Wednesday 7 March 2007
The establishment of left-right asymmetry in mammals is a good example of how multiple cell biological processes coordinate in the formation of a basic body plan.
The leftward movement of fluid at the ventral node, called nodal flow, is the central process in symmetry breaking on the left-right axis.
How nodal flow is interpreted to create left-right asymmetry has been a matter of debate.
The leftward movement of membrane-sheathed particles, called nodal vesicular parcels (NVPs), may result in the activation of the non-canonical Hedgehog signaling pathway, an asymmetric elevation in intracellular Ca(2+) and changes in gene expression.