Research Project
3499620
Despite advantages of disease control, frozen human sperm has been rarely used universally for donor artificial insemination because of perceived low fertility. Glycerol (which may be contraceptive in humans as with other species) and egg yolk protein (which may be antigenic) can be removed by serial dilution or centrifugation; such processes damage sperm. We are developing practical approaches for use of cryopreserved sperm. We will evaluate a seminal container which: (a) is insoluble in aqueous media during loading and freezing; (b) develops, after thawing and immersion in appropriate diluent solutions, pores whose size and number allow egress of extender and cryoprotectant at a controlled rate (minimizing cell damage) while sperm remain in the container; and (c) is directly attachable to a device for facile insemination. Chicken semen will be used because of (a) sensitivity of their sperm to cryoprotectant and freeze-thaw damage and (b) statistically valid fertility data are easily obtained. Five experiments will evaluate: (a) rate of egress of cryoprotectant from the container; (b) lack of toxicity of container material to sperm; (c) extent of damage to sperm when containers are tested for removal of cryoprotectant from unfrozen samples; (d) as in (c) but frozen-thawed sperm; and (e) fertility of sperm cryopreserved in these prototype containers.
