Fig. 7. BMP4 treatment induces Kitl sensitivity and Kit expression in Kit-negative and Kit-positive spermatogonia. (A) Mean of the fold increase of [³H]thymidine incorporating cells from three independent experiments. Asterisks indicate the presence of statistical significance (P<0.001). (B) Kit immunoprecipitation and in vitro autophosphorylation from 4 dpn spermatogonia total extracts, treated or untreated with BMP4 for 24 hours. (C) Northern blot analysis for c-kit expression in 7 dpn spermatogonia RNAs, treated or untreated with BMP4 for 24 hours.