Fig. 1

Flow cytometry data: a FSC-SSC pattern obtained as well as the gate used to select spermatozoa for further analysis steps; b shows the regions of analysis used in the acrosome status assay. Lower right: live, reacted, green; Upper right: dead damaged, olive; Lower left: live, non-reacted, grey; Upper left: dead, non-reacted, dark red; c, d results from analysis of mitochondrial membrane status of spermatozoa from a dairy bull and a beef bull, respectively. Indicated are the regions of analysis for spermatozoa with high MMP (orange) and low MMP (green). Events inside the gate for spermatozoa, but outside the regions of analysis, are shown in red