title: Enhancer-PRE communication contributes to the expansion of gene expression domains in proliferating primordia.
abstract: Trithorax-group and Polycomb-group proteins interact with chromosomal elements, termed PRE/TREs, to ensure stable heritable maintenance of the transcriptional state of nearby genes. Regulatory elements that bind both groups of proteins are termed maintenance elements (MEs). Some of these MEs maintain the initial activated transcriptional state of a nearby reporter gene through several rounds of mitosis during development. Here, we show that expression of hedgehog in the posterior compartment of the Drosophila wing results from the communication between a previously defined ME and a nearby cis-regulatory element termed the C enhancer. The C enhancer integrates the activities of the Notch and Hedgehog signalling pathways and, from the early wing primordium stage, drives expression to a thin stripe in the posterior compartment that corresponds to the dorsal-ventral compartment boundary. The ME maintains the initial activated transcriptional state conferred by the C enhancer and contributes to the expansion, by growth, of its expression domain throughout the posterior compartment. Communication between the ME and the C enhancer also contributes to repression of gene expression in anterior cells. Most interestingly, we present evidence that enhancers and MEs of different genes are interchangeable modules whose communication is involved in restricting and expanding the domains of gene expression. Our results emphasize the modular role of MEs in regulation of gene expression within growing tissues.
authors.affiliation: Institute for Research in Biomedicine (IRB Barcelon), Baldiri Reixac, 10-12, 08028 Barcelona, Spain.
authors.forename: Lidia
authors.initials: L
authors.lastname: Pérez
authors.forename: Lara
authors.initials: L
authors.lastname: Barrio
authors.forename: David
authors.initials: D
authors.lastname: Cano
authors.forename: Ulla-Maj
authors.initials: UM
authors.lastname: Fiuza
authors.forename: Mariana
authors.initials: M
authors.lastname: Muzzopappa
authors.forename: Marco
authors.initials: M
authors.lastname: Milán
mesh_terms: D000818:Animals; D001483:Base Sequence; D049109:Cell Proliferation; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism; D004330:Drosophila / Q000033:anatomy & histology* / Q000196:embryology* / Q000502:physiology; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D004742:Enhancer Elements, Genetic; D044127:Epigenesis, Genetic; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter; D053823:Hedgehog Proteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009024:Morphogenesis / Q000502:physiology; D017956:Photoreceptor Cells, Invertebrate / Q000166:cytology / Q000502:physiology; D063146:Polycomb-Group Proteins; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D020218:Response Elements; D016415:Sequence Alignment; D015398:Signal Transduction / Q000502:physiology; D014921:Wings, Animal / Q000033:anatomy & histology / Q000196:embryology / Q000502:physiology
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D029721:Drosophila Proteins; D053823:Hedgehog Proteins; D063146:Polycomb-Group Proteins; D012097:Repressor Proteins; C512571:trx protein, Drosophila