Revisiting the phylogeny of phylum Ctenophora: a molecular perspective

Abstract

The phylogenetic relationships of deep metazoans, specifically in the phylum Ctenophora, are not totally understood. Previous studies have been developed on this subject, mostly based on morphology and single gene analyses (rRNA sequences). Several loci (protein coding and ribosomal RNA) from taxa belonging to this phylum are currently available on public databases (e.g. GenBank). Here we revisit Ctenophora molecular phylogeny using public sequences and probabilistic methods (Bayesian inference and maximum likelihood). To get more reliable results multi-locus analyses were performed using 5.8S, 28S, ITS1, ITS2 and 18S, and IPNS and GFP-like proteins. Best topologies, consistent with both methods for each data set, are shown and analysed. Comparing the results of the pylogenetic reconstruction with previous research, most clades showed the same relationships as the ones found with morphology and single gene analyses, consistent with hypotheses made in previous research. There were also some unexpected relationships clustering species from different orders.