Proteome size as a function of complexity. Total numbers of amino acids (AA) are shown for each proteome as a function of the complexity of the organism, measured by the number of cell types the organism has. The total sum of the longest variants, presumably corresponding to the main isoforms, is shown with green (plants) and red (eukaryotes without plants) triangles whereas blue dots indicate the alternative complements where all the known variants for a gene are included. Both the main isoform proteomes and the alternative splice complements follow a power function, with an exponent of 0.25/0.19 (eukaryotes without and with plants) and 0.27, respectively. Abbreviated species names are shown for some plants and the alternative proteomes: Aga, Anopheles gambiae; Ath, Arabidopsis thaliana; Bfl, Branchiostoma floridae; Bta, Bos taurus; Cel, Caenorhabditis elegans; Cfa, Canis familiaris; Cin, Ciona intestinalis; Ddi, Dictyostelium discoideum; Dme, Drosophila melanogaster; Dre, Danio rerio; Fca, Felis silvestris cattus; Gga, Gallus gallus; Has, Homo sapiens; Mmu, Mus musculus; Rno, Rattus norvegicus; Ppa, Physcomitrella patens; Ptr, Pan troglodytes; Tni, Tetraodon nigroviridis; Tru, Takifugu rubripes; Vvi, Vitis vinifera; Xtr, Xenopus tropicalis; Zma, Zea mays. See Additional file 3 for the full list of proteomes.
Schad et al. Genome Biology 2011 12:R120 doi:10.1186/gb-2011-12-12-r120