Information processing at the foxa node of the sea urchin endomesoderm specification network.
The foxa regulatory gene is of central importance for endoderm specification across Bilateria, and this gene lies at an essential node of the well-characterized sea urchin endomesoderm gene regulatory network (GRN). Here we experimentally dissect the cis-regulatory system that controls the complex pattern of foxa expression in these embryos. Four separate cis-regulatory modules (CRMs) cooperate to control foxa expression in different spatial domains of the endomesoderm, and at different times. A detailed mutational analysis revealed the inputs to each of these cis-regulatory modules. The complex and dynamic expression of foxa is regulated by a combination of repressors, a permissive switch, and multiple activators. A mathematical kinetic model was applied to study the dynamic response of foxa cis-regulatory modules to transient inputs. This study shed light on the mesoderm-endoderm fate decision and provides a functional explanation, in terms of the genomic regulatory code, for the spatial and temporal expression of a key developmental control gene.
de-Leon
Smadar Ben-Tabou
SB
Division of Biology 156-29, California Institute of Technology, Pasadena, CA 91125, USA. smadar@caltech.edu
Davidson
Eric H
EH
D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D022202:Chromosomes, Artificial, Bacterial / Q000235:genetics; D004247:DNA / Q000235:genetics / Q000378:metabolism; D004707:Endoderm / Q000196:embryology / Q000378:metabolism; D051858:Forkhead Transcription Factors / Q000235:genetics* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D053263:Gene Regulatory Networks; D005816:Genetic Complementation Test; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D008648:Mesoderm / Q000196:embryology / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D009154:Mutation; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D047270:Strongylocentrotus purpuratus / Q000196:embryology* / Q000235:genetics* / Q000378:metabolism
D051858:Forkhead Transcription Factors; D012333:RNA, Messenger; D011994:Recombinant Proteins; D049452:Green Fluorescent Proteins; D004247:DNA