ZNRF3 functions in mammalian sex determination by inhibiting canonical WNT signaling

Abigail Harris (1) , Pam Siggers (1) , Silvia Corrochano (1) , Nick Warr (1) , Danielle Sagar (1) , Daniel Grimes (2) , Makoto Suzuki (2) , Rebecca Burdine (2) , Feng Cong (3) , Bon-Kyoung Koo (4) , Hans Clevers (4) , Isabelle Stévant (5) , Serge Nef (5) , Sara Wells (1) , Raja Brauner (6, 7) , Bochra Ben Rhouma (8) , Neïla Belguith (8) , Caroline Eozenou (9) , Joelle Bignon-Topalovic (9) , Anu Bashamboo (9) , Ken Mcelreavey (9) , Andy Greenfield (1)

1 MRC Harwell - Medical Research Coucil Harwell [Oxford, UK]
2 Department of Molecular Biology [Princeton]
3 NIBR - Novartis Institutes for BioMedical Research
4 Hubrecht Institute [Utrecht, Netherlands]
5 UNIGE - Université de Genève = University of Geneva
6 Fondation Ophtalmologique Adolphe de Rothschild [Paris]
7 UPD5 - Université Paris Descartes - Paris 5
8 FMS - Faculté de médecine - Faculty of Medicine [Sfax, Tunisie]
9 Génétique du Développement humain - Human developmental genetics

Mammalian sex determination is controlled by the antagonistic interactions of two genetic pathways: The SRY-SOX9-FGF9 network promotes testis determination partly by opposing proovarian pathways, while RSPO1/WNT-β-catenin/FOXL2 signals control ovary development by inhibiting SRY-SOX9-FGF9. The molecular basis of this mutual antagonism is unclear. Here we show that ZNRF3, a WNT signaling antagonist and direct target of RSPO1-mediated inhibition, is required for sex determination in mice. XY mice lacking ZNRF3 exhibit complete or partial gonadal sex reversal, or related defects. These abnormalities are associated with ectopic WNT/β-catenin activity and reduced Sox9 expression during fetal sex determination. Using exome sequencing of individuals with 46,XY disorders of sex development, we identified three human ZNRF3 variants in very rare cases of XY female presentation. We tested two missense variants and show that these disrupt ZNRF3 activity in both human cell lines and zebrafish embryo assays. Our data identify a testis-determining function for ZNRF3 and indicate a mechanism of direct molecular interaction between two mutually antagonistic organogenetic pathways.

Keywords: sex determination; organogenesis; DSD; WNT signaling; ZNRF3

Domains: Human genetics

Abigail Harris, Pam Siggers, Silvia Corrochano, Nick Warr, Danielle Sagar, et al.. ZNRF3 functions in mammalian sex determination by inhibiting canonical WNT signaling. Proceedings of the National Academy of Sciences of the United States of America, 2018, 115 (21), pp.5474-5479. ⟨10.1073/pnas.1801223115⟩. ⟨pasteur-02872465⟩