(IMAGE) Max-Planck-Gesellschaft Caption This is a still from a time-lapse movie showing a zebrafish embryo making its body segments sequentially and rhythmically. Waves of oscillating gene expression are visible in pseudo-color sweeping from the posterior to the anterior through the unsegmented tissue. The anterior end of this unsegmented tissue moves steadily into these on-coming waves, creating a Doppler effect that contributes to the rhythm of segmentation. Credit Max Planck Institute of Molecular Cell Biology and Genetics 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.