Effects of somatic tissue cryopreservation on puma (Puma concolor L, 1771) tissue integrity and cell preservation after in vitro culture.

Somatic resource banks play a crucial role in the conservation of genetic diversity, allowing for the preservation of biological samples from different populations. Puma somatic cells can be recovered from these banks and used in assisted techniques toward enhancing their multiplication and conservation. In response to the population reduction of this ecologically importance species, we aimed to evaluate the capacity of cryopreservation of somatic tissues on the maintenance of the integrity and quality of the cells recovered after culture, with the aim of establishing a somatic tissue bank that will allow for the safeguarding of a wide genetic sampling of pumas. Cryopreservation increased the thickness of the corneum layer in the tissues, and the number of perinuclear halos and empty gaps. Nevertheless, cryopreservation was able to maintain normal fibroblast patterns, even showing an increase in the percentage of collagen fibers. Cryopreservation maintained the proliferative potential of the tissues and the parameters evaluated during in vitro culture, mainly regarding the viability, proliferative activity, and apoptosis levels. Nevertheless, cells from cryopreserved tissues showed decreased metabolism and mitochondrial membrane potential when compared to cells from non-cryopreserved tissues. In summary, we demonstrated for the first time that puma somatic tissues subjected to cryopreservation are viable and maintain tissue integrity, featuring minimal changes after warming. Although viable somatic cells are obtained from these tissues, they undergo alterations in their metabolism and mitochondrial membrane potential. Improvements in the conservation conditions of somatic samples are needed to increase the quality of somatic tissue banks in this species.