Phylogeny of Ciona miRNA families in the deuterostome lineage. Newly identified conserved Ciona miR families (shaded circles) and previously known Ciona miRs (dark circles) are grouped with homologous miR families from representative deuterostome species (echinoderm, Strongylocentrotus purpuratus; hemichordate, Saccoglossus kowalevskii; Amphioxus, Branchiostoma floridae). Missing miRs are shown as empty circles. It is evident from the phylogenetic tree that the miR repertoire from Ciona is closely related to the vertebrate miRs.
Hendrix et al. Genome Biology 2010 11:R39 doi:10.1186/gb-2010-11-4-r39