Tissue tectonics: towards a quantitative understanding of morphogenesis

The morphogenesis of embryos involves substantial reorganisation of many hundreds or thousands of cells. We know much of how individual cells move but understand far less of how tissues are able to attain their shape. We approached this problem by developing a framework with which we can measure and analyse the fundamental morphogenetic signatures of cell and tissue behaviour. We begin with a record of traced and tracked 3D cell shapes and locations, for many hundreds of cells. From this raw data we derive high resolution measures of the rate and direction of tissue deformation, cell shape change and cell rearrangements. When mapped in time and space across the embryo this gives a complete record of morphogenesis. Statistical methods campare maps from wild type and experimental embryos, showing where and when the dynamics of development become altered. We are using this approach to study the development of the vertebrate central nervous system. Dissection of forebrain and spinal development in these ways shows that complex tissue morphogenesis can be achieved using a small number of conserved developmental mechanisms.