Fig. 4: Ectopic Emx2 expression disrupts afferent neuronal segregation pattern independent of hair bundle orientation in the utricle.
From: Function of bidirectional sensitivity in the otolith organs established by transcription factor Emx2
a, a’ Anti-β spectrin antibody (red) staining of a control utricle showing hair bundles in the medial region pointing towards the lateral (a’, yellow arrows, n = 4). Compared to the control, Sox2CreER; RosaEmx2 utricle administered with tamoxifen (TM) at E13.5 (b) shows mostly reversed hair bundle orientation in the medial region (b’, white arrows, n = 4) but TM administration at E15.5 (c) resulted in largely normal hair bundle orientation (c’, yellow arrows, n = 4) with a few HCs showing opposite orientation (white arrows). d–f Segregated afferent innervation of control (d, n = 5) is disrupted in Sox2CreER; RosaEmx2 utricles administered with TM at E13.5 (e, n = 10) and E15.5 (f, n = 7). g The relative cb signal was significantly lower in the lateral region (Dunn’s pairwise tests, control vs. E13.5, n = 5, z = 2.59, p = 0.015; control vs. E15.5, n = 4, z = 3.04, p = 0.007) but higher in the intermed–medial region of Sox2CreER; RosaEmx2 utricles treated with tamoxifen at E13.5 or E15.5 when compared to controls (n = 4) (Dunn’s pairwise tests, control vs. E13.5, z = −3.0, p = 0.008; control vs. E15.5, z = −2.23, p = 0.039). Thus, the decrease in cb signals between the lateral and intermed_medial regions were not significant in Sox2CreER; RosaEmx2 utricles administered with tamoxifen at either E13.5 or E15.5 (Dunn’s pairwise tests, E13.5, z = 1.21, p = 0.23; E15.5, z = 1.90, p = 0.12). The two-sided Dunn’s pairwise comparison tests were applied. In boxplots, boxes represent the interquartile range (IQR), and the thick lines inside show the median. Whiskers denote the lowest and highest values within 1.5 times the IQR. h Schematic summary of hair bundle orientation and innervation pattern in control and Sox2CreER; RosaEmx2 utricles and cristae administered with tamoxifen at E13.5 or E15.5. Scale bar = 100 μm in a–c, d–f; 25 μm in a’–c’. Source data are provided as a Source data file.
