Vitrification of Ovarian Tissue from Non-Human Primates

Abstract

Background: One of the strategies to preserve genetic material from nonhuman primates (NHP) consists in the implementation of germplasm banks, for future application in reproductive biotechniques, as well as for biomedical research. Based on the success rates achieved in human, there is a prominent possibility to succeed also with NHP. However, studies with NHP are still scarce, especially regarding the cryopreservation of ovarian tissue.Review: Neotropical non-human primates, especially males, have been used in research related to reproductive biotechniques in Brazil. Regarding research on female reproduction and ovarian tissue preservation, most studies were performed using domestic animals as models. Current concepts and controversies in the restoration of gametes in adult females does not exclude the needs to preserve ovarian tissue. Importantly, ovarian tissue can be collected and preserved even after the death of the donors, being applied when finding dead females. Furthermore, collection of ovarian biopsies is also feasible and will not affect reproductive function. Among the cryopreservation methods, the vitrification has been indicated due to practical logistic, as well as because it will avoid the formation of large intracellular ice crystals, and it is claimed that ovarian stromal damage will be decreased under vitrification. Considering the number of threatened primate species and the needs to preserve their habitat, but also their gametes, development of preservation protocols are needed. Among the procedures, vitrification appears as a practical method to be applied in the near future. Although a low number of studies is reported, most of them were performed in the recent years. In this context, this article reviews recent information on the vitrification of ovarian tissue of non-human primates. Due to the limited number of studies in these species, observed data are compared with the literature in domestic and human mammals.Conclusion: Despite the advances summarized here, it is possible to conclude that there is still a need to improve procedures for the preservation of genetic material, including in post-mortem situations. The technique of vitrification, therefore, consists of a feasible and promising option. However, it is needed to study properly the methods of vitrification, as well as the introduction of new systems and supplements to minimize or avoid the cell damage caused by the cryopreservation procedure (physical and chemical).