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Updated: Sep 2, 2026

Frequency and Distribution of Crossovers in Caenorhabditis elegans Meiosis by SNP Genotyping using Real-time PCR
Published on: July 11, 2025
Polymorphism can extensively reshape the genome-wide crossover landscape in Arabidopsis thaliana
Benoît Madec1,2, Maëla Sémery1,3, Qichao Lian4,5
1Université Paris-Saclay, Commissariat à l'Énergie Atomiques et aux Énergies Alternatives (CEA), Centre National de la Recherche Scientifique (CNRS), Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France.
Abstract:
Meiotic recombination, via the formation of crossovers (COs), re-assorts parental alleles and dictate which traits are inherited together, or not. The recombination rate is not homogeneous across the genome, and uncovering the causes of these fluctuations can inform our understanding of recombination and genome evolution. In this study we show that presence of sequence divergence (polymorphism) between homologous chromosomes can dictate where crossovers are formed in Arabidopsis thaliana. Indeed, presence of polymorphism increases the local recombination rate, turning cold regions of the genome hot. This relocation occurs at the expense of non-polymorphic regions, which become colder. This global overhaul of the CO landscape is dependent on the mismatch repair (MMR) machinery. Our data suggests that MMR has a pro-CO role, driving COs to regions of the genome where it could detect sequence differences between homologous chromosomes. Our study demonstrates that polymorphism can be a major recombination driver in A. thaliana.
Related Concept Videos
Overview of Transposition and Recombination
Gene Conversion
Crossing Over
Crossing Over
Gene Duplication and Divergence
The duplicated copies of the gene are called Paralogs. Paralogs with similar sequences and functions form a gene family. Across several species, a large number of gene families are characterized.
Formation of Species

