Animal models for fertility preservation in the male.

Fertility preservation in the male is routinely focused on sperm. In clinical and veterinary settings, cryopreservation of sperm is a widely used tool. However, the goals for male fertility preservation differ between experimental models, maintenance of livestock, conservation of rare species, and fertility protection in men. Therefore very different approaches exist, which are adapted to the specialized needs for each discipline. Novel tools for male fertility preservation are explored targeting immature germ cells in embryonic or immature testes. Many options might be developed to combine germline preservation and generation of sperm ex vivo leading to interesting new perspectives. This review highlights current and future options for male fertility preservation with a special focus on animal models and a consideration of the various disciplines in need of novel tools.