INHERITANCE OF HAIR CONSTRICTIONS IN MICE

Stanley J. Mann ¹ and William E. Straile ¹

¹ Skin and Cancer Hospital of Temple University Health Sciences Center, Philadelphia, Pennsylvania 19140

The frequencies of multi-constricted hairs in the pelage is the same (75%) in the caudal mid-dorsum of C57BL/10 and CBA inbred mice, but there are more single-constricted hairs in C57BL mice (9.41%) than in CBA mice (0.13%). This structural feature is used as a basis for genetic analysis of the hair coat.—The frequency of single-constricted hairs (4.41%) in F₁ mice is intermediate between the frequencies observed in the CBA and C57BL parent strains. Data from the F₂ crosses and backcrosses to the respective parent strains indicate that the presence of numerous single-constricted hairs in the pelage is an inherited characteristic. The mode of inheritance is controlled primarily by a semi-dominant autosomal gene (single-constriction; Hct), without the involvement of maternal factors.