Coarsening dynamics can explain meiotic crossover patterning in both the presence and absence of the synaptonemal complex

eLife, Journal Year: 2023, Volume and Issue: 12

Published: Feb. 27, 2023

The shuffling of genetic material facilitated by meiotic crossovers is a critical driver variation. Therefore, the number and positions crossover events must be carefully controlled. In Arabidopsis, an obligate repression nearby on each chromosome pair are abolished in mutants that lack synaptonemal complex (SC), conserved protein scaffold. We use mathematical modelling quantitative super-resolution microscopy to explore mechanistically explain pattering Arabidopsis lines with full, incomplete, or synapsis. For zyp1 mutants, which SC, we develop coarsening model precursors globally compete for limited pool pro-crossover factor HEI10, dynamic HEI10 exchange mediated through nucleoplasm. demonstrate this capable quantitatively reproducing predicting experimental patterning foci intensity data. Additionally, find combining both SC- nucleoplasm-mediated can wild-type pch2 display partial Together, our results reveal regulation SC-defective likely acts same underlying mechanism, differing only spatial compartments diffuses.

Language: Английский

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The regulation of meiotic crossover distribution: a coarse solution to a century-old mystery?

Biochemical Society Transactions, Journal Year: 2023, Volume and Issue: 51(3), P. 1179 - 1190

Published: May 5, 2023

Meiotic crossovers, which are exchanges of genetic material between homologous chromosomes, more evenly and distantly spaced along chromosomes than expected by chance. This is because the occurrence one crossover reduces likelihood nearby events — a conserved intriguing phenomenon called interference. Although interference was first described over century ago, mechanism allowing coordination fate potential sites half chromosome away remains elusive. In this review, we discuss recently published evidence supporting new model for patterning, coined coarsening model, point out missing pieces that still needed to complete fascinating puzzle.

Language: Английский

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Improving Yield and Yield Stability in Winter Rye by Hybrid Breeding

Plants, Journal Year: 2022, Volume and Issue: 11(19), P. 2666 - 2666

Published: Oct. 10, 2022

Rye is the only cross-pollinating small-grain cereal. The unique reproduction biology results in an exceptional complexity concerning genetic improvement of rye by breeding. a close relative wheat and has strong adaptation potential that refers to its mating system, making this overlooked cereal readily adjustable changing environment. breeding addresses emerging challenges food security associated with climate change. systematic identification, management, use valuable natural diversity became feasible option outbreeding following establishment hybrid late 20th century. In article, we review most recent technological advances improve yield stability winter rye. Based on recently released reference genome sequences, SMART approaches are described counterbalance undesired linkage drag effects major restorer genes grain yield. We present development gibberellin-sensitive semidwarf hybrids as novel plant innovation based approach different from current methods increasing productivity wheat. Breeding new cultivars improved performance resilience indispensable for renaissance healthy minor homogeneous commodity cultural relevance Europe allows comparatively smooth but substantial complementation rye-based diets, supporting necessary restoration balance between human action nature.

Language: Английский

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Diversity in Recombination Hotspot Characteristics and Gene Structure Shape Fine-Scale Recombination Patterns in Plant Genomes

Molecular Biology and Evolution, Journal Year: 2024, Volume and Issue: 41(9)

Published: Sept. 1, 2024

During the meiosis of many eukaryote species, crossovers tend to occur within narrow regions called recombination hotspots. In plants, it is generally thought that gene regulatory sequences, especially promoters and 5' 3' untranslated regions, are enriched in hotspots, but this has been characterized a handful species only. We also lack clear description fine-scale variation rates genic little known about hotspot position intensity plants. To address question, we constructed maps from genetic polymorphism data inferred hotspots 11 plant species. detected gradients most yet varied shape depending on specific locations structure. further characterize gradients, decomposed them according structure by rank number exons. generalized previously observed pattern organized around boundaries coding promoters. However, our results provided new insight into relative importance end genes some possible location away Variation among seemed driven more than differences size or Our shed light at very fine scale, revealing diversity complexity emerging interaction between

Language: Английский

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Genetic dissection of MutL complexes in Arabidopsis meiosis

Nucleic Acids Research, Journal Year: 2025, Volume and Issue: 53(5)

Published: Feb. 27, 2025

Abstract During meiosis, homologous chromosomes exchange genetic material through crossing over. The main crossover pathway relies on ZMM proteins, including ZIP4 and HEI10, is typically resolved by the MLH1/MLH3 heterodimer, MutLγ. Our analysis shows that while MUS81 may partially compensate for MutLγ loss, its role remains uncertain. However, our multiple mutant unlikely to be sole resolvase of ZMM-protected recombination intermediates when absent. Comparing genome-wide maps mlh1 mutants with ZMM-deficient lines varying HEI10 levels reveals interference persists in but weakened. significant reduction also increases aneuploidy offspring. loss can suppressed eliminating FANCM helicase. Combined lower-than-expected chiasma frequency, this suggests absence, some are ultimately DNA helicases and/or their complexes Top3α. Elevated MLH1 or MLH3 expression moderately misregulation drastically reduces numbers plant fertility, highlighting importance tight control levels. By contrast, PMS1, a component MutLα endonuclease, appears uninvolved Together, these findings demonstrate unique ZMM-dependent regulation.

Language: Английский

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MSH2 stimulates interfering and inhibits non-interfering crossovers in response to genetic polymorphism

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Oct. 23, 2023

Meiotic crossovers can be formed through the interfering pathway, in which one crossover prevents another from forming nearby, or by an independent non-interfering pathway. In Arabidopsis, local sequence polymorphism between homologs stimulate a MSH2-dependent manner. To understand how MSH2 regulates two pathways, we combined Arabidopsis mutants that elevate with msh2 mutants. We demonstrate blocks at polymorphic loci, is opposite effect to crossovers. also observe MSH2-independent inhibition highly sites. measure recombination along chromosome arms lines differing patterns of heterozygosity and increase boundaries heterozygous homozygous regions. Here, show master regulator meiotic DSB repair antagonistic effects on crossovers, shapes landscape relation interhomolog polymorphism.

Language: Английский

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The rate of chromosomal inversion fixation in plant genomes is highly variable

Evolution, Journal Year: 2023, Volume and Issue: 77(4), P. 1117 - 1130

Published: Feb. 11, 2023

Abstract Chromosomal inversions are theorized to play an important role in adaptation by preventing recombination, but testing this hypothesis requires understanding of the rate inversion fixation. Here, we use chromosome-level whole-genome assemblies for 32 genera plants ask how fast accumulate and what factors affect rate. We find that on average species 4–25 per million generations, is highly variable, no correlation between sequence divergence or repeat content number proportion genome was inverted only a small with chromosome size. also regions depleted genes enriched TEs compared genomic background. This suggests idiosyncratic forces, like natural selection demography, controlling fix.

Language: Английский

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Crossover interference mechanism: New lessons from plants

Frontiers in Cell and Developmental Biology, Journal Year: 2023, Volume and Issue: 11

Published: May 19, 2023

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

Language: Английский

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Using ddRADseq to assess the genetic diversity of in-farm and gene bank cacao resources in the Baracoa region, eastern Cuba, for use and conservation purposes

Frontiers in Plant Science, Journal Year: 2024, Volume and Issue: 15

Published: March 5, 2024

The Baracoa region, eastern Cuba, hosts around 80 % of the country cacao ( Theobroma L.) plantations. Cacao plants in farms are diverse origin and propagation, with grafted hybrid being more common ones. Less frequent from cuttings, TSH progeny, traditional Cuban cacao. A national gene bank is also present Baracoa, 282 accessions either prospected Cuba or introduced other countries. breeding program associated started 1990s based on agro-morphological descriptors. genetic diversity resources has been poorly described, except for cacao, affecting proper development planting policies region. To assess population structure we genotyped both (CG) (CF) applying a new ddRADseq protocol After data processing, two SNPs datasets containing 11,425 6,481 high-quality were generated 238 CG 135 CF plants, respectively. unevenly distributed along 10 chromosomes laid mainly noncoding regions genome. Population analysis these SNP identified seven four groups samples, Clustering using UPGMA principal component mostly agree results. Amelonado was predominant ancestry, accounting 49.22 57.73 total. Criollo, Contamana, Iquitos, Nanay ancestries detected while Nacional Marañon backgrounds only CG. Genetic differentiation among F ST ranging 0.071 to 0.407) higher than : 0.093–0.282). parameters showed similar values samples. lowest had highest proportion ancestry. These results should contribute reinforcing ongoing updating farms, an impact social economic life

Language: Английский

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Methylomes as key features for predicting recombination in some plant species

Plant Molecular Biology, Journal Year: 2024, Volume and Issue: 114(2)

Published: March 8, 2024

Abstract Knowing how chromosome recombination works is essential for plant breeding. It enables the design of crosses between different varieties to combine desirable traits and create new ones. This because meiotic crossovers homologous chromatids are not purely random, various strategies have been developed describe predict such exchange events. Recent studies used methylation data chromosomal in rice using machine learning models. approach proved successful due presence a positive correlation CHH context cytosine rates chromosomes. paper assesses question if can be four species: Arabidopsis, maize, sorghum, tomato. The results indicate association certain species, with varying degrees strength their relationships. CG CHG contexts show negative recombination. Methylation was key effectively predicting sorghum tomato, mean determination coefficient 0.65 ± 0.11 0.76 0.05, respectively. In addition, values predicted experimental were 0.83 0.06 0.90 0.05 confirming significance methylomes both monocotyledonous dicotyledonous species. predictions Arabidopsis maize as accurate, likely comparatively weaker relationships recombination, contrast where stronger associations observed. To enhance accuracy predictions, further evaluations sets closely related each other might prove beneficial. general, this methylome-based method holds great potential reliable strategy offering valuable insights breeders quest develop novel improved varieties.

Language: Английский

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