Project description:Dam identification (DamID) is a powerful technique to generate genome-wide maps of chromatin protein binding. Due to its high sensitivity it is particularly suited to study the genome interactions of chromatin proteins in small tissue samples in model organisms such as Drosophila. Here we report an intein-based approach to tune the expression level of Dam and Dam-fusion proteins in Drosophila by addition of a ligand to fly food. This helps to suppress toxic effects of Dam. In addition we describe a strategy for genetically controlled expression of Dam in a specific cell type in complex tissues. We demonstrate the utility of the latter by generating a glia-specific map of Polycomb in small samples of brain tissue. We determined DamID scores for Polycomb, normalized by Dam only control, for Drosophila larval central brain, larval fat bodies and repo+ glial cells of larval central brain. All samples were performed with 2 biological replicates. In case of Dam only control for larval central brain, each biological replicate was performed with 3 technical replicates.
Project description:We made Polycomb (PC) and histone H3 lysine 27 trimethylation (H3K27me3) chromatin binding maps in central brain tissue from 3rd instar larvae, allowing us to make a direct comparison to our 4C data (http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE23166). Our results demonstrate that our PC and H3K27me3 maps are highly similar, and fit with previously identified hallmarks of PcG-bound chromatin, namely: PC and H3K27me3 co-occur in the genome as large contiguous domains that largely repress transcription of the underlying genes, which encode important regulators of development. Keywords: Genome binding/occupancy profiling by genome tiling array DamID experiments for Polycomb were performed in Drosophila larval brain tissue. Samples were hybridized to 380k NimbleGen arrays with 300 bp probe spacing.
Project description:This SuperSeries is composed of the following subset Series: GSE23166: Interactions among Polycomb domains are guided by chromosome architecture GSE26693: Gene expression profiling in wild type and In(3LR)sep larval brain tissue (Drosophila) Refer to individual Series
