Propagation and Interpretation of Nodal Signaling

Abstract

The Nodal signaling pathway is integral to the development of many animal phyla, plays a conserved role in patterning the germ layers of all vertebrates, and has been implicated in numerous cancers and developmental diseases. Despite Nodal’s importance and status as a paradigm for the study of morphogens, how Nodal signaling propagates through developing embryos to form a gradient of activity and how that gradient is in turn interpreted by target genes have remained questions lacking satisfactory answers. My graduate work focused on answering these two questions. By combining quantitative microscopy with classical embryology and computational modeling, we uncovered previously unknown mechanisms of Nodal gradient formation and maintenance. Furthermore, my work has led to the development of a novel set of quantitative experimental and computational techniques for studying how genes activated by Nodal achieve distinct patterns of expression in the early zebrafish embryo.