In vitro development and chimeric efficiency of mouse-porcine interspecies chimeric embryos in different culture systems / 生物工程学报

With the advancements of stem cells and regenerative medicine, interspecies chimera has become a hot topic and will pave a new way of providing donor sources in organ transplantation. However, the interspecies chimera is confronted with a number of scientific questions and technical obstacles, including selections of appropriate embryonic stage and appropriate culture medium; those factors will deeply influence the developmental balance between donor cells and receptor embryos. Due to its relatively rapid reproductive cycle and similar organ size to human's, porcine is a very potential donor candidate to study these questions. To compare the development and chimeric efficiency of interspecies embryos, we tested and evaluated three different culture systems, PZM-3 (Porcine zygotic medium), culture medium for iPSCs (N2B27) and 3.5 h of N2B27 before PZM-3 (N2B27(3.5 h)), and two different embryonic stages, 8-cell and blastocyst in mouse-porcine chimeric embryos using parthenogenetically activated porcine embryos and mouse induced pluripotent stem cells (miPS). The results showed that, PZM-3 was beneficial for both development of chimeric embryos and miPSCs proliferation in porcine embryos in the 8-cell injection group. After early blastocyst injection, the chimeric efficiency did not appear significantly different among the three culture systems but was lower than 8-cell injection. In summary, the results suggest that 8-cell injection and PZM-3 culture medium are more beneficial to the in vitro development and chimeric efficiency of mouse-porcine chimeric embryos.

The Development of Human Embryos in the Buffalo Rat Liver(BRL) Cell Coculture / 대한산부인과학회잡지

Culture requirements for in vitro development of human preimplantation embryos have not been fully defined. Helper cells in coculture would pave the way for repro-ducible embryo culture system of in vitro fertilization-embryo transfer(IVF-ET) in human. The purpose of this study is to evaluate the influence of BRL cells in coculture on human embryo development in vitro. Supernumerary 2-8 cell stage embryos from IVF-ET patients were used in this experiment. The embryos were assigned to two treatments, one for conventional embryo culture in 2 ml of Ham's F10 + 15% huamn serum(control), and the other for the coculture trial. Monlayer for the coculture of embryos was prepared by plating 1X 10(5) viable BRL cells per well in 4-well tissue culture plate 48 hours prior to the onset of coculture. In twenty four hours after plating, all wells were washed out and 0.5 ml of the medium was placed into the well and then preincubated. Embryos were scored according to embryo quality, assigned to each treatment and further cultured for 5 days. A total of 63 embryos from 10 patients were randomized(23 controls, 40 coculure). With grade I embryos, higher percentage of embryos in coculture group developed to blastocyst stage(61.3%) than in control group(30.7%, p < 0.05). With grade II and III embryos, no differences in the rates of development to morula and blastocyst sta-ge were found between control and coculture groups. The overall rates of development to morula and blastocyst stage were 65.2% and 21.7%, 77.5% and 50.0% for control and coculture, respectively. Differences in the development to blastocyst stage were found between control and coculture groups(p < 0.05). The data indicate that BRL cell coculture improves human embryo development to balstocyst stage in vitro.