Figure 2

Figure 2 ybx1 promotes rapid HC regeneration and atoh1a expression after damage.

(A) Representative images show phalloidin staining of HCs in post-ablation and control NMs from wild-type, heterozygous, and homozygous ybx1 mutant larvae (scale bar = 4 µm). (B and C) Quantification of HCs and DAPI ⁺ nonsensory cells from post-ablation and control NMs. Each data point represents a single NM. (D and E) Representative images of Ybx1 immunostaining across NMs from wild-type, heterozygous, and homozygous ybx1 mutant larvae (scale bar = 10 µm). Inset images show Ybx1 accumulation (arrowheads) in atoh1a⁺ cells (inset scale bars = 5 µm). (F) Quantification of Ybx1 immunofluorescence in atoh1a⁺ cells from wild-type (N = 4) and heterozygous ybx1 mutant (N = 3) larvae. Data points represent individual atoh1a⁺ HC progenitors or young HCs across wild-type (n = 27) and mutant (n = 21) categories. (G) Representative fluorescence images show atoh1a expression in newly regenerated HCs from wild-type and heterozygous ybx1 mutant larvae. dTomato marks HCs’ apical surfaces and the growing kinocilia (arrowhead) in older HCs (scale bar = 4 µm). (H and I) Quantification of new HCs in control and 12–24 hpa NMs from wild-type and heterozygous ybx1 mutant larvae. (J) Proposed model of atoh1a transcriptional regulation during pre-ablation, early-phase, and late-phase HC regeneration. Where shown, average quantities represent mean values across the pooled data points and the error bars represent SEMs. Complete descriptions of quantifications and statistical analyses can be found in the Methods section and Supplementary Tables (*, p < 0.05; **, p < 0.01).