Expression from another K6 gene (yellow) explains hair growth in double knockout mice.
By knocking out the two known keratin 6 (K6) genes in mice, Wojcik et al. (page 619) have discovered a third murine K6 gene, and simultaneously created a promising model system for studying keratin function in more detail. In an effort to study the function of K6, the authors generated a mouse line lacking both K6a and K6b, and found that plaques develop on the tongues of these mice and cause the majority to die of starvation within two weeks of birth. Surprisingly, and in contrast to a previously described mouse K6a/b knockout line, ∼25% of the mice survive to adulthood and grow normal hair and nails. Further analysis uncovered a previously undescribed murine K6 gene, an ortholog of the K6hf gene from human hair follicles, which the authors have...
