Invagination (VIDEO) European Molecular Biology Laboratory This video is under embargo. Please login to access this video. To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Caption This is a side view of the invagination process in a fruit fly embryo. The outer/apical surface of the cells contracts, while the inner/basal surface relaxes. This coordinated process generates a force that drives the cell towards the inside of the embryo. This is the first step towards the development of an organ. Credit IMAGE: Daniel Krüger / EMBL Usage Restrictions None 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.