Establishment and Characterization of Fibroblast Cell Line Derived from Siberian Tiger (Panthera tigris altaica)

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.

Evaluation of the damage caused by in vitro culture and cryopreservation to dermal fibroblasts derived from jaguars: An approach to conservation through biobanks

Ex-situ conservation strategies such as the formation of somatic cell banks are valuable tools for the conservation of jaguars, whose population has been declining in recent years. Once properly established, these cells can be successfully leveraged for future applications. We aimed to assess the effects of in vitro culture and cryopreservation on the establishment of fibroblasts derived from jaguars. Initially, we identified five dermal fibroblastic lines using morphology and immunophenotyping assays; these lines were then subjected to two experiments. In the first experiment, the viability, metabolism, and proliferative activity of cells at different passages (first, third, and tenth) were evaluated. In the second experiment, the cells were cryopreserved and the levels of reactive oxygen species (ROS), mitochondrial membrane potential (ΔΨm) and apoptosis were evaluated after one, three, and ten passages. Noncryopreserved cells were used as controls. The in vitro culture after first, third, and tenth passages and cryopreservation conditions did not affect the proliferative activity and viability. However, cells cultured until tenth passage and frozen/thawed cells showed reduced metabolism. In addition, cryopreserved cells showed higher levels of intracellular ROS and altered ΔΨm when compared with those of noncryopreserved cells. Finally, frozen/thawed cells cultured after ten passages showed reduced proliferative activity and number of viable cells than did frozen/thawed cells cultured after one and three passages. In summary, we have shown that viable fibroblasts can be established from jaguar skin and that although these cells do not show altered viability and proliferative activity, they do undergo damage during extended culture and cryopreservation.

Cellular Characterization and Effects of Cryoprotectant Solutions on the Viability of Fibroblasts from Three Brazilian Wild Cats

Preserving genetic material in cryogenic conditions presents a viable alternative for the protection of species' gene variability. However, there is an enormous need to establish and test cryopreservation protocols that are suitable for each diverse cell type to guarantee technical success in the long run. Considering this, fibroblasts from jaguar (Panthera onca), oncilla (Leopardus tigrinus), and pampas cat (Leopardus colocolo) were subjected to cell characterization and then cryopreservation in different cryoprotectant solutions (2.5%, 10% dimethyl sulfoxide [DMSO] or CryoSOfree™). Further testing was conducted to determine each solution's performance in preserving cell viability. In culture, a growth curve to assess cellular growth potential showed that exponential proliferation lasts for about the first 50 hours of in vitro culturing, declining in pace afterward. L. colocolo and L. tigrinus presented no difference in cell viability while using 2.5% DMSO protocols. P. onca cells did not present difference on viability for both concentrations of DMSO. Protocols using CryoSOfree resulted in a decreased viability of P. onca fibroblasts. Morphological differences between fibroblasts among the species were noted under bright field microscopy and scanning electron microscopy. L. colocolo and P. onca cells are fusiform, and L. tigrinus are spherical. All cells presented cytoplasmic projections. Transmission electron microscopy revealed vacuoles and secretion granules, indicating intense cell activity after thawing. Differences found in the efficiency of cryopreservation protocols according to the type of cryoprotectant indicate that species react differently to freezing and thawing processes. This research evaluates key aspects of in vitro protocols for cryopreservation of wild animals, which need to be optimized to guarantee successful cell culturing. More suitable protocols lead to increased efficiency in establishing fibroblast cryobanks and also facilitating the use of wild cats' cells in cloning techniques, contributing directly to preserving wild fauna.

Use of somatic cell banks in the conservation of wild felids

The conservation of biological resources is an interesting strategy for the maintenance of biodiversity, especially for wild felids who are constantly threatened with extinction. For this purpose, cryopreservation techniques have been used for the long-term storage of gametes, embryos, gonadal tissues, and somatic cells and tissues. The establishment of these banks has been suggested as a practical approach to the preservation of species and, when done in tandem with assisted reproductive techniques, could provide the means for reproducing endangered species. Somatic cell banks have been shown remarkable for the conservation of genetic material of felids; by merely obtaining skin samples, it is possible to sample a large group of individuals without being limited by factors such as gender or age. Thus, techniques for somatic tissue recovery, cryopreservation, and in vitro culture of different wild felids have been developed, resulting in a viable method for the conservation of species. One of the most notable conservation programs for wild felines using somatic samples was the one carried out for the Iberian lynx, the most endangered feline in the world. Other wild felids have also been studied in other continents, such as the jaguar in South America. This review aims to present the technical progress achieved in the conservation of somatic cells and tissues in different wild felids, as well address the progress that has been achieved in a few species.

The Effects of Cryopreservation on Different Passages of Fibroblast Cell Culture in Brown Brocket Deer (Mazama gouazoubira)

The brown brocket deer Mazama gouazoubira is 1 of the 10 recognized brocket deer of the Neotropical region. Recently, this species has suffered a population decline due to current threats, mainly poaching and habitat loss. Several studies have shown that some endangered species can benefit from interspecies somatic cell nuclear transfer technology through the use of their somatic cells, such as the fibroblasts. Thus, the aim of this study was to verify the viability and the effect of cryopreservation on fibroblasts after several passages. For this purpose, fibroblast cells were cultured until passages 4, 7, and 10 (cultured control groups) and cryopreserved in cryotubes (frozen/warmed groups). The cellular viability, functionality, and percentage of cells undergoing necrosis and apoptosis were evaluated. The survival rates were always higher than 80% irrespective of the tested group, except for passage 10 in the frozen/warmed group. Population doubling time of cultured cells from passage 10 was significantly higher than that of passages 4 and 7, exhibiting low metabolic activity and a higher percentage of cells in initial apoptosis. In conclusion, the M. gouazoubira fibroblast-derived cell line provides an essential resource for further studies regarding reproductive biotechniques and is likely to be useful as an ex situ conservation strategy.

In vitro culture of somatic cells derived from ear tissue of collared peccary (Pecari tajacu Linnaeus, 1758) in medium with different requirements

ABSTRACT: The maintenance of metabolic activities during the in vitro culture of somatic cells of wild animals, especially collared peccary (Pecari tajacu), is an interesting step in conservation of these cells for the use in nuclear transfer. In this context, it is necessary to optimize the culture conditions of somatic cells by the establishment of appropriate supplementation to the media. Therefore, this study aimed to analyze the composition of the culture means of somatic cell derived from ear tissue of collared peccaries, evaluating concentrations of fetal bovine serum (FBS; 10% vs. 20%) and epidermal growth factor (EGF; 5ng/mL vs. 10ng/mL). Tissues were submitted to primary culture and subcultures for 40 days and cells were analyzed for morphology, adhesion, subconfluence, and proliferative activity to develop the growth curve and to determine the population doubling time (PDT), viability, and functional/metabolic activity. No difference was observed between the concentrations of FBS for several parameters, except for viability [FBS10: 85.6% vs. FBS20: 98.2%], PDT [FBS10: 155.4h vs. 77.2h], and functional/metabolic assay [FBS10: 0.57-0.55 vs. FBS20: 0.82-0.99 (D5-D7)]. For the EGF in culture, no difference was observed in the evaluated parameters. In all experiments, the growth curves were typical S-shape and the cells passed through a lag, logarithmic, and plateau phase. In conclusion, 20% FBS is suitable for the recovery of somatic cells; nevertheless, EGF does not improve the quality of growing these cells. To our knowledge, this is the first study culturing somatic cells of collared peccaries.

Construction of a full-length enriched cDNA library and preliminary analysis of expressed sequence tags from Bengal Tiger Panthera tigris tigris

In this study, a full-length enriched cDNA library was successfully constructed from Bengal tiger, Panthera tigris tigris, the most well-known wild Animal. Total RNA was extracted from cultured Bengal tiger fibroblasts in vitro. The titers of primary and amplified libraries were 1.28 × 106 pfu/mL and 1.56 × 109 pfu/mL respectively. The percentage of recombinants from unamplified library was 90.2% and average length of exogenous inserts was 0.98 kb. A total of 212 individual ESTs with sizes ranging from 356 to 1108 bps were then analyzed. The BLASTX score revealed that 48.1% of the sequences were classified as a strong match, 45.3% as nominal and 6.6% as a weak match. Among the ESTs with known putative function, 26.4% ESTs were found to be related to all kinds of metabolisms, 19.3% ESTs to information storage and processing, 11.3% ESTs to posttranslational modification, protein turnover, chaperones, 11.3% ESTs to transport, 9.9% ESTs to signal transducer/cell communication, 9.0% ESTs to structure protein, 3.8% ESTs to cell cycle, and only 6.6% ESTs classified as novel genes. By EST sequencing, a full-length gene coding ferritin was identified and characterized. The recombinant plasmid pET32a-TAT-Ferritin was constructed, coded for the TAT-Ferritin fusion protein with two 6× His-tags in N and C-terminal. After BCA assay, the concentration of soluble Trx-TAT-Ferritin recombinant protein was 2.32 ± 0.12 mg/mL. These results demonstrated that the reliability and representativeness of the cDNA library attained to the requirements of a standard cDNA library. This library provided a useful platform for the functional genome and transcriptome research of Bengal tigers.