In toto live imaging of mouse morphogenesis and new insights into neural tube closure.

In the field of developmental biology, live imaging is a powerful tool for studying, in real time, the dynamic behaviors of tissues and cells during organ formation. Mammals, which develop in utero, have presented a challenge for live imaging. Here, we offer a novel, prolonged and robust live imaging system for visualizing the development of a variety of embryonic tissues in the midgestation mouse embryo. We demonstrate the advantages of this imaging system by following the dynamics of neural tube closure during mouse embryogenesis and reveal extensive movements of the cranial neural tissue that are independent of neural fold zipping.