Fig. 3

Scenarios of a single protein with tandem kinase domains and examples of potential gene fusion and fission events. a Four scenarios of a single protein with tandem kinase domains and their domain-based orthologs. Arrows represent orthologous pairs. The number of cases for each scenario is shown in parentheses. b Example of Scenario 3 and phylogenetic tree analysis on the fusion event of TAOK1 orthologs and PIK3C2A orthologs. Human TAOK1’s and PIK3C2A’s domain-based orthologs in 245 species were aligned, concatenated (represented by a dotted line if these two domains are from different species), and used to build a phylogenetic tree. Species names are labeled at the leaves of the circular-mode phylogenetic tree. The leaves are colored according to the clade of the species (refer to legend). Black stars mark the species with a TAOK1-PIK3C2A fused gene. The time when potential fusion events occurred is indicated by red stars on the tree. c Example of Scenario 4 and analysis of the fission event of OBSCN orthologs. The domain-based orthologs of human OBSCN’s two kinase domains in 80 species were used to build a phylogenetic tree. Black triangles mark the species with fission events. Red triangles indicate the time when potential fission events occurred