FIG. 3.

Stra8 and Dnmt3l expressions in PGCs aggregated with Sertoli cells. XX and XY PGCs at 11.5 dpc were aggregated with Seroli cells at 12.5, 15.5, or 18.5 dpc and cultured with RAR inhibitor (0, 10⁻⁶ M) for 6 days. As controls, XX and XY 11.5-dpc urogenital ridges (UGR) were cultured under the same conditions. In the presence of RAR inhibitor, Stra8 expression levels were decreased in the germ cells of all groups (A). In contrast, Dnmt3l expression levels were detected only in PGCs aggregated with 12.5-dpc Sertoli cells in the presence of RAR inhibitor (B). Stra8 expression levels are shown relative to those of XX UGR cultured for 4 days. The expression level of XY UGR cultured for 4 days is set at 1 to show the relative expression levels of Dnmt3l in each group. Only XY PGCs were used for making aggregates with 15.5- and 18.5-dpc Sertoli cells. Normalization of expression was achieved relative to the amplification of Actb. Values are mean ± SEM from 3 separate experiments.