Dkk4 and Eda Regulate Distinctive Developmental Mechanisms for Subtypes of Mouse Hair

作者：Cui Chang Yi^*; Kunisada Makoto; Piao Yulan; Childress Victoria; Ko Minoru S H; Schlessinger David

来源：PLos One, 2010, 5(3): e10009.

DOI：10.1371/journal.pone.0010009

The mouse hair coat comprises protective "primary'' and thermo-regulatory "secondary'' hairs. Primary hair formation is ectodysplasin (Eda) dependent, but it has been puzzling that Tabby (Eda(-/y)) mice still make secondary hair. We report that Dickkopf 4 (Dkk4), a Wnt antagonist, affects an auxiliary pathway for Eda-independent development of secondary hair. A Dkk4 transgene in wild-type mice had no effect on primary hair, but secondary hairs were severely malformed. Dkk4 action on secondary hair was further demonstrated when the transgene was introduced into Tabby mice: the usual secondary follicle induction was completely blocked. The Dkk4-regulated secondary hair pathway, like the Eda-dependent primary hair pathway, is further mediated by selective activation of Shh. The results thus reveal two complex molecular pathways that distinctly regulate subtype-based morphogenesis of hair follicles, and provide a resolution for the longstanding puzzle of hair formation in Tabby mice lacking Eda.

• 出版日期2010-4-1