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

PLoS Genetics, Journal Year: 2024, Volume and Issue: 20(6), P. e1011329 - e1011329

Published: June 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.

Language: Английский

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

Molecular Biology and Evolution, Journal Year: 2024, Volume and Issue: 41(3)

Published: Feb. 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.

Language: Английский

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Uncharted territories: Solving the mysteries of male meiosis in flies

PLoS Genetics, Journal Year: 2024, Volume and Issue: 20(3), P. e1011185 - e1011185

Published: March 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.

Language: 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, Journal Year: 2024, Volume and Issue: 41(9)

Published: Aug. 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.

Language: Английский

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The functional organisation of the centromere and kinetochore during meiosis

Current Opinion in Cell Biology, Journal Year: 2025, Volume and Issue: 94, P. 102486 - 102486

Published: Feb. 26, 2025

Language: Английский

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CTCF-anchored chromatin loop dynamics during human meiosis

BMC Biology, Journal Year: 2025, Volume and Issue: 23(1)

Published: March 20, 2025

Abstract Background During meiosis, the mammalian genome is organised within chromatin loops, which facilitate synapsis, crossing over and chromosome segregation, setting stage for recombination events generation of genetic diversity. Chromatin looping thought to play a major role in establishment cross overs during prophase I diploid early primary spermatocytes. However, conformation dynamics human meiosis are difficult study experimentally, due transience each cell division difficulty obtaining stage-resolved populations. Here, we employed machine learning framework trained on single ATAC-seq RNA-seq data predict CTCF-anchored spermatogenesis, including types at different stages meiosis. Results We find dramatic changes genome-wide patterns throughout meiosis: compared pre-and-post meiotic germline types, loops spermatocytes more abundant, variable between individual cells, evenly spread genome. In preparation first division, also include longer stretches DNA, encompassing than half total These loop structures then influence rate initiation resolution as overs. contrast, later mature sperm stages, evidence compaction, with being confined telomeric ends chromosomes. Conclusion Overall, that do not orchestrate gene expression seen but important roles recombination, influencing positions DNA breakage events.

Language: Английский

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Light-controlled Spo11-less meiotic DNA breaks by MagTAQing lead to chromosomal aberrations

Nucleic Acids Research, Journal Year: 2025, Volume and Issue: 53(7)

Published: April 10, 2025

Abstract TAQing technologies are based on the restriction enzyme-induced DNA double-strand break (DSB) formation in living cells, which results large-scale genomic rearrangements and phenotypic alterations. Originally, system requires heat treatments to activate enzymes, sometimes leads cell toxicity or stress responses. Here, we developed a blue-light-controlled MagTAQing system, induces DSBs exclusively upon blue-light exposure by assembling split enzymes via Magnet modules. Application of mitotic budding yeast cells successfully triggered various exposure. Since this technology enables conditional induction specific tissues, employed meiotic lacking recombinase Spo11 induce artificial DSBs. Consequently, Spo11-independent resulted aneuploidies nonallelic homologous recombinations between repetitive sequences such as ribosomal retrotransposons. These suggest pivotal role Spo11-induced recombination preventing chromosomal abnormality.

Language: Английский

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Mapping of meiotic recombination in human preimplantation blastocysts

G3 Genes Genomes Genetics, Journal Year: 2023, Volume and Issue: 13(4)

Published: Feb. 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.

Language: Английский

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

PLoS Genetics, Journal Year: 2023, Volume and Issue: 19(2), P. e1010347 - e1010347

Published: Feb. 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

Language: Английский

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

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

Published: Jan. 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.

Language: Английский

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