First published online October 26, 2007
Development 134, 2201e (2007)
© The Company of Biologists Limited
Mesoderm migration lights up
A pivotal event during gastrulation is mesoderm migration. In
Drosophila embryos, presumptive mesoderm cells invaginate, undergo an
epithelial-to-mesenchymal transition (EMT), and then spread over the ectoderm
to form a monolayer. On p.
3975, Murray and Saint investigate what types of cell rearrangements
occur during this example of mesoderm spreading. They express photoactivatable
GFP fused to 
-Tubulin in all the cells of fly embryos, photoactivate
sections of mesoderm or small numbers of mesodermal cells as gastrulation
begins, and then follow the migration of these fluorescent cells over
non-fluorescent ectodermal cells. The researchers find that those cells in
contact with the ectoderm immediately after the EMT migrate dorsolaterally as
a group, but are sometimes overtaken by cells not in contact with the
ectoderm. Murray and Saint conclude that mesodermal cells use a combination of
strategies to form a monolayer: directional dorsolateral migration (presumably
towards chemoattractants expressed in the dorsal ectoderm), strong adhesion
between mesodermal and ectodermal cells, and some intercalation during the
final stages.
Related articles in Development:
- Photoactivatable GFP resolves Drosophila mesoderm migration behaviour
- Michael J. Murray and Robert Saint
Development 2007 134: 3975-3983.
[Abstract]
[Full Text]
