Phylogenetic relationships of the cloned <i>B. improvisus</i> NAKs.

Abstract

<p>A phylogenetic tree was constructed using N-terminal truncated NAK sequences from <i>B. improvisus</i> and other metazoan organisms, e.g. humans, zebrafish, insects, crustaceans, and other invertebrates, as well as choanoflagellates. As outgroup, Na⁺/K⁺ ATPases from the slime mold <i>Dictyostelium</i> were used. In addition, human H⁺/K⁺ ATPase was added. The <i>B. improvisus</i> Nak1 sequence was found in the same clade as other arthropod Nak1 sequences. However, no clear-cut orthologues to the <i>Balanus</i> Nak2 were found. In general, Nak2 sequences have diverged more rapidly in relation to Nak1. Nak1 branches are shown in red, Nak2 branches in green. The divergent <i>Drosophila</i> NAK (CG3701) branch and the <i>C. elegans</i> catp-4 branch are shown in black. Choanoflagellate NAKs are shown in blue. <i>Balanus</i> Nak1 and Nak2 are marked with arrows. Scale bar shows expected number of changes per site. For abbreviations of species names and accession numbers see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0077069#pone.0077069.s009" target="_blank">Table S3</a>.</p