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Analysis of LINE-1 Retrotransposition at the Single Nucleus Level
Published on: April 23, 2016
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Tyrosine Recombinase Retrotransposons and Transposons
Russell T M Poulter1, Margi I Butler1
1Department of Biochemistry, University of Otago, Dunedin 9054, New Zealand.
Microbiology Spectrum
|June 25, 2015
Summary
Tyrosine recombinase (YR) retrotransposons are found across eukaryotes and are classified into three main groups. These mobile elements likely evolved from a fusion of DNA transposons and retrotransposons early in eukaryotic evolution.
Area of Science:
- Molecular Biology
- Evolutionary Biology
- Genetics
Background:
- Tyrosine recombinase (YR) retrotransposons are mobile genetic elements found in eukaryotes.
- The DIRS1 element from Dictyostelium discoideum was the first described YR retrotransposon.
- Replication involves free circular DNA intermediates and site-specific integration.
Purpose of the Study:
- To investigate the diversity and evolutionary origins of YR retrotransposons.
- To understand the relationship between YR retrotransposons and other mobile elements.
Main Methods:
- Phylogenetic analysis using reverse transcriptase/ribonuclease H (RT/RH) and YR sequences.
- Comparative sequence analysis of YR retrotransposons and cryptons.
Main Results:
- YR retrotransposons are widespread in fungi, plants, and animals, falling into three distinct clades: DIRS, PAT-like, and Ngaro.
- Cryptons, a group of eukaryote DNA transposons, also possess tyrosine recombinases.
- Crypton YRs show sequence similarity to those in YR retrotransposons.
Conclusions:
- YR retrotransposons likely originated from the integration of a crypton-like DNA transposon carrying YR into a retrotransposon encoding RT/RH.
- This event occurred early in eukaryotic evolution.
- The findings provide insights into the evolution of mobile genetic elements.
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