The evolutionary origins of our own phylum, the chordates, have been a topic of intense debate for the past 200 years. Despite broad interest in the issue, little consensus has emerged from this intense research scrutiny. Recent advances in our understanding of the relationships between the groups of animals closely related to chordates, and the technological advances from molecular genetics, make this key issue much more experimentally tractable. This work investigates the developmental biology of a phylum called hemichordates, which is one of the most closely related groups to chordates. Approach: This project examines how the mesoderm and endoderm are set up in this phylum. The mesoderm is a tissue layer that gives rise to many of the key innovations of our own phylum such as skeleton and the associated complex musculature. The endoderm gives rise to our complex gut and associated glands. Expected results: Investigating the role of genes with conserved roles in inducing and patterning chordate endoderm and mesoderm will help reconstruct the early evolution of these tissue layers and how they were modified and diversified to produce the critical morphological structures that define our phylum. A comparative study of the gene networks involved in endoderm and mesoderm development will give additional insights into how they function in vertebrates. Broader impacts: This project will involve the training and participation of undergraduate and graduate students at the University of Chicago. The PI and graduate students will present the results at a broad range of institutions and internally conferences.
