Fig 3

Foxj1 controls the expression of OSN-specific genes, but not ciliary motility genes.

(A) Single-cell transcriptome analysis of ciliated OSNs from wild-type zebrafish, mouse, and human showing low expression of genes encoding axonemal dynein and motility-associated components in OSNs as compared to MCCs. (B) Whole-mount in situ hybridization of dnah5, dnah8, and dnah9 in foxj1a,b double mutant zebrafish embryos at 3 dpf showing absence of gene expression in the periphery of the nasal placodes (highlighted with white dashed line) that primarily consists of OSNs, whereas expression in MCCs at the rim of the cavity (n = 10 for each gene). MCCs are depleted in foxj1a/b double mutants, and, therefore, expression of these genes were absent in the nasal placodes (bottom panel) (n = 5 for dnah5, n = 6 for dnah8, n = 4 for dnah9). Scale bars = 10 μm. (C-C”) Double fluorescent labeling of dnah9 (C), ccdc40 (C’), and odad1 (C”) (green) with ciliated-OSN marker ompb (magenta) and MCC marker cimap1b (blue) by HCR in situ hybridization in wild-type embryo at 3 dpf showing coexpression of dnah9, ccdc40, and odad1 with cimap1b (n = 3), but not with ompb (n = 3). (D, D’) RNA sequencing of foxj1a and foxj1b mutant embryos showed a significant decrease in the expression of the ciliated-OSN marker ompb (D) and cnga4 (D’) in foxj1b mutant embryos but not in foxj1a mutants. (E, F) In situ hybridization in 4 dpf larvae showed reduced expression of ompb (E) and cnga4 (F) in nasal placodes of foxj1a/b double mutant embryos (n = 3). Scale Bars = 20 μm (A-C”), 10 μm (E, E’). Raw data files are available in Mendeley Data (https://data.mendeley.com/datasets/2pn963jn6y). dpf, days post fertilization; HCR, hybridization chain reaction; MCC, motile multiciliated cell; OSN, olfactory sensory neuron.