Fig. 1. The absence of SYCP3 results in disassembly of the STAG3 cohesin core. Wild-type (A,B,E,F,I,J) or Sycp3^–/– (C,D,G,H,K,L) oocytes were spread and triple-stained with antisera against STAG3 (red), SYCP1 (green) and CREST (white); the stages of meiosis are indicated to the left. An integral axial core labelled by STAG3 antiserum is observed in wild-type pachytene (A,B) and late diplotene (E,F) oocytes. By contrast, the STAG axial core is prematurely fragmented at late diplotene in Sycp3-deficient oocytes (G,H). Yellow labelling indicates co-staining of STAG3 and SYCP1. Arrows in G,H mark STAG3 filaments that are retained in regions that have not yet desynapsed. Bars, 10 µm.