Saving wild ungulate diversity through enhanced management and sperm cryopreservation

Abstract

Wild ungulates throughout the world face the impending risk of extinction. Small founding population size, lack of interest in exhibiting wild ungulates and declining space in zoos are not sustaining ex situ populations. Animals managed in ex situ collections continue to experience >20% neonate loss globally. To ensure population sustainability there is a critical need to: (1) manage ungulates in large herds, increasing mate choice and reproductive efficiency; (2) improve husbandry and genetic management; and (3) develop consistent assisted reproductive technologies, including sperm cryopreservation and AI. Recently, new models in the management of ungulates have begun to emerge. Animal managers and researchers are also beginning to exploit advances in genomics to improve genetic management of their collections. Furthermore, the past decade has witnessed significant advances particularly in semen collection and cryopreservation in numerous species. Advances in gonadal tissue cryopreservation now offer additional opportunities to preserve male genomes. The new knowledge generated is enabling the creation of genetic (sperm) banks to rescue and enhance reproductive management of wild ungulates. The present paper reviews the threats to ungulate populations, the status and relevance of animal management and biomaterial banking efforts to ensure long-term survival of these charismatic species.

Protein signatures of seminal plasma from bulls with contrasting frozen-thawed sperm viability

“…Sperm cryopreservation, artificial insemination (AI) and in vitro fertilization followed by embryo transfer are among the most used assisted reproductive technologies (ARTs), allowing genetic selection of farm animals 1 , conservation of wild and endangered species 2 , successful pregnancies for infertile couples 3 and preservation of fertility in cancer patients 4 . Successful implementation of ARTs depends on cost-effective and efficient cryopreservation of sperm cells.…”

Current perspectives on ruminant sperm freezability: Harnessing molecular changes related to semen quality through omics technologies

“…Over the years, substantial progress has been made toward the improvement of assisted reproductive technologies (ARTs) for domestic and wild animals. Sperm cryopreservation allowed for the long-term storage and utilization of male gametes from organisms with superior genetics (Ugur et al, 2019), declining conservation status, or even those at the brink of extinction (Pukazhenthi, 2016). Recently, the ruminant spermatozoa have been vitrified (Arando et al, 2017;Pradieé et al, 2018), and their freezing medium was supplemented with nanoparticles (Hozyen et al, 2020;Khalil et al, 2019) and other novel compounds (Batissaco et al, 2020;Fang et al, 2020).…”

Horse ooplasm supports in vitro preimplantation development of zebra ICSI and SCNT embryos without compromising YAP1 and SOX2 expression pattern

“…Efforts for the preservation of wild equids are needed for the maintenance of animal population and genetic variability among individuals. To accomplish these goals, in addition to natural breeding, conservation programs can be enhanced by using assisted reproductive techniques (ART) to achieve optimal genetic management of endangered species and overcome infertility issues [7,8]. Among ART, cryopreservation of gametes combined with in vitro embryo production are powerful tools for rescuing endangered animals or to preserve the genetics of critically endangered species.…”

“…Understanding the reproductive biology and generating comparative knowledge across species is essential to design and execute species-specific ART for animal conservation programs [7]. Although vast progress has been made in ART for the domestic horse and a select group of wild equids (Persian onager and Przewalski's horse), there is no information on preimplantation embryo development in wild equids.…”