To shape a developing animal, individual cell movements must be coordinated over long distances. Two recent studies help show how this is achieved during convergence and extension of the Drosophila germ-band, where polarity within the plane of the embryonic epithelium biases junction remodeling to polarize cell intercalation.
Baum, B. (2004, September 7). Animal development: Crowd control. Current Biology. Cell Press. https://doi.org/10.1016/j.cub.2004.08.047