Effects of vitrification techniques on the formation of skin cryobank of the ocelot (Leopardus pardalis).

BACKGROUND: Skin cryobanks represent important tools for the conservation of the maximum genetic representation of a population, especially those with a certain degree of threat to extinction, such as the ocelot. A relevant step towards the proper establishment of these banks is the definition of adequate cryopreservation techniques for the conservation of the skin. OBJECTIVE: We evaluated the effects of two different techniques [direct vitrification in cryovials (DVC) and solid-surface vitrification (SSV)] for the preservation of ear skin derived from ocelot. MATERIALS & METHODS: For both techniques, we vitrified the ear skin using Dulbeccos modified Eagles medium with 3.0 M dimethyl sulfoxide, 0.25 M sucrose, and 10% fetal bovine serum. Non-cryopreserved tissues were used as control (control group). All tissues were analyzed for their morphometric characteristics by conventional histology and morphological / functional analysis by cell ability during the culture. RESULTS: While tissues cryopreserved by DVC showed similar values for dermis thickness and number of perinuclear halos to the control, tissues cryopreserved by SSV showed similarities to the control regarding the number of melanocytes, percentage of collagen fibers, and numbers of viable cells by apoptosis analysis. Additionally, none of the vitrification techniques affected stratum corneum thickness, number of keratinocytes, tissue proliferative activity, cell viability, or metabolism. CONCLUSION: Both vitrification techniques (DVC and SSV) can be used for the conservation of ocelot skin; however, SSV guarantees a higher cellular quality after in vitro tissue culture in most of the parameters evaluated, such as viability, metabolism, and apoptosis analysis. doi.org/10.54680/fr23110110412.

Evaluation of different cryoprotectant solutions for the cryopreservation of somatic tissues of Dasyprocta leporina (Linnaeus, 1758).

BACKGROUND: Somatic tissue banks represent important tools for the conservation of wild mammals, aiming at the immediate maintenance and safeguarding of biological samples. For agouti, Dasyprocta leporina, studies on the formation of these banks are still scarce, especially regarding protocols of the best cryoprotectant solution employed. OBJECTIVE: To optimize the cryoprotectant solution [ethylene glycol (EG), dimethyl sulfoxide (DMSO), sucrose (SUC)] used for the cryopreservation of agouti somatic tissues. MATERIALS AND METHODS: We treated ear tissues with various cryoprotectant solutions: 3.0 M EG (EG group), 3.0 M EG and 0.25 M SUC (EG-SUC group), 3.0 M DMSO (DMSO group), 3.0 M DMSO and 0.25 M SUC (DMSO-SUC group), 1.5 M EG and 1.5 M DMSO (EG-DMSO group) and 1.5 M EG, 1.5 M DMSO and 0.25 M SUC (EG-DMSO-SUC group). Non-cryopreserved tissues were used as controls. All tissues were analyzed for their ultrastructural and morphometric characteristics by scanning electron microscopy and conventional histology. RESULTS: EG-DMSO-SUC was found to be the optimal cryoprotectant solution in terms of the evaluated parameters, such as thickness of the dermis and skin, number of perinuclear halos, proliferative potential, number of empty lacunas and degenerated chondrocytes. CONCLUSION: Agouti somatic tissue cryopreservation may serve for its conservation and as an experimental model for the development of preservation methods for species of the same genus that are either vulnerable or critically endangered.

Cryopreservation of Collared Peccary (Pecari tajacu Linnaeus, 1758) Somatic Cells is Improved by Sucrose and High Concentrations of Fetal Bovine Serum.

BACKGROUND: The formation of somatic cell banks is affected by, amongst other factors, the cryoprotectant solution used. The selection of an effective solution, therefore, is a primary parameter. OBJECTIVE: We optimized the cryoprotectant used for collared peccary somatic cell cryopreservation. MATERIALS AND METHODS: We categorized cells into different groups based on their cryopreservation and evaluated the morphology, viability, proliferative activity, metabolism, and oxidative stress. One group was cryopreserved in 10% DMSO with 10% fetal bovine serum (DMSO-10FBS), and another with 50% FBS (DMSO-50FBS). The cryopreservation of both groups included the presence of 0.2 M sucrose (DMSO-SUC-10FBS and DMSO-SUC-50FBS). Non-cryopreserved cells and cells cryopreserved with 10% DMSO (DMSO) supplemented with 0.2 M sucrose (DMSO-SUC) were used as controls. RESULTS: There was no difference observed in morphology or viability among the groups. Proliferative activity was reduced in DMSO-10FBS when compared to controls. Although cryopreservation reduced metabolism, no difference was observed among solutions. A lower level of reactive oxygen species was observed in cells of DMSO-SUC-50FBS when compared to other cryoprotectants. Only cells of DMSO-SUC-50FBS had mitochondrial potential similar to non-cryopreserved cells. CONCLUSION: 10% DMSO supplemented with 50% FBS and 0.2 M SUC was observed to be the most efficient cryoprotectant for preserving collared peccary somatic cells.