Spatiotemporal mechanisms of morphogen gradient interpretation.
Few mechanistic ideas from the pre-molecular era of biology have had as enduring an impact as the morphogen concept. In the classical view, cells in developing embryos obtain positional information by measuring morphogen concentrations and comparing them with fixed concentration thresholds; as a result, graded morphogen distributions map into discrete spatial arrangements of gene expression. Recent studies on Hedgehog and other morphogens suggest that establishing patterns of gene expression may be less a function of absolute morphogen concentrations, than of the dynamics of signal transduction, gene expression, and gradient formation. The data point away from any universal model of morphogen interpretation and suggest that organisms use multiple mechanisms for reading out developmental signals in order to accomplish specific patterning goals.
Department of Developmental and Cell Biology and Center for Complex Biological Systems, University of California, Irvine, CA 92697-2300, USA.
Marcos
M
Nahmad
Arthur D
AD
Lander
D000818:Animals; D019521:Body Patterning / Q000235:genetics / Q000502:physiology; D004625:Embryo, Nonmammalian / Q000196:embryology* / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D053823:Hedgehog Proteins / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D009024:Morphogenesis; D015398:Signal Transduction; D049490:Systems Biology / Q000379:methods
D053823:Hedgehog Proteins