Andrew C. Oates

Andrew C. Oates, MPI-CBG Dresden The vertebrate embryo precisely segments its body axis into somites as it grows by elongation, providing a challenging system in which to analyze genetic, cellular and systems-level phenomena during development. The regular periodicity of embryonic somitogenesis is underlain by the segmentation clock, a population of coupled, noisy cellular oscillators with complex spatiotemporal organization. Recently, mathematical modeling has thrown some light on the nature of coupling between these cells that allows the population to stay synchronised. Using quantitative gene perturbation methods, we have been able to describe and test a mean-field theory of coupled phase oscillators that predicts the location of segmentation defects along the embryonic axis as a characteristic synchrony decay time depending on the coupling strength. Insights into the origin of oscillations in the embryo, and the reversibility of the synchronised state also followed from this theory. But these are only first steps towards understanding: For example, how the spatial patterns of organization are generated, the role of growth and of signaling delays, as well as how the period of the clock is controlled are the subject of a new spatially extended delayed coupling theory developed in conjunction with the group of Frank Julicher at the MPI-PKS, and experimentally verified in our lab. The use of quantitative experimentation in conjunction with theory and simulation will be critical to understanding this developmental process across temporal and spatial scales.