A highly specific microRNA-mediated mechanism silences LTR retrotransposons of strawberry
| Autor: | Mirko Moser, Nada Šurbanovski, Matteo Brilli, Azeddine Si-Ammour |
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| Rok vydání: | 2015 |
| Předmět: |
0301 basic medicine
Transposable element Small interfering RNA Small RNA Retroelements LTR retrotransposon Primer binding site Locus (genetics) Retrotransposon Plant Science Biology Fragaria 03 medical and health sciences Multienzyme Complexes Fragaria vesca Endoribonucleases microRNA Genetics Gene silencing RNA Small Interfering tRNA miRNA Polyribonucleotide Nucleotidyltransferase Settore BIO/11 - BIOLOGIA MOLECOLARE Terminal Repeat Sequences Degradome Cell Biology MicroRNAs 030104 developmental biology RNA Plant Transcriptome Genome Plant RNA Helicases |
| Zdroj: | The Plant Journal. 85:70-82 |
| ISSN: | 0960-7412 |
| Popis: | Small RNAs are involved in a plethora of functions in plant genomes. In general, transcriptional gene silencing is mediated by 24-nucleotide siRNAs and is required for maintaining transposable elements in a silenced state. However, microRNAs are not commonly associated with transposon silencing. In this study, we performed small RNA transcriptome and degradome analyses of the Rosaceae model plant Fragaria vesca (the woodland strawberry) at the genome-wide level, and identified miRNA families and their targets. We report a highly specific mechanism of LTR retrotransposon silencing mediated by an abundant, ubiquitously expressed miRNA (fve-miR1511) generated from a single locus. This miRNA specifically targets LTR retroelements, silencing them post-transcriptionally by perfectly pairing to the highly conserved primer binding site for methionyl initiator tRNA that is essential for reverse transcription. We investigated the possible origins of this miRNA, and present evidence that the pre-miR1511 hairpin structure probably derived from a locus coding for tRNA(iM) (et) through a single microinversion event. Our study shows that this miRNA targets retrotransposons specifically and constitutively, and contributes to features such as genome stability, size and architecture in a far more direct way than previously thought. |
| Databáze: | OpenAIRE |
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