Fig. 5. Histone macroH2A1.2 begins to concentrate in the XY-body at early pachytene of spermatocytes (blue, DAPI; green, anti-gammaH2AX; red, anti-macroH2A1.2). The gammaH2AX antibody stains the X and Y chromatin before it condenses at late zygotene (AD) where a `tadpole-shaped' structure is visible. At this stage no detectable concentration of macroH2A1.2 could be found. However, once condensation has started at early pachytene (E-H) histone macroH2A1.2 begins to appear over the XY-body. Scale bars: 25 µm.