Ectopic growth of mouse whiskers from implanted lengths of plucked vibrissa follicles.

A method for transplanting whole or partial whisker follicles from adult mice to a site beneath the kidney capsule of syngeneic mice is described. Follicles were removed from the upper lip and the growing whiskers plucked. The follicles were either left intact or divided into two parts by transection and implanted under the kidney capsule. The intact whole follicles remained viable and regenerated whiskers which were later shed. The lower one-half or one-third follicle implants reorganized their base and produced a short, curled whisker. On the other hand, none of the upper one-half or two-thirds implants regenerated a dermal papilla, and no whisker production was observed. However, when a single dermal papilla which had been dissected out from another follicle was introduced into each upper follicle cavity in contact with the cut edge, a bulbar region emerged, and subsequently, a long, thick, medullated whisker developed from the implants. This technique should be useful in studying the induction and regeneration of adult mouse whiskers.