How RNA impacts DNA repair.

The central dogma of molecular biology posits that genetic information flows unidirectionally, from DNA, to RNA, and finally to protein. However, this directionality is broken in some cases, such as reverse transcription where RNA is converted to DNA by retroviruses and certain transposable elements. Our genomes have evolved and adapted to the presence of reverse transcription. Similarly, our genome is continuously maintained by several repair pathways to reverse damage due to various endogenous and exogenous sources. More recently, evidence has revealed that RNA, while in certain contexts may be detrimental for genome stability, is involved in promoting certain types of DNA repair. Depending on the pathway in question, the size of these DNA repair-associated RNAs range from one or a few ribonucleotides to long fragments of RNA. Moreover, RNA is highly modified, and RNA modifications have been revealed to be functionally associated with specific DNA repair pathways. In this review, we highlight aspects of this unexpected layer of genomic maintenance, demonstrating how RNA may influence DNA integrity.