How Do Vertebrates Make Their Body Plan?

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My research group studies the initial generation of the body axis that  occurs during embryogenesis. Using amphibians as a model vertebrate system, we investigate the cross-talk beween transcription factors and signaling pathways to determine their role in specifiying neural and mesodermal cell fates along the body axis during early embryo development. Frogs, like people, are vertebrates, and the regulation of early embryonic development in all of the vertebrates is carried out by the same gene products regardless, of species. Thus, the frog (Xenopus laevis) is an excellent system to learn how all vertebrates make their body plan. One of the earliest and most dramatic events in early development is the formation of the body axes. As  early embryos, we all start out as a round egg cell, which then rapidly divides into  groups of cells, with ball-like form. At a critical stage, cells migrate and elongate to make our typical body plan: the head - tail axis (anterior - posterior), the back - stomach axis (dorsal - ventral) and finally the left - right axis. Cells must know what they are doing along theses  body axes. Not only must a cell decide its own identity, a decision to be muscle, blood or nerve for instance. Cells must also define their position along the axis. In the nervous system for example, a cell in the anterior-head makes a forebrain-derived neuron or an eye cell, whereas a nerve cell in the posterior-tail region makes a motor neuron. This location-dependence of cell fate is based on the capability of cells to monitor their position with respect to the developing embyonic axes. In my lab, we are working on the genetic and cellular interactions determining how cells of the early mesoderm and nervous system acquire these different axial cell fates during early development.

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