Figure 1

Phylogenetic analysis of Ct-Piwi1 and Ct-Piwi2 sequences. The argonaute and piwi subfamilies are indicated by a red and blue line, respectively. Ct-Piwi1 and Ct-Piwi2 are both members of the Piwi subfamily of Argonaute proteins. Ct-Piwi2 clusters in a sub-group, indicated by a green line, containing other Piwi2 or Piwi-like proteins from broad metazoan taxa. The tree shown is a Bayesian consensus tree with posterior probabilities placed above the nodes. Maximum likelihood bootstrap support values are included where the tree topology agreed with the Bayesian analysis, and are placed below the nodes. Species abbreviations: Amphi, Branchiostoma floridae; Bm, Bombyx mori; Ce, Caenorhabditis elegans; Ct-, Capitella teleta; Ci-, Ciona intestinalis; Che, Clytia hemisphaerica; Dm, Drosophila melanogaster; Hro-, Helobdella robusta; Hs, Homo sapiens; Lg, Lottia gigantea; Mm, Mus musculus; Nv, Nematostella vectensis; Pdu-, Platynereis dumerilii; Pc, Podocoryne carnea; Sp, Strongylocentrotus purpuratus. JGI protein ID number is indicated for C. teleta outgroup and sequences from H. robusta, L. gigantea, and N. vectensis. NCBI accession number is indicated for C. intestinalis. Gene locus number is indicated for B. floridae.