Reproductive performance of New Zealand White rabbits after depletion of apoptotic spermatozoa.

The objective of this study was to assess the utility of the magnetic-activated cell sorting (MACS) technique used for improving characteristics and quality of insemination doses by the elimination ofapoptotic rabbit spermatozoa from a heterospermic pool (Experiment 1) as well as from the ejaculates of individual bucks (Experiment 2). Superparamagnetic microbeads conjugated with annexin V eliminated spermatozoa with externalized phosphatidylserine via MACS. The control (untreated) and magnetically separated spermatozoa (in both E1 and E2) were used for artificial insemination of hormonally treated rabbit does. MACS separation of spermatozoa yielded two fractions: annexin V-negative (AnV) and annexin V-positive (AnV+). The CASA analysis after MACS sperm sorting revealed that the proportion of apoptotic spermatozoa in the semen of New Zealand White bucks varied from 7 to 20%. Transmission electron microscopy revealed that MACS treatment might eliminate spermatozoa with membrane damages and released acrosomal matter. However, the MACS separation (in both E1 and E2) did not affect the reproductive parameters of rabbit does.