Laboratory mice strain information

Most laboratory mice have contributions from both Mus musculus musculus and Mus musculus domesticus. There is evidence that smaller contributions also may have come from Mus musculus molossinus and Mus musculus castaneus. Therefore, they should not be referred to by species name, but rather as laboratory mice or by use of a specific strain or stock name. (In addition, some recently developed laboratory mouse strains are derived wholly from other Mus species or other subspecies, such as M. spretus). The laboratory mouse genome, including its retroelements, is a mosaic and an artificial creation, and there is no true "wildtype" laboratory mouse. There are over 450 inbred strains that have arisen during the last century but the great majority of biomedical resaerch, including genomic research, is based on a relatively few mouse strains, including C57BL/6, BALB/c, C3H/He, 129, FVB, and outbred Swiss stocks.

Common Inbred mice strains and their pathology

C57BL/6 (B6) mice:

Gold standard background strain for GEM's, genome of this strain has been fully sequenced. B6 mice were initially bred for their longevity. Their melanism is manifested by their coat colour. melanin pigment in heart valves, splenic capsule and meninges.

Spontaneous diseases: Hydrocephalus, hippocampal neurodegeneration, microphtalmia, anophtalmia, age-related cochlear degeneration (hearing loss), malocclusion and pulmonary proteinosis.

Common neoplasms: Lymphoma (especially B-cell), haemangiosarcoma, and pituitary adenoma (especially prolactin-secreting cells)

BALB/c mice:

Albinos. Mature males are rather pugilistic.

Spontaneous diseases: Dystrophic epicardial mineralisation of the right ventricular free wall, myocardial degeneration, auricular thrombosis, corneal opacities, hypocallosity (corpus callosus hypoplasia or even aplasia), age-related hearing loss.

BALB mice are markedly ressistant to amyloidosis.

Common neoplasms: Lung adenomas, lymphoma, Harderian gland tumours, myoepitheliomas of salivary, preputial, and other exocrine glands and adrenal adenomas.

C3H/He mice:

Agouti (brown) mice that are blind due to rd1 mutation in the Pde6b gene.

Spontaneous diseases: Focal myocardial and skeletal mineralisation and myocardial degeneration, alopecia areata (females more than males).

Common neoplasms: They are more susceptible to exogenous murine mammary tumours virus (MMTV)-induced mammary tumours and develop a relatively high incidence of mammary neoplasia later in life due to endogenous MMTV. Other common tumours include hepatocellular tumours.

129 mice:

Represent the most frequent source of embryonic stem cells (ES cells). The 129 mouse is not a single strain, and in fact the "129" is represented by 16 recognised strains and substrains.

Spontaneous diseases: Hypercallosity, megaoesophagus, pulmonary proteinosis and epithelial hyalinosis, blepharitis, and conjunctivitis.

Common neoplasms: Testicular teratomas, lung tumours, Harderian gland tumours, ovarian tumours, and haemangiosarcomas.

FVB/N mice:

Inbred swiss mice, they are blind due to homozygosity of rd1 allele (Pde6b gene).

Spontaneous diseases: Seizures, mammary hyperplasia

Common neoplasms: Tumours of the lung, pituitary gland, Harderian gland, and liver. Also lymphomas and pheochromocytomas.

References

• Brayton, C., Justice, M. and Montgomery, (2001) Evaluating Mutant Mice: Anatomic Pathology. Vet Pathol 38: 1-9.

• Percy, D.H., and Barthold, S.W. (2007) Pathology of laboratory rodents and rabbits. Blackwell Publishing. pp. 3-123.

• http://www.informatics.jax.org/greenbook/index.shtml