Fig. 4

a Proportion of genes in each category that have a one-to-one ortholog in human, fly, and worm, as defined by the modENCODE consortium [16]. b Pearson’s correlation coefficient between gene expression in each human organ and the corresponding one in every other species. The correlation is computed across all the genes in each class separately. c Promoter sequence conservation measured as the average PhastCons signal at TSS (in a window between 3000 bp upstream and 500b p downstream of the TSS). Promoter sequence conservation is higher for TVGs than for SVGs (p=4×10⁻⁴, Mann–Whitney test). Proportion of genes with a promoter category based on CAGE signal [27]. Broad: All the promoters of a gene are broad; sharp: all the promoters of a gene are sharp; mixed: a gene has at least one broad and one sharp promoter; unassigned: none of the promoters of a gene have an assigned category. d Proportion of genes in each category covered by CpG islands (as defined in Wu et al. [17]). SVGs have higher CpG island coverage at their promoter than TVGs (p=6×10⁻⁵, chi-squares test). e H3K4me3 average signal at TSS (±3000 bp) of a subset of SVGs, heart-specific TVGs, and others. Genes in each category are filtered to have comparable levels of expression (“Methods”). f Proportion of genes in each category with an associated GWAS trait or OMIM disease. cc correlation coefficient, SVG species-variable gene, TSS, transcription start site, TVG tissue-variable gene