Simple Transportation of Genetically Engineered Mice via Cold Storage Techniques.

Live genetically modified (GM) mice are often shipped in transportation cages. However, the shipment of live mice is sometimes associated with difficulties. Recently, we developed an alternative means to transport GM mice via cold storage techniques for sperm and embryos. Cold storage of the cauda epididymis, the male reproductive organ for storing mature sperm, can maintain the fertility of sperm in cold preservation medium for 10 days. The sperm can then be used to produce embryos or pups via in vitro fertilization and embryo transfer. Conversely, cold-stored two-cell embryos maintain developmental ability for 4 days. The embryos can be used to produce pups via embryo transfer. Cold transport techniques are being increasingly employed to create local and global networks between research institutes for the shipment of GM mice. In this text, we described a cold transport technique for sperm and two-cell embryos in mice.