Cell Reorganization During Gastrulation (IMAGE) California Institute of Technology Caption During gastrulation, a single-layered tube of cells collapses and then begins to spread. Credit Science/Angelike Stathopoulos, Caltech Usage Restrictions Credit to be given as above License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.