Fig. 3. BMP4 induces [3H]thymidine incorporation in postnatal
spermatogonia. Proliferative response to BMP4 and Kitl in 4 and 7 dpn isolated
spermatogonia. Mean of the fold increase of [3H]thymidine
incorporating cells for at least four independent experiments. Bars represent
the standard deviation. Asterisks indicate the presence of statistical
significance (P<0.001).