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Megasatellite formation and evolution in vertebrate genes
Stéphane Descorps-Declère1, Guy-Franck Richard2
1Institut Pasteur, Université Paris Cité, Bioinformatics and Biostatistics Hub, 25 rue du Dr Roux, 75015 Paris, France.
Cell Reports
|September 14, 2022
Summary
Large tandem repeats called megasatellites have expanded in vertebrate genomes, particularly after fish radiation and in therian mammals. These repeats play a dynamic role in genome evolution.
Area of Science:
- Genomics
- Evolutionary Biology
- Molecular Biology
Background:
- Eukaryotic genomes have evolved increased complexity and gene repertoire since proto-eukaryote formation.
- Tandem repeats, specifically megasatellites, are significant genetic elements contributing to this genomic expansion.
Purpose of the Study:
- To conduct a genome-wide analysis of large tandem repeats (megasatellites) across 58 vertebrate species.
- To investigate the evolutionary history and genomic distribution of megasatellites.
Main Methods:
- Genome-wide analysis of 58 vertebrate genomes.
- Identification and characterization of large tandem repeats (megasatellites).
Main Results:
- Two major expansion bursts of megasatellites were identified: one post-Agnatha/Gnathostomata radiation and another in therian mammals.
- Megasatellites are frequently located in subtelomeric regions.
- Genes associated with megasatellites are involved in transcription regulation, intracellular trafficking, and cell membrane metabolism.
- Young megasatellites contain numerous introns, suggesting a process of exon-intron duplication followed by intronic mutation and degradation.
Conclusions:
- Megasatellite evolution is a dynamic and ongoing process in vertebrate genomes.
- The observed patterns suggest a mechanism involving duplication and subsequent modification of exon-intron segments.
- Megasatellite distribution and associated genes offer insights into genome evolution and complexity.
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