Editing Primary transcript (section)

===R-loops===

[[R-loop]]s are formed during transcription. An R-loop is a three-stranded nucleic acid structure containing a DNA-RNA hybrid region and an associated non-template single-stranded DNA.  Actively transcribed regions of [[DNA]] often form R-loops that are vulnerable to [[DNA damage (naturally occurring)|DNA damage]].  Introns reduce R-loop formation and DNA damage in highly expressed yeast genes.<ref name="pmid28757210">{{cite journal | vauthors = Bonnet A, Grosso AR, Elkaoutari A, Coleno E, Presle A, Sridhara SC, Janbon G, Géli V, de Almeida SF, Palancade B | title = Introns Protect Eukaryotic Genomes from Transcription-Associated Genetic Instability | journal = Molecular Cell | volume = 67 | issue = 4 | pages = 608–621.e6 | date = August 2017 | pmid = 28757210 | doi = 10.1016/j.molcel.2017.07.002 | doi-access = free }}</ref>