Functional Redundancy of Frizzled 3 and Frizzled 6 in Planar Cell Polarity Control of Mouse Hair Follicles

The study demonstrated that Frizzled 3 (Fzd3) and Frizzled 6 (Fzd6) played redundant roles in controlling the planar cell polarity (PCP) of mouse hair follicles. The loss of either Fzd3 or Fzd6 alone did not significantly disrupt hair follicle orientation, but the combined loss led to noticeable defects, including vertically oriented hair follicles and a complete loss of anterior-posterior polarity. Fzd6 was found to be uniformly distributed in skin epithelial cells, and Cthrc1 was identified as a potential downstream effector enhancing Wnt/PCP signaling. These findings highlighted the importance of Fzd3 and Fzd6 in maintaining proper hair follicle orientation through PCP signaling pathways.