Mouse strain development and maintenance project
at the National Institute of Genetics
History of the project
Approximately 10 strains of rat and mouse were transferred from the Faculty of Science of Hokkaido University in 1948 by Toshihide Yoshida, the former Director of the Department of Cell Genetics, and the preservation of mouse strains at the National Institute of Genetics began. After that, strains imported from foreign countries and wild mice collected from overseas academic research joined in, and the scale increased.
In 1975, the Genetic Stock Research Center was established, and maintenance of inbred mouse/rat strains and teratoma high-harbor strain mouse strains began.
As the National Institute of Genetics moved to a national university joint use institution in 1984, it was reorganized as the Genetic Strains Research Center, and at the same time, these strains were maintained in the Mammalian Genetic Resources Laboratory. Strain maintenance of reference strains, mutant strains and H2 congenic mice was continued in this laboratory with the help of the Cancer Focus, Committee on Experimental Animals. In addition, "Mouse strain maintenance project cost for immunogenetic research" was recognized as strain preservation expenses from 1985, and mouse wild-derived strains, congenic strains that introduced the H2 gene complex derived from wild mice, and chromosome recombination have been maintained in the 1st Mouse Breeding Building. Some of these strains were made SPF by Caesarean section method and fertilized egg transfer method, and were transferred to the mouse facility of the Genetic Stock Research Center. We started the cryopreservation of mouse fertilized eggs from 1982, and from 1996, we started the mouse strain preservation project by frozen embryos.
In 1997, the name of the center was changed to the Genetic Strains Research Center, and the name of the laboratory was changed to the Mammalian Genetics Laboratory. In 1997, part of the mouse strain in the facility was found to be infected with Pasteurella pneumoniae, so all strains were transferred to the 1st Mouse Breeding Building and cleaned by frozen embryo transfer.
In 2003, the new facility, Animal Research Building, was completed, and all the cleaned mouse strains were moved to the new facility. After that, all the mice were kept in the SPF environment.
In 2019, the first year of Reiwa, with the reorganization of NIG, the Mouse Genomics Resource Laboratory (MGRL), Department of Gene Function and Phenomics, took over the business. At that time, although the mouse strains will continue to be preserved, most of the subsidized business will be transferred to the RIKEN BioResource Center, except for some. Instead, NIG decided to focus on the business to support research and phenotypic analysis using various mouse strains, especially wild strains (Bioresource Mouse Business). At that time, as a resource, we added a new wild-type heterogeneous stock (WHS), which was genetically mixed with eight wild strains.
About microbiological quality
Genetic resource mouse project
With the elucidation of genomic information in life sciences, it is an urgent task to elucidate the causes of more complex multifactorial diseases, not just phenotypic abnormalities caused by simple mutations. For that purpose, understanding of complex systems and elucidation of the mechanism of inheritance have been required.
During its history, the National Institute of Genetics has been collecting wild mice from all over the world and promoting establishment of the new strains. These strains exhibit unique genetic traits not found in traditional standard inbred strains. In particular, wild-derived strains are called Mishima batteries, and their usefulness has been shown in behavioral studies.
From 2019, the MGRL newly took charge of the business. Through joint research, we support phenotypic analysis and molecular genetic analysis using these Mishima batteries and related strains for universities and research institutions in Japan and overseas.
Development of new experimental mouse strains
An important issue in life science after genome sequencing is the elucidation of the relationship between genome sequences and biological functions. To that end, in addition to mutant strains that have impaired specific gene functions, it is necessary to analyze genetic strains that exhibit diverse phenotypic traits, with genetic mutations accumulating in many genes over evolutionary time.
The National Institute of Genetics has been collecting and breeding wild mice from all over the world for many years. These strains have unique genetic characteristics not found in traditional standard inbred strains. In the MGRL, as a new-generation biological genetic resource for systematically clarifying the relationship between genomic sequences and biological functions, wild-derived heterogeneous stocks containing mixed genomes between strains of different genetic origins (WHS) etc. are made.