Canine Spermatogonial Stem Cells: The State of the Art and Future Perspectives

In recent decades, the growing interest in fertility rate improvements in livestock species, considering their high economic value in terms of production, has prompted the devel-opment of new methodological approaches associated with the use of male germline stem cells. The significant potential of spermatogonial stem cells (SSCs) to self-renew and dif-ferentiate into mature spermatozoa makes them potentially useful for transplantation into testicular tissue, as well as for new biotechnological methodologies. More recently, canine SSCs have also been investigated, since dogs are considered an optimal animal model of human reproduction, development, and disease. Characterization studies of canine SSCs (cSSCs) have revealed interesting aspects in relation to their potential clinical application in reproduction. Against this background, this review provides an update on the main aspects of cSSC biology, focusing also on the genetic regulators of self-renewal and differ-entiation processes and different isolation methods. Finally, novel views on the potential clinical transplantation of canine SSCs into recipient testicular tissue are also discussed.