Centromere scission drives chromosome shuffling and reproductive isolation

Proceedings of the National Academy of Sciences, Год журнала: 2020, Номер 117(14), С. 7917 - 7928

Опубликована: Март 19, 2020

A fundamental characteristic of eukaryotic organisms is the generation genetic variation via sexual reproduction. Conversely, significant large-scale genome structure variations could hamper reproduction, causing reproductive isolation and promoting speciation. The underlying processes behind rearrangements are not well understood include chromosome translocations involving centromeres. Recent genomic studies in Cryptococcus species complex revealed that generated centromere recombination have reshaped genomes different species. In this study, multiple DNA double-strand breaks (DSBs) were CRISPR/Cas9 system at centromere-specific retrotransposons human fungal pathogen neoformans resulting DSBs repaired a manner, leading to formation interchromosomal new telomeres, similar chromothripsis-like events. newly strains harboring exhibited normal vegetative growth but failed undergo successful reproduction with parental wild-type strain. One these produce any spores, while another produced ∼3% viable progeny. germinated progeny aneuploidy for chromosomes showed improved fertility both parents. All translocation events accompanied without detectable change gene sequences thus suggest chromosomal alone may play an underappreciated role onset

Язык: Английский

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The evolving species concepts used for yeasts: from phenotypes and genomes to speciation networks

Fungal Diversity, Год журнала: 2021, Номер 109(1), С. 27 - 55

Опубликована: Июнь 26, 2021

Here we review how evolving species concepts have been applied to understand yeast diversity. Initially, a phenotypic concept was utilized taking into consideration morphological aspects of colonies and cells, growth profiles. Later the biological added, which data from mating experiments. Biophysical measurements DNA similarity between isolates were an early measure that became more broadly with advent sequencing technology, leading sequence-based using comparisons parts ribosomal DNA. At present phylogenetic employ sequence rDNA other genes are universally in fungal taxonomy, including yeasts, because various studies revealed relatively good correlation divergence. The application genome information is becoming increasingly common, strongly recommend use complete, rather than draft genomes improve our understanding their genetic dynamics. Complete allow in-depth on evolvability and, consequently, they belong. Hybridization seems common phenomenon has observed all major lineages contain yeasts. Note hybrids may greatly differ post-hybridization development. Future studies, initially some model or complexes shift traditional as isolated clusters genetically compatible cohesive speciation network such interconnected by processes, hybridization.

Язык: Английский

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Essential genes encoded by the mating-type locus of the human fungal pathogen Cryptococcus neoformans

mBio, Год журнала: 2025, Номер unknown

Опубликована: Фев. 25, 2025

ABSTRACT Fungal sexual reproduction is controlled by the mating-type ( MAT ) locus. In contrast to a majority of species in phylum Basidiomycota that have tetrapolar systems, opportunistic human pathogen Cryptococcus neoformans employs bipolar system, with two mating types and α) determined single locus unusually large (~120 kb) contains more than 20 genes. While several genes are associated development, others control conserved cellular processes (e.g., cargo transport protein synthesis), which five MYO2 , PRT1 RPL22 RPL39 RPO41 been hypothesized be essential. this study, through genetic analysis involving sporulation heterozygous diploid deletion mutants, as well some cases construction analyses conditional expression alleles these genes, we confirmed exception both other four indeed essential for cell viability. We further showed while not essential, its function critical infectious spore production, faithful cytokinesis, adaptation growth at high temperature, pathogenicity vivo . Our results demonstrate presence divergent between cells opposite types. discuss possible mechanisms maintain functional rapidly evolving genomic region context fungal evolution. IMPORTANCE Sexual long-term evolutionary success. cell-type identity governed locus, typically highly different show α encoded C. fifth gene, had predicted fact dispensable However, allele important cytokinesis pathogenicity. study highlights need careful determining complementary high-throughput approaches. Additionally, provides insights into function, maintenance, evolution fast-evolving regions.

Язык: Английский

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On the evolution of variation in sexual reproduction through the prism of eukaryotic microbes

Proceedings of the National Academy of Sciences, Год журнала: 2023, Номер 120(10)

Опубликована: Март 3, 2023

Almost all eukaryotes undergo sexual reproduction to generate diversity and select for fitness in their population pools. Interestingly, the systems by which sex is defined are highly diverse can even differ between evolutionarily closely related species. While most commonly known form of determination involves males females animals, eukaryotic microbes have as many thousands different mating types same Furthermore, some species found alternatives prefer grow clonally yet infrequent facultative reproduction. These organisms mainly invertebrates microbes, but several examples also present among vertebrates suggesting that alternative modes evolved multiple times throughout evolution. In this review, we summarize sex-determination variants across tree life suggest provide unique opportunities study these processes detail. We propose understanding variations serve a foundation evolution why how it first place.

Язык: Английский

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Distinct evolutionary trajectories following loss of RNA interference in Cryptococcus neoformans

Proceedings of the National Academy of Sciences, Год журнала: 2024, Номер 121(47)

Опубликована: Ноя. 13, 2024

While increased mutation rates typically have negative consequences in multicellular organisms, hypermutation can be advantageous for microbes adapting to the environment. Previously, we identified two hypermutator

Язык: Английский

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Mating-Type Locus Organization and Mating-Type Chromosome Differentiation in the Bipolar Edible Button Mushroom Agaricus bisporus

Genes, Год журнала: 2021, Номер 12(7), С. 1079 - 1079

Опубликована: Июль 16, 2021

In heterothallic basidiomycete fungi, sexual compatibility is restricted by mating types, typically controlled two loci: PR, encoding pheromone precursors and receptors, HD, types of homeodomain transcription factors. We analysed the single mating-type locus commercial button mushroom variety, Agaricus bisporus var. bisporus, related variety burnettii. identified location using genetic map genome information, corresponding to HD locus, PR having lost its role. found mip1 β-fg genes flanking as in several Agaricomycetes, copies gene, an additional HD2 copy reference A. HD1 detected a 140 kb-long inversion between burnettii heterokaryon, trapping genes, gene fragments genes. The varieties had islands transposable elements at spanning 35 kb genome. Linkage analyses showed region with low recombination variety. high differentiation alleles both varieties, indicating ancient event suppression, followed more recently suppression through across whole chromosomes constituting stepwise many other sex chromosomes.

Язык: Английский

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Factors enforcing the species boundary between the human pathogens Cryptococcus neoformans and Cryptococcus deneoformans

PLoS Genetics, Год журнала: 2021, Номер 17(1), С. e1008871 - e1008871

Опубликована: Янв. 19, 2021

Hybridization has resulted in the origin and variation extant species, hybrids continue to arise despite pre- post-zygotic barriers that limit their formation evolutionary success. One important system maintains species boundaries prokaryotes eukaryotes is mismatch repair pathway, which blocks recombination between divergent DNA sequences. Previous studies illuminated role of component Msh2 blocking genetic during meiosis. Loss results increased interspecific bacterial yeast models, viability progeny derived from hybrid crosses. Hybrid isolates two pathogenic fungal Cryptococcus neoformans deneoformans , are isolated regularly both clinical environmental sources. In present study, we sought determine if loss would relax boundary C . We found crosses these parents lack produced with high levels aneuploidy. Whole-genome sequencing revealed few instances among did not identify lacking Msh2. Several structures associated sexual reproduction when incubated alone on nutrient-rich medium light, a novel phenotype These findings represent unique, unexpected case where rendering defective result meiotic across boundary. This suggests alternative pathways or other components homeologous enforce basidiomycete species.

Язык: Английский

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An evolutionary genomic approach reveals both conserved and species-specific genetic elements related to human disease in closely related Aspergillus fungi

Genetics, Год журнала: 2021, Номер 218(2)

Опубликована: Май 4, 2021

Aspergillosis is an important opportunistic human disease caused by filamentous fungi in the genus Aspergillus. Roughly 70% of infections are Aspergillus fumigatus, with rest stemming from approximately a dozen other species. Several these pathogens closely related to A. fumigatus and belong same taxonomic section, section Fumigati. Pathogenic species frequently most nonpathogenic ones, suggesting pathogenicity evolved multiple times independently. To understand repeated evolution pathogenicity, we performed comparative genomic analyses on 18 strains 13 species, including 8 Fumigati, which aimed identify genes, both ones previously connected virulence as well never before implicated, whose differs between nonpathogens. We found that genes were present all half those virulence, but few section- or species-specific. Evolutionary rate identified over 1700 evolutionary differed nonpathogens dozens rates specific taxa. Functional testing deletion mutants 17 transcription factor-encoding eight affect either fungal survival model phagocytic killing, host animal disease, both. These results suggest involved conserved species-specific genetic elements, illustrating how approach informs study disease.

Язык: Английский

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Illuminating the Cryptococcus neoformans species complex: unveiling intracellular structures with fluorescent-protein-based markers

Genetics, Год журнала: 2024, Номер 227(3)

Опубликована: Май 16, 2024

Abstract Cryptococcus neoformans is a fungal pathogen of the top critical priority recognized by World Health Organization. This clinically important fungus also serves as eukaryotic model organism. A variety resources have been generated to facilitate investigation C. species complex, including congenic pairs, well-annotated genomes, genetic editing tools, and gene deletion sets. Here, we set strains with all major organelles fluorescently marked. We tested short organelle-specific targeting sequences successfully labeled following fusing fluorescence protein: plasma membrane, nucleus, peroxisome, mitochondrion. used native cryptococcal Golgi late endosomal proteins fused fluorescent protein label these two organelles. These markers were verified via colocalization using dyes. All constructs for tags integrated in an intergenic safe haven region. organelle-marked examined growth various phenotypes. demonstrated that tagged could be employed track interaction host phagocytosis assays. allowed us discover remarkable differences dynamics targeted different during sexual reproduction. Additionally, revealed “dormant” spores transcribed synthesized their own trafficked appropriate subcellular compartments, demonstrating are metabolically active. anticipate newly will greatly further biology pathogenesis.

Язык: Английский

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Homeodomain protein Sxi1α regulates cell-cell fusion during distinct sexual reproduction modes inCryptococcus deneoformans

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2025, Номер unknown

Опубликована: Фев. 14, 2025

Sex-specific homeodomain ( HD ) proteins are key regulators of cell identity and sexual development in fungi, typically functioning as heterodimers to regulate transcription. In the human fungal pathogens Cryptococcus neoformans deneoformans , Sxi1α Sxi2 a (sex-induced 1α 2 have been characterized interacting partners that play critical roles during x α reproduction. Given dominance cells natural populations unisexual reproduction, which predominantly involves same-sex (α α) mating, remain unclear. To elucidate functions we first used AlphaFold3 predict their structures, revealed potential for both heterodimeric homodimeric complexes. We subsequently deleted SXI1 SXI2 hyperfilamentous self-fertile C. strains XL280 XL280α. Disruption these genes did not result noticeable defects vegetative growth, virulence-associated traits, colony morphology, sporulation, or competitiveness either crosses. Surprisingly, absence significantly increased cell-cell fusion rate suggesting novel inhibitory role Sxi1α, independent partner . Together, our findings an unexpected function regulating fusion, may contribute predominance MAT isolates global conservation population is mating type.

Язык: Английский

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