title: The Capacity to Act in Trans Varies Among Drosophila Enhancers.
abstract: The interphase nucleus is organized such that genomic segments interact in cis, on the same chromosome, and in trans, between different chromosomes. In Drosophila and other Dipterans, extensive interactions are observed between homologous chromosomes, which can permit enhancers and promoters to communicate in trans Enhancer action in trans has been observed for a handful of genes in Drosophila, but it is as yet unclear whether this is a general property of all enhancers or specific to a few. Here, we test a collection of well-characterized enhancers for the capacity to act in trans Specifically, we tested 18 enhancers that are active in either the eye or wing disc of third instar Drosophila larvae and, using two different assays, found evidence that each enhancer can act in trans However, the degree to which trans-action was supported varied greatly between enhancers. Quantitative analysis of enhancer activity supports a model wherein an enhancer's strength of transcriptional activation is a major determinant of its ability to act in trans, but that additional factors may also contribute to an enhancer's trans-activity. In sum, our data suggest that a capacity to activate a promoter on a paired chromosome is common among Drosophila enhancers.
authors.affiliation: Biology Department, Bowdoin College, Brunswick, Maine 04011.
authors.forename: Amanda J
authors.initials: AJ
authors.lastname: Blick
authors.affiliation: Biology Department, Bowdoin College, Brunswick, Maine 04011.
authors.forename: Ilana
authors.initials: I
authors.lastname: Mayer-Hirshfeld
authors.affiliation: Biology Department, Bowdoin College, Brunswick, Maine 04011.
authors.forename: Beatriz R
authors.initials: BR
authors.lastname: Malibiran
authors.affiliation: Biology Department, Bowdoin College, Brunswick, Maine 04011.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Cooper
authors.affiliation: Biology Department, Bowdoin College, Brunswick, Maine 04011.
authors.forename: Pieter A
authors.initials: PA
authors.lastname: Martino
authors.affiliation: Biology Department, Bowdoin College, Brunswick, Maine 04011.
authors.forename: Justine E
authors.initials: JE
authors.lastname: Johnson
authors.affiliation: Biology Department, Bowdoin College, Brunswick, Maine 04011 jbateman@bowdoin.edu.
authors.forename: Jack R
authors.initials: JR
authors.lastname: Bateman
mesh_terms: D000818:Animals; D004330:Drosophila / Q000235:genetics* / Q000378:metabolism; D004742:Enhancer Elements, Genetic; D015870:Gene Expression; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D009928:Organ Specificity / Q000235:genetics; D015534:Trans-Activators / Q000378:metabolism; D015533:Transcriptional Activation; D014921:Wings, Animal
chemical_list: D015534:Trans-Activators
keywords: RMCE; interchromosomal interactions; long-range enhancer; somatic homolog pairing; transvection