HRS

Inbr. F79 (J). Albino, b,c,d. Origin: Hairless (hr) stock from Crew to Carnochan to Heston to Chase, to E.L.Green 1952, to Les 1956, to M.C.Green 1959, to J 1964. Maintained by mating +/hr females with hr/hr males.

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Characteristics

Homozygous hairless mice lose their hair at about 10 days. The complete hair is lost from the follicle. After a time a few thin fuzzy hairs grow again, but are soon lost. These are exclusively guard hairs. There is hyperkeratosis of the stratified epithelium and the upper part of the hair canals. Hair club formation is abnormal and the lower part of the follicles tends to separate from the upper part. The isolated lower parts develop into cysts, which may become large and numerous (M. C. Green, 1966). About 45% of hrhr mice develop leukaemia by 8-10 months compared with only 1% in hr/+ mice. Graft versus host assay shows that hrhr mice are immunologically hyporesponsive, which may be associated with the high leukaemia incidence (I'Anson and Gasser, 1973). Similarly, Heiniger et al., (1974) found 70% leukaemia at 8 months in hrhr mice but only 20% in hr/+. Difference thought to be due to a functional immune deficiency. Large kidney/body weight ratio (1/21) (Schlager, 1968). High lymphocyte phytohaemagglutinin response (13/43) (Heiniger et al., 1975., 1975).

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Heiniger H. J., Meier H., Kaliss N., Cherry M., Chen H. W., and Stoner R. D. (1974) Hereditary immunodeficiency and leukemogenesis in HRS/J mice. Cancer Res. 34, 201-211.

Heiniger H. J., Taylor B. A., Hards E. J., and Meier H. (1975) Heritability of the phytohaemagglutinin responsiveness of lymphocytes and its relationship to leukemogenesis. Cancer Res. 35, 825-831.

I'Anson V. A. and Gasser D. L. (1973) Relationship between graft-vs-host reactivity and possession of the high leukaemia genotype hr/hr. J. Immunol. 111, 1604-1609.

Schlager G. (1968) Kidney weight in mice: strain differences and genetic determination. J. Hered. 59, 171-174.

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INBRED STRAINS OF MICE
Updated 9 Apr. 1998
Michael FW Festing
MRC Toxicology Unit, Hodgkin Building,
University of Leicester, UK