Fig. 9. DNA fragmentation was detected by TUNEL staining of sections of Hsp47^–/– mutant mouse embryos at 10.5 dpc. (A-D) Sections of wild-type and Hsp47^–/– embryos at 9.5 dpc (A,B) and 10.5 dpc (C,D) were analysed for DNA fragmentation by TUNEL staining. A strong signal was detected in Hsp47^–/– embryos at 10.5 dpc (D) but not at 9.5 dpc (B), whereas no significant signals were detected in the wild-type embryos at either time point (A,C). Bar, 50 µm.