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Strain Detail: HR mice

Strain information
Resource No. nbio003
Strain name HR
Strain Nomenclature
Common name/Synonyms hairless mice, Alopecia model mice
Strain types inbred
Background strain
Institution The Institute of Medical Science, the university of Tokyo (IMSUT)
Developer unknown
Conditions of distribution In publishing the research results obtained by use of the mice, mention in the article that the mice are derived from IMSUT. :contact us
Animal Health Report
Strain description
Photo of HR mice

This HR strain was established by the introduction of hairless allele (hr) to BALB/c from hairless mice derived from USA at IMSUT. Then the mice were introduced into National Institute of Health/National Institute of Infectious Diseases in 1981.

HR mice are normal until the first hair cycle started in the embryonic stage, but they don't have the second hair cycle normally started in 2-3 weeks old. Therefore, it's characteristic that they have their hairs until 2-3 weeks, but later they will lose their hairs from the back of their heads to tails.

Genetic analysis in our bank revealed that the HR mice share the same hairless mutation as HRS/J, Skh:HR-1 and Hos:HR-1. Based on the analysis, we estalisheda genotyping PCR for hairless alleles(Ref. 4).

Generally, the homozygous females can't take care of her pups because of mammary gland anomaly. Therefore, this strain should be maintained by mating between homozygous (hairless) males and heterozygous (normal hair) females. These mice are useful for studies related skins because skin tumors are induced easily by chemical mutagens.

About hair cycle

The hair cycle goes through three stages called anagen, catagen and telogen (1). Hair matrix cells divide and make hairs in the stage of anagen. In the catagen stage, hair matrix cells disappear by apoptosis. This apoptosis event is related with TGF-β1 (2). Through the process of telogen after a period of fixed time, hair matrix cells divide again and make new hairs in the next stage of anagen after old hairs fall out.

  1. Alonso L, and Fuchs E. (2006) The hair cycle. J. Cell. Sci. 119(Pt 3):391-3. Review [PMID:16443746]
  2. Foitzik K, Lindner G, Mueller-Roever S, Maurer M, Botchkareva N, Botchkarev V, Handjiski B, Metz M, Hibino T, Soma T, Dotto GP, and Paus R. (2000) Control of murine hair follicle regression (catagen) by TGF-β1 in vivo. FASEB J. 14(5):752-60. [PMID:10744631]
  3. Fukui M, Ito K, Kawamura S, Sudo K, and Suzuki K. (1975) Glomerular changes in hairless mice: a light, immunofluorescent and electron microscopic study. Jpn. J. Exp. Med. 45(6):535-40. [PMID:1232469]
  4. Suzuki O, Koura M, Noguchi Y, Uchio-Yamada K, and Matsuda J. (2013) Zygosity determination in hairless mice by PCR based on Hrhr gene analysis. Exp. Anim. 62(3):267-73. [PMID:23903062]
Resource information
Cryopreserved sperm In-house Genotype hr/hr
From other institutions Genotype
Cryopreserved embryo In-house Mating System IVF : (hr/+) female x (hr/hr) male
Genotype hr/hr, hr/+
Medium EFS40
From other institutions Mating System
Strain status / Availability Cryopreserved sperm Within 1 month
Cryopreserved embryo Within 1 month
Live animals Approx. 2 months
Gene information
Mutation types spontaneous mutation
Gene symbol Hr
Gene name hairless
Genotyping information Genotyping PCR for Hr alleles in PDF format.