Transgenic Mice

• DNA or BAC injection into one embryo
• Reimplantation into foster females
• Husbandry and weaning
• Sample collection for genetic characterization in founder mice
• Health report
• Delivery of founder mice

• Package I services
• Breeding to F1 generation
• Sample collection and screening of up to 50 mice
• Delivery of heterozygous F1 mice

With DNA transgenesis technology, our microinjection experts inject the DNA vector designed and prepared by PHENOMIN-ICS directly into the pronuclei of zygotes, effectively bringing your custom transgenic mouse models to life with founders available in as few as three to four months. As with CRISPR/Cas9*, a large genetic background panel for mice is available. Download our technical sheet

The C57BL/6 substrains are the mouse models most commonly used as background for creating transgenic mice (over 75%). These are followed by the 129 line of mice. The reliance on so few backgrounds, however, can be limiting to scientific research. It has been demonstrated that the exact same mutation in two different inbred backgrounds can lead to very different phenotypes. Sittig et al. (Neuron 2016) demonstrates low generalizability of mouse null allele phenotypes across a panel of F1 genetic backgrounds. For further information, please watch our webinar. 

While knockout and knockin mice provide a means of controlling the expression and function of a particular gene, in some cases, it may be more useful to monitor cellular activity (timing and cell type expression) or to track the subcellular localization of a specific gene or protein. In these cases, transgenic (reporter) mice are ideal.

For basic cancer research, applications can include:

• Validation of candidate cancer genes
• Determining cells‐of‐origin of cancers
• Deciphering spontaneous metastasis formation
• Studying the contribution of the tumor microenvironment
• Imagining and testing new therapeutic proofs of concept

The term "transgenic mouse model" is sometimes used to describe all genetically modified mice, and has sometimes been confused with knockin mice. Random transgenic mice are models that have the DNA material randomly inserted into the genome (a trans-gene) whereas with knockin and targeted transgenic mice the process is targeted and the desired gene is inserted into a specific locus via CRISPR/Cas9* or homologous recombination. This locus could be to mimic expression using an endogenous gene’s promoter, or be stable expression of the transgene from a safe location.

Our team of scientists will work with you to determine the best model creation approach to suit your research, and can guide your development and selection from our large panel of available mouse genetic backgrounds (C57BL/6N, 129S2/SvPas, FVB/N, etc.).

When the DNA is integrated, it could be placed under its own (strong) promoter, leading to high levels of expression (good for disease models) and an earlier or more robust phenotype. However, as the desired gene is placed randomly in the host genome, the new transgenic mouse model may not be as relevant a model of human disease. Characterization would be needed to determine how many copies of the transgene integrated and where they inserted. For further advice on using knockin, knockout, and random or targeted transgenic mice, please consult our scientific team. For further information, please visit the International Society for Transgenic Technologies (ISTT).

The use of CRISPR/Cas9 to edit genomes can lead to reductions in the number of mice and rats used in research. "In individual studies, there is a great opportunity for reduction," says one scientist. Learn why she calls for "an increase in sophistication in genome editing... [and] in the sensitivity and reproducibility of in vivo phenotyping tests." Read the full story

CRISPR-Cas9 enables transgenic mice to be generated more quickly and more precisely than ever. Classical methods of genome editing in rodent models are effective, but slow. Using CRISPR/Cas9 to selectively introduce DNA damage and let cells repair themselves naturally reduces the timeline from months or years, to a matter of weeks. Read the full story