Chromosome segregation during spermatogenesis occurs through a unique center-kinetic mechanism in holocentric moth species

PLoS Genetics, Год журнала: 2024, Номер 20(6), С. e1011329 - e1011329

Опубликована: Июнь 24, 2024

Precise regulation of chromosome dynamics in the germline is essential for reproductive success across species. Yet, mechanisms underlying meiotic chromosomal events such as homolog pairing and segregation are not fully understood many Here, we employ Oligopaint DNA FISH to investigate holocentric pantry moth, Plodia interpunctella , compare our findings new previous studies silkworm Bombyx mori which diverged from P . over 100 million years ago. We find that both spermatogenesis initiated at gene-rich ends. Additionally, species form rod shaped cruciform-like bivalents metaphase I. However, unlike telomere-oriented mechanism observed can orient multiple different ways Surprisingly, kinetochores consistently assemble non-telomeric loci toward center chromosomes regardless where centers located bivalent. sister do seem be paired these Instead, four distinct easily Despite this, clear end-on microtubule attachments lateral co-orienting separated kinetochores. These challenge classical view paired, poleward-facing required accurate separation meiosis Our here highlight importance exploring fundamental processes non-model systems, employing novel organisms lead discovery biology.

Язык: Английский

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Stepwise recombination suppression around the mating-type locus in an ascomycete fungus with self-fertile spores

PLoS Genetics, Год журнала: 2023, Номер 19(2), С. e1010347 - e1010347

Опубликована: Фев. 10, 2023

Recombination is often suppressed at sex-determining loci in plants and animals, self-incompatibility or mating-type fungi. In fungal ascomycetes, recombination suppression around the locus associated with pseudo-homothallism, i . e production of self-fertile dikaryotic sexual spores carrying two opposite mating types. This has been well studied species complexes from different families Sordariales : Podospora anserina Neurospora tetrasperma However, it unclear whether this intriguing association holds other species. We show here that Schizothecium tetrasporum , a fungus third family order also produces mostly was due to high frequency second meiotic division segregation locus, indicating occurrence single systematic crossing-over event between centromere, as P The typical organization, plus MAT1-1-1 pseudogene MAT1-2 haplotype. High-quality genome assemblies types analyses revealed region 1.47 Mb locus. detected three evolutionary strata, stepwise extension suppression. strata displayed no rearrangement transposable element accumulation but gene losses disruptions were present, precisely margins. Our findings indicate convergent evolution across multiple ascomycete particular pattern had extended stepwise. pseudo-homothallism lineages presence disruption limits are consistent recently proposed mechanism sheltering deleterious alleles explain

Язык: Английский

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Formation of Different Polyploids Through Disrupting Meiotic Crossover Frequencies Based on cntd1 Knockout in Zebrafish

Molecular Biology and Evolution, Год журнала: 2024, Номер 41(3)

Опубликована: Фев. 29, 2024

Abstract Polyploidy, a significant catalyst for speciation and evolutionary processes in both plant animal kingdoms, has been recognized long time. However, the exact molecular mechanism that leads to polyploid formation, especially vertebrates, is not fully understood. Our study aimed elucidate this phenomenon using zebrafish model. We successfully achieved an effective knockout of cyclin N-terminal domain containing 1 (cntd1) CRISPR/Cas9 technology. This resulted impaired formation meiotic crossovers, leading cell-cycle arrest during metaphase triggering apoptosis spermatocytes testes. Despite these defects, mutant (cntd1−/−) males were still able produce limited amount sperm with normal ploidy function. Interestingly, females, it was capacity egg production altered. haploid, aneuploid, unreduced gametes. alteration enabled us obtain triploid tetraploid from cntd1−/− cntd1−/−/− respectively. Furthermore, tetraploid-heterozygous produced reduced-diploid gametes yielded all-triploid or all-tetraploid offspring when crossed wild-type (WT) zebrafish, Collectively, our findings provide direct evidence supporting crucial role crossover defects process polyploidization. particularly evident generation eggs fish and, potentially, other vertebrate species.

Язык: Английский

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Uncharted territories: Solving the mysteries of male meiosis in flies

PLoS Genetics, Год журнала: 2024, Номер 20(3), С. e1011185 - e1011185

Опубликована: Март 15, 2024

The segregation of homologous chromosomes during meiosis typically requires tight end-to-end chromosome pairing. However, in Drosophila spermatogenesis, male flies segregate their without classic synaptonemal complex formation and recombination, instead compartmentalizing homologs into subnuclear domains known as territories (CTs). How find each other the nucleus are separated CTs has been one biggest riddles biology. Here, we discuss our current understanding pairing CT review recent data on how linked partitioned flies.

Язык: Английский

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The genetic architecture of recombination rates is polygenic and differs between the sexes in wild house sparrows (Passer domesticus)

Molecular Biology and Evolution, Год журнала: 2024, Номер 41(9)

Опубликована: Авг. 24, 2024

Abstract Meiotic recombination through chromosomal crossing-over is a fundamental feature of sex and an important driver genomic diversity. It ensures proper disjunction, allows increased selection responses, prevents mutation accumulation; however, it also mutagenic can break up favorable haplotypes. This cost–benefit dynamic likely to vary depending on mechanistic evolutionary contexts, indeed, rates show huge variation in nature. Identifying the genetic architecture this key understanding its causes consequences. Here, we investigate individual rate wild house sparrows (Passer domesticus). We integrate pedigree data identify autosomal crossover counts (ACCs) intrachromosomal allelic shuffling (r¯intra) 13,056 gametes transmitted from 2,653 individuals their offspring. Females had 1.37 times higher ACC, 1.55 r¯intra than males. ACC were heritable females males (ACC h2 = 0.23 0.11; 0.12 0.14), but cross-sex additive correlations low (rA 0.29 0.32 for r¯intra). Conditional bivariate analyses showed that all measures remained after accounting values opposite sex, indicating sex-specific evolve somewhat independently. Genome-wide models are polygenic driven by many small-effect loci, which act trans as global modifiers. Our findings have different potential birds, providing compelling mechanism evolution sexual dimorphism recombination.

Язык: Английский

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Mapping of meiotic recombination in human preimplantation blastocysts

G3 Genes Genomes Genetics, Год журнала: 2023, Номер 13(4)

Опубликована: Фев. 3, 2023

Abstract Recombination is essential for physical attachments and genetic diversity. The Han Chinese population the largest ethnic group worldwide, therefore, construction of a map regarding recombination essential. In this study, 164 240 couples who underwent preimplantation testing monogenic diseases or segmental rearrangement were included in analysis. Blastocysts probands from by single nucleotide polymorphism array location was determined haplotype phase transitions parent-offspring pairs at loci where parents heterozygous. vitro fertilization embryos constructed expectation–maximization algorithm with chip-level data. Our results confirmed that homologous occurred more often maternal chromosomes, age effect significant recombination. A total 6,494 hotspots (32.3%) identified genes Online Mendelian Inheritance Man. uniform association between aneuploidy not established. addition, carriers breakpoints reciprocal translocations analyzed, locations found partly overlapped hotspots, implying possible similar mechanism behind both events. This study highlights significance constructing map, which may improve accuracy analysis diseases. Overlapping translocation are worthy further investigation.

Язык: Английский

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Temporal and Functional Relationship between Synaptonemal Complex Morphogenesis and Recombination during Meiosis

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2024, Номер unknown

Опубликована: Янв. 11, 2024

During prophase of meiosis I, programmed double strand breaks (DSBs) are processed into crossovers, a critical requirement for segregation homologous chromosomes (homologs) and genome haploidization in sexually reproducing organisms. Crossovers form via recombination close temporospatial association with morphogenesis the synaptonemal complex (SC), proteinaceous structure that connects paired homologs along their length during pachytene stage. Synapsis paradigm interplay between higher order chromosome DNA metabolism, yet temporal functional relationship remains poorly understood. Probing linkage these processes budding yeast, we show SC assembly is associated distinct threshold number unstable D-loops. The transition from bona fide paranemic D-loops to plectonemic DSB single end invasions (SEIs) completed midpachynema, when fully assembled. Double Holliday junctions (dHJs) at time desynapsis resolved crossovers diplonema. central element component Zip1 shepherds through three transitions, including first exchange second capture, as well dHJ resolution. mediates SEI formation independent its polymerization whereas precocious interferes junction Together, our findings indicate controls while assembled but also beyond disassembly, possibly by establishing spatial constraints sites.

Язык: Английский

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Crossover Interference Mediates Multiscale Patterning Along Meiotic Chromosomes

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2024, Номер unknown

Опубликована: Янв. 31, 2024

The classical phenomenon of crossover interference is a one-dimensional spatial patterning process that produces evenly spaced crossovers during meiosis. Quantitative analysis diagnostic molecules along budding yeast chromosomes reveals this also sets up second, interdigitated pattern related but longer periodicity, in "two-tiered" process. second tier corresponds to previously mysterious minority set crossovers. Thus, toto, the two tiers account for all detected events. Both spatially clustered assemblies three types ("triads") representing major components meiotic (crossover recombination complexes and chromosome axis synaptonemal complex components), give focal domainal signals, respectively. Roles are suggested. All observed effects economically synthetically explained if mediated by mechanical forces prophase chromosomes. Intensity levels triad further modulated, dynamically, conserved protein remodeler Pch2/TRIP13.

Язык: Английский

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COSA-1 mediated pro-crossover complex formation promotes meiotic crossing over in C. elegans

Nucleic Acids Research, Год журнала: 2024, Номер 52(8), С. 4375 - 4392

Опубликована: Фев. 27, 2024

Accurate chromosome segregation during meiosis requires the establishment of at least one crossover (CO) between each pair homologous chromosomes. CO formation depends on a group conserved pro-CO proteins, which colocalize CO-designated sites late meiotic prophase I. However, it remains unclear whether these proteins form functional complex and how they promote in vivo. Here, we show that COSA-1, key component required for formation, interacts with other factors, MSH-5 ZHP-3, via its N-terminal disordered region. Point mutations impair interactions do not affect designation, but strongly hinder accumulation COSA-1 result defective formation. These defects can be partially bypassed by artificially tethering an interaction-compromised derivate to ZHP-3. Furthermore, revealed into distinct foci is assemble 'recombination nodules'. prevent early recombination intermediates from being dismantled RTEL-1 helicase protect intermediates, such as Holliday junctions, until are resolved CO-specific resolvases. Altogether, our findings provide insight mediated assembly contribution

Язык: Английский

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Formation and resolution of meiotic chromosome entanglements and interlocks

Journal of Cell Science, Год журнала: 2024, Номер 137(13)

Опубликована: Июль 1, 2024

ABSTRACT Interactions between parental chromosomes during the formation of gametes can lead to entanglements, entrapments and interlocks unrelated chromosomes. If unresolved, these topological constraints misregulation exchanges chromosome mis-segregation. Interestingly, configurations are largely resolved by time aligned pachytene. In this Review, we highlight inevitability topologically complex discuss possible mechanisms resolve them. We focus on dynamic nature a conserved chromosomal interface – synaptonemal movements that accompany meiosis as potential constraints. advantages nematode Caenorhabditis elegans for understanding biophysical features axis could contribute underlying interlock resolution. addition, using zebrafish, Danio rerio, model understand how entanglements avoided resolved.

Язык: Английский

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