Comparative Motility of X and Y Chromosome-Bearing Bovine Sperm Separated on the Basis of DNA Content by Flow Sorting

A combination of flow cytometric sperm sorting of X and Y chromosome-bearing sperm (X and Y sperm) and computer-assisted sperm analysis (CASA) for measuring sperm motility allows assess- ment of motion parameters in the two populations. Bull sperm were separated into X and Y populations by flow cytometry following staining with the DNA-binding dye Hoechst 33342. The motion parameters differed de- pending on sperm concentration. Decreasing sperm concentration resulted in higher velocities and straighter trajectories. The concentrations of control (stained- unsorted and unstained-unsorted) and flow-sorted sperm were therefore adjusted to similar numbers (5 3 10 6