Small-RNA-Mediated Genome-wide trans-Recognition Network in Tetrahymena DNA Elimination
| Autor: | Katrina J. Woolcock, Martin A. Gorovsky, Jan H. Suhren, Kensuke Kataoka, Kazufumi Mochizuki, Tomoko Noto, Azusa Hayashi |
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| Rok vydání: | 2014 |
| Předmět: |
Transposable element
Small RNA Heterochromatin Protozoan Proteins Genome Article Tetrahymena thermophila 03 medical and health sciences chemistry.chemical_compound Gene Knockout Techniques 0302 clinical medicine Gene silencing Gene Silencing RNA Small Interfering Molecular Biology 030304 developmental biology Genetics 0303 health sciences biology Tetrahymena Cell Biology Argonaute DNA Protozoan biology.organism_classification 3. Good health chemistry Conjugation Genetic Argonaute Proteins DNA Transposable Elements Genome Protozoan 030217 neurology & neurosurgery DNA RNA Protozoan |
| Zdroj: | Molecular Cell |
| ISSN: | 1097-4164 |
| Popis: | Summary Small RNAs are used to silence transposable elements (TEs) in many eukaryotes, which use diverse evolutionary solutions to identify TEs. In ciliated protozoans, small-RNA-mediated comparison of the germline and somatic genomes underlies identification of TE-related sequences, which are then eliminated from the soma. Here, we describe an additional mechanism of small-RNA-mediated identification of TE-related sequences in the ciliate Tetrahymena. We show that a limited set of internal eliminated sequences (IESs) containing potentially active TEs produces a class of small RNAs that recognize not only the IESs from which they are derived, but also other IESs in trans. This trans recognition triggers the expression of yet another class of small RNAs that identify other IESs. Therefore, TE-related sequences in Tetrahymena are robustly targeted for elimination by a genome-wide trans-recognition network accompanied by a chain reaction of small RNA production. Graphical Abstract Highlights • Two types of siRNAs (scnRNAs) are expressed in Tetrahymena sexual reproduction • Early-scnRNAs are produced from Type-A IESs containing potentially active transposons • Early-scnRNAs trans-recognize Type-B IESs and trigger late-scnRNA production in cis • Late-scnRNA production forms trans-recognition network for robust IES elimination Noto et al. show that a class of Tetrahymena small RNAs from internal eliminated sequences (IESs) containing potentially active transposons recognize not only the IESs from which they are derived but also other IESs in trans, triggering the expression of another class of small RNAs and ensuring robust DNA elimination. |
| Databáze: | OpenAIRE |
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