Planar Cell Polarity Effector Gene Intu Regulates Cell Fate-Specific Differentiation of Keratinocytes Through the Primary Cilia

This study investigated the role of the planar cell polarity (PCP) effector gene Intu in hair follicle formation in mice. Disrupting Intu in embryonic epidermis led to arrested hair follicle morphogenesis due to the failure of follicular keratinocytes to differentiate. This disruption also caused a near-complete loss of primary cilia in epidermal and follicular keratinocytes and suppressed the hedgehog signaling pathway, although epidermal stratification, differentiation programs, and barrier function remained unaffected. The findings demonstrated that tissue-specific PCP effector genes regulate keratinocyte differentiation through primary cilia in a cell fate- and context-dependent manner, crucial for interpreting polarity signals from core PCP components.