrogen and androgen administration in vivo. Moreover, this study raises the possibility that E1 and T are involved in the sex change as precursors for E2 and 11KT, respectively. J. Exp. Zool. 317A:552–560, 2012. © 2012 Wiley Periodicals, Inc.