Peptide signalling during angiosperm seed development: Fig. 1.

Fig. 1

Retinoic acid signalling during development.

Retinoic acid (RA) is a vitamin A-derived, non-peptidic, small lipophilic molecule that acts as ligand for nuclear RA receptors (RARs), converting them from transcriptional repressors to activators. The distribution and levels of RA in embryonic tissues are tightly controlled by regulated synthesis through the action of specific retinol and retinaldehyde dehydrogenases and by degradation via sp...

Signalling interactions during facial development

The development of the vertebrate face is a dynamic multi-step process which starts with the formation of neural crest cells in the developing brain and their subsequent migration to form, together with mesodermal cells, the facial primordia. Signalling interactions co-ordinate the outgrowth of the facial primordia from buds of undifferentiated mesenchyme into the intricate series of bones and ...

Wnt signalling during limb development.

Wnts control a number of processes during limb development--from initiating outgrowth and controlling patterning, to regulating cell differentiation in a number of tissues. Interactions of Wnt signalling pathway components with those of other signalling pathways have revealed new mechanisms of modulating Wnt signalling, which may explain how different responses to Wnt signalling are elicited in...

Eph/ephrin signalling during development.

Eph receptors and their membrane-tethered ligands have important functions in development. Trans interactions of Eph receptors with ephrins at cell-cell interfaces promote a variety of cellular responses, including repulsion, attraction and migration. Eph-ephrin signalling can be bi-directional and controls actin cytoskeleton dynamics, thereby leading to changes in cellular shape. This article ...