R loops form when a transcript hybridizes to a complementary DNA locus to result in an RNA–DNA hybrid and a displaced single DNA strand. Such structures can have detrimental cellular roles by causing genome instability. However, recent studies have provided detailed views of genome-wide R-loop occurrences and uncovered various apparently beneficial roles in gene regulation. This Review discusses our latest understanding of the contrasting functions of R loops and the implications for genome regulation and various diseases.
- José M. Santos-Pereira
- Andrés Aguilera