Cell Cycle Synchronization of Bison (Bos Gaurus) Fibroblasts Derived from Ear Piece Collected Post-mortem

Effects of Incubation Time and Method of Cell Cycle Synchronization on Collared Peccary Skin-Derived Fibroblast Cell Lines

The success of cloning by somatic cell nuclear transfer depends on the efficiency of nuclear reprogramming, with the cycle stage of the donor cell playing a crucial role. Therefore, the aim was to evaluate three different approaches for cell cycle synchronization: (i) serum starvation (SS) for 1 to 4 days, (ii) contact inhibition (CI) for 1 to 3 days, and (iii) using cell cycle regulatory inhibitors (dimethyl sulfoxide, cycloheximide, cytochalasin B, or 6-dimethylaminopurine) for 1 and 2 days, in terms of their effects on synchronization in G0/G1 phases and viability of collared peccary skin fibroblasts. Flow cytometry analysis revealed that SS for 4 days (79.0% ± 1.6) and CI for 3 days (78.0% ± 1.4) increased the percentage of fibroblasts in G0/G1 compared to growing cells GC (68.1% ± 8.6). However, SS for 3 and 4 days reduced the viability evaluated by differential staining (81.4% ± 0.03 and 81.6% ± 0.06) compared to growing cells (GC, 95.9% ± 0.06). CI did not affect the viability at any of the analyzed time intervals. No cell cycle inhibitors promoted synchronization in G0/G1. These results indicate that CI for 3 days was the most efficient method for cell cycle synchronization in peccary fibroblasts.

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.