FIGURE 7.

SOX9-mediated regulation of Er71 transcription and models for the role of ER71 in male gonads. A, ChIP assay in 15P-1 cells. Immunoprecipitations were performed with anti-SOX9 antibodies (Abcam ab3697), control rabbit IgG or no antibody. DNA from the Er71 promoter (−334 to +28), an Er71 region ranging from exon 6 to exon 7, or the 3′-UTR of Sox9 (2664–3023) was PCR amplified. B, down-regulation of Sox9 with shRNA in 15P-1 cells. Shown are levels of Sox9 and Er71 mRNA. Statistical significance was determined with Student's t test. C, during gonadal differentiation, Er71 transcription is up-regulated by SRY in parallel to Sox9 gene expression. D, after SRY expression has subsided, ER71 and SOX9 mutually sustain their expression.