Effect of methyl-beta-cyclodextrin on the viability and acrosome damage of sex-sorted sperm in frozen-thawed bovine semen

Abstract

Background: The regulation of methyl-beta-cyclodextrin (MBCD) on cryodamage on X- and Y-sperm during cryo- preservation of semen was investigated. The semen was collected from ten healthy bulls of proven fertility by an arti- ficial vagina. The bovine sperm treated with MBCD fresh solution (0, 1, 5, 10, and 20 mM). The sperms were evaluated for viability and acrosome damage using flow cytometry. Moreover, X- and Y-sperm in frozen-thawed bovine semen were sorted by flow cytometry after Hoechst 33342-dyed, and the viability and acrosome damage of sperms were analyzed. Results: Sperm viability in frozen-thawed semen was decreased by MBCD (p < 0.05), also the acrosome damage of sperm was significantly increased (p < 0.05). Moreover, we sorted X- and Y-sperm from frozen-thawed bovine semen for observing the viability and acrosome damage on the separated X- and Y-sperm after MBCD treatment. Viability of X-sperm was significantly lower than that of Y-sperm (p < 0.05). Also, acrosome damage of X-sperm was significantly higher than Y-sperm (p < 0.05). Conclusions: Methyl-beta-cyclodextrin enhances damage of sperm in frozen-thawed bovine semen, and X-sperm is more sensitive than Y-sperm in cell damage. These results demonstrate that MBCD can inhibit viability of spermatozoa in frozen-thawed bovine semen (for X-sperm, especially).