Fig. 2: Association between transcriptomic distances and odorant receptor similarity levels.

a 1152 mouse odorant receptor (OR) phylogeny. Colored bars show the transcriptomic identity of the olfactory sensory neuron (OSN) population expressing a given OR. Colored dots indicate that the corresponding OR belongs to the gene cluster analyzed in (c, d). b Schematics of the different metrics used to express distance between pairs of OSN populations. From left to right, transcriptomic distance (Euclidean distance between centroids of OSN population transcriptomes in the PCA space), genomic distance (base pairs between OR gene start codons), amino acid difference (sum of Miyata amino acid replacement scores between OR protein sequences). c Pairwise transcriptomic distances between OSN populations expressing OR genes in the same cluster on chromosome 14. The orange box highlights H element-regulated OR genes. The dotted line in the pairwise distance matrix encompasses comparisons between OR genes under control of the H element. d Same analysis as in (c) but for OR genes under the control of the P element, on chromosome 7. e Distribution of transcriptomic distances per bins of either genomic distances (top) or amino acid differences (bottom), for all pairs of ORs belonging to the same class and the same gene cluster (n = 3602 pairs). Transcriptomic distances and genomic distances: Spearman’s rank correlation ρ = 0.16, ***p < 0.001, n = 2598 pairs. Transcriptomic distances and amino acid differences: Spearman’s rank correlation ρ = 0.29, ***p < 0.001, n = 222 pairs. Correlation scores (ρ) and associated p values between the transcriptomic distances and each of the different metrics was calculated for the pairs included in the three first bins. f Proportions of closely related pairs of OSN populations across bins of transcriptomic distances. Close pairs are defined depending on either their genomic distance or their amino acid differences. g Transcriptomic distance distribution of four categories of OSN population pairs defined by a combination of their genomic distances and amino acid differences. ***p < 0.001, ns p > 0.05; two-sided Wilcoxon rank test, p values were adjusted with a Bonferroni correction. Exact p values are provided in Supplementary Table 1. Source data are provided as a Source Data file.