Importation Program at The Jackson Laboratory
Purpose
Our importation procedure has a three-fold purpose: (1) safeguard the high health status of animals currently maintained in the research and resource colonies of the Laboratory, (2) allow investigators to import animals needed for their research programs, and (3) improve the health status of animals being imported by eliminating viruses and other pathogens they may harbor. The importation program interacts with the diagnostic and Genetic Quality Control (GQC) laboratories to assure that mice are of the appropriate genotype and are free of pathogens.
Importance
The importance of this program can not be overstated; within the last year we have detected evidence of prior infection with one or more viruses in as many as 48% of the strains imported for use by the scientific community. All mice being imported to The Jackson Laboratory are quarantined in flexible film isolators upon arrival and subjected to microbial evaluations. At present the importation facility houses 20 isolators for use by the Induced Mutant Resource. Mice are maintained in isolators where they are mated and their progeny derived by hysterectomy derivation or embryo transfer. Mice of a defined flora are the source of foster mothers or embryo recipients. After derivation, mice are maintained in a quarantine facility. When the derived litters are weaned, the foster mothers and embryo recipients are tested for specific pathogens prior to weaned animals being released to the animal colonies. The health status of the rederived mice is determined by the Laboratory Animal Health (LAH)-Diagnostic Laboratory. Mice at various stages of the importation process are checked for the presence of selected microorganisms by microscopic examination, culture, serology and PCR.
Time Required for Importation
The median time to level 4 distribution (Available as breeder pairs or individual mice) is 7 months after a strain arrives in our Importation Facility. Circumstances such as the number of animals we initially receive for the hysterectomy derivation process, the genotype of the animals and how well they breed in isolators determines the actual time to reach distribution. In rare instances this may be longer than 7 months.
Many of the targeted mutant and transgenic animals imported for the IMR are maintained as heterozygotes because homozygous animals are non-viable or infertile. LAH-GQC personnel genotype the animals by PCR or Southern blotting to identify heterozygotes or hemizygotes in order to properly mate animals maintained in isolators and to assure that sufficient numbers of mice of the appropriate genotype are available when they are released.
