Research

NemPhyl: Reconstructing Nemertean Phylogeny using phylogenomic tools

Nemerteans have played a key role in our understanding of animal evolution, in part due to their odd combination of a functional acoelomate body plan with a typical mesoderm derived from the mesentoblast (=coelomate condition). The internal phylogeny of the group has been investigated using morphological and molecular approaches, but many questions remain to be answered both in species-level taxonomy/delimitation and in their internal phylogenetic relationships. While target gene approaches have undoubtedly contributed towards our knowledge of the relationships within the group, new sequencing technology allows to generate sequence data with an unprecedented ease and at relatively low costs to attempt to solve those aspects that remain recalcitrant.

Thanks to the support from Göteborgs universitet, we have gathered a group of 17 nemertean workers from institutions in 8 countries to come up with a plan to advance nemertean systematics in many fronts. On the molecular ground, we have selected 20 target species (8 palaeonemerteans, 5 heteronemerteans, 7 hoplonemerteans) to add to 2 existing EST projects. Novel EST data will be generated from cDNA libraries obtained from existing or future collections of specimens preserved in RNAlater with the aim of having 22 broadly distributed species for phylogenomic reconstruction. In addition we proposed to collect 35 additional species but with a lower priority. Sperm ultrastructure data will also be obtained for 70-80% of the species utilized in the phylogenomic approach, depending on the availability of mature males. An explicit data matrix using the same 22 exemplar species will be generated synthesizing new morphological and anatomical data as well as integrating characters already available in the literature or provided by the investigators. Finally, a collection of field observations should accompany the data collection for all the species studied. Uploading nemertean species pages in EOL was also discussed.

This meeting served to launch several initiatives to investigate important questions within the phylum Nemertea as well as to plan for future collaborative research among the participants.