BNMC Seminar: Complexity and control in animal development

Arthur D. Lander
Professor, Department of Developmental and Cell Biology, Department of Biomedical Engineering
Director, Center for Complex Biological Systems
University of California, Irvine

UCI

Explaining the development of multicellular animals—including processes such as growth, differentiation, patterning and regeneration–has long been a major goal of biology.  Until recently, experimental work has focused almost entirely on the identification of mechanisms—cellular, molecular and genetic—that cause such processes to happen.  Yet development is remarkable not only for the fact that it happens, but for the fact that it is extremely well controlled, precisely specifying pattern and size in the face of genetic, epigenetic and environmental variability and noise.  My laboratory pursues the hypothesis that much of the (at times) perplexing complexity that has been observed in the signaling pathways underlying animal development evolved specifically for the purpose of control.  To test this hypothesis, we use both modeling and experimentation to explore the potential benefits and drawbacks of complex developmental circuitry.  My talk will focus on developmental events that are regulated by morphogens—diffusible molecules that coordinate the establishment of spatial pattern—and chalones—secreted feedback inhibitors of cell growth and lineage expansion.  I will describe ways in which performance objectives such as parameter insensitivity, noise suppression, and desirable dynamics are served by some of the complex signaling networks within which such molecules are embedded.