Nipbl localization on spermatocyte chromosomes. Immunofluorescence images of chromosome spreads stained with antibodies against Nipbl (green) and other marker proteins. No significant difference was observed in Nipbl signal patterns visualized by three Nipbl antibodies independently used for staining at each meiotic prophase stage (see the main text). Therefore these images represent localization of both Nipbl A and B isoforms. DNA was counterstained with DAPI. E, early; M, mid; L, late. Scale bars 10 μm. (A) Anti-Sycp3 (red) marks the AE/LE of synaptonemal complex. More than 20 nuclei were analyzed by each Nipbl antibody in each stage. (B) Anti-Rec8 (red) represents localization of cohesin that overlaps with the AE/LE during the stages shown. More than 15 nuclei were examined in each stage.