The segmentation clock is an oscillating genetic network
thought to govern the rhythmic and sequential subdivision of
the elongating body axis of the vertebrate embryo into
somites: the precursors of the segmented vertebral column.
Understanding how the rhythmic signal arises, how it achieves
precision and how it patterns the embryo remain challenging
issues. Recent work has provided evidence of how the period
of the segmentation clock is regulated and how this affects the
anatomy of the embryo. The ongoing development of real-
time clock reporters and mathematical models promise novel
insight into the dynamic behavior of the clock.
Key words: Gradient, Modeling, Negative feedback, Oscillator,
The segmented anatomy of the vertebrate embryo is evident in the
two bilaterally symmetrical rows of somites that flank the
notochord along the body axis. These blocks of mesodermal cells
give rise primarily to bone, muscle and skin of the adult body,