ABSTRACT

The greasy (Gs) mutation arose among descendants of an irradiated male, but it is considered to be of spontaneous origin. Greasy mutations have been found to be an allele of tabby (Ta). Greasy is a semidominant mutation that maps to Chromosome X. Affected mice (homozygous females and hemizygous males) have shiny fur, similar to tabby, but do not have bare patches caudal to the ears or the dark mid-dorsal stripe of agouti mice. The hair had an oily appearance and texture when palpated. Plucked hair from a 6-week-old male Gs/Y mouse revealed the presence of all hair types. Characteristic constrictions were evident, but the sharp angulation of the hairs at these sites was missing. Plucked hair from the 7-month-old male consisted almost exclusively of abnormal zigzag-like hairs. Histologic examination of skin sections from the 6-week-old greasy and control and the 7-month-old greasy mice revealed morphologically normal meibomian, sebaceous, and eccrine glands.