Region-Specific Reversal of Epidermal Planar Polarity in the Rosette Fancy Mouse

The study investigates the planar cell polarity (PCP) pathway in the rosette fancy mouse, which exhibits unique posterior-specific whorls in its fur. Researchers discovered that hair follicles in the posterior region have reversed orientations, creating a mirror image of epidermal polarity. This trait is linked to a missense mutation in the core PCP gene Fzd6, affecting its membrane localization due to altered N-linked glycosylation. Despite this, other PCP proteins still localize asymmetrically. The findings suggest that the PCP axis rotates 180° in the posterior region, indicating that PCP patterning can be regionally decoupled, leading to the observed whorls.