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Figure 9: Minimum-evolution tree of Δ12 and Δ15 homologous genes of cyanobacteria and eukaryotic algae. About 300 positions spanning the three histidine-boxes were employed. Colored branches indicate different groups of proteins. Red: Clade 1, green: Clade 2, magenta: Clade 3, blue: Clade 4, orange: Clade 5. Sequences from 37 sequenced cyanobacterial genomes are shown by their acronyms and accession numbers (locus tags). Other sequences are shown by their accession numbers, labels, and strain names. Desaturase genes that have been functionally characterized are indicated on the tree by their labels. Bootstrap values from minimum-evolution analyses are listed to the left of each node, with values more than 50 are shown.