Echinodermata is a very rich group of organisms which is comprised of sea urchins, sea stars, brittle stars, sea lilies and sea cucumbers, and as a phylum represents the second most number of species in Deuterostomia. Due to the close phylogenetic relationship with Chordata and their tractable laboratory use, echinoderms serve as valuable systems for studying developmental biology. Furthermore, echinoderms are found extensively in the fossil record and as such are an excellent model system for studying evolutionary biology. As critical as echinoderms are in these areas of research, the phylogenetic relationships are very contentious, and the DNA and RNA sequence availability is relatively poor. In order to resolve these two issues, we sequenced and assembled de novo transcriptomes of twenty species of echinoderms from all five extant classes of echinoderms. With these data, we constructed a phylogenetic tree that is well-supported; using multiple phylogenetic methods and sampling depths. Using these results, we were then able to test evolutionary transitions that have occurred in echinoderms, including fertilization, early development, and germ line determination. Echinodermata will continue to be a valuable resource in many fields of scientific study and the data from this body of work will greatly facilitate that research through the availability of DNA and RNA sequences and a robust phylogenetic tree.
Reich, Adrian,
"Evolutionary transitions within Echinodermata"
(2014).
Molecular Biology, Cell Biology, and Biochemistry Theses and Dissertations.
Brown Digital Repository. Brown University Library.
https://doi.org/10.7301/Z0639N3K
