Abstract

Dr Ertugrul Ozbudak, Senior Research Associate, Stowers Institute for Medical Research, Missouri, USA.



The development of multicellular organisms is controlled by transcriptional networks. Deciphering the role of these networks requires a full understanding of the transcriptome regulation during embryogenesis. Several microarray studies have characterized the temporal evolution of the transcriptome during development in different organisms. In all cases, however, experiments were performed on whole embryos, thus averaging gene expression among many different tissues. Here we took advantage of the local synchrony of the differentiation process in the paraxial mesoderm. This provides a unique opportunity to study the systems level properties of muscle differentiation. Using high-resolution, spatiotemporal profiling of the early stages of muscle development in the zebrafish embryo, we identified a major reorganization of the transcriptome taking place in the presomitic mesoderm (PSM). We further show that the differentiation process is associated to a striking spatial compartmentalization of cellular physiological programs. Particularly, we identify a tight segregation of cell cycle/DNA metabolic processes and translation/oxidative metabolism. Using temporal perturbation experiments followed by transcriptome profiling, we also unraveled the gene regulatory network that is controlled by four signaling pathways (FGF, WNT, RA and Notch) functioning in the PSM.

Host: Prof. Philip Ingham