You are currently viewing the summary.
View Full TextLog in to view the full text
AAAS login provides access to Science for AAAS members, and access to other journals in the Science family to users who have purchased individual subscriptions.
More options
Download and print this article for your personal scholarly, research, and educational use.
Buy a single issue of Science for just $15 USD.
Summary
Biological clocks all typically keep to a 24-hour schedule, which is logical because it helps keep organisms in tune with the normal day length. But now scientists have come across a new kind of biological clock, one that not only has a much shorter cycle, but also appears to be driven by a different kind of mechanism. In the 28 November issue of Cell, researchers report evidence that such a clock paces the development of the somites, blocks of tissue that form in regular arrays along the spinal cord of vertebrate embryos and give rise to vertebrae and muscles. They found that in the developing chick embryo, a gene called chairy undergoes repeated 90-minute cycles of activity, which seem to specify the orderly delineation of somites in the growing embryo.
