Testicular gene expression in SCARKO mice during prepuberty

To unravel the molecular mechanisms mediating the effects of androgens on spermatogenesis, testicular gene expression was compared in mice with a Sertoli cell-selective androgen receptor knockout (SCARKO) and littermate controls on postnatal d 10. At this age testicular cell composition is still comparable in SCARKOs and controls. Microarray analysis identified 692 genes with significant differences in expression. A more than 2-fold up- or downregulation by androgen action in Sertoli cells was observed for 28 and 6 genes respectively. The biological relevance of the strongly upregulated genes was supported by the finding that several of them were previously described to be androgen-regulated or essential for spermatogenesis. Serine protease inhibitors were overrepresented in the same subgroup suggesting a role for androgens in cell junction dynamics and tissue restructuring events during spermatogenesis. A time course experiment (d8-d20), followed by cluster analysis allowed the identification of typical expression patterns of differentially expressed testicular genes during initiation of spermatogenesis. Three genes with a pattern closely resembling that of Pem, a prototypal androgen-regulated gene in Sertoli cells, were selected for confirmation by RT-PCR and further analysis. The data confirm that the SCARKO model allows identification of novel androgen-regulated genes in the testis.

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Denolet E, De Gendt K, Allemeersch J, Engelen K, Marchal K, Van Hummelen P, Tan KA, Sharpe RM, Saunders PT, Swinnen JV, Verhoeven G