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Updated: Sep 10, 2025
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Real-Time Quantification of the Effects of IS200/IS605 Family-Associated TnpB on Transposon Activity
Published on: January 20, 2023
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Chromosomal Inversions Mediated by Tandem Insertions of Transposable Elements.
Robin Aasegg Araya1, William B Reinar1,2, Ole K Tørresen1
1Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Oslo 0316, Norway.
Genome Biology and Evolution
|August 21, 2025
Summary
Transposable elements, particularly those with inverted repeats, are enriched at inversion breakpoints in Atlantic cod. This suggests they drive chromosomal inversions, influencing evolution.
Area of Science:
- Genomics
- Evolutionary Biology
- Molecular Biology
Background:
- Chromosomal inversions are vital evolutionary drivers, linking coadapted alleles and influencing phenotypes.
- Mapping inversion breakpoints is challenging due to repetitive DNA, including transposable elements.
- Transposable elements are mobile genetic sequences implicated in genome evolution.
Purpose of the Study:
- To identify and quantify transposable elements at inversion breakpoints in Atlantic cod.
- To investigate the role of transposable elements in the formation of large-scale chromosomal inversions.
- To leverage high-quality genome assemblies for detailed breakpoint analysis.
Main Methods:
- Utilized three long-read-based reference genome assemblies of Atlantic cod ecotypes (Norwegian Coastal, Northeast Arctic, Celtic).
- Analyzed four previously reported large-scale inversions.
- Identified and quantified transposable elements within inversion breakpoint regions.
Main Results:
- Detected significant enrichment of transposable element orders/superfamilies with terminal inverted repeats at breakpoints on chromosomes 1, 7, and 12.
- Discovered tandem accumulation of miniature inverted-repeat transposable elements (hAT transposons) at breakpoints of the inverted haplotype in Northeast Arctic cod (chromosomes 1 and 7).
- Observed high sequence similarity in tandemly arranged transposable elements at breakpoints.
Conclusions:
- Transposable elements, especially those with terminal inverted repeats, are strongly associated with chromosomal inversion breakpoints in Atlantic cod.
- Ectopic recombination between similar transposable elements likely drives the formation of these inversions.
- Transposable elements play a significant role in facilitating chromosomal reorganizations with major evolutionary consequences.
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