With their complex life cycle and highly derived body plan, echinoderms are unique among bilaterians. Although early development has been intensively studied, the molecular mechanisms underlying development of the adult echinoderm and its unusual radial body plan are largely unknown. To investigate the evolution of developmental changes in gene expression underlying radial body plan development...

Viruses are the most abundant biological entities on Earth, killing 10–20% of oceanic biomass each day. However, despite their ecological importance, viruses inhabiting many echinoderms, cnidarians, urochordates, and marine arthropods have not been investigated with significant breadth. We conducted a broad survey of the viral assemblages inhabiting these hosts through viral metagenomics and ph...

DNA barcoding has proven an effective tool for species identification in varied groups of marine invertebrates including crustaceans, molluscs, polychaetes and echinoderms. In this study, we further validate its utility by analyzing almost half of the 300 species of Echinodermata known from Canadian waters. COI sequences from 999 specimens were assigned to 145 BINs. In most cases, species discr...

Today's progress in molecular analysis and, in particular, the increased availability of genome sequences have enabled us to investigate photoreceptor cells (PRCs) in organisms that were formerly inaccessible to experimental manipulation. Our studies of marine non-chordate deuterostomes thus aim to bridge a gap of knowledge regarding the evolution of deuterostome PRCs prior to the emergence of ...

Inferring the development of the earliest echinoderms is critical to uncovering the evolutionary assembly of the phylum-level body plan but has long proven problematic because early ontogenetic stages are rarely preserved as fossils. Here, we use synchrotron tomography to describe a new early post-metamorphic blastoid echinoderm from the Carboniferous (approx. 323 Ma) of China. The resulting th...

The time of origin of the animal phyla is controversial. Abundant fossils from the major animal phyla are found in the Cambrian, starting 544 million years ago. Many paleontologists hold that these phyla originated in the late Neoproterozoic, during the 160 million years preceding the Cambrian fossil explosion. We have analyzed 18 protein-coding gene loci and estimated that protostomes (arthrop...

Conservation of the cortical granule serine protease during fertilization in echinoderms was tested both functionally in sea stars, and computationally throughout the echinoderm phylum. We find that the inhibitor of serine protease (soybean trypsin inhibitor) effectively blocks proper transition of the sea star fertilization envelope into a protective sperm repellent, whereas inhibitors of the ...

Feeding arms carrying coelomic extensions of the theca are thought to be unique to crinoids among stemmed echinoderms. However, a new two-armed echinoderm from the earliest Middle Cambrian of Spain displays a highly unexpected morphology. X-ray microtomographic analysis of its arms shows they are polyplated in their proximal part with a dorsal series of uniserial elements enclosing a large coel...

Faunal inventories are extremely important, especially when focused on neglected groups, such as echinoderms, and concentrated on areas under intense anthropic activity such as the SAo Sebastilo Channel in Brazil (23 degrees 41' - 23 degrees 54' S and 45 degrees 19' - 45 degrees 30' W). Intertidal and upper sublittoral zone collections were performed at five sites of the Channel's continental m...

Deuterostomes comprise a monophyletic group of animals that include chordates, xenoturbellids, and the Ambulacraria, which consists of echinoderms and hemichordates. The ancestral chordate probably had 14 Hox genes aligned linearly along the chromosome, with the posterior six genes showing an independent duplication compared to protostomes. In contrast, ambulacrarians are characterized by a dup...