ABSTRACT
During development, the embryo undergoes dramatic and relatively rapid changes in form. The shape changes that characterize morphogenesis are not simply a manifestation of regional differences in growth rates. Rather, many are caused primarily by complex 3-D tissue deformations driven by active cellular and subcellular forces.1-6 Embryologists, biophysicists, and engineers have expended considerable effort studying these mechanisms, but one surprising aspect of this eld may be how much remains unknown about the physical mechanisms of morphogenesis. This is especially true for understanding how cell-level activity is coordinated to change tissue-level morphology. The main purpose of this chapter is to provide an overview of the current state of knowledge in this eld.
