The Rho GTPase Regulator ARHGEF3 Orchestrates Hair Placode Budding by Coordinating Cell Fate and P-Cadherin Patterning in Mice

The study identifies ARHGEF3 as a crucial regulator in hair placode development in mice, orchestrating cell fate and P-cadherin patterning. ARHGEF3 is essential for restricting cell fate domains and coordinating P-cadherin gradients, which are vital for proper hair follicle morphogenesis and angling. In Arhgef3 knockout embryos, disruptions in P-cadherin gradients and reduced F-actin accumulation lead to aberrant epithelial organization and increased straight hair follicle downgrowth. Despite normal epidermal development, the absence of ARHGEF3 results in larger placodes and altered hair germ orientation. The study, involving 4 to 5 embryos per genotype, suggests ARHGEF3's broader role in epithelial morphogenesis and tissue patterning, warranting further exploration.