Effect of stem cell media on the development of porcine parthenogenetic embryos Einfluss von Stammzellmedien auf die Entwicklung porziner parthenogentischer Embryonen

As induced pluripotent stem cells (iPS) can be artificially produced from farm animals, the generation of animals for disease models and xenotransplantation by chimera formation of iPS cells with embryos is possible. However, embryos and stem cells have totally different requirements concerning the culture media. The aim of this study was to find optimal culture conditions for both cell types by testing the development of porcine parthenogenetic embryos in different culture media. Porcine parthenogenetic embryos were cultured in different media mixtures of the standard embryo culture medium (PZM-3) and stem cell media beginning at day 3 (4–8 cell) or day 4 (early morula) after activation (1.0 kV/cm for 45 μs, followed by incubation with 2 mM 6-DMAP for 3 h). If not otherwise indicated, total embryo number used per medium mixture was 74–110, subdivided into 3–4 repeats. It was shown, that the blastocyst rate from day 3 embryos in PZM-3 (n = 12, 305 embryos) was significantly higher (41.0%) than in both stem cell media (ES medium 1.3%, ciPS medium 3.7%). A mixture of PZM-3 with 25% or 50% stem cell medium improved the blastocyst rate (16.2–25.0%). The results for the day 4 embryos were different. Blastocyst rate in PZM-3 (34.7%, n = 10, 251 embryos) was between the rates of ES medium (39.0%) and ciPS medium (34.1%). Developmental rates in media mixtures (40.5–46.4%) were even better than in PZM-3. It can be concluded that the development of parthenogenetic embryos in pure stem cell medium is possible beginning on day 4 after activation, however medium-specific differences have to be considered. For porcine parthenogenetic embryos beginning on day 3, a mixture of PZM-3 and stem cell medium is recommended.