BAC and YAC Libraries for Exploring Metazoan Origins

University Of California-Irvine, Irvine CA

Investigators

Abstract

0208335 Steele A complete description of the evolutionary history of multicellular animals will require detailed information on the content, organization, and regulatory mechanisms of the genomes of animals from phyla throughout the animal phylogenetic tree. Of particular importance for such studies are species that diverged early from the rest of the animals and unicellular organisms which are close relatives of animals. Features of the genomes of such organisms which are shared with more recently diverged animals would then be ones which were present in the ancestor of all modern animals. The goal of this project is to prepare and archive bacterial artificial chromosome libraries from Nematostella vectensis (a sea anemome which is a member of the early diverging animal phylum Cnidaria) and from the choanoflagellate Monosiga brevicollis, a unicellular organism closely related to multicellular animals. These libraries will provide important resources for addressing a variety of questions related to the origins, evolution, and development of multicellular animals. Such questions include: How did the Hox family of developmental regulatory genes evolve? When did various other developmental regulatory gene families appear during animal evolution? How closely related are choanoflagellates and multicellular animals, and what genes were necessary to make the transition from unicellularity to multicellularity? What happened at the genome level when nerves were added to multicellular animals? What cell adhesion and intercellular signaling molecules were present in the common ancestor of modern animals? Are cnidarian genes organized into operons, as suggested by the presence of spliced leader addition in this phylum? In addition to providing material for analysis of animal evolution, the libraries will facilitate the isolation of gene promoters, which will be essential for the development of functional assays in these organisms and for dissecting gene regulatory networks. The libraries generated by this project will be freely available to the research community. Information on the libraries and their availability will be provided through various means, including appropriate scientific newsgroups and web sites.