Publication - Article

Revisiting the phylogeny of phylum Ctenophora: a molecular perspective

Abstract

The phylogenetic relationships of deep metazoans, specifically in the phylum Ctenophora (inside and outside the phylum), are not totally understood. Several loci (protein coding and ribosomal RNA) from organisms belonging to this phylum are currently available on public databases (e.g. GenBank). Previous studies take into account the ribosomal data and the protein data separately. In this study, we perform a meta-analysis of previously published data together. The published data of this phylum have been used in previous phylogenetic analyses inside the phylum and consist in nuclear ribosomal data, such as 18S, 5.8S, ITS1, ITS2, and protein-coding markers such as NFP (non-fluorescent protein). Previous studies concentrate their efforts toward the analyses of ribosomal data or the protein-coding marker separately. Now we take into account these markers together for an upgrade of the phylogenetic analysis of this phylum. We also test several markers such as 28S, IPNS, Tyrosine aminotransferase and HLH domaincontaining protein for the improvement of the study. This markers were analyzed by Bayesian Inference (MrBayes) and Maximum Likelihood (Garli and RAxML), individually and concatenated, showing improvement in the orders placement and presenting new interesting relationship between the paraphyletic order Cydippida and the other ctenophores. These analyses also include sequences from undescribed species that have been reported in GenBank which improved the alignment matrices and support values of some nodes. Adding the undescribed species suggests interesting and well supported clades, the posterior identification of this species would led to an improvement on the ctenophore’s taxonomy.