Researchers unveil stem cell models of human spine development
More than 20 years ago, the lab of developmental biologist Olivier Pourquié discovered a sort of cellular clock in chicken embryos where each “tick” stimulates the formation of a structure called a somite that ultimately becomes a vertebra. In the ensuing years, Pourquié and others further illuminated the mechanics of this so-called segmentation clock across many organisms, including creation of the first models of the clock in a lab dish using mouse cells. While the work has improved knowledge of normal and abnormal spine development, no one has been able to confirm whether the clock exists in humans — until now. Pourquié led one of two separate teams reporting today in Nature that after decades of effort, they have created the first lab-dish models of the segmentation clock that use stem cells derived from adult human tissue. The achievements not only provide the first evidence that the segmentation clock ticks in humans, but also give the scientific community...