Figure 4. Motif distribution of PD1, PD-L1 and PD-L2 genes in representative vertebrate species. Motifs of these genes from representative species from each group are predicted using MEME suite (http://meme-suite.org/) based on amino acid sequences. All sequences are separated by 5 conservative motifs with colors, including motif 1 (red), motif 2 (cyan), motif 3 (green), motif 4 (purple) and motif 5 (brown).