Symposium: Model Systems for the Basal Metazoans: Cnidarians, Ctenophores, and Placozoans (SICB Annual Meeting to be held in New Orleans, LA - January 2004 )

Northern Illinois University, Dekalb IL

Investigators

Abstract

Intellectual Merits What was the nature of the first animals? How have animals characteristics evolved since their origin? How can we best utilize such knowledge? These are a few of the questions that can be illuminated by comparative and evolutionary studies of animals. Studies of .worms and flies,. the best-studied invertebrate model systems of modern biology, have provided considerable insight into such questions. Nevertheless, most recent phylogenies of animals suggest that nematodes (worms) and arthropods (flies) not only may be relatively derived animals but may also share some derived characteristics. The same recent phylogenies (and older ones as well) generally agree that the basal, non- bilaterian metazoans are represented by four groups: sponges, placozoans, cnidarians, and ctenophores. At this time, sponges would seem deserving of an entirely separate treatment, in part because they exhibit several primitive features and in part because their systematics is in a state of flux. The remaining three groups include: (1) ctenophores, which are often considered to be the sister group of the bilaterians, (2) cnidarians, which include some of the best-studied basal metazoans, and (3) placozoans, which exhibit a number of unique and enigmatic characteristics including the smallest genome yet found in a metazoan. In evolutionary and comparative studies it is often the character states of the basal taxa that have a decisive influence on interpretations of character state changes throughout the cladogram. Without detailed knowledge of the basal metazoans, it is impossible to provide an effective comparative framework for animal evolution. Developing a clearer picture of character evolution in the metazoans requires both robust phylogenies and well-documented character states of these crucial basal taxa. With the recent initiation of genomic projects using cnidarians (e.g. the hydroid EST project and the Nematostella BAC library project), it would be timely to consider what sorts of cnidarian model systems should be developed and how these systems can be used. Considerations of how ctenophores and placozoans can complement and contrast to cnidarian models are also essential. In this context, we propose a Society for Integrative and Comparative Biology (SICB) symposium, .Model systems for the basal metazoans: cnidarians, ctenophores, and placozoans.. The goals of the symposium will be to bring together a diverse group of molecular, cellular, organismal, and evolutionary biologists to discuss appropriate basal metazoan models and the topics of integrative and comparative biology that these models are particularly relevant to. A simultaneous SICB symposium, .Sponges: new views of old animals. will nicely complement our efforts. To have a significant impact on the subsequent development of these models, these discussions must occur soon. Broader Impacts Every effort has been made to invite a diverse group of participants, including women, people of minority background, as well as graduate students, post-docs, and junior faculty. A noteworthy feature of the SICB annual meeting is its emphasis on young investigators. Typically, more than half of those in attendance are Ph.D. students, postdoctoral fellow, and young faculty. Qualified undergraduates and high school teachers from the surrounding community are also welcomed. SICB mounts an extensive program of discounted registration and subsistence support for Ph.D. students; literally every graduate student member who presents at the meeting and requests such support will receive it. Thus, SICB symposium participants receive exposure to a broad cross-section of the relevant scientific community. Symposium proceedings will be published in Integrative and Comparative Biology.