First published online January 16, 2004
Development 131, 301e (2004)
© The Company of Biologists Limited
Dissecting convergent extension
The extracellular polysaccharide Hyaluronan (HA) regulates cell
proliferation, adhesion and migration by organising the extracellular matrix
and participating with signal transduction pathways. Studies on HA tend to
concentrate on its role in cancer, but Bakkers et al.
(p. 525) now show that
HA is required for the migration of several mesodermal cell types during
vertebrate development. Convergent extension occurs during gastrulation:
lateral cells move towards the dorsal side (convergence) and the dorsal axis
extends (extension). Using zebrafish, the authors demonstrate that the HA
synthase Has2 is required for dorsal convergence but not extension of the
dorsal axis, confirming that, although they are closely linked, convergence
and extension are independent. In addition, the Has2 enzyme reaction product
– probably HA – activates the small GTPase Rac1. This results in
lamellipodia formation and the subsequent migration of
has2-expressing cells, indicating that HA has an autocrine and
instructive, rather than a structural, role during cell migration.
Related articles in Development:
- Has2 is required upstream of Rac1 to govern dorsal migration of lateral cells during zebrafish gastrulation
- Jeroen Bakkers, Carina Kramer, Joris Pothof, Nicolette E. M. Quaedvlieg, Herman P. Spaink, and Matthias Hammerschmidt
Development 2004 131: 525-537.
[Abstract]
[Full Text]
