Fig. 1

A maximum likelihood phylogenetic (Phyml, LG + I + G) tree of human and cnidarian SLC9s (protein sequences were previously aligned by Clustal Omega). Phylogenetic analysis of S. pistillata SLC9 sequences with functionally characterized SLC9s in H. sapiens grouped cnidarian SLC9s within three different subfamilies: subfamily A, including plasma membrane and organelle homologs, which are represented in blue and red, respectively; subfamily B, which is represented in orange; and subfamily C, which is represented in yellow. Cnidarian species include Stylophora pistillata (Spi), Acropora digitifera (Adi), Nematostella vectensis (Nve), Aiptasia pallida (Apa), Corallium rubrum (Cru), Dendronephthya gigantea (Dgi), Amplexidiscus fenestrafer (Afe), and Discosoma sp. (Dsp). Chordata species include Homo sapiens (Hsa)