Cryopreservation of epididymal spermatozoa collected by needle biopsy from cynomolgus monkeys (Macaca fascicularis)

We have examined the motility, morphology, and cryopreservation of epididymal spermatozoa collected by needle biopsy from cynomolgus monkeys (Macaca fascicularis). At collection, epididymal sperm (23×1064×106 sperm/sample; 611×106116×106 sperm/ ml; n=18) were alive (792%), motile (672%), and exhibited intact membranes (652%). Sperm maintained at room temperature in handling medium exhibited decreased motility over time, but head-to-head agglutination was limited. Tris egg-yolk extender containing 6% glycerol and dimethylsulfoxide (DMSO) did not signi?cantly affect functional morphology, whereas extender containing propanediol signi?cantly reduced motility, survival, and membrane integrity. Cryostorage reduced all measures of functional morphology independent of cryoprotectant. Post-thaw motility was superior for glycerol and DMSO compared to propanediol. Variation in glycerol concentration (4, 6, and 8%) produced equivocal effects on sperm functional morphology post-thaw. Needle biopsy may be a useful technique for laboratory and ?eld-based collection of spermatozoa from nonhuman primates. Key words: agglutination – cryoprotectant – extender – morphology – motility – nonhuman primate – sperm