Partial Interchangeability of Fz3 and Fz6 in Tissue Polarity Signaling for Epithelial Orientation and Axon Growth and Guidance

The study explored the mechanistic similarities between different polarity processes in mammals by examining the interchangeability of frizzled 3 (Fz3) and frizzled 6 (Fz6) in tissue polarity signaling. Researchers found that Fz3 could fully rescue hair follicle and Merkel cell polarity defects in Fz6-null mice, while Fz6 could partially rescue axon growth and guidance defects in Fz3-null mice. This suggested that Fz3 and Fz6 functioned in a conserved manner across these contexts. Additionally, the study identified a previously unrecognized pattern of papillae on the tongue's dorsal surface, which also depended on redundant signaling by Fz3 and Fz6. These findings provided strong evidence for a close mechanistic relationship between various anatomically diverse polarity processes.