Meilin Zou, Sergey Shabala, Chenchen Zhao & Meixue Zhou

Theoretical and Applied Genetics; April 2024; vol. 137; article 86

Figure: Prof. Meilin Zou, University of Tasmania, Australia

Key message

Recent developments in understanding the distribution and distinctive features of recombination hotspots are reviewed and approaches are proposed to increase recombination frequency in coldspot regions.

Abstract

Recombination events during meiosis provide the foundation and premise for creating new varieties of crops. The frequency of recombination in different genomic regions differs across eukaryote species, with recombination generally occurring more frequently at the ends of chromosomes. In most crop species, recombination is rare in centromeric regions. If a desired gene variant is linked in repulsion with an undesired variant of a second gene in a region with a low recombination rate, obtaining a recombinant plant combining two favorable alleles will be challenging. Traditional crop breeding involves combining desirable genes from parental plants into offspring. Therefore, understanding the mechanisms of recombination and factors affecting the occurrence of meiotic recombination is important for crop breeding. Here, we review chromosome recombination types, recombination mechanisms, genes and proteins involved in the meiotic recombination process, recombination hotspots and their regulation systems and discuss how to increase recombination frequency in recombination coldspot regions.

See https://link.springer.com/article/10.1007/s00122-024-04590-4

Figure 1: Four recombination types. a The process of homologous recombination involves the DNA double-strand break and rejoining the strands. It results in an exchange of genetic information between the homologous chromosomes. b The yellow and orange blocks represent the segments at the sites of nonhomologous recombination. It does not require sequence homology between the DNA molecules and can introduce mutations at the site of the break. c Site-specific recombination catalyzed by site-specific recombinase enzymes, is usually observed between two different DNA molecules among bacteriophages, bacteria, and unicellular eukaryotes. d The red block represents the transposable element of DNA which could be integrated into the genome