Nodal morphogens.
Nodal signals belong to the TGF-beta superfamily and are essential for the induction of mesoderm and endoderm and the determination of the left-right axis. Nodal signals can act as morphogens-they have concentration-dependent effects and can act at a distance from their source of production. Nodal and its feedback inhibitor Lefty form an activator/inhibitor pair that behaves similarly to postulated reaction-diffusion models of tissue patterning. Nodal morphogen activity is also regulated by microRNAs, convertases, TGF-beta signals, coreceptors, and trafficking factors. This article describes how Nodal morphogens pattern embryonic fields and discusses how Nodal morphogen signaling is modulated.
Schier
Alexander F
AF
Department of Molecular and Cellular Biology, Harvard Stem Cell Institute, Center for Brain Science, Broad Institute, Harvard University, Cambridge, Massachusetts 02138, USA. schier@mcb.harvard.edu <schier@mcb.harvard.edu>
D000818:Animals; D019521:Body Patterning; D004058:Diffusion; D004707:Endoderm / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D055458:Left-Right Determination Factors / Q000378:metabolism; D008648:Mesoderm / Q000378:metabolism; D035683:MicroRNAs / Q000378:metabolism; D008954:Models, Biological; D009024:Morphogenesis; D055457:Nodal Protein / Q000378:metabolism / Q000502:physiology*; D011499:Protein Processing, Post-Translational; D015398:Signal Transduction; D016212:Transforming Growth Factor beta / Q000378:metabolism
D055458:Left-Right Determination Factors; D035683:MicroRNAs; D055457:Nodal Protein; D016212:Transforming Growth Factor beta