ABSTRACT
The first description of a captured mouse with long, black, silklike hair was mentioned a form of angora hair over a century ago. As adults, the angora mice had a very thick, soft pelt. Breeding studies demonstrated this mutation to be autosomal recessive. It was later mapped to Chromosome 5. All four types of pelage hairs (zigzags, auchenes, awls, and guard hair) are significantly longer than normal. The largest difference was found in the guard hairs. The zigzag hairs are longer than controls, due to the presence of an additional segment above the three normally found beyond the wavy portion of the shaft above the bulb. The mechanisms involved in the increased hair length in the angora mutation are due to abnormalities in the epidermis, based on retention of the phenotype following dermal-epidermal recombination grafts and in aggregation chimeras. A rare dominant mutation in humans results in extreme generalized hypertrichosis.
