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Updated: Jun 27, 2026
11:40
Preparation of the Mgm101 Recombination Protein by MBP-based Tagging Strategy
Published on: June 25, 2013
On the origin of PRDM9-guided recombination hotspots
Francisco Úbeda1, Reinhard Bürger2, Frederic Fyon1
1Department of Biology, Royal Holloway University of London, Egham TW20 0EX, United Kingdom.
Summary
Meiotic recombination hotspots are guided by PRDM9 in mammals and open chromatin in birds. A new model shows PRDM9-guided hotspots persist by increasing crossover probability through symmetric binding, balancing evolutionary stability.
Area of Science:
- Genetics
- Evolutionary Biology
- Population Genetics
Background:
- Meiotic recombination is crucial for genome stability and variation across vertebrates.
- Two distinct mechanisms guide recombination hotspots: PRDM9-dependent (mammals) and PRDM9-independent (birds).
- PRDM9-guided hotspots are transient due to DNA motif erosion, while bird hotspots are stable.
Purpose of the Study:
- To investigate the evolutionary persistence of PRDM9-guided recombination hotspots alongside non-PRDM9-guided ones.
- To model the competitive dynamics between these two hotspot determination mechanisms.
Main Methods:
- Developed a population genetic model.
- Simulated competition between PRDM9-guided and non-PRDM9-guided recombination hotspots.
- Analyzed the impact of symmetric versus asymmetric homologous chromosome binding on crossover outcomes.
Main Results:
- Non-PRDM9-guided hotspots are generally favored for generating sufficient crossovers for chromosome segregation.
- PRDM9-guided hotspots can be advantageous when symmetric binding increases crossover resolution.
- PRDM9's sequence specificity creates a trade-off, favoring its persistence under specific selection pressures.
Conclusions:
- PRDM9-guided hotspots can persist due to enhanced symmetric binding, despite reducing overall crossover rates.
- Species lacking PRDM9 are vulnerable to crossover failure, while PRDM9-dependent species risk sensitivity to binding disruptions.
- Intermediate selection regimes allow for the stable coexistence of both hotspot types.
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