Fig. 4

Gene density dynamics of Hox and Wnt5–7 microsyntenies across planulozoans. A Normalized gene density (observed/random, n is the number of blocks) in Wnt5–7 and Hox microsyntenic blocks (including duplicates and/or split ones) found in extant metazoan taxa (rows). Colors note whether median normalized gene density of the block is higher in observed or randomly sampled blocks (see legend). Vivid colors note a statistically significant difference (p < 0.05, Wilcoxon rank-sum test). Distributions of normalized gene density of both these blocks can be found in Supplementary Fig. 10. Wnt5–7 (B) and Hox (C) microsyntenic blocks displayed as graphs; nodes are gene families, edge lengths are the minimum normalized distance (distance in base pairs, normalized by assembly size) found between any given orthogroup pair within the taxonomic group. Self-edges are the minimum distance found between genes belonging to the same orthogroup. Reciprocal of raw gene density of Wnt5–7 (D) and Hox (E) as a function of assembly size, using a log-log scale. The upper and lower limits of the gray band correspond to the regression line explaining reciprocal gene density as a function of assembly size (Supplementary Fig. 3), and the regression line explaining reciprocal of the double of gene density as a function of assembly size, respectively. Both these values correspond to the tentative thresholds of 1 and 2 of the normalized gene density for identifying high and low gene density regimes, respectively