International Mammalian Genome Society

I17 Establishment of Mouse Embryo/SPERM Bank at the Center for Animal Resources and Development, Kumamoto University, Japan

Naomi Nakagata, Takaki Nishikawa, Tatsuyuki Nakashima, Kayo Kawano, Tsuyoshi Shimoda, Shuji Tsuchiyama, Gen Yamada, Naoko Nakamura, Kazuhiro Noguchi, Shigeru Kyuwa, Toru Urano, Ken-ichi Yamamura. Center for Animal Resources & Development, Kumamoto University,2-1-1 Honjo, Kumamoto 860-0811, Japan

The Jackson Laboratory in USA and the Medical Research Council in England have already established embryo banks and have been providing a service for the cryopreservation of valuable mouse stocks. In 1999, the Center for Animal Resources and Development at Kumamoto University in Japan also expanded their embryo/sperm bank on a large scale. In particular the bank is intended to safeguard unique genetic material and to make it readily available to the scientific community. The bank contains mutant and transgenic stocks, congenic lines and wild mice.

Our bank system offers the following essential services:

1. Freezing of embryos and spermatozoa: In general 2-cell embryos obtained by fertilization in vitro are cryopreserved by a simple vitrification. For most strains our goal is to freeze a minimum of 500 embryos. We also freeze epididymal spermatozoa from mutant and transgenic lines.
2. Viability testing of frozen stocks: The viability of all stocks is tested by transferring samples of thawed embryos to foster mothers to assess the proportion capable of normal development to live-born young. The foster mothers and offspring are maintained in an isolator until regular microbiological diagnostic investigations. In the case of frozen spermatozoa, a part of each stock is thawed and the motility and fertilization ability of them are observed.
3. Analysis of DNA: In the transgenic lines, the transgenicity is confirmed by PCR analysis of genomic DNA from the tail tissue of 4-week-old mice.
4. Regular microbiological diagnostic investigations: Some of the offspring from frozen embryos are tested for viral, bacterial and parastic pathogens at 8 weeks of age.
5. Distribution of stocks: Mainly, we have been freezing embryos and spermatozoa from transgenic mice energetically. As we move into the 21^st century, we expect that requests for quality-ensured stocks will be fulfilled by dispatching frozen embryos and spermatozoa in a dry shipper for recovery in-house. Alternatively, we can supply breeding nuclei. Thus, we believe the growing need for transgenic strains can be met.