R-loops at microRNA encoding loci promote co-transcriptional processing of pri-miRNAs in plants

• DOI: 10.1038/s41477-022-01125-x
• Publication Date: 2022-04-21T15:06:28Z
• Authors: Lucia Gonzalo; Ileana Tossolini; Tomasz Gulanicz; Damian A. Cambiagno; Anna Kasprowicz-M...; Dariusz Jan Smoli...; María Florencia M...; Federico D. Ariel; Sebastian Marquardt; Zofia Szweykowska...; Artur Jarmolowski; Pablo A. Manavella
• Keywords: Transcription; Drosha; RNA polymerase II

In most organisms, the maturation of nascent RNAs is coupled to transcription. Unlike in animals, RNA polymerase II (RNAPII) transcribes microRNA genes (MIRNAs) as long and structurally variable pri-miRNAs plants. Current evidence suggests that miRNA biogenesis complex assembly initiates early during transcription However, it unknown whether processing occurs co-transcriptionally. Here, we used native elongating transcript sequencing data imaging techniques demonstrate plant We found entire co-transcriptionally for processed from loop hairpin but requires a second nucleoplasmic step those base. Furthermore, co- post-transcriptional mechanisms co-exist miRNAs dynamic balance. Notably, discovered R-loops, formed near start site region MIRNAs, promote co-transcriptional pri-miRNA processing. our results suggest neofunctionalization miRNAs, boosting countless regulatory scenarios.