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. This series represents the time course data from d 8, d 10, d 12, d 16 and d 20. The expression data from the additional SCARKO vs control comparison on d 10 is represented by series GSE2260 ("Testicular gene expression in SCARKO mice at day 10"). Keywords: time-course