How to grow a spine

(Harvard Medical School) In a paper published Sept. 21 in Cell, Harvard Medical School genetics professor Olivier Pourquié -- whose lab discovered the segmentation clock 20 years ago -- and colleagues report that they used mouse cells to reconstitute a stable version of this clockwork for the first time in a petri dish, leading to several new discoveries about where the clock is located, what makes it tick and how the vertebral column takes shape.