Formation of the contraction pole (CP) (VIDEO) Institute of Science and Technology Austria This video is under embargo. Please login to access this video. Caption Formation of the contraction pole. Microscopic time-lapse of cell shape changes in ascidian oocytes after fertilization: From an unfertilized egg to contraction pole initiation to contraction pole formation to contraction pole absorption. Credit ©Caballero-Mancebo et al./Nature Physics Usage Restrictions Free to use when reporting about paper. License Original 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.