Embryo Technology Laboratory
Modern technology for animal welfare and efficient breeding management
In the interest of both animal welfare and the reproducibility of experiments, it is essential to maintain a defined health status (specific pathogen-free; SPF) in our animal breeding facility. For this purpose, we use the method of so-called embryo transfer. Embryo technology can also be used to cryopreserve temporarily unneeded mouse lines in order to limit the number of animals bred to the absolute minimum. The DRFZ maintains a state-of-the-art embryo technology laboratory for these technologies at its Berlin-Marienfelde site.
The following services are offered:
1) Embryotransfer. To guarantee a defined health status in the SPF breeding area, new transgenic mouse lines have to be imported via embryotransfer. Two cell embryos (generated by IVF or classical mating) are washed extensively to remove any pathogens and implanted into pseudopregnant foster mice.
2) Cryopreservation of mouse sperm and embryos. Mouse strains which are temporarily not needed can be stored as 2-cell embryos or sperm in liquid nitrogen. Frozen material is also an option for world-wide shipping of transgenic mouse lines.
3) In vitro fertilization. IVF is used to recover mouse lines from frozen sperm and is generally a very efficient method to generate mouse embryos.
Fig. 1: Workflow of services offered by the Embryo Technology Laboratory. In vitro fertilization (IVF) is used to generate large numbers of 2-cell embryos. These embryos as well as sperm from transgenic mice can be cryoconserved in liquid nitrogen. To remove any pathogens, embryos are washed extensively before transfer into pseudo-pregnant foster mice inside the SPF facility.
Fig. 2: Washing of embryos. The fertilized oocyte is protected by the zona pellucida which is impermeable for pathogens. Residual sperm is still sticking to the zona.
Fig. 3: Developmental stages of mouse embryos. a) Sperm and oocytes (hidden in the cumulus cells) 5 min after IVF. b) 45 min after IVF, sperm almost completely dissolved the cumulus cells. c) 2-cell embryos. d) 4- and 8-cell embryos. e) Morula stage. f) Blastocysts.
Scientific facility management
Dr. Andreas Hutloff
Paolo Rosellini Tognetti
- Dr. Uwe Klemm, Max-Planck-Institut für Infektionsbiologie, Berlin
- Dr. Geert Michel, Transgene Technologien, FEM, Charité Universitätsmedizin Berlin
- Ronald Naumann, Max-Planck-Institut für Molekulare Zellbiologie und Genetik, Dresden
- Frank Zimmermann, Biotechnologielabor, Universität Heidelberg
- Leibniz-Institut für Nutztierbiologie, Dummerstorf