Sequence alignment of the potential Platynereis BPI with homologues from other organisms. (A) The partial sequence of the BPI from P. dumerilii (Platynereis, AM697673), was aligned with sequences from C. elegans (Caenorhab., NP_510689), from S. purpuratus (Strongylo., XP_001192950), and from Homo sapiens (Human_BPI, NP_001716; Human_BPI2, NP_777592; Human_BPI3, NP_079503; Human_LBP, NP_004130) As out-group we used human cholesteryl ester transfer protein (Human_CETP, NP_000069). Red color indicates 80% consensus and blue color 40% consensus. (B) A Bayesian protein tree was generated using the aligned region of proteins and we found that Platynereis BPI exhibit highest relation to the C. elegans BPI. However, the analysis reveals that BPI from P. dumerilii is more ancestral in sequence when compared to BPI from C. elegans. Posterior probabilities are plotted at the nodes. The scale bar represents the substitutions per site according to the model of amino acid evolution applied.