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Updated: May 26, 2026

Dissection of Larval Zebrafish Gonadal Tissue
Published on: April 26, 2017
Male sex determination: insights into molecular mechanisms
Kathryn McClelland1, Josephine Bowles, Peter Koopman
1Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia.
Abstract:
Disorders of sex development often arise from anomalies in the molecular or cellular networks that guide the differentiation of the embryonic gonad into either a testis or an ovary, two functionally distinct organs. The activation of the Y-linked gene Sry (sex-determining region Y) and its downstream target Sox9 (Sry box-containing gene 9) triggers testis differentiation by stimulating the differentiation of Sertoli cells, which then direct testis morphogenesis. Once engaged, a genetic pathway promotes the testis development while actively suppressing genes involved in ovarian development. This review focuses on the events of testis determination and the struggle to maintain male fate in the face of antagonistic pressure from the underlying female programme.
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