Gerasimov Evgeny S, Gasparyan Anna A, Afonin Dmitry A, Zimmer Sara L, Kraeva Natalya, Lukeš Julius, Yurchenko Vyacheslav, Kolesnikov Alexander
Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow 119991, Russia.
Martsinovsky Institute of Medical Parasitology, Tropical and Vector Borne Diseases, Sechenov University, Moscow 119435, Russia.
Nucleic Acids Res. 2021 Apr 6;49(6):3354-3370. doi: 10.1093/nar/gkab114.
Uridine insertion/deletion (U-indel) editing of mitochondrial mRNA, unique to the protistan class Kinetoplastea, generates canonical as well as potentially non-productive editing events. While the molecular machinery and the role of the guide (g) RNAs that provide required information for U-indel editing are well understood, little is known about the forces underlying its apparently error-prone nature. Analysis of a gRNA:mRNA pair allows the dissection of editing events in a given position of a given mitochondrial transcript. A complete gRNA dataset, paired with a fully characterized mRNA population that includes non-canonically edited transcripts, would allow such an analysis to be performed globally across the mitochondrial transcriptome. To achieve this, we have assembled 67 minicircles of the insect parasite Leptomonas pyrrhocoris, with each minicircle typically encoding one gRNA located in one of two similar-sized units of different origin. From this relatively narrow set of annotated gRNAs, we have dissected all identified mitochondrial editing events in L. pyrrhocoris, the strains of which dramatically differ in the abundance of individual minicircle classes. Our results support a model in which a multitude of editing events are driven by a limited set of gRNAs, with individual gRNAs possessing an inherent ability to guide canonical and non-canonical editing.
线粒体信使核糖核酸（mRNA）的尿苷插入/缺失（U-插入缺失）编辑是原生生物动质体纲所特有的，它会产生典型的以及可能无功能的编辑事件。虽然人们已经充分了解了为U-插入缺失编辑提供所需信息的引导（g）RNA的分子机制及其作用，但对于其明显容易出错的本质背后的驱动力却知之甚少。对gRNA:mRNA对进行分析，可以剖析给定线粒体转录本特定位置的编辑事件。一个完整的gRNA数据集，再加上一个完全表征的mRNA群体，其中包括非典型编辑的转录本，将能够在整个线粒体转录组中全局地进行这样的分析。为了实现这一点，我们组装了昆虫寄生虫梨形细滴虫的67个微小环，每个微小环通常编码一个位于两个不同来源、大小相似的单元之一中的gRNA。从这一相对有限的注释gRNA集合中，我们剖析了梨形细滴虫中所有已识别的线粒体编辑事件，该寄生虫的菌株在各个微小环类别的丰度上有很大差异。我们的结果支持一种模型，即大量的编辑事件是由一组有限的gRNA驱动的，单个gRNA具有引导典型和非典型编辑的内在能力。
