Light-mediated planar polarization of cone photoreceptorcilia contributes to visual acuity in mammals

Planar cell polarity (PCP) is essential to optimize information processing and functional response in many tissues. While the fly eye is a classic example of PCP, it remains unknown whether PCP exists in the mammalian retina and whether it plays a part in vision. Here we used 3D reconstructions of the mouse retina to show that the basal body of cone photoreceptor cilia, but not rods, is systematically located on the side of the cell facing the centre of the retina. We further show that light is required during a critical window of development to establish cone PCP, and that both cone transducin and the G-protein signaling modulator protein 2 are required to mediate this effect. Importantly, we report that disruption of cone PCP impairs visual acuity. This work uncovers a non-canonical PCP pathway, mediated by light, and identifies cone PCP as a feature supporting mammalian vision.