Figure 6

Figure 6

Loss of the ndrg2 gene in Tg(Brn3c:mGFP) zebrafish (Danio rerio) influenced hair cells’ (HCs’) differentiation through Notch signaling without changes in HCs’ apoptosis and supporting cells. (A) Results of HC apoptosis assay in normal and ndrg2 mutant larvae at 72 hpf. Immunofluorescence images were shown to recognize the nucleus (blue color), HC (green color), and cleaved caspase-3 signal (red color) in a single HC cluster in posterior lateral line (pLL). Scale bars: 10 µm. (B) Results of supporting cell proliferation assay in normal and ndrg2 mutant larvae. Immunofluorescence micrographs were displayed to identify the HC (green color), supporting cell (red color) and proliferating cell (blue color) in a single neuromast in pLL at 96 hpf. Alexa Fluor^TM 647 used to detect BrdU was painted in pseudo blue color to distinguish from the red color of Alexa Fluor^TM 555 labeling SOX2. The purplish-red signals in the last column of overlapped fluorescence images represented the proliferating supporting cells. Scale bars: 10 µm. (C) Representative images of HC cluster (green color) and functional HC cluster (red color) in single neuromast in pLL at 72 hpf in control, ndrg2 mutants and treatment with Notch inhibitor LY411575 groups, respectively. Scale bars: 10 µm. (D) Statistical analysis of the number of HCs and functional HCs per neuromast at 72 hpf in control, ndrg2 mutants and treatment with Notch inhibitor LY411575 groups, respectively (n = 30). (E,F) Statistical analysis of the number of supporting cells and proliferating supporting cells per neuromast at 96 hpf in normal and ndrg2 mutant larvae (n = 30). Symbols of **** above bars represent p < 0.0001. ns, no significance.