Sealing the Gaps (IMAGE) National University of Singapore Caption Forces exerted by the cells surrounding the gap (dotted blue line) extend away at first, then direct inwards, towards the gap, during contraction of the 'purse-string' cable (red filaments). Credit Mechanobiology Institute, National University of Singapore Usage Restrictions Please credit accordingly. 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.