Project description:Here we report the identification of genomic regions of DNA bound by Dp1 in Drosophila S2R+ cells. Dp1 is a dimerization partner of several E2F transcription factors and is needed for E2F target promoter binding. We find that Dp1 binds the promoter regions of genes important for oxidative phosphorylation. This result is important since our data demonstrates that expression of several oxidative phosphorylation genes is down-regulated in dDP mutant Drosophila 3rd instar larval eye imaginal discs. These ChIP-seq results suggest that the mechanism by which dDP regulates expression of these genes is direct. In addition, we have confirmed a number of these Dp1 bound gene promoters by conventional Chromatin Immunoprecipitation. Examination of Dp1 bound regions of genomic DNA in S2R+ cells.
Project description:This chapter presents methods to conduct and analyze genome-wide chromatin immunoprecipitation of the cohesin complex and the Nipped-B cohesin loading factor in Drosophila cells using high-throughput DNA sequencing (ChIP-seq). Procedures for isolation of chromatin, immunoprecipitation, and construction of sequencing libraries for the Ion Torrent Proton high throughput sequencer are detailed, and computational methods to calculate occupancy as input-normalized fold-enrichment are described. The results obtained by ChIP-seq are compared to those obtained by ChIP-chip (genomic ChIP using tiling microarrays), and the effects of sequencing depth on the accuracy are analyzed. ChIP-seq provides similar sensitivity and reproducibility as ChIP-chip, and identifies the same broad regions of occupancy. The locations of enrichment peaks, however, can differ between ChIP-chip and ChIP-seq, and low sequencing depth can splinter broad regions of occupancy into distinct peaks.
Project description:Drosophila X chromosomes are subject to dosage compensation in males and are known to have a specialized chromatin structure in the male soma. We are interested in how specific chromatin structure change contributes to X chromosome hyperactivity and dosage compensation. We have conducted a global analysis of localize two dosage compensation complex dependent histone marks H4AcK16 and H3PS10 and one dosage compensation complex independent histone mark H3diMeK4 in the genome, especially on X chromosome by ChIP-chip approach in both male and female adult flies. We also probed general genomewide chromatin structure by deep DNA sequencing of sheared ChIP input DNA from male and female adult flies. Chromatin immunoprecipitations were performed in 5-7 day aged adult male and female flies with three histone modification antibodies. ChIP enriched DNA and input DNA was labeled by Cy3 or Cy5 dye separately and hybridized simultaneously to the Drosophila FlyGEM arrays. At least two biological replicates were performed for each antibody and sex. DNA-seq (NIDDK-Drosophila-Illumina-DNASeq) were performed on ChIP-input sheared DNA to check the general chromatin structure of different chromosome.
Project description:Trithorax group (TrxG) proteins counteract Polycomb silencing by an as yet uncharacterized mechanism. A well-known member of the TrxG is the histone methyltransferase Absent, Small, or Homeotic discs 1 (ASH1). In Drosophila ASH1 is needed for the maintenance of Hox gene expression throughout development, which is tightly coupled to preservation of cell identity. In order to understand the molecular function of ASH1 in this process, we performed affinity purification of tandem-tagged ASH1 followed by mass spectrometry (AP-MS) and identified FSH, another member of the TrxG as interaction partner. Here we provide genome-wide chromatin maps of both proteins based on ChIP-seq. Our Dataset comprises of 4 ChIP-seq samples using chromatin from S2 cells which was immunoprecipitated, using antibodies against Ash1, FSH-L and FSH-SL.
Project description:Here we improved BiTS-ChIP (Bonn et al, Nature Protocols 7, 978-994 (2012)) to identify active enhancer and promoter elements genome wide in the 104 cardiomyocytes that constitute the Drosophila heart tube and represents only ~0.5% of the total cell content of the embryo. A transgenic Drosophila strain expressing nuclear GFP under the control of a cardiac specific enhancer (TinC*>GFP) was used for staged embryo collections at stages 13-14 (10-13h of development). After embryo fixation and dissociation, intact fixed nuclei were fluorescent labelling. Purification of this rare nuclear population was achieved by a two-step sorting procedure, yielding ~98% purity. Chromatin was extracted and used for immunoprecipitation and sequencing (ChIP-seq) to analyze chromatin modifications at promoters (H3K4me3 and H3K27ac) and enhancers (H3K27ac). Two independent biological replicates (from FACS sorting, chromatin preparations and ChIP-Seq) were performed for each mark and sequenced using Illumina HiSeq.
Project description:ChIP-seq study analysing adult Drosophila melanogaster head, glial, neuronal and fat body, as well as embryonic RNA pol II and H2A.v binding by employing the GAL4-UAS system to generate GFP-fusion proteins and ChIP-seq