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Updated: Jun 20, 2026
11:52
Analysis of LINE-1 Retrotransposition at the Single Nucleus Level
Published on: April 23, 2016
Rotifer rDNA-specific R9 retrotransposable elements generate an exceptionally long target site duplication upon
Eugene A Gladyshev1, Irina R Arkhipova
1Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, MA 02543, USA.
Gene
|September 12, 2009
Summary
R9 retrotransposons were found in the 28S RNA genes of bdelloid rotifers, a unique freshwater invertebrate. These elements insert into a novel DNA sequence, creating a large duplication.
Area of Science:
- Genomics
- Molecular Biology
- Evolutionary Biology
Background:
- Eukaryotic ribosomal DNA genes often harbor non-LTR retrotransposable elements from the R2 clade.
- These elements utilize site-specific insertion into multicopy targets to maintain genomic integrity.
- Bdelloid rotifers are small freshwater invertebrates known for asexual reproduction and desiccation tolerance.
Purpose of the Study:
- To describe R9 retrotransposons, members of the R2 clade, found within the 28S RNA genes of bdelloid rotifers.
- To characterize the unique insertion site and target site duplication associated with R9 elements.
- To discuss the implications for bdelloid genome organization and retrotransposon evolution.
Main Methods:
- Identification and characterization of R9 retrotransposons in bdelloid rotifer genomes.
- Analysis of the target sequence within the 28S ribosomal DNA gene.
- Quantification of target site duplication length.
Main Results:
- R9 retrotransposons share structural similarity with other R2 clade elements.
- R9 elements exhibit site-specific insertion into a previously undescribed target sequence in the 28S gene.
- An unusually large target site duplication of 126 base pairs was observed.
Conclusions:
- The findings reveal novel aspects of retrotransposon insertion mechanisms in bdelloid rotifers.
- The unique target sequence and duplication size provide insights into bdelloid genome dynamics.
- This study contributes to understanding the evolutionary persistence of R2 clade elements in eukaryotes.
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