Crossover interference mechanism: New lessons from plants

Abstract

Plants are the source of our understanding of several fundamental biological principles. It is well known that Gregor Mendel discovered the laws of Genetics in peas and that maize was used for the discovery of transposons by Barbara McClintock. Plant models are still useful for the understanding of general key biological concepts. In this article, we will focus on discussing the recent plant studies that have shed new light on the mysterious mechanisms of meiotic crossover (CO) interference, heterochiasmy, obligatory CO, and CO homeostasis. Obligatory CO is necessary for the equilibrated segregation of homologous chromosomes during meiosis. The tight control of the different male and female CO rates (heterochiasmy) enables both the maximization and minimization of genome shuffling. An integrative model can now predict these observed aspects of CO patterning in plants. The mechanism proposed considers the Synaptonemal Complex as a canalizing structure that allows the diffusion of a class I CO limiting factor linearly on synapsed bivalents. The coarsening of this limiting factor along the SC explains the interfering spacing between COs. The model explains the observed coordinated processes between synapsis, CO interference, CO insurance, and CO homeostasis. It also easily explains heterochiasmy just considering the different male and female SC lengths. This mechanism is expected to be conserved in other species.

Plant reproduction research in Latin America: Toward sustainable agriculture in a changing environment

“…Class I crossovers represent most crossovers (80% in Arabidopsis) and interfere with each other's formation, whereas those of class II are in the minority; the two classes do not show mutual interference (Lian et al., 2022). Regulation of the class I pathway is under control of factors ZIP4/SPO22/PH1 (a tetratricopeptide repeat TPR ‐like superfamily protein), MER3 (a DNA helicase), HEI10 (a RING finger‐containing protein), PTD (a DNA ligase‐like protein), SHOC1/ZIP2 (an XPF endonuclease‐like protein), and the resolvases MSH4, MSH5, and MLH1 (Rafiei & Ronceret, 2023). However, formation of class II crossovers is regulated by two pathways: MUS81 and Fanconi Anemia Complementation Group D2 (FANCD2) pathways (Rafiei & Ronceret, 2023).…”

“…Regulation of the class I pathway is under control of factors ZIP4/SPO22/PH1 (a tetratricopeptide repeat TPR ‐like superfamily protein), MER3 (a DNA helicase), HEI10 (a RING finger‐containing protein), PTD (a DNA ligase‐like protein), SHOC1/ZIP2 (an XPF endonuclease‐like protein), and the resolvases MSH4, MSH5, and MLH1 (Rafiei & Ronceret, 2023). However, formation of class II crossovers is regulated by two pathways: MUS81 and Fanconi Anemia Complementation Group D2 (FANCD2) pathways (Rafiei & Ronceret, 2023). The endonuclease MUS81 (GEN1 in rice) targets recombination intermediates such as D‐loops and Holliday Junctions to promote crossover formation (10%–15%), and the FANCD2 pathway promotes crossover formation at a rate of 5% (Kurzbauer et al., 2018; Rafiei & Ronceret, 2023).…”

“…However, formation of class II crossovers is regulated by two pathways: MUS81 and Fanconi Anemia Complementation Group D2 (FANCD2) pathways (Rafiei & Ronceret, 2023). The endonuclease MUS81 (GEN1 in rice) targets recombination intermediates such as D‐loops and Holliday Junctions to promote crossover formation (10%–15%), and the FANCD2 pathway promotes crossover formation at a rate of 5% (Kurzbauer et al., 2018; Rafiei & Ronceret, 2023).…”

“…A line of work of great interest is the establishment of crossovers between homologous chromosomes during plant meiosis. Meiotic crossovers are physical links between homologous chromosomes that are formed due to the exchange of parental sequences (Rafiei & Ronceret, 2023). Their distribution and number along chromosomes are not random, but in general at least one obligate crossover will be formed between each pair of chromosomes to guarantee proper segregation during metaphase I (Girard et al, 2023).…”

Interference Length reveals regularity of crossover placement across species

“…Moreover, CO positions are not independent, but exhibit a phenomenon known as crossover interference [1][2][3]: If chromosomes posses multiple COs, they tend to be spaced more widely than expected by chance. The mechanism governing this CO interference is debated [4][5][6][7][8][9][10][11][12][13][14][15][16], in part because it is challenging to quantify CO interference reliably and to compare it across species, mutants, and chromosomes.…”