PLK4 Induced Aster Formation (IMAGE) Instituto Gulbenkian de Ciencia Caption PLK4 induced aster formation around centrioles. Credit Zitouni Sihem and Susana Montenegro Gouveia (IGC). Usage Restrictions Credits should be mentioned every time this image is used. 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.