转录聚合酶催化的新型RNA复制子的出现，这一成果由美国斯坦福大学医学院Andrew Z. Fire课题组经过不懈努力而取得。相关论文在线发表在2020年3月26日出版的《科学》杂志上。

在体外利用T7噬菌体转录聚合酶进行RNA复制作为实验模型，研究人员鉴定了数百种新复制的RNA，并确定了复制的三种机械标记（亚末端从头开始、RNA变形和间断滚环合成）并描述了以DNA为模板产生新RNA复制子的起源机制。这些结果为自然界中存在的RNA遗传元件的起源和复制提供了模型；并且为作为遗传物质的多种RNA在细胞环境中繁殖提供了一种手段。

据悉，转录聚合酶具有以某些RNA为模板产生RNA的异常模式，从而具有以RNA为信息载体的复制和进化系统。宿主的转录聚合酶可复制两类致病性RNA（动物体内的δ型肝炎病毒和植物类病毒）。

附：英文原文

Title: Transcription polymerase–catalyzed emergence of novel RNA replicons

Author: Nimit Jain, Lucas R. Blauch, Michal R. Szymanski, Rhiju Das, Sindy K. Y. Tang, Y. Whitney Yin, Andrew Z. Fire

Issue&Volume: 2020/03/26

Abstract: AbstractTranscription polymerases can exhibit an unusual mode of regenerating certain RNA templates from RNA, yielding systems that can replicate and evolve with RNA as information carrier. Two classes of pathogenic RNAs (Hepatitis delta virus in animals and viroids in plants) are copied by host transcription polymerases. Using in vitro RNA replication by the transcription polymerase of T7 bacteriophage as an experimental model, we identify hundreds of new replicating RNAs, define three mechanistic hallmarks of replication (subterminal de novo initiation, RNA shape-shifting and interrupted rolling circle synthesis) and describe emergence from DNA seeds as a mechanism for the origin of novel RNA replicons. These results inform models for the origins and replication of naturally occurring RNA genetic elements and suggest a means by which diverse RNA populations could be propagated as hereditary material in cellular contexts.

DOI: 10.1126/science.aay0688

Source: https://science.sciencemag.org/content/early/2020/03/25/science.aay0688