Mapping Native R-Loops Genome-wide Using a Targeted Nuclease Approach

Publication date: 29 October 2019Source: Cell Reports, Volume 29, Issue 5Author(s): Qingqing Yan, Emily J. Shields, Roberto Bonasio, Kavitha SarmaSummaryR-loops are three-stranded DNA:RNA hybrids that are implicated in many nuclear processes. While R-loops may have physiological roles, the formation of stable, aberrant R-loops has been observed in neurological disorders and cancers. Current methods to assess their genome-wide distribution rely on affinity purification, which is plagued by large input requirements, high noise, and poor sensitivity for dynamic R-loops. Here, we present MapR, a method that utilizes RNase H to guide micrococcal nuclease to R-loops, which are subsequently cleaved, released, and identified by sequencing. MapR detects R-loops formed at promoters and active enhancers that are likely to form transient R-loops due to the low transcriptional output of these regulatory elements and the short-lived nature of enhancer RNAs. MapR is as specific as existing techniques and more sensitive, allowing for genome-wide coverage with low input material in a fraction of the time.Graphical Abstract

Source: Cell Reports - October 31, 2019 Category: Cytology Source Type: research