*4.2. Phylogenetic Analysis*

Phylogenetic analysis was used to support the assignment of the predicted OvoA sequences from marine arthropods, to establish their relationship to each other and to those from other metazoans. An unrooted phylogenetic tree was generated using OvoA amino acid sequences deduced from this study and from known marine metazoans [1]. The selected sequences included organisms from Mollusca, Chordata, Hemichordata, Echinodermata, Placozoa, and Porifera phylum (Table S2). An unrooted phylogenetic tree was generated using amino acid sequences that were aligned using ClustalW software (Galaxy version 2.1 [48]). FASTTREE was used to build a maximum-likelihood phylogenetic tree (Galaxy Version 2.1.10+ galaxy1) using the protein evolution model JTT+ CAT [49].
