title: Circular Concatemers of Ultra-Short DNA Segments Produce Regulatory RNAs.
abstract: In the ciliated protozoan Paramecium tetraurelia, Piwi-associated small RNAs are generated upon the elimination of tens of thousands of short transposon-derived DNA segments as part of development. These RNAs then target complementary DNA for elimination in a positive feedback process, contributing to germline defense and genome stability. In this work, we investigate the formation of these RNAs, which we show to be transcribed directly from the short (length mode 27 bp) excised DNA segments. Our data support a mechanism whereby the concatenation and circularization of excised DNA segments provides a template for RNA production. This process allows the generation of a double-stranded RNA for Dicer-like protein cleavage to give rise to a population of small regulatory RNAs that precisely match the excised DNA sequences. VIDEO ABSTRACT.
authors.affiliation: Institute of Cell Biology, University of Bern, Baltzerstrasse 4, 3012 Bern, Switzerland.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Allen
authors.affiliation: Institute of Cell Biology, University of Bern, Baltzerstrasse 4, 3012 Bern, Switzerland.
authors.forename: Iris
authors.initials: I
authors.lastname: Hug
authors.affiliation: Institute of Cell Biology, University of Bern, Baltzerstrasse 4, 3012 Bern, Switzerland.
authors.forename: Sylwia
authors.initials: S
authors.lastname: Pabian
authors.affiliation: Institute of Cell Biology, University of Bern, Baltzerstrasse 4, 3012 Bern, Switzerland.
authors.forename: Iwona
authors.initials: I
authors.lastname: Rzeszutek
authors.affiliation: Institute of Cell Biology, University of Bern, Baltzerstrasse 4, 3012 Bern, Switzerland.
authors.forename: Cristina
authors.initials: C
authors.lastname: Hoehener
authors.affiliation: Institute of Cell Biology, University of Bern, Baltzerstrasse 4, 3012 Bern, Switzerland. Electronic address: mariusz.nowacki@izb.unibe.ch.
authors.forename: Mariusz
authors.initials: M
authors.lastname: Nowacki
mesh_terms: D002467:Cell Nucleus / Q000378:metabolism; D000072481:DNA Ligase ATP / Q000378:metabolism; D004251:DNA Transposable Elements; D044708:DNA, Concatenated; D005090:Exodeoxyribonucleases / Q000378:metabolism; D016805:Paramecium tetraurelia / Q000166:cytology / Q000235:genetics* / Q000378:metabolism; D012313:RNA / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: D004251:DNA Transposable Elements; D044708:DNA, Concatenated; D012313:RNA; D005090:Exodeoxyribonucleases; D000072481:DNA Ligase ATP
keywords: DNA concatemers; DNA elimination; DNA repair; Dicer; Ligase IV; Paramecium; Piwi-interacting RNA; ciliates; circular DNA; small RNA; transcription; transposable elements