netic analyses of acoels are strongly affected by a long-branch attraction (LBA) artefact. When we minimize LBA, we find consistent support for a position of both acoelomorphs and Xenoturbella within the deuterostomes. The most likely phylogeny links Xenoturbella and Acoelomorpha in a clade we call Xenacoelomorpha.
The Evolution of Simplicity: The Xenacoelomorpha Genome Project
We are currently sequencing the genomes of 5 different species of Xenacoelo- morpha. Based on draft assemblies, we have started analyzing the phylogenetic order, intron conservation, gene loss and gain, synapomorphies, Hox and homeobox genes of these organisms. In collaboration with international experts we also annotate these genomes.
Proteomics of sea urchin skeletal elements
Using mass spectrometry-based methods, we have identified 231 proteins in the matrix of the S. purpuratus spicule matrix. Approximately two thirds of the iden- tified proteins are either known or predicted to be extracellular proteins or transmembrane proteins with large ectodomains. The most abundant proteins of the spicule matrix are SM50-, SM30- and MSP130-related proteins, matrix metal- loproteases and carbonic anhydrase.