Morphogen rules: design principles of gradient-mediated embryo patterning
journal contributionposted on 19.08.2021, 09:38 by James Briscoe, Stephen Small
The Drosophila blastoderm and the vertebrate neural tube are archetypal examples of morphogen-patterned tissues that create precise spatial patterns of different cell types. In both tissues, pattern formation is dependent on molecular gradients that emanate from opposite poles. Despite distinct evolutionary origins and differences in time scales, cell biology and molecular players, both tissues exhibit striking similarities in the regulatory systems that establish gene expression patterns that foreshadow the arrangement of cell types. First, signaling gradients establish initial conditions that polarize the tissue, but there is no strict correspondence between specific morphogen thresholds and boundary positions. Second, gradients initiate transcriptional networks that integrate broadly distributed activators and localized repressors to generate patterns of gene expression. Third, the correct positioning of boundaries depends on the temporal and spatial dynamics of the transcriptional networks. These similarities reveal design principles that are likely to be broadly applicable to morphogen-patterned tissues.
BicoidDrosophila blastodermGene regulatory networkMorphogen interpretationSonic hedgehogVertebrate neural tubeAnimalsBlastodermBody PatterningDrosophila melanogasterEmbryo, NonmammalianGene Expression Regulation, DevelopmentalGene Regulatory NetworksModels, TheoreticalNeural TubeSignal TransductionTime FactorsTranscription FactorsTranscription, GeneticBriscoe U11756054106 Biological Sciences11 Medical and Health Sciences