title: Stepwise Progression of Embryonic Patterning.
abstract: It is long established that the graded distribution of Dorsal transcription factor influences spatial domains of gene expression along the dorsoventral (DV) axis of Drosophila melanogaster embryos. However, the more recent realization that Dorsal levels also change with time raises the question of whether these dynamics are instructive. An overview of DV axis patterning is provided, focusing on new insights identified through quantitative analysis of temporal changes in Dorsal target gene expression from one nuclear cycle to the next ('steps'). Possible roles for the stepwise progression of this patterning program are discussed including (i) tight temporal regulation of signaling pathway activation, (ii) control of gene expression cohorts, and (iii) ensuring the irreversibility of the patterning and cell fate specification process.
authors.affiliation: Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
authors.forename: Jeremy E
authors.initials: JE
authors.lastname: Sandler
authors.affiliation: Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA. Electronic address: angelike@caltech.edu.
authors.forename: Angelike
authors.initials: A
authors.lastname: Stathopoulos
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000235:genetics*; D004331:Drosophila melanogaster / Q000235:genetics* / Q000254:growth & development; D047108:Embryonic Development / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics; D015398:Signal Transduction / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics
chemical_list: D009687:Nuclear Proteins; D014157:Transcription Factors
keywords: Dorsal transcription factor; Drosophila embryo; dorsal–ventral patterning; dynamics; morphogen gradients; spatiotemporal gene expression