SOX8 is expressed during testis differentiation in mice and synergizes with SF1 to activate the Amh promoter in vitro.
Sox8 is a member of the Sox family of developmental transcription factor genes and is closely related to Sox9, a key gene in the testis determination pathway in mammals. Like Sox9, Sox8 is expressed in the developing mouse testis around the time of sex determination, suggesting that it might play a role in regulating the expression of testis-specific genes. An early step in male sex differentiation is the expression of anti-Müllerian hormone (AMH) in Sertoli cells. Expression of the Amh gene during sex differentiation requires the interaction of several transcription factors, including SF1, SOX9, GATA4, WT1, and DAX1. Here we show that SOX8 may also be involved in regulating the expression of Amh. Expression of Sox8 begins just prior to that of Amh at 12 days post coitum (dpc) in mouse testes and continues beyond 16 dpc in Sertoli cells. In vitro assays showed that SOX8 binds specifically to SOX binding sites within the Amh minimal promoter and, like SOX9, acts synergistically with SF1 through direct protein-protein interaction to enhance Amh expression, albeit at lower levels compared with SOX9. SOX8 and SOX9 appear to have arisen from a common ancestral gene and may have retained some common functions during sexual development. Our data provide the first evidence that SOX8 may partially compensate for the reduced SOX9 activity in campomelic dysplasia and substitute for Sox9 where Sox9 is either not expressed or expressed too late to be involved in sex determination or regulation of Amh expression.
Institute for Molecular Bioscience, The University of Queensland, Brisbane 4072, Australia.
Goslik
G
Schepers
Megan
M
Wilson
Dagmar
D
Wilhelm
Peter
P
Koopman
D000818:Animals; D054304:Anti-Mullerian Hormone; D001483:Base Sequence; D001665:Binding Sites; D002454:Cell Differentiation; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000378:metabolism; D005786:Gene Expression Regulation; D005982:Glutathione Transferase / Q000378:metabolism; D006023:Glycoproteins; D006131:Growth Inhibitors / Q000378:metabolism; D017403:In Situ Hybridization; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D055757:SOXE Transcription Factors; D012708:Sertoli Cells / Q000378:metabolism; D019849:Sex Determination Processes; D013735:Testicular Hormones / Q000378:metabolism; D013737:Testis / Q000166:cytology* / Q000196:embryology; D013997:Time Factors; D014157:Transcription Factors / Q000096:biosynthesis* / Q000378:metabolism; D015533:Transcriptional Activation
D004268:DNA-Binding Proteins; D006023:Glycoproteins; D006131:Growth Inhibitors; D055757:SOXE Transcription Factors; C498639:Sox8 protein, mouse; D013735:Testicular Hormones; D014157:Transcription Factors; D054304:Anti-Mullerian Hormone; D005982:Glutathione Transferase