TY  - JOUR
A1  - Struck, Torsten H.
A1  - Paul, Christiane
A1  - Hill, Natascha
A1  - Hartmann, Stefanie
A1  - Hoesel, Christoph
A1  - Kube, Michael
A1  - Lieb, Bernhard
A1  - Meyer, Achim
A1  - Tiedemann, Ralph
A1  - Purschke, Guenter
A1  - Bleidorn, Christoph
T1  - Phylogenomic analyses unravel annelid evolution
JF  - Nature : the international weekly journal of science
N2  - Annelida, the ringed worms, is a highly diverse animal phylum that includes more than 15,000 described species and constitutes the dominant benthic macrofauna from the intertidal zone down to the deep sea. A robust annelid phylogeny would shape our understanding of animal body-plan evolution and shed light on the bilaterian ground pattern. Traditionally, Annelida has been split into two major groups: Clitellata (earthworms and leeches) and polychaetes (bristle worms), but recent evidence suggests that other taxa that were once considered to be separate phyla (Sipuncula, Echiura and Siboglinidae (also known as Pogonophora)) should be included in Annelida(1-4). However, the deep-level evolutionary relationships of Annelida are still poorly understood, and a robust reconstruction of annelid evolutionary history is needed. Here we show that phylogenomic analyses of 34 annelid taxa, using 47,953 amino acid positions, recovered a well-supported phylogeny with strong support for major splits. Our results recover chaetopterids, myzostomids and sipunculids in the basal part of the tree, although the position of Myzostomida remains uncertain owing to its long branch. The remaining taxa are split into two clades: Errantia (which includes the model annelid Platynereis), and Sedentaria (which includes Clitellata). Ancestral character trait reconstructions indicate that these clades show adaptation to either an errant or a sedentary lifestyle, with alteration of accompanying morphological traits such as peristaltic movement, parapodia and sensory perception. Finally, life history characters in Annelida seem to be phylogenetically informative.
Y1  - 2011
U6  - https://doi.org/10.1038/nature09864
SN  - 0028-0836
VL  - 471
IS  - 7336
SP  - 95
EP  - U113
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Hartmann, Stefanie
A1  - Helm, Conrad
A1  - Nickel, Birgit
A1  - Meyer, Matthias
A1  - Struck, Torsten H.
A1  - Tiedemann, Ralph
A1  - Selbig, Joachim
A1  - Bleidorn, Christoph
T1  - Exploiting gene families for phylogenomic analysis of myzostomid transcriptome data
JF  - PLoS one
N2  - Background: In trying to understand the evolutionary relationships of organisms, the current flood of sequence data offers great opportunities, but also reveals new challenges with regard to data quality, the selection of data for subsequent analysis, and the automation of steps that were once done manually for single-gene analyses. Even though genome or transcriptome data is available for representatives of most bilaterian phyla, some enigmatic taxa still have an uncertain position in the animal tree of life. This is especially true for myzostomids, a group of symbiotic ( or parasitic) protostomes that are either placed with annelids or flatworms.
 Methodology: Based on similarity criteria, Illumina-based transcriptome sequences of one myzostomid were compared to protein sequences of one additional myzostomid and 29 reference metazoa and clustered into gene families. These families were then used to investigate the phylogenetic position of Myzostomida using different approaches: Alignments of 989 sequence families were concatenated, and the resulting superalignment was analyzed under a Maximum Likelihood criterion. We also used all 1,878 gene trees with at least one myzostomid sequence for a supertree approach: the individual gene trees were computed and then reconciled into a species tree using gene tree parsimony.
 Conclusions: Superalignments require strictly orthologous genes, and both the gene selection and the widely varying amount of data available for different taxa in our dataset may cause anomalous placements and low bootstrap support. In contrast, gene tree parsimony is designed to accommodate multilocus gene families and therefore allows a much more comprehensive data set to be analyzed. Results of this supertree approach showed a well-resolved phylogeny, in which myzostomids were part of the annelid radiation, and major bilaterian taxa were found to be monophyletic.
Y1  - 2012
U6  - https://doi.org/10.1371/journal.pone.0029843
SN  - 1932-6203
VL  - 7
IS  - 1
PB  - PLoS
CY  - San Fransisco
ER  -