Strain Selection & Phenotyping

Investigators are encouraged to research the literature thoroughly, talk to colleagues, and review strain datasheets. The strain datasheets have literature using the specific strain curated into a reference list. The most popular strain is not always the best tool for answering a given research question.

For very similar appearing strains, there may be slight differences in expression patterns. Please review the strain datasheets side-by-side carefully. That information may be found in either the Detailed Description or the Genetics sections, particularly the Molecular Note.

In the Details tabs of the strain datasheets is a subsection called Control Suggestions; see that section for a given strain's recommended controls.

Generally, if a mutation is maintained on a standard inbred background, that inbred strain is the appropriate control.

If a mutation is maintained on either a mixed or segregating genetic background, wild-type mice (phenotypically non–mutant mice) from the colony are the best controls. However, because many of our genetically engineered strains are maintained by homozygous matings, wild-type controls from the colony may not be available.

F2 hybrids are often used as approximate physiological controls for strains carrying targeted mutations (knockouts) on mixed backgrounds involving two strains, for example, the C57BL/6 x 129 background (designated B6;129). The F2 generation is produced by F1 x F1 matings. The genetic background of C57BL/6J x 129 F2 mice varies among littermates because of gene segregation from the F1 hybrid parents. Although these F2 mice are only an approximate genetic match to the B6;129 background, they do contain only genes derived from either the C57BL/6 or 129 genetic backgrounds. We currently distribute two C57BL/6J x 129 F2 hybrids, differing primarily in their 129 substrain progenitor:

The controls noted in the strain details for mice carrying targeted mutations are selected to most appropriately match the 129 strain used to derive the ES cell lines (Simpson et al. 1997).

Note: The B6129F1 hybrids are usually less appropriate controls than are the F2 hybrids because the parental alleles of F1 mice are not segregating as opposed to those on a mixed B6;129 background.

Look in the Development section of the strain datasheet for this information.

We may. Please navigate to the Related Strains section on the datasheet and select "By Allele." If this allele is available on other backgrounds, they should be listed there.

This information should either be explicitly described on the strain datasheet in the Development section, or, immediately below the Overview in the Genetic Overview section under "Generation."

Learn more about generation number

Pricing information can be found by clicking on the Pricing and Availability tab at the top of the strain datasheet.

JMCRS focuses on maintenance and distribution of the strains, and ensuring their genetic integrity and high health status. For detailed phenotype information characteristics on the majority of strains (including detailed protocols), we refer to peer-reviewed, published reports. Tech support may also refer customers to our online strain datasheets or the Mouse Phenome Database for phenotype information.

Limited data for select strains can be found online in the Disease/Phenotype sections of those strains' datasheets.