APS March Meeting 2011
Volume 56, Number 1
Monday–Friday, March 21–25, 2011;
Dallas, Texas
Abstract: P7.00001 : Contractile forces driving embryonic development
8:00 AM–8:36 AM
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Author:
Proper development of an organism requires an orchestrated
interplay of large sets of components. Recent developments in
live fluorescent imaging methods allow the visualization of many
key proteins in cells and tissues. Developing quantitative image
analysis methods to measure the dynamics of shape changes in
individual cells is central for understanding how a tissue gets
sculpted, what molecular machineries are driving this process,
and what interactions between cells are regulating it. In this
talk, I will present recent advances in our understanding of the
dynamical processes during morphogenesis, focusing on the example
of tissue folding and invagination at the beginning of
gastrulation in Drosophila. I show that this process is driven by
a contractile multicellular actomyosin meshwork that dynamically
forms within a few minutes at the cell surfaces. In individual
cells, contraction is pulsed, with phases of contraction
interrupted by pauses in which the cell size is maintained, i.e.
a ratchet type dynamics that reduces the surface area of cells
incrementally. Measuring the dynamics of whole cell shape changes
in 2-photon live imaging data reveals that contraction pulses
drive cell lengthening and relocation of cell nuclei, two
transformations that are essential for successful invagination of
tissue. This analysis further shows that over subsequent stages
of invagination, during which cells undergo an elaborate sequence
of shape changes, the volume of individual cells is a preserved
quantity. These results shed new light on the forces and cellular
dynamics driving tissue morphogenesis and are a step towards a
quantitative understanding of how an organism's shape and
internal structure arises in development.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2011.MAR.P7.1