![]() to guide the transposases to unspooled regions of DNA bordering active genes. CUT&Tag attaches a transposase to a molecule that recognizes and binds to those marks. When genes are switched on, the proteins reading them leave chemical marks on the histones they pass. Like ATAC-seq, it also uses transposases to cut the genome, but it allows more control over where the cuts occur. To find the link between unspooled DNA and active genes, Henikoff et al. Furthermore, although ATAC-seq can identify unspooled sections of DNA, it cannot provide a direct connection between active genes and unwrapped DNA. Unfortunately, the data from ATAC-seq are often noisy (there are random factors that produce a signal that is detected but is not a ‘real’ result), so more sequencing is required to differentiate between real signal and noise, increasing the expense of ATAC-seq experiments. The 'transposase' in the acronym is an enzyme that cuts areas of DNA that are not wound around histones and prepares them for detection by DNA sequencing. ![]() The most popular way to map which regulatory elements are exposed is using a technique called Assay for Transposase-Accessible Chromatin using sequencing, or ATAC-seq for short. Determining which regulatory elements are exposed at any given time can provide useful information about what is happening inside a cell, but the procedure can be expensive. These elements attract the proteins that help read and copy nearby genes so the cell can make new proteins. When genes turn on, the nucleosomes unwrap, exposing sections of genetic code called 'gene regulatory elements'. Not only do nucleosomes keep the genetic code organized, they also control whether the proteins that can switch genes on or off have access to the DNA. Each of these structures contains a short section of DNA wound around a cluster of proteins called histones. eLife digestĬells keep their DNA tidy by wrapping it into structures called nucleosomes. ![]() As H3K4 methylation is produced by transcription at promoters and enhancers, our method identifies transcription-coupled accessible regulatory sites. Thus, chromatin accessibility maps can be produced in parallel with CUT&Tag maps of other epitopes with all steps from nuclei to amplified sequencing-ready libraries performed in single PCR tubes in the laboratory or on a home workbench. Here, we show that by simply modifying the tagmentation conditions for histone H3K4me2 or H3K4me3 CUT&Tag, antibody-tethered tagmentation of accessible DNA sites is redirected to produce chromatin accessibility maps that are indistinguishable from the best ATAC-seq maps. CUT&Tag is a tagmentation-based epigenomic profiling method in which antibody tethering of Tn5 to a chromatin epitope of interest profiles specific chromatin features in small samples and single cells. A popular example is ATAC-seq, whereby Tn5 transposase inserts sequencing adapters into accessible DNA (‘tagmentation’). Chromatin accessibility mapping is a powerful approach to identify potential regulatory elements.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |