ALLELES: hr-1+ (wild-type), hr-1 (mutant).
PHENOTYPE: Mature deer mice have no hair except vibrissae and sometimes scattered body hairs. The trait can be recognized when animals begin to shed the first coat, about two or three weeks of age. The claws tend to elongate and assume a spiral twist. The skin becomes somewhat corrugated in many instances.
INTERACTION: Epistatic to several genes which influence pelage color, particularly those which are not evident in the very young deer mice.
SOURCE: 1918 and 1921. Scripps Institution. Hairless had an independent appearance among two separate lines of descent of P.m. gambelii. The first appeared from a normal wild-caught female mated to her cage-bred normal offspring. The second appeared among offspring of albino and yellowing mutant stocks unrelated to the lines which produced the first hairless.
REFERENCE: Sumner (1924).