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Title: Rolling‐circle amplification of centromeric Helitrons in plant genomes
Summary

The unusual eukaryoticHelitrontransposons can readily capture host sequences and are, thus, evolutionarily important. They are presumed to amplify by rolling‐circle replication (RCR) because some elements encode predicted proteins homologous toRCRprokaryotic transposases. In support of this replication mechanism, it was recently shown that transposition of a batHelitrongenerates covalently closed circular intermediates. Another strong prediction is thatRCRshould generate tandemHelitronconcatemers, yet almost allHelitronsidentified to date occur as solo elements in the genome. To investigate alternative modes ofHelitronorganization in present‐day genomes, we have applied the novel computational tool HelitronScanner to 27 plant genomes and have uncovered numerous tandem arrays of partially decayed, truncatedHelitronsin all of them. Strikingly, most of theseHelitrontandem arrays are interspersed with other repeats in centromeres. Many of these arrays have multipleHelitron5′ ends, but a single 3′ end. The number of repeats in any one array can range from a handful to several hundreds. We propose here anRCRmodel that conforms to the presentHelitronlandscape of plant genomes. Our study provides strong evidence that plantHelitronsamplify byRCRand that the tandemly arrayed replication products accumulate mostly in centromeres.

 
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NSF-PAR ID:
10117538
Author(s) / Creator(s):
 ;  ;  
Publisher / Repository:
Wiley-Blackwell
Date Published:
Journal Name:
The Plant Journal
Volume:
88
Issue:
6
ISSN:
0960-7412
Page Range / eLocation ID:
p. 1038-1045
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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