Figure 4: NFI paralogue gradients regulate zonal OR expression.

(A) Heatmaps showing differentially expressed transcription factors in immediate neuronal precursor (INP) and immature olfactory sensory neuron (iOSN) cells isolated from either dorsal, dorsomedial or ventral olfactory epithelium. The shown transcription factors are significantly differentially expressed between dorsal and ventral cells with an adjusted p-value of <0.05, at least a three-fold change in expression, and an expression level of at least 15 TPM. A broader list of zonal transcription factors is included in Supplementary Table S1. The heatmaps are sorted based on expression in ventral cells and the color bar above each heatmap shows the log2 fold change in ventral cells relative to dorsal cells.

(B) Expression levels of NFIA, NFIB, and NFIX at four stages of OSN development in dorsal cells (red), dorsomedial cells (green) and ventral cells (blue).

(C, D) Comparison of OR gene expression in NFI ABX triple knockout and control cells from the whole MOE. NFI transcription factors are deleted either in olfactory progenitors (C) using the Krt5-CreER driver or in mOSNs (D) using the OMP-IRES-Cre driver (as illustrated in Supplementary Figure S4). At the right of each panel, scissors indicate the differentiation stage of NFI ABX deletion, and a red box marks the cell type that was FAC-sorted for RNA-seq analysis. Asterisk: Wilcoxon rank sum test p-value < 0.001.

(E) OR expression in NFI ABX triple knockout, NFI AB double knockout, NFIX knockout, NFI ABX triple heterozygous and control mOSNs from ventrally dissected MOE. Knockout was induced in progenitors with the Krt5-CreER driver. Plots show a different pattern of OR gene transcription in the different genotypes. Quantification of differentially expressed ORs for the three knockout genotypes is shown in Supplementary Figure S4.