We demonstrate that this axon turning event requires planar cell polarity (PCP) signaling and is disrupted in <i>Vangl2</i> and <i>Celsr1</i> knockout mice, and that VANGL2 acts non-autonomously from the cochlea to direct turning.
Together, our findings identify distinct roles for Vangl2 and Glypican4/PCP signaling during membrane protrusion formation and demonstrate that cell-matrix interactions underlie Vangl2-dependent regulation of protrusive activities in migrating gastrula cells.
Strikingly, Vangl2 and Fz6 mutant follicles collectively rotate with opposing directionalities, suggesting that redundant core PCP signals contribute to their directed realignment.