Midblastula Transition (IMAGE) Stowers Institute for Medical Research Caption The dorsal-ventral patterning gene snail (shown in red) is one of the few genes that are active before as well as after the midblastula transition. The segmentation gene paired (shown in green) is turned on during the transition. Cell nuclei are shown in blue. Credit Image: Courtesy of Kai Chen 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.