Altered SOX9 genital tubercle enhancer region in hypospadias

Rajini Sreenivasan; Christopher T Gordon; Sabina Benko; Robb de Iongh; Stefan Bagheri-Fam; Stanislas Lyonnet; Vincent Harley

doi:10.1016/j.jsbmb.2016.10.009

Altered SOX9 genital tubercle enhancer region in hypospadias

J Steroid Biochem Mol Biol. 2017 Jun:170:28-38. doi: 10.1016/j.jsbmb.2016.10.009. Epub 2016 Oct 29.

Authors

Rajini Sreenivasan¹, Christopher T Gordon², Sabina Benko², Robb de Iongh³, Stefan Bagheri-Fam⁴, Stanislas Lyonnet², Vincent Harley⁵

Affiliations

¹ Molecular Genetics and Development, Hudson Institute of Medical Research, Melbourne, Victoria, Australia; Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, Victoria, Australia; Monash University, Melbourne, Victoria, Australia.
² Laboratory of Embryology and Genetics of Congenital Malformations, Institut National de la Santé et de la Recherche Médicale (INSERM) U1163, Institut Imagine, Paris, France; Paris Descartes-Sorbonne Paris Cité University, Institut Imagine, Paris, France.
³ Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, Victoria, Australia.
⁴ Molecular Genetics and Development, Hudson Institute of Medical Research, Melbourne, Victoria, Australia; Monash University, Melbourne, Victoria, Australia.
⁵ Molecular Genetics and Development, Hudson Institute of Medical Research, Melbourne, Victoria, Australia; Monash University, Melbourne, Victoria, Australia. Electronic address: vincent.harley@hudson.org.au.

PMID: 27989796
DOI: 10.1016/j.jsbmb.2016.10.009

Abstract

Human mutations in the SOX9 gene or its regulatory region can disrupt testicular development, leading to disorders of sex development (DSDs). Our previous work involving the genomic analysis of isolated DSD patients revealed a 78kb minimal sex determining region (RevSex) far upstream of SOX9 that was duplicated in 46,XX and deleted in 46,XY DSDs. It was postulated that RevSex contains a gonadal enhancer. However, the most highly conserved sub-region within RevSex, called SR4, was neither responsive to sex determining factors in vitro nor active in the gonads of transgenic mice, suggesting that SR4 may not be functioning as a testicular enhancer. Interestingly, SR4 transgenic mice showed reporter activity in the genital tubercle, the primordium of the penis and clitoris, a previously unreported domain of Sox9 expression. SOX9 protein was detected in the genital tubercle, notably in the urethral plate epithelium, preputial glands, ventral surface ectoderm and corpus cavernosa. SR4 may therefore function as a Sox9 genital tubercle enhancer, mutations of which could possibly lead to hypospadias, a birth defect seen in the DSD patients in the RevSex study. SR4 activity and the observed SOX9 expression pattern suggest that SR4 may function as a Sox9 genital tubercle enhancer. However, conditional ablation of Sox9 in the genital tubercle using Shh-Cre/+;Sox9^flox/flox mice revealed no genital tubercle abnormalities, possibly due to compensation by similar Sox factors. To conclude, we have identified a novel regulatory enhancer driving Sox9 expression during external genitalia development.

Keywords: Disorder of sex development; Enhancer; Genital tubercle; Hypospadias; SOX9.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Cell Line
Female
Genitalia, Female*
Genotype
Humans
Hypospadias / genetics*
Male
Mice
Mice, Inbred C57BL
Mice, Knockout
Mice, Transgenic
Mutation
Regulatory Sequences, Nucleic Acid / genetics*
SOX9 Transcription Factor / genetics*

Substances

SOX9 Transcription Factor
SOX9 protein, human
Sox9 protein, mouse