Effects of duration of electric pulse on in vitro development of cloned cat embryos with human artificial chromosome vector

Determining Influence of Culture Media and Dose-Dependent Supplementation with Basic Fibroblast Growth Factor on the Ex Vivo Proliferative Activity of Domestic Cat Dermal Fibroblasts in Terms of Their Suitability for Cell Banking and Somatic Cell Cloning of Felids

Dermal fibroblasts are commonly used as donors of genetic material for somatic cell nuclear transfer in mammals. Basic fibroblast growth factor (bFGF) is a cytokine that regulates proliferation and differentiation of different cell types. The study was aimed at optimizing the cell culture protocol for cat dermal fibroblasts by assessing the influence of culture media and different doses of bFGF on proliferation of fibroblasts and their viability in terms of cell banking and somatic cloning of felids. In Experiment I, skin biopsies of domestic cats were cultured in DMEM (D) and/or DMEM/F12 (F), both supplemented with 5 ng bFGF/ml (D-5, F-5, respectively). After the primary culture reached ~80% of confluency, the cells were passaged (3–4 times) and cultured in media with (D-5, F-5) or without (D-0, F-0) bFGF. To determine the optimal doses of bFGF, in Experiment II, secondary fibroblasts were cultured in DMEM with 0 (D-0), 2.5 (D-2.5), 5 (D-5) or 10 (D-10) ng bFGF/ml. The results showed that in D-5 the cells proliferated faster than in D-0, F-5 and F-0. Due to their poor proliferation, passages IV were not performed for cells cultured in F-0. In experiment II, a dose-dependent effect of bFGF on proliferation of cat dermal fibroblasts was found. In D-5 and D-10, the cells exhibited higher (P<0.05) proliferation compared with D-0. In D-2.5 the cells showed a tendency to proliferate slower than in D-5 and D-10 and at the same faster than in D-0. In conclusion. DMEM supplemented with bFGF provides better proliferation of domestic cat dermal fibroblasts culture than DMEM/F12. Supplementation of culture medium with bFGF has a beneficial effect on cat dermal fibroblast proliferation and could be recommended for addition to culture media.

Combinations of chromosome transfer and genome editing for the development of cell/animal models of human disease and humanized animal models

Chromosome transfer technology, including chromosome modification, enables the introduction of Mb-sized or multiple genes to desired cells or animals. This technology has allowed innovative developments to be made for models of human disease and humanized animals, including Down syndrome model mice and humanized transchromosomic (Tc) immunoglobulin mice. Genome editing techniques are developing rapidly, and permit modifications such as gene knockout and knockin to be performed in various cell lines and animals. This review summarizes chromosome transfer-related technologies and the combined technologies of chromosome transfer and genome editing mainly for the production of cell/animal models of human disease and humanized animal models. Specifically, these include: (1) chromosome modification with genome editing in Chinese hamster ovary cells and mouse A9 cells for efficient transfer to desired cell types; (2) single-nucleotide polymorphism modification in humanized Tc mice with genome editing; and (3) generation of a disease model of Down syndrome-associated hematopoiesis abnormalities by the transfer of human chromosome 21 to normal human embryonic stem cells and the induction of mutation(s) in the endogenous gene(s) with genome editing. These combinations of chromosome transfer and genome editing open up new avenues for drug development and therapy as well as for basic research.