Genome-wide binding patterns of group B Sox proteins in four Drosophila species
ABSTRACT: We used DamID-seq to analyze the genome-wide binding patterns of the group B Sox proteins Dichaete and SoxNeuro in four species of Drosophila: D. melanogaster, D. simulans, D. yakuba and D. pseudoobscura. Both binding site turnover between species and a comparison of the binding properties of the two partially-redundant transcription factors were analyzed. We found that, despite widespread turnover, genomic intervals that are commonly bound by both Dichaete and SoxNeuro are highly conserved in Drosophila. DamID for Dichaete (Dichaete-Dam) was performed in D. melanogaster, D. simulans, D. yakuba and D. pseudoobscura, while DamID for SoxNeuro (SoxN-Dam) was performed in D. melanogaster and D. simulans. The control experiment, Dam-only, was performed in all species. Three biological replicates were sequenced for each condition in each species.
Project description:We have adapted the DamID protocol for use with high throughput sequencing. We have used DamID to identify the positions within the Drosophila genome where the transcription factor DSX is bound. We sequenced DpnI-digested genomic DNA from fly tissues containing UAS-Dam (control) or UAS-Dam-DsxF or UAS-Dam-DsxM. We have performed DamID-seq on adult male and female fatbody and on ovary. We used two biological replicates for each tissue and sex.
Project description:Dichaete is a developmentally important transcription factor, known to be involved in basic biological processes including segmentation and nervous system development among others. The aim of this experiment was to gain further insight into the role of Dichaete during early embryogenesis, by finding out where in the genome it's binding using the DamID technique. 3 independent biological replicates. Embryos between 2-7 h old were collected. The sample embryos contained a Dichaete-Dam methylase fusion, while the control embryos had a Dam methylase only to simulate the background level of methylation not specific to transcription factor binding.
Project description:Comparison of DamID profiles and LAD patterning across cell types reveals regions of variable LADs LmnB1 interactions at the nuclear periphery of C57Bl/6 pro-B cells and fibroblasts were identified by DamID in duplicate for both pro-B and fibroblasts (4 samples total). For each sample, Dam-LmnB1/Dam-only Log2 ratios of chromosomes 11 and 12 were calculated, lifted over to mm9, duplicates were normalized and averaged together.
Project description:To gain genome wide information on the association of EZH2 with promoter regions in HeLa cells, DamID experiments and subsequent analysis by promoter arrays (Affymetrix GeneChip Human Promoter 1.0R ) were performed. The DamID method uses fusions of the bacterial Dam DNA methylase and the protein of interest, to direct the enzymatic activity to the protein’s genomic binding sites, where the DNA is methylated. Methylated DNA is then extracted, enriched and further analysed by microarray. EZH2 is the enzymatic subunit of the Polycomb Repressive Complex 2, which deposits the H3K27me3 mark on chromatin. This mark is associated with low gene expression, either in polycomb repressed regions or, in combination with methylation of H3K4, at poised promoters. An EZH2-T416A mutant (EZH2-mTP5) fails to bind to NIPP1, a factor implied in the regulation of PRC2 binding to a subset of target regions. To obtain a genome wide picture of differential binding of EZH2-WT and the EZH2-mTP5 mutant to promoter regions, the mutant was subjected to DamID/microanalysis as well. DamID of EZH2-WT (2 replicates) and EZH2-mTP5(T416A)(2 replicates) vs. control (Dam without fused protein)(4 samples)
Project description:Stem cells reside in a specialized microenvironment, called niche, which provides essential signals controlling stem cell behavior. Proper niche architecture is a key for normal stem cell function, yet only few upstream regulators are known. Here we report that the Hox transcription factor Abd-B, active in pre-meiotic spermatocytes, affects niche positioning in the Drosophila testis by regulating integrin localization in differentiated somatic cyst cells. Loss of Abd-B results in cell non-autonomous effects within the niche including centrosome misorientation in germline stem cells (GSCs) and reduced GSC divisions in larval testis, leading to a dramatic reduction of pre-meiotic stages in adult testes. By identifying Abd-B binding regions throughout the genome, we find that Abd-B mediates its effects on niche function by directly controlling at multiple levels the localization and thus signaling activity of the Sevenless (Sev) ligand, Bride of Sevenless (Boss), via its direct targets src42A and sec63. In sum, our data show for the first time that Abd-B through local signaling provides positional cues for integrin localization, which is critical for niche localization and architecture, and ensures proper niche function and GSC activity. DamID (DNA adenine methyltransferase identification) method was used to identify direct Abd-B target genes in the Drosophila 3rd instar larval testis Dam was fused to the N terminus of Abd-B and transgenic flies were generated. For identifying Abd-B targets in the Drosophila testis the fusion protein was expressed from the uninduced minimal Hsp70 promoter of the UAS vector pUAST (Brand and Perrimon, 1993). As a control for nonspecific Dam activity, transgenic flies expressing the Dam alone were used (Choksi et al., 2006). Subsequently, genomic DNA was extracted from 3rd instar larval testes, expressing either the Dam-Abd-B fusion protein or the Dam protein alone using a specific protocol (Tolhuis et al., 2011); and van Steensel personal communication). Two individual replicates, for Dam-AbdB and Dam alone, have been generated. Following a methylation-sensitive DNA digestion and PCR amplification, DNA fragments from Dam-Abd-B and control DNA were labeled and hybridized to genomic Affymetrix arrays in duplicates (Protocol available at “www.flychip.org.uk”).
Project description:This data consists of RNA-seq data of whole animal white pre pupa of four Drosophila species: Drosophila melanogaster, Drosophila simulans, Drosophila yakuba, and Drosophila pseudoobscura. The processed RPKM values are calculated following the method in Garber et al 2011 Nature Methods paper. Examination of H3K27me3 in 4 Drosophila species and its correlation with gene expression levels in the same development stage relevant ChIP-seq data can be found in GSE25663, GSE25668
Project description:Protein phosphatase 1 (PP1) is a Ser/Thr phosphatase that has been implicated in many key cellular functions including transcriptional regulation. Due to its involvement these many processes, it becomes difficult to directly link PP1 to transcriptional regulation on the chromatin level as no direct genomic binding sites have been identified. Previous work has failed to address this as the most common method used, namely chromatin immunoprecipitation (ChIP), is an antibody-dependent technique and currently no ChIP-grade PP1 antibodies have been developed. Using DamID, an alternative to ChIP, we have identified PP1 isoform-specific binding sites on the promoter regions of genes. We also identified the binding sites of three main PP1 regulatory subunits (R-subunits) in order to identify potential PP1 holo-enzymes binding sites. Our study revealed the full extent of PP1 isoform specific binding an allowed us to investigate the dependency of the R-subunits on PP1 for chromatin targeting. This data establishes PP1 as a chromatin interactor and allow for the identification of direct effects PP1 can have on the regulation of the genes on whose promoter it is bound. HeLa stable cell lines were created using constructs derived from pIND-(V5)-EcoDam. These constructs express trace amounts of Dam or C-terminal fusions with PP1α, PP1β, PP1γ and three R-subunits, PNUTS, NIPP1 and RepoMan, both wildtype (WT) and their PP1-binding mutants (RATA). Two independent stable cell lines were set up for each of the constructs. DamID-DNA was labeled and hybridized to a GeneChip Human Promoter 1.0R Array (Affymetrix, Santa Clara, CA, USA). The tiling array readouts were analyzed with the “model-based analysis of tiling arrays” (MAT) algorithm (version 1.0.0) against the hg19 reference genome. We normalized two biological replicates of each Dam-fusion over two Dam-only biological replicates. Each biological repeat consisted of 2 technical repeats pooled together prior to hybridization to the tiling array.
Project description:We asked if the perinuclear position of chromosome arms in C. elegans depends on the histone methyltransferases MET-2 and SET-25. To this end, we performed LMN-1-DamID in wild-type (N2) and mutant (set-25 met-2) strains. LMN-1-DamID signal on chromosome arms was significantly reduced in the mutant. Three biological replicas were performed for each genotype. For one replica dyes were swapped. For each replica methylated DNA amplified from a strain expressing LMN-1-Dam was competitively hybridized against DNA amplified from a strain expressing GFP-Dam.
Project description:Laminopathies are caused by mutations in components of the nuclear envelope (NE). While most NE components are widely expressed, laminopathies affect only a subset of tissues. However, the understanding of the molecular mechanisms that explain this phenomenon is still elusive. Here we have performed a genome wide DamID analysis in adult C. elegans nematodes comparing the DNA association profile of two components of the NE, Lamin/LMN-1 and Emerin/EMR-1. Although both proteins were associated to silent DNA, EMR-1 showed a predominant role in the anchoring of muscle and neuronal promoters to the nuclear periphery. Deletion of either EMR-1 or LEM-2, another integral NE protein, caused local changes in nuclear architecture with both increased and decreased LMN-1 association. Comparison of Dam::LMN-1 and Dam::EMR-1 DNA assotiation in wild type strains and Dam::LMN-1 DNA association in wild type, lem-2(tm1582) and emr-1(gk119) mutant backgrounds.
Project description:This is a dataset which comprises the following two different kinds of genomic data in Drosophila species: First, triplicate ChIP-seq data of CTCF (CCCTC binding factor) binding profiles in each of the four closely related Drosophila species : Drosophila melanogaster, Drosophila simulans, Drosophila yakuba and Drosophila pseudoobscura at white pre pupa stage; Second, triplicate RNA-seq data of white pre pupa whole animals of three Drosophila species: Drosophila melanogaster, Drosophila simulans and Drosophila yakub. The binding site/region/peaks are called using a modified method of QuEST( please see details in our related publication). The sequence read counts and RPKM values are calculated following the method in Mortazavi et al 2008 Nature Methods paper. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf Overall design: Examination of CTCF binding in 4 Drosophila species and their correlation with gene expression levels in the same development stages