Sperm Structure (IMAGE) Japan Science and Technology Agency Caption Upper: Diagrams of the zebrafish sperm and the cross-sectional view of sperm flagella. Lower: Detailed structure of zebrafish sperm flagella was revealed by cryo-electron tomography. Axonemal dyneins, which generate bending of flagella, are colored to show distinct dynein subtypes. Credit Kikkawa lab, The University of Tokyo Usage Restrictions The image is only used with "Provided by Kikkawa lab, The University of Tokyo." 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.