Biology Reference
In-Depth Information
FIGURE 11.11
Control of the machinery of locomotion by the Ephrin-A
e
EphA signalling system.
characteristic of an active leading edge to that characteristic of the trailing edge of a cell, or
the main shaft of a growth cone (
Figure 11.11
).
Migratory cells have no choice but to interact with their substrate (because, except for
swimming cells like spermatozoa, they have no other way of moving). The molecules they
find there can affect their migration either by direct mechanical means or by signalling to
components of the locomotory machinery. The targets of these signals are the same as those
of chemotactic signalling, so that integration of the various guidance cues impinging on a cell
takes place at the level of the locomotive machinery itself. The integration is local; the deci-
sion whether to migrate at all may be taken at the level of gene expression by the whole cell
but the decision about where to go is taken very much by micro-domains in and near the
leading edge. The following chapter will describe how the ability of cells to perform nano-
meter scale integration of signals can be used to allow them to perform highly complex feats
of navigation and even to help each other as they do.
Reference List
1. Cantat I, Misbah C, Saito Y. Vesicle propulsion in haptotaxis: A local model.
Eur Phys J E
2004;
:403
e
12.
3
2. Letourneau PC. Cell-to-substratum adhesion and guidance of axonal elongation.
Dev Biol
1975;
:92
e
101.
44
