title: Chromatin insulators specifically associate with different levels of higher-order chromatin organization in Drosophila.
abstract: Chromatin insulators are required for proper temporal and spatial expression of genes in metazoans. Here, we have analyzed the distribution of insulator proteins on the 56F-58A region of chromosome 2R in Drosophila polytene chromosomes to assess the role of chromatin insulators in shaping genome architecture. Data show that the suppressor of Hairy-wing protein [Su(Hw)] is found in three structures differentially associated with insulator proteins: bands, interbands, and multi-gene domains of coexpressed genes. Results show that bands are generally formed by condensation of chromatin that belongs to genes containing one or more Su(Hw) binding sites, whereas, in interbands, Su(Hw) sites appear associated with open chromatin. In addition, clusters of coexpressed genes in this region form bands characterized by the lack of CP190 and BEAF-32 insulator proteins. This pattern correlates with the distribution of specific chromatin marks and is conserved in nurse cells, suggesting that this organization may not be limited to one cell type but represents the basic organization of interphasic chromosomes.
authors.affiliation: Department of Biochemistry, Cellular and Molecular Biology, The University of Tennessee, M407 Walters Life Sciences, 1414 Cumberland Avenue, Knoxville, TN 37996, USA.
authors.forename: Heather A
authors.initials: HA
authors.lastname: Wallace
authors.forename: Maria P
authors.initials: MP
authors.lastname: Plata
authors.forename: Hyuck-Joon
authors.initials: HJ
authors.lastname: Kang
authors.forename: Misty
authors.initials: M
authors.lastname: Ross
authors.forename: Mariano
authors.initials: M
authors.lastname: Labrador
mesh_terms: D000818:Animals; D000076246:CCCTC-Binding Factor; D002843:Chromatin / Q000737:chemistry / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics* / Q000378:metabolism; D005136:Eye Proteins / Q000378:metabolism; D005786:Gene Expression Regulation; D049750:Genome, Insect; D038101:Insulator Elements; D007399:Interphase / Q000235:genetics; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D008957:Models, Genetic; D009687:Nuclear Proteins / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism*
chemical_list: C452919:BEAF-32 protein, Drosophila; D000076246:CCCTC-Binding Factor; C107964:CP190 protein, Drosophila; C524946:CTCF protein, Drosophila; D002843:Chromatin; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D005136:Eye Proteins; D008869:Microtubule-Associated Proteins; D009687:Nuclear Proteins; D012097:Repressor Proteins; C083738:su(Hw) protein, Drosophila