Prof Andy Oates
MRC Mill Hill
Patterning the embryonic body plan with
oscillations
13th March, 1pm
June Lloyd Seminar Room (PUW4), ICH
ABSTRACT
In sequentially segmenting animals such as vertebrates, the rhythm of segmentation was
reported to be governed by the time-scale of genetic oscillations that periodically trigger new
segment formation. In this segmentation clock scenario, a genetic oscillator sets the time of
morphological segment formation directly. However, we present real-time measurements of
these genetic oscillations in developing zebrafish embryos showing that their time-scale is not
sufficient to explain the temporal period of segmentation. A second time-scale, the rate of tissue
shortening, contributes to the period of segmentation through a Doppler effect. This contribution
is modulated by a gradual change in the oscillation profile across the tissue. These two effects
are wave phenomena involving the entire population of cells and the deformation of the tissue.
We conclude that the rhythm of segmentation is an emergent property controlled by the timescale of genetic oscillations, the change of oscillation profile, and tissue shortening.