Fig. 1

Distribution of algal selenoproteomes. Selenoprotein families predicted based on the genomic sequences of 36 algal species. The taxonomic tree of these organisms is shown on the left (based on ref [29, 30]). In the tree, a green branch indicates a high-level selenium-containing organism (with a number of selenoproteins in a single species > = 20), and a red branch represents a low-level organism (with a number of selenoproteins in a single species <= 2). On the right, the taxonomic classification of different groups of algae is shown in different colors. The presence or absence of a selenoprotein and/or its homologs in each organism is highlighted in the pie graphs: The green, orange, and gray colors represent selenoproteins, Cys-containing homologs, and homologs containing other residues, respectively. The sizes of the whole pie and each sector represent the number of genes in the corresponding groups. The first bar on the right shows the number of selenoprotein families in different algae. The meaning of the various colors in the cylinder is consistent with the color in the pie chart matrix (green: Sec, orange: Cys, gray: others). While the length of the column represents the total number of protein families in each species, the two-color column (green and orange) indicates that the multiple protein families in the species include both Sec-containing and Cys-containing members. The rightmost blue bar chart shows the number of selenoprotein genes found in the genome of each species