Mouse Gene Editing

We gene edit several different strains of mice, including C57BL/6, Balb/c, DBA2, and NOD-scid for use as disease models. Mouse model generation can use either CRISPR/CAS9 EGE™ or ESC-based gene editing technologies, for which the turnaround times are 6-8 months and 9-12 months, respectively. Mice are often the preferred mammalian model organisms due to their short life cycle and close genetic resemblance to humans. Particularly, humanized mouse models have great potential.  Mice happen to be the best studied mammalian model organism with abundant genomic, transcriptomic, proteomic, and phenotypic collections.

• Strain: Laboratory mouse strains are either outbred or inbred. Outbred mice are usually bred to maintain maximum heterozygosity, whereas inbred mice are usually bred to maintain maximum homozygosity. Inbred strains (also called inbred lines) are particular species that have individual mice nearly identical to each other in genotype due to long inbreeding. A strain is inbred when it has undergone at least 20 generations of brother x sister or offspring x parent mating, at which point at least 98.6% of the loci in an individual of the strain will be homozygous, and each individual can be treated effectively as clones. C57BL/6(N and J), BALB/c, Fvb, A/J, C3H, CBA, DBA/2 etc. are inbred mouse strains.

• CRISPR/EGE™ or ESC/HR: At Biocytogen, 85% mouse and 100% rat gene editing projects are generated via EGE™ technology. Although EGE™ technology is comparatively cheaper and offers faster turnaround times compared to ESC-based projects, projects where the knockin size is greater than 15kb still necessitate the use of ESC/HR technology.

• Superovulation: Superovulation has been used in the production of transgenic mice since the late 1980s to artificially induce ovulation of large numbers of oocytes from limited numbers of female mice. Superovulation facilitates the generation of genetically engineered mice and reduces the number of animals used.
• Breeding: Breeding is one of the critical steps to generate genetically engineered mouse models. A suitable breeding environment is important to have large litter sizes and shorten the timelines to produce mouse models. Biocytogen’s AAALAC accredited SPF animal facilities provide optimal breeding environments. Our experts design the most efficient breeding scheme to save on costs and time for our customers.

CRISPR Knockin Mouse Application Example:

Humanized CD3ε Mouse Model Generation and Validation

Targeting Strategy

mRNA Expression Analysis

RT-PCR analysis of the B-hCD3ε gene: hCD3ε mRNA was detected in splenocytes isolated from homozygous B-hCD3ε mice.

Protein Expression Analysis

Splenocytes from both wild type (WT) C57BL/6 and homozygous B-hCD3ε mice were analyzed by flow cytometry.

Results: Mouse CD3+ cells were detectable in the WT C57BL/6 mice, whereas human CD3+ cells were detectable in the homozygous knockin mouse B-hCD3ε.