The repair of DNA double-strand breaks occurs through a series of defined steps that are evolutionarily conserved and well-understood in most experimental organisms. However, it is becoming increasingly clear that repair does not occur in isolation from other DNA transactions. Transcription of DNA produces topological changes, RNA species, and RNA-dependent protein complexes that can dramatically influence the efficiency and outcomes of DNA double-strand break repair. The transcription-associated history of several double-strand break repair factors is reviewed here, with an emphasis on their roles in regulating R-loops and the emerging role of R-loops in coordination of repair events. Evidence for nucleolytic processing of R-loops is also discussed, as well as the molecular tools commonly used to measure RNA-DNA hybrids in cells.

DNA双链断裂的修复是通过一系列确定的步骤进行的，这些步骤在大多数实验生物中都是进化上保守的，并且得到了很好的理解。但是，越来越清楚的是，修复并非与其他DNA事务孤立地进行。DNA的转录会产生拓扑变化，RNA种类和RNA依赖的蛋白质复合物，这些复合物会极大地影响DNA双链断裂修复的效率和结果。本文回顾了几种双链断裂修复因子的转录相关历史，重点是它们在调节R环中的作用以及R环在修复事件协调中的新兴作用。还讨论了R环进行核酸水解加工的证据，以及通常用于测量细胞中RNA-DNA杂种的分子工具。