GENE REGULATORY NETWORKS AND THE EVOLUTION OF IMMUNE CELL DEVELOPMENT
Jonathan Rast, University of Toronto
Jonathan P. Rast 1,2, , Katherine M. Buckley,3, Catherine Schrankel 2, Nicholas Schuh 1, and Eric Ho 1,4
1. Department of Medical Biophysics; 2. Department of Immunology, University of Toronto, Toronto, ON
3. Department of Biological Sciences, The George Washington University, Washington, D.C.; National
Cancer Institute, National Institutes of Health, Bethesda, MD.
Cells that are specialized for immune defense are widespread through bilaterian animals but it is difficult to determine where evolutionary homology lies from a purely morphological perspective. Clearly similar cell types tend to be restricted within phyla and little detail is known about the molecular characteristics of immune cells in most animal groups. In principle developmental gene regulatory networks (GNRs) offer a level of comparison that can be used to solve this problem. We have characterized transcription factor function in the development of immunocytes in the purple sea urchin larva and have characterized regulatory interconnections that direct development from mesoderm to differentiated cell types. Similarities with vertebrates that suggest that regulatory circuitry is shared between chordates and echinoderms. As this type of information becomes more complete, hypotheses about the evolution of these cell systems will become more accessible to experimental validation and the utility of invertebrate models to shed light on more complex vertebrate systems will be increased.