ABSTRACT
The hairy ears mutation occurred in the offspring of a neutron-irradiated male mouse. Hairy ears have a suppressing effect on crossing over on Chromosome 15 near the mutations caracul (Ca) and dominant megacolon (Dom). The hairy ears mutation is lethal in homozygous (Eh/Eh) mice. Heterozygotes have small ears (pinna) with a tuft of hair on the inner surface. The pinna are not crinkled like short ears (se/se) mice. Examination of two 4-week-old male mice revealed that dorsal skin follicles of both mice were in anagen. Hypertrichosis of the ears is a well-described entity in man. It consists of the presence of long, often dark hairs growing from the helix of the pinna. The inheritance pattern of this trait remains unclear. Both Y-linked and autosomal transmission patterns have been proposed. One hypothesis involves the interaction of two genetic loci, one on the homologous segment of the X and Y chromosomes and another on the nonhomologous region of the Y.
