Figure 2.

Comparison of the appearance of heterozygote (+/−) and homozygote (−/−) cathepsin L-deficient mice with wild-type (+/+) mice. For each group, the animal on the left is the homozygote. Heterozygote littermates are centrally positioned, and wild-type mice are on the right. (a) Three-month-old females, homozygotes display the characteristic phenotype detectable at weaning of reduced hair length and a reduction in density with hair of a dull greasy appearance; heterozygotes display a normal phenotype at this age. (b) Nine-month-old females, homozygotes display total alopecia; heterozygotes display pronounced partial hair loss. (c) Nine-month-old homozygote male knockouts exhibit baldness with patchy areas of sparse hair. Heterozygotes exhibit small areas of hair loss. All wild-type animals exhibited normal hair phenotype.