Project description:Determining the genomic localization of chromatin features is an essential aspect of investigating gene expression control, and ChIP-Seq has long been the gold standard technique for interrogating chromatin landscapes. Recently, the development of alternative methods, such as CUT&Tag, have provided researchers with alternative strategies that eliminate the need for chromatin purification, and allow for in situ investigation of histone modifications and chromatin bound factors. Mindful of technical differences, we set out to investigate whether distinct chromatin modifications were equally compatible with these different chromatin interrogation techniques. We found that ChIP-Seq and CUT&Tag performed similarly for modifications known to reside at gene regulatory regions, such as promoters and enhancers, but major differences were observed when we assessed enrichment over heterochromatin-associated loci. Unlike ChIP-Seq, CUT&Tag detects robust levels of H3K9me3 at a substantial number of repetitive elements, with especially high sensitivity over evolutionarily young retrotransposons. IAPEz-int elements for example, exhibited underrepresentation in mouse ChIP-Seq datasets but strong enrichment using CUT&Tag. Additionally, we identified several euchromatin-associated proteins that co-purify with repetitive loci and are similarly depleted when applying ChIP-based methods. This study reveals that our current knowledge of chromatin states across the heterochromatin portions of the mammalian genome is extensively incomplete, largely due to36 limitations of ChIP-Seq. We also demonstrate that newer in situ chromatin fragmentation-based techniques, such as CUT&Tag and CUT&RUN, are more suitable for studying chromatin modifications over repetitive elements and retrotransposons.
Project description:Genomic DNA of a Holstein male, that was used for multiple tissue ATAC-seq experiments, was sequenced. The sequences were used for ATAC-seq peak calling as a background.
Project description:Genomic information is encoded on a wide range of distance scales, ranging from tens of base pairs to megabases. We developed a multiscale framework to analyze and visualize the information content of genomic signals. Different types of signals, such as GC content or DNA methylation, are characterized by distinct patterns of signal enrichment or depletion across scales spanning several orders of magnitude. These patterns are associated with a variety of genomic annotations, including genes, nuclear lamina associated domains, and repeat elements. By integrating the information across all scales, as compared to using any single scale, we demonstrate improved prediction of gene expression from Polymerase II ChIP-seq measurements and we observed that gene expression differences in colorectal cancer are not most strongly related to gene body methylation, but rather to methylation patterns that extend beyond the single-gene scale. ChIP-seq data of six proteins in primary murine bone marrow macrophage cells (BMMs) under unstimulated and lipopolysaccharide (LPS) stimulated conditions. The BMMs were cultured from female C57BL/6 mice (age 8-12 weeks). Amongst these six proteins were three transcription factors (TFs), ATF340, NFκB/p50 and NFκB/p65, all of which are involved in regulating macrophage activation by microbial molecular components such as LPS. The other three ChIP-seq targets were RNA polymerase II (Pol II), and two chromatin modification marks: acetylation of histone H4 (H4ac) and tri-methylation of histone H3 lysine 27 (H3K27me3).
Project description:We report genome-wide distribution of germ cell-specific linker histone variant H1T in cancer cell line AGS, MDA-MB-231, and mouse embryonic stem cells (mESCs). We found that H1T expressed not only testis but also non-germ cells such as cancer cells and pluripotent stem cells and showed the biased distribution at rDNA repeat unit. Moreover, on the rDNA region, H1T regulated the chromatin structure and pre-rRNA expression. This study using ChIP-seq analysis provides genomic distribution of H1T in non-germinal cells. ChIP-seq analysis of linker histone H1T in AGS, MDA-MB-231 and mESCs