Fig. 2
Distribution of complex genes across different age categories in the five species. a–d for Mm, Mus musculus; e–h for Gg, Gallus gallus; i–l for Dr, Danio rerio; m–p for Dm, Drosophila melanogaster; q–t for Ce, Caenorhabditis elegans. The percentages of complex protein-coding genes (PCGs) in each age degree category were calculated and divided by the expected percentage. Heat map showing the fold enrichment values obtained from this division. The expected percentage was the percentage of each type of complex PCGs in the genome of each species, represented as ‘background (%)’ in the right region of the figure. Gene complexity was measured by gene length (GL), cis-regulatory module number (CRMN), protein length (PL) and domain number including repeats in one protein (DNIR) for each species, and the results of the most complex PCGs are shown in the figure. The full result data, including other complexity degrees, are in Additional file 1: Table S8. The abbreviations of age degree names: GOT_Mode, gene origin time from the consensus mode gene age dataset, GOT_Ens, gene origin time from the EnsemblCompara database; LDT, last duplication time; and DOT, the origin time of the youngest domain in one protein. The abbreviations of the grades for each age type of each species are listed in Additional file 1: Table S7. For the convenience of presentation, the V grades of the LDT and DOT of Mus musculus were the combination of V and VI grades shown in Additional file 1: Table S7. The over- or under-representation strengths of the complex genes in each age degree category were estimated and are represented by − log (p) or log (p), respectively (see “Methods”). All of the PCGs in each species were used as the background in the over-/under- representation analysis. The symbols in this figure: ++++ , over-represented and P < 1E−50; +++, over-represented and 1E−50 ≤ P < 1E−10; ++, over-represented and 1E−10 ≤ P < 0.05; +, over-represented but P > 0.05; −−−− , under-represented and P < 1E−10; −−−, under-represented and 1E−50 ≤ P < 10-10; −−, under-represented and 10-10 ≤ P < 0.05; −, under-represented but P > 0.05