Meiosis: Dances Between Homologs

Annual Review of Genetics, Journal Year: 2023, Volume and Issue: 57(1), P. 1 - 63

Published: Oct. 3, 2023

The raison d'être of meiosis is shuffling genetic information via Mendelian segregation and, within individual chromosomes, by DNA crossing-over. These outcomes are enabled a complex cellular program in which interactions between homologous chromosomes play central role. We first provide background regarding the basic principles this program. then summarize current understanding events recombination and three processes that involve whole chromosomes: homolog pairing, crossover interference, chiasma maturation. All these implemented direct physical interaction complexes with underlying chromosome structures. Finally, we present convergent lines evidence meiotic may have evolved coupling to late-stage mitotic morphogenesis.

Language: Английский

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PRDM9 drives the location and rapid evolution of recombination hotspots in salmonid fish

PLoS Biology, Journal Year: 2025, Volume and Issue: 23(1), P. e3002950 - e3002950

Published: Jan. 6, 2025

In many eukaryotes, meiotic recombination occurs preferentially at discrete sites, called hotspots. various lineages, hotspots are located in regions with promoter-like features and evolutionarily stable. Conversely, some mammals, driven by PRDM9 that targets away from promoters. Paradoxically, induces the self-destruction of its this triggers an ultra-fast evolution mammalian is ancestral to all animals, suggesting a critical importance for program, but has been lost lineages surprisingly little effect on meiosis success. However, it unclear whether function described mammals shared other species. To investigate this, we analyzed landscape several salmonids, genome which harbors one full-length truncated paralogs. We identified initiation sites Oncorhynchus mykiss mapping DNA double-strand breaks (DSBs). found DSBs clustered positioned promoters, enriched H3K4me3 H3K36me3 location depended genotype Prdm9 . observed high level polymorphism zinc finger domain , indicating diversification positive selection. Moreover, population-scaled maps O kisutch Salmo salar revealed rapid turnover caused target motif erosion. Our results imply conserved across vertebrates peculiar evolutionary runaway active hundred million years.

Language: Английский

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Diversity and determinants of recombination landscapes in flowering plants

PLoS Genetics, Journal Year: 2022, Volume and Issue: 18(8), P. e1010141 - e1010141

Published: Aug. 30, 2022

During meiosis, crossover rates are not randomly distributed along the chromosome and their location may have a strong impact on functioning evolution of genome. To date, broad diversity recombination landscapes among plants has rarely been investigated formal comparative genomic approach is still needed to characterize assess determinants species chromosomes. We gathered genetic maps genomes for 57 flowering plant species, corresponding 665 chromosomes, which we estimated large-scale landscapes. found that number per spans limited range (between one five/six) whatever genome size, there no single relationship across between map length size. Instead, general relative size chromosomes rate, while absolute constrains basal rate each species. At level, identified two main patterns (with few exceptions) proposed conceptual model explaining broad-scale distribution crossovers where both telomeres centromeres play role. These correspond globally underlying gene distribution, affects how efficiently genes shuffled at meiosis. results raised new questions only but also

Language: Английский

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Exploring impact of recombination landscapes on breeding outcomes

Proceedings of the National Academy of Sciences, Journal Year: 2023, Volume and Issue: 120(14)

Published: March 27, 2023

Plant breeding relies on crossing-over to create novel combinations of alleles needed confer increased productivity and other desired traits in new varieties. However, crossover (CO) events are rare, as usually only one or two them occur per chromosome each generation. In addition, COs not distributed evenly along chromosomes. plants with large genomes, which includes most crops, predominantly formed close ends, there few the swaths around centromeres. This situation has created interest engineering CO landscape improve efficiency. Methods have been developed boost globally by altering expression anti-recombination genes increase rates certain parts changing DNA methylation patterns. progress is being made devise methods target specific sites. We review these approaches examine using simulations whether they indeed capacity efficiency programs. found that current alter can produce enough benefits for programs be attractive. They genetic gain recurrent selection significantly decrease linkage drag donor loci schemes introgress a trait from unimproved germplasm an elite line. genome sites were also provide advantage when introgressing segment harboring desirable quantitative loci. recommend avenues future research facilitate implementation

Language: Английский

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Crossover patterning through kinase-regulated condensation and coarsening of recombination nodules

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2021, Volume and Issue: unknown

Published: Aug. 27, 2021

Abstract Meiotic recombination is highly regulated to ensure precise segregation of homologous chromosomes. Evidence from diverse organisms indicates that the synaptonemal complex (SC), which assembles between paired chromosomes, plays essential roles in crossover formation and patterning. Several additional “pro-crossover” proteins are also required for intermediates become crossovers. These typically form multiple foci or nodules along SCs, later accumulate at fewer, widely spaced sites. Here we report C. elegans CDK-2 stabilize all stabilizes interactions among pro-crossover factors by phosphorylating MSH-5. Additionally, show conserved RING domain ZHP-3/4 diffuse SC remain dynamic following their accumulation Based on these previous findings propose a model arise through spatially restricted biomolecular condensation then undergo coarsening process, resulting interference.

Language: Английский

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Meiosis in budding yeast

Genetics, Journal Year: 2023, Volume and Issue: 225(2)

Published: Aug. 24, 2023

Abstract Meiosis is a specialized cell division program that essential for sexual reproduction. The two meiotic divisions reduce chromosome number by half, typically generating haploid genomes are packaged into gametes. To achieve this ploidy reduction, meiosis relies on highly unusual chromosomal processes including the pairing of homologous chromosomes, assembly synaptonemal complex, programmed formation DNA breaks followed their processing crossovers, and segregation chromosomes during first division. These embedded in carefully orchestrated differentiation with multiple interdependencies between metabolism, morphogenesis, waves gene expression together ensure correct delivered to next generation. Studies budding yeast Saccharomyces cerevisiae have established essentially all fundamental paradigms meiosis-specific metabolism uncovered components molecular mechanisms underlie these conserved processes. Here, we provide an overview stages key model system highlight how basic genome stability, architecture, cycle control been adapted unique outcome meiosis.

Language: Английский

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Predicting recombination suppression outside chromosomal inversions in Drosophila melanogaster using crossover interference theory

Heredity, Journal Year: 2023, Volume and Issue: 130(4), P. 196 - 208

Published: Feb. 1, 2023

Language: Английский

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Positive and negative regulators of RAD51/DMC1 in homologous recombination and DNA replication

DNA repair, Journal Year: 2023, Volume and Issue: 134, P. 103613 - 103613

Published: Dec. 13, 2023

Language: Английский

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Fine-scale contemporary recombination variation and its fitness consequences in adaptively diverging stickleback fish

Nature Ecology & Evolution, Journal Year: 2024, Volume and Issue: 8(7), P. 1337 - 1352

Published: June 5, 2024

Despite deep evolutionary conservation, recombination rates vary greatly across the genome and among individuals, sexes populations. Yet impact of this variation on adaptively diverging populations is not well understood. Here we characterized fine-scale landscapes in an divergent pair marine freshwater threespine stickleback from River Tyne, Scotland. Through whole-genome sequencing large nuclear families, identified genomic locations almost 50,000 crossovers built maps for marine, hybrid individuals at a resolution 3.8 kb. We used these to quantify factors driving rates. found strong heterochiasmy between but also differences ecotypes. Hybrids showed evidence significant suppression overall map length individual loci. Recombination were lower only within marine-freshwater-adaptive loci, loci same chromosome, suggesting selection linked gene 'cassettes'. temporal sampling along natural zone, that recombinants traits associated with reduced fitness. Our results support predictions divergence cis-acting modifiers, whose functions are disrupted hybrids, may play important role maintaining

Language: Английский

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PRDM9 drives the location and rapid evolution of recombination hotspots in salmonids

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: March 7, 2024

Abstract In many eukaryotes, meiotic recombination occurs preferentially at discrete sites, called hotspots. various lineages, hotspots are located in regions with promoter-like features and evolutionarily stable. Conversely, some mammals, driven by PRDM9 that targets away from promoters. Paradoxically, induces the self-destruction of its this triggers an ultra-fast evolution mammalian is ancestral to all animals, suggesting a critical importance for program, but has been lost lineages surprisingly little effect on meiosis success. However, it unclear whether function described mammals shared other species. To investigate this, we analyzed landscape several salmonids, genome which harbors one full-length truncated paralogs. We identified initiation sites Oncorhynchus mykiss mapping DNA double-strand breaks (DSBs). found DSBs clustered positioned promoters, enriched H3K4me3 H3K4me36 marks location depended genotype Prdm9 . observed high level polymorphism zinc finger domain , not Moreover, population-scaled maps O. kisutch Salmo salar revealed rapid turnover caused target motif erosion. Our results imply conserved across vertebrates peculiar evolutionary runaway active hundred million years.

Language: Английский

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