“…Moreover, a fertilityassociated protein, osteopontin (OPN), an acidic glycoprotein occurring in the bovine SP, has been shown to induce capacitation and improve viability of spermatozoa by inhibiting the apoptotic pathways [39,41]. Bovine SP proteins, collectively known as binder of sperm (BSP) proteins (BSP1, BSP 3, and BSP 5), bind to choline phospholipids in the sperm plasma membrane and are implicated in semen freezability [22,39,41,42]. Recently, it has been conirmed that BSP1, one of the most abundantly expressed BSP proteins (representing approximately 25-47% of the total proteins in bovine SP), consists of four molecular forms that have varying cryoprotective efects on the bull spermatozoa [42].…”