Analysis of Sexed Sperm by Flow Cytometry in Hanwoo (Korean Native Cattle)

This study evaluated a sexed sperm ability to produce embryos by flow cytometer. Hanwoo bulls sperm were separated to X and Y sperm via Hoechst 33342 stained with near UV laser or performed the pre-sorted without near UV laser beam in flow cytometry. Pre-sorted sperm had significantly higher viability (84±1.15 %, p<0.05) compared to other sorted groups in frozen-thawed semen. For fresh semen, pre-sorted sperm had the higher viability (79±3 %, p<0.05) than those of the X and Y sperm (44.7±1.67 and 41.7±1.2 %) separated by differences of DNA content. On the other hand, pre-sorted and X sperm sorted according to differences in DNA content had significantly higher viabilities (24.3±1.2 and 25.7±0.9 %, p<0.05) compared to that of the sorted Y sperm (13.7±1.2 %) in the hypoosmotic swelling test. The proportion acrosome reaction in the sorted X sperm was higher (55.0±1.7 and 45.0±1.5 %) than those of the sorted Y-sperm (32.3±0.9 %, p<0.05). However, the sperm morphologies of the sorted groups were not significantly differences. In conclusion, the sex-sorting procedure by flow cytometry affected some characteristics of Hanwoo sperm. Further study is needed to determine the optimal procedures to enhance male and female embryos and sorting accuracy.