Skin pathology of hairless and rhino mutant mice

“Hairless" (Hr^hr) mice develop a syndrome characterized by loss of hair after growth of the first pelage, rudimentary mammary gland development, abnormal growth of the nails and a high incidence of thymic lymphomas (2,3).

The "rhino" mutation (e.g. Hr^rh-J) is allelic with "hairless" and is a more severe manifestation of the "hairless” mutation (1).

Four features characterize the skin of these mutants:

• The formation of comedones (pilary cysts)
• The formation of dilated sebaceous gland ducts
• Granulomatous inflammation in the dermis associated with rupture of the follicles
• Generalized acanthosis and orthokeratosis (4). Multiple cutaneous ulcers and various degrees of tail amputation may develop when males are housed together.

References

1. Mann, S.J. (1971). Hair loss and cyst formation in hairless and rhino mutant mice, Anat. Rec. 170:485-499.

2. Meier, H., Myers, D.D., Huebner, R.J. (1969). Genetic control by the hr-locus of susceptibility and resistance to leukemia. Proc. Natl. Acad. Sci. USA 63:759-766.

3. Morrissey, P.J., Parkinson, D.R., Schwartz, R.S., Waksal, S.D. (1980). Immunologic abnormalities in HRS/J mice. Specific deficit in T cell lymphocyte helper function in a mutant mouse. J. Immunol. 125:1558-1562.

4. Sundberg, J.P., Dunstan, R.W., Compton, J.G., (in press). Hairless mouse, HRS/J-hr/hr. in Integumentary system, Monographs on pathology of laboratory animals. Jones, T.C., Mohr, U., Hunt, R.D. (Eds.), Springer-Verlag, Heidelberg.