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.
Bibliographical noteFunding Information:
Russian Science Foundation [19-74-10008 to E.S.G.; 19-15-00054 to V.Y.]; ERC CZ [LL1601 to J.L.]; European Regional Developmental Funds [OPVVV16 019/0000759 to V.Y., N.K., J.L.]; University of Ostrava [SGS/2020 to V.Y.]; American Heart Association [16SDG26420019 to S.L.Z.].
© 2021 The Author(s) 2021. Published by Oxford University Press on behalf of Nucleic Acids Research.