Fig. 1. Conservation of WOM expression signatures across mammals.

(A) RNA-seq was performed on six species, representing three mammalian lineages: Carnivora, Rodentia, and Primates. Species color scheme used is kept consistent across all figures and is as follows: light green, dog; orange, mouse; brown, rat; dark gray, marmoset; light blue, macaque; fuchsia, human. Ma, million years; Hsap, H. sapiens; Mmul, M. mulatta; Cjac, C. jacchus; Rnor, R. norvegicus; Mmus, M. musculus; Cfam, C. familiaris. (B) PCA of the expression levels for the 9725 “one-to-one” orthologs. Percentages of the variance explained by the PCs are indicated in parentheses. PC1 separates rodents from primates, PC2 separates Old World from New World primates and hominins, and PC3 separates dog from the other five species. (C) Heatmap of the expression levels of the canonical markers of the main cell populations present in the WOM samples. RNA expression levels are represented on a log₁₀ scale of normalized counts (NC) plus one (0, not expressed; 5, highly expressed). There is conservation of expression among all species. mOSNs, mature OSNs; iOSNs, immature OSNs; GBCs, globose basal cells; HBCs, horizontal basal cells; SUSs, sustentacular cells. No CHL1 ortholog was annotated in the rat genome version analyzed (black squares).