Fig. 5.

Mosaic analysis of Par3 function in hair cell PCP. (A–B) Fgf20^Cre/+-mediated mosaic OC at P0. (A) Both mT+ and mG+ hair cells in the control had normal PCP. (B) Both mT+ and mG+ hair cells in Par3-mosaic OC had misoriented and/or misshapen hair bundles. (C–H) Examples of mT+ (C–E) and mG+ (F–H) hair cells with a misoriented hair bundle and/or off-center kinocilium. Cyan, acetylated tubulin staining. Arrows indicate the kinocilium. (C′–H′) Single optical sections 4 μm below C–H showing supporting cells surrounding the hair cell. (I) Quantification of hair bundle orientation. n = 76 (mT+) and 81 (mG+) hair cells from three controls; n = 87 (mT+) and 91 (mG+) from three mutants. (J) Quantification of the off-center kinocilium. n = 544 (mT+) and 1,194 (mG+) hair cells from three embryos. Three types of defects were scored separately, namely misoriented hair bundle with normal shape (gray bars), misshapen hair bundle with normal orientation (magenta bars), and misoriented and misshapen hair bundle (blue bars). (I and J) Error bars represent SEM (I) and SD (J). ***P < 0.001. ns, not significant. (K–P) In contrast to the control (K), planar polarity of hair cell basal body/centrioles (marked by GFP-Centrin2) was disrupted in Fgf20^Cre/+; Par3^flox/flox OC (L–P). White arrowheads indicate the mother centriole/basal body, and yellow arrowheads indicate the daughter centriole. Lateral is up in all images. (Scale bars: A and B, 6 μm; and C–H′ and K–P, 3 μm.)