Video from Aulehla A., W. Wiegraebe, V. Baubet, M. B. Wahl, C. Deng, M. Taketo, M. Lewandoski, O. Pourquié. 2008. A beta-catenin gradient links the clock and wavefront systems in mouse embryo segmentation. Nat Cell Biol.10(2):186-93. Epub 2007 Dec 23. PubMed PMID: 18157121.