scholarly journals Rewiring Meiosis for Crop Improvement

2021 ◽  
Vol 12 ◽  
Author(s):  
Pallas Kuo ◽  
Olivier Da Ines ◽  
Christophe Lambing
Keyword(s):  
Plant Breeding ◽  
Chromosome Segregation ◽  
Meiotic Recombination ◽  
Meiotic Chromosome ◽  
Crop Improvement ◽  
Plant Performance ◽  
Dna Double Strand Breaks ◽  
Chromosome Engineering ◽  
Division Process ◽  
New Varieties

Meiosis is a specialized cell division that contributes to halve the genome content and reshuffle allelic combinations between generations in sexually reproducing eukaryotes. During meiosis, a large number of programmed DNA double-strand breaks (DSBs) are formed throughout the genome. Repair of meiotic DSBs facilitates the pairing of homologs and forms crossovers which are the reciprocal exchange of genetic information between chromosomes. Meiotic recombination also influences centromere organization and is essential for proper chromosome segregation. Accordingly, meiotic recombination drives genome evolution and is a powerful tool for breeders to create new varieties important to food security. Modifying meiotic recombination has the potential to accelerate plant breeding but it can also have detrimental effects on plant performance by breaking beneficial genetic linkages. Therefore, it is essential to gain a better understanding of these processes in order to develop novel strategies to facilitate plant breeding. Recent progress in targeted recombination technologies, chromosome engineering, and an increasing knowledge in the control of meiotic chromosome segregation has significantly increased our ability to manipulate meiosis. In this review, we summarize the latest findings and technologies on meiosis in plants. We also highlight recent attempts and future directions to manipulate crossover events and control the meiotic division process in a breeding perspective.

scholarly journals Massive crossover elevation via combination of HEI10 and recq4a recq4b during Arabidopsis meiosis

2018 ◽  
Vol 115 (10) ◽  
pp. 2437-2442 ◽  
Author(s):  
Heïdi Serra ◽  
Christophe Lambing ◽  
Catherine H. Griffin ◽  
Stephanie D. Topp ◽  
Divyashree C. Nageswaran ◽  
...  
Keyword(s):  
Meiotic Recombination ◽  
Homologous Chromosome ◽  
Crop Improvement ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Dsb Repair ◽  
Strand Breaks ◽  
Homologous Chromosomes ◽  
Meiotic Dsbs ◽  
Competing Pathways

During meiosis, homologous chromosomes undergo reciprocal crossovers, which generate genetic diversity and underpin classical crop improvement. Meiotic recombination initiates from DNA double-strand breaks (DSBs), which are processed into single-stranded DNA that can invade a homologous chromosome. The resulting joint molecules can ultimately be resolved as crossovers. In Arabidopsis, competing pathways balance the repair of ∼100–200 meiotic DSBs into ∼10 crossovers per meiosis, with the excess DSBs repaired as noncrossovers. To bias DSB repair toward crossovers, we simultaneously increased dosage of the procrossover E3 ligase gene HEI10 and introduced mutations in the anticrossovers helicase genes RECQ4A and RECQ4B. As HEI10 and recq4a recq4b increase interfering and noninterfering crossover pathways, respectively, they combine additively to yield a massive meiotic recombination increase. Interestingly, we also show that increased HEI10 dosage increases crossover coincidence, which indicates an effect on interference. We also show that patterns of interhomolog polymorphism and heterochromatin drive recombination increases distally towards the subtelomeres in both HEI10 and recq4a recq4b backgrounds, while the centromeres remain crossover suppressed. These results provide a genetic framework for engineering meiotic recombination landscapes in plant genomes.

Sex-Specific Differences in Meiotic Chromosome Segregation Revealed by Dicentric Bridge Resolution in Mice

Genetics ◽  
2002 ◽  
Vol 162 (3) ◽  
pp. 1367-1379 ◽  
Author(s):  
Kara E Koehler ◽  
Elise A Millie ◽  
Jonathan P Cherry ◽  
Paul S Burgoyne ◽  
Edward P Evans ◽  
...  
Keyword(s):  
Chromosome Segregation ◽  
Meiotic Recombination ◽  
Recombination Event ◽  
Meiotic Chromosome ◽  
Mammalian Species ◽  
Paracentric Inversion ◽  
Chromosome Behavior ◽  
Inverted Region ◽  
Dicentric Chromosomes ◽  
Chromatid Cohesion

Abstract The meiotic properties of paracentric inversion heterozygotes have been well studied in insects and plants, but not in mammalian species. In essence, a single meiotic recombination event within the inverted region results in the formation of a dicentric chromatid, which usually breaks or is stretched between the two daughter nuclei during the first meiotic anaphase. Here, we provide evidence that this is not the predominant mode of exchange resolution in female mice. In sharp contrast to previous observations in other organisms, we find that attempts to segregate the dicentric chromatid frequently result not in breakage, stretching, or loss, but instead in precocious separation of the sister centromeres of at least one homolog. This often further results in intact segregation of the dicentric into one of the meiotic products, where it can persist into the first few embryonic divisions. These novel observations point to an unusual mechanism for the processing of dicentric chromosomes in mammalian oogenesis. Furthermore, this mechanism is rare or nonexistent in mammalian spermatogenesis. Thus, our results provide additional evidence of sexual dimorphism in mammalian meiotic chromosome behavior; in “stressful” situations, meiotic sister chromatid cohesion is apparently handled differently in males than in females.

scholarly journals Positive regulation of meiotic DNA double-strand break formation by activation of the DNA damage checkpoint kinase Mec1(ATR)

Open Biology ◽  
2013 ◽  
Vol 3 (7) ◽  
pp. 130019 ◽  
Author(s):  
Stephen Gray ◽  
Rachal M. Allison ◽  
Valerie Garcia ◽  
Alastair S. H. Goldman ◽  
Matthew J. Neale
Keyword(s):  
Dna Damage ◽  
Chromosome Segregation ◽  
Meiotic Chromosome ◽  
Strand Break ◽  
Genetic Exchange ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
Complex Process ◽  
Dna Double Strand Break ◽  
Dna Damage Signalling

During meiosis, formation and repair of programmed DNA double-strand breaks (DSBs) create genetic exchange between homologous chromosomes—a process that is critical for reductional meiotic chromosome segregation and the production of genetically diverse sexually reproducing populations. Meiotic DSB formation is a complex process, requiring numerous proteins, of which Spo11 is the evolutionarily conserved catalytic subunit. Precisely how Spo11 and its accessory proteins function or are regulated is unclear. Here, we use Saccharomyces cerevisiae to reveal that meiotic DSB formation is modulated by the Mec1(ATR) branch of the DNA damage signalling cascade, promoting DSB formation when Spo11-mediated catalysis is compromised. Activation of the positive feedback pathway correlates with the formation of single-stranded DNA (ssDNA) recombination intermediates and activation of the downstream kinase, Mek1. We show that the requirement for checkpoint activation can be rescued by prolonging meiotic prophase by deleting the NDT80 transcription factor, and that even transient prophase arrest caused by Ndt80 depletion is sufficient to restore meiotic spore viability in checkpoint mutants. Our observations are unexpected given recent reports that the complementary kinase pathway Tel1(ATM) acts to inhibit DSB formation. We propose that such antagonistic regulation of DSB formation by Mec1 and Tel1 creates a regulatory mechanism, where the absolute frequency of DSBs is maintained at a level optimal for genetic exchange and efficient chromosome segregation.

scholarly journals Activation of meiotic recombination by nuclear import of the DNA break hotspot-determining complex in fission yeast

2021 ◽  
Vol 134 (4) ◽  
pp. jcs253518 ◽  
Author(s):  
Mélody Wintrebert ◽  
Mai-Chi Nguyen ◽  
Gerald R. Smith
Keyword(s):  
Chromosome Segregation ◽  
Meiotic Recombination ◽  
High Specificity ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Nuclear Entry ◽  
Strand Breaks ◽  
Protein Complex Formation ◽  
Complex Process ◽  
Localization Signal

ABSTRACTMeiotic recombination forms crossovers important for proper chromosome segregation and offspring viability. This complex process involves many proteins acting at each of the multiple steps of recombination. Recombination initiates by formation of DNA double-strand breaks (DSBs), which in the several species examined occur with high frequency at special sites (DSB hotspots). In Schizosaccharomyces pombe, DSB hotspots are bound with high specificity and strongly activated by linear element (LinE) proteins Rec25, Rec27 and Mug20, which form colocalized nuclear foci with Rec10, essential for all DSB formation and recombination. Here, we test the hypothesis that the nuclear localization signal (NLS) of Rec10 is crucial for coordinated nuclear entry after forming a complex with other LinE proteins. In NLS mutants, all LinE proteins were abundant in the cytoplasm, not the nucleus; DSB formation and recombination were much reduced but not eliminated. Nuclear entry of limited amounts of Rec10, apparently small enough for passive nuclear entry, can account for residual recombination. LinE proteins are related to synaptonemal complex proteins of other species, suggesting that they also share an NLS, not yet identified, and undergo protein complex formation before nuclear entry.This article has an associated First Person interview with Mélody Wintrebert, joint first author of the paper.

scholarly journals ATR/Mec1 prevents lethal meiotic recombination initiation on partially replicated chromosomes in budding yeast

eLife ◽  
2013 ◽  
Vol 2 ◽  
Author(s):  
Hannah G Blitzblau ◽  
Andreas Hochwagen
Keyword(s):  
Chromosome Segregation ◽  
Budding Yeast ◽  
Meiotic Chromosome ◽  
Double Strand Breaks ◽  
Genome Integrity ◽  
Dna Double Strand Breaks ◽  
Rapid Loss ◽  
Replication Checkpoint ◽  
Strand Breaks ◽  
Cdc7 Kinase

During gamete formation, crossover recombination must occur on replicated DNA to ensure proper chromosome segregation in the first meiotic division. We identified a Mec1/ATR- and Dbf4-dependent replication checkpoint in budding yeast that prevents the earliest stage of recombination, the programmed induction of DNA double-strand breaks (DSBs), when pre-meiotic DNA replication was delayed. The checkpoint acts through three complementary mechanisms: inhibition of Mer2 phosphorylation by Dbf4-dependent Cdc7 kinase, preclusion of chromosomal loading of Rec114 and Mre11, and lowered abundance of the Spo11 nuclease. Without this checkpoint, cells formed DSBs on partially replicated chromosomes. Importantly, such DSBs frequently failed to be repaired and impeded further DNA synthesis, leading to a rapid loss in cell viability. We conclude that a checkpoint-dependent constraint of DSB formation to duplicated DNA is critical not only for meiotic chromosome assortment, but also to protect genome integrity during gametogenesis.

scholarly journals Application of Genomics and Phenomics in Plant Breeding for Climate Resilience

2020 ◽  
pp. 53-66
Author(s):  
Noel Ndlovu
Keyword(s):  
Plant Breeding ◽  
Crop Improvement ◽  
Cost Effective ◽  
Breeding Systems ◽  
Plant Performance ◽  
Biological Study ◽  
Interdisciplinary Field ◽  
Climate Resilience ◽  
Next Generation Sequencing Ngs ◽  
Evolution Of Genomes

Advances in the fields of genomics and phenomics are currently creating significant foundations for the sustainable intensification of plant breeding initiatives targeting climate resilience. Genomics is a biological study that focuses on architecture, function, editing, mapping, and evolution of genomes. It can be applied extensively in climate resilience breeding for cost-effective, rapid, and high-through put genotyping, phenotyping, and trait mapping. The efficacy of genomics-assisted breeding (GAB) is strongly hinged on the high resolution and robustness of Next Generation Sequencing (NGS) and CRISPR/Cas9-based Gene Editing systems. The integration of genomics and phenomics in crop improvement can upscale the efficiency of breeding systems targeting climate resilience and hasten cultivar release cycle. Phenomics is an interdisciplinary field that focuses on the enhanced measurement of plant performance, growth, and composition. Similarly, phenomics has revolutionized the efficacy of plant breeding off-trial initiatives established to phenotypically characterize and study diversity levels of collected germplasm. Field phenomics tools such as the phenonet, phenomobile, and phenonetwork have proven to be efficient in capturing large sums of multiscale and multidimensional experimental data. The main purpose of this review article is to present a summarized account of the probable applications of integrated systems of genomics and phenomics in plant breeding for climate resilience in major crops.

scholarly journals CRISPR targeting of MEIOTIC-TOPOISOMERASE VIB-dCas9 to a recombination hotspot is insufficient to increase crossover frequency in Arabidopsis

2021 ◽  
Author(s):  
Nataliya E. Yelina ◽  
Sabrina Gonzalez-Jorge ◽  
Dominique Hirsz ◽  
Ziyi Yang ◽  
Ian R. Henderson
Keyword(s):  
Meiotic Recombination ◽  
Crop Improvement ◽  
Double Strand Breaks ◽  
Crossover Frequency ◽  
Dna Double Strand Breaks ◽  
Crop Breeding ◽  
Catalytic Subunits ◽  
Strand Breaks ◽  
Homologous Chromosomes ◽  
Meiotic Crossover

AbstractDuring meiosis, homologous chromosomes pair and recombine, which can result in reciprocal crossovers that increase genetic diversity. Crossovers are unevenly distributed along eukaryote chromosomes and show repression in heterochromatin and the centromeres. Within the chromosome arms crossovers are often concentrated in hotspots, which are typically in the kilobase range. The uneven distribution of crossovers along chromosomes, together with their low number per meiosis, creates a limitation during crop breeding, where recombination can be beneficial. Therefore, targeting crossovers to specific genome locations has the potential to accelerate crop improvement. In plants, meiotic crossovers are initiated by DNA double strand breaks (DSBs) that are catalysed by SPO11 complexes, which consist of two catalytic (SPO11-1 and SPO11-2) and two non-catalytic subunits (MTOPVIB). We used the model plant Arabidopsis thaliana to target a dCas9-MTOPVIB fusion protein to the 3a crossover hotspot via CRISPR. We observed that this was insufficient to significantly change meiotic crossover frequency or pattern within 3a. We discuss the implications of our findings for targeting meiotic recombination within plant genomes.

scholarly journals ANKRD31 regulates spatiotemporal patterning of meiotic recombination initiation and ensures recombination between heterologous sex chromosomes in mice

2018 ◽  
Author(s):  
Frantzeskos Papanikos ◽  
Julie A.J. Clément ◽  
Erika Testa ◽  
Ramya Ravindranathan ◽  
Corinne Grey ◽  
...  
Keyword(s):  
Sex Chromosomes ◽  
Meiotic Recombination ◽  
Meiotic Chromosome ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
Homologous Chromosomes ◽  
Y Chromosomes ◽  
Genome Wide ◽  
A Genome ◽  
Pseudoautosomal Regions

AbstractOrderly segregation of chromosomes during meiosis requires that crossovers form between homologous chromosomes by recombination. Programmed DNA double-strand breaks (DSBs) initiate meiotic recombination. We identify ANKRD31 as a critical component of complexes of DSB-promoting proteins which assemble on meiotic chromosome axes. Genome-wide, ANKRD31 deficiency causes delayed recombination initiation. In addition, loss of ANKRD31 alters DSB distribution owing to reduced selectivity for sites that normally attract DSBs. Strikingly, ANKRD31 deficiency also abolishes uniquely high rates of recombination that normally characterize pseudoautosomal regions (PARs) of X and Y chromosomes. Consequently, sex chromosomes do not form crossovers leading to chromosome segregation failure in ANKRD31-deficient spermatocytes. These defects are accompanied by a genome-wide delay in assembling DSB-promoting proteins on axes and a loss of a specialized PAR-axis domain that is highly enriched for DSB-promoting proteins. Thus, we propose a model for spatiotemporal patterning of recombination by ANKRD31-dependent control of axis-associated complexes of DSB-promoting proteins.

The repair of endo/exogenous DNA double-strand breaks and its effects on meiotic chromosome segregation in oocytes

2019 ◽  
Vol 28 (20) ◽  
pp. 3422-3430 ◽  
Author(s):  
Jun-Yu Ma ◽  
Xie Feng ◽  
Xin-Yi Tian ◽  
Lei-Ning Chen ◽  
Xiao-Yan Fan ◽  
...  
Keyword(s):  
Chromosome Segregation ◽  
Meiotic Chromosome ◽  
Genomic Structure ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Developmental Defects ◽  
Exogenous Dna ◽  
Strand Breaks ◽  
Dna Dsbs ◽  
Number Variation

Abstract Germ cell-derived genomic structure variants not only drive the evolution of species but also induce developmental defects in offspring. The genomic structure variants have different types, but most of them are originated from DNA double-strand breaks (DSBs). It is still not well known whether DNA DSBs exist in adult mammalian oocytes and how the growing and fully grown oocytes repair their DNA DSBs induced by endogenous or exogenous factors. In this study, we detected the endogenous DNA DSBs in the growing and fully grown mouse oocytes and found that the DNA DSBs mainly localized at the centromere-adjacent regions, which are also copy number variation hotspots. When the exogenous DNA DSBs were introduced by Etoposide, we found that Rad51-mediated homologous recombination (HR) was used to repair the broken DNA. However, the HR repair caused the chromatin intertwined and impaired the homologous chromosome segregation in oocytes. Although we had not detected the indication about HR repair of endogenous centromere-adjacent DNA DSBs, we found that Rad52 and RNA:DNA hybrids colocalized with these DNA DSBs, indicating that a Rad52-dependent DNA repair might exist in oocytes. In summary, our results not only demonstrated an association between endogenous DNA DSBs with genomic structure variants but also revealed one specific DNA DSB repair manner in oocytes.

scholarly journals SCF Ensures Meiotic Chromosome Segregation Through a Resolution of Meiotic Recombination Intermediates

PLoS ONE ◽  
2012 ◽  
Vol 7 (1) ◽  
pp. e30622 ◽  
Author(s):  
Shin-ya Okamoto ◽  
Masamitsu Sato ◽  
Takashi Toda ◽  
Masayuki Yamamoto
Keyword(s):  
Chromosome Segregation ◽  
Meiotic Recombination ◽  
Meiotic Chromosome
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