A phylogenomic investigation into the origin of multicellular animals.

One of the most profound, yet poorly understood, evolutionary events in the tree of life is the origin of complex multicellular lineages, such as animals, fungi, or plants. This proposal focuses on the elucidation of the evolutionary changes that took place during the transition from protozoan unicellular lineages to one of those multicellular groups: the animals or metazoans. To clarify the genomic innovations that evolved prior to and after the origin of animals, we will carry out an EST survey of two unicellular protist parasite lineages: Capsaspora owczarzaki and the ichthyosporean Sphaeroforma arctica, recently shown to be closely related to choanoflagellates and animals, This research program is aimed at understanding a key biological question but also has clear implications for biomedical research. By understanding the genetic innovations prior to the origin of animals, we might characterize the ancestral functions of animal-specific gene families. This will be an important step towards a full understanding of the evolution and function of crucial developmental, cell adhesion and cell-to-cell communication genes in higher eukaryotes, ultimately improving our understanding of the role of these genes in health and disease.