RESUMEN
Trichoderma reesei is an economically important enzyme producer with several unique meiotic features. spo11, the initiator of meiotic double-strand breaks (DSBs) in most sexual eukaryotes, is dispensable for T. reesei meiosis. T. reesei lacks the meiosis-specific recombinase Dmc1. Rad51 and Sae2, the activator of the Mre11 endonuclease complex, promote DSB repair and chromosome synapsis in wild-type and spo11Δ meiosis. DNA methyltransferases (DNMTs) perform multiple tasks in meiosis. Three DNMT genes (rid1, dim2 and dimX) differentially regulate genome-wide cytosine methylation and C:G-to-T:A hypermutations in different chromosomal regions. We have identified two types of DSBs: type I DSBs require spo11 or rid1 for initiation, whereas type II DSBs do not rely on spo11 and rid1 for initiation. rid1 (but not dim2) is essential for Rad51-mediated DSB repair and normal meiosis. rid1 and rad51 exhibit a locus heterogeneity (LH) relationship, in which LH-associated proteins often regulate interconnectivity in protein interaction networks. This LH relationship can be suppressed by deleting dim2 in a haploid rid1Δ (but not rad51Δ) parental strain, indicating that dim2 and rid1 share a redundant function that acts earlier than rad51 during early meiosis. In conclusion, our studies provide the first evidence of the involvement of DNMTs during meiotic initiation and recombination.
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Serine(S)/threonine(T)-glutamine(Q) cluster domains (SCDs), polyglutamine (polyQ) tracts and polyglutamine/asparagine (polyQ/N) tracts are Q-rich motifs found in many proteins. SCDs often are intrinsically disordered regions that mediate protein phosphorylation and protein-protein interactions. PolyQ and polyQ/N tracts are structurally flexible sequences that trigger protein aggregation. We report that due to their high percentages of STQ or STQN amino acid content, four SCDs and three prion-causing Q/N-rich motifs of yeast proteins possess autonomous protein expression-enhancing activities. Since these Q-rich motifs can endow proteins with structural and functional plasticity, we suggest that they represent useful toolkits for evolutionary novelty. Comparative Gene Ontology (GO) analyses of the near-complete proteomes of 26 representative model eukaryotes reveal that Q-rich motifs prevail in proteins involved in specialized biological processes, including Saccharomyces cerevisiae RNA-mediated transposition and pseudohyphal growth, Candida albicans filamentous growth, ciliate peptidyl-glutamic acid modification and microtubule-based movement, Tetrahymena thermophila xylan catabolism and meiosis, Dictyostelium discoideum development and sexual cycles, Plasmodium falciparum infection, and the nervous systems of Drosophila melanogaster, Mus musculus and Homo sapiens. We also show that Q-rich-motif proteins are expanded massively in 10 ciliates with reassigned TAAQ and TAGQ codons. Notably, the usage frequency of CAGQ is much lower in ciliates with reassigned TAAQ and TAGQ codons than in organisms with expanded and unstable Q runs (e.g. D. melanogaster and H. sapiens), indicating that the use of noncanonical stop codons in ciliates may have coevolved with codon usage biases to avoid triplet repeat disorders mediated by CAG/GTC replication slippage.
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Dictyostelium , Drosophila melanogaster , Animales , Ratones , Codón de Terminación/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Dictyostelium/genética , Proteínas Fúngicas/metabolismo , Glutamina/metabolismoRESUMEN
Establishing apicobasal polarity, involving intricate interactions among polarity regulators, is key for epithelial cell function. Though phosphatase of regenerating liver (PRL) proteins are implicated in diverse biological processes, including cancer, their developmental role remains unclear. In this study, we explore the role of Drosophila PRL (dPRL) in photoreceptor cell development. We reveal that dPRL, requiring a C-terminal prenylation motif, is highly enriched in the apical membrane of developing photoreceptor cells. Moreover, dPRL knockdown during retinal development results in adult Drosophila retinal degeneration, caused by hid-induced apoptosis. dPRL depletion also mislocalizes cell adhesion and polarity proteins like Armadillo, Crumbs, and DaPKC and relocates the basolateral protein, alpha subunit of Na+/K+-ATPase, to the presumed apical membrane. Importantly, this polarity disruption is not secondary to apoptosis, as suppressing hid expression does not rescue the polarity defect in dPRL-depleted photoreceptor cells. These findings underscore dPRL's crucial role in photoreceptor cell polarity and emphasize PRL's importance in establishing epithelial polarity and maintaining cell survival during retinal development, offering new insights into PRL's role in normal epithelium.
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Proteínas de Drosophila , Drosophila , Animales , Drosophila/metabolismo , Proteínas de Drosophila/metabolismo , Monoéster Fosfórico Hidrolasas/metabolismo , Células Fotorreceptoras de Invertebrados/metabolismo , Hígado/metabolismo , Polaridad Celular/genéticaRESUMEN
In recent years, brain diseases have seriously threatened human health due to their high morbidity and mortality. Achieving efficient drug delivery to provide satisfactory therapeutic outcomes is currently the greatest challenge in treating brain diseases. The main challenges are the structural peculiarities of the brain and the inability to transport drugs across the blood-brain barrier. Biomimetic nanodelivery systems (BNDSs) applied to the brain have been extensively developed in the preclinical phase to surmount these challenges. Considering the inherent properties of BNDSs, the substantially enhanced ability of BNDS to carry therapeutic agents and their higher selectivity toward lesions offer new opportunities for developing safe and effective therapies. This review summarizes brain-targeting nanotherapies, particularly advanced therapies with biomimetic nano-assistance. Prospects for developing BNDSs and the challenges of their clinical translation are discussed. Understanding and implementing biomimetic nanotherapies may facilitate the development of new targeted strategies for brain disorders.
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Encefalopatías , Nanopartículas , Humanos , Sistema de Administración de Fármacos con Nanopartículas , Nanomedicina , Biomimética , Encéfalo , Sistemas de Liberación de Medicamentos , Barrera HematoencefálicaRESUMEN
Background and Aim: Ropeginterferon alfa-2b is a novel mono-pegylated, extra-long-acting interferon. It is administered infrequently and showed good tolerability and clinical activity for the chronic hepatitis B or C treatment in our previous Phase 2 clinical trials. This study aims to validate the potency and safety of this novel agent in a Phase 3 chronic viral hepatitis setting. Methods: Patients with chronic hepatitis C genotype 2 were randomized to receive subcutaneous injections of ropeginterferon alfa-2b biweekly or the conventional pegylated interferon alfa-2b weekly for 24 weeks, combined with ribavirin. The primary endpoint was to assess the safety and antiviral potency of ropeginterferon alfa-2b by the non-inferiority in sustained virologic response at 12 weeks after treatment. Results: A total of 222 patients were enrolled. Ropeginterferon alfa-2b group showed a favorable safety profile. Side effects that were generally associated with prior interferon therapies, including neutropenia, asthenia, fatigue, alopecia, dizziness, decreased appetite, nausea, flu-like symptoms including myalgia, pyrexia, and headache, and administration site reactions, were notably less in the ropeginterferon alfa-2b group. The cumulative incidence of adverse events of special interest was also notably higher in the control group. The primary endpoint was met and ropeginterferon alfa-2b showed a better SVR12 rate of 79.8% than 71.9% of the control group. Conclusion: Ropeginterferon alfa-2b is efficacious and has a favorable safety profile as compared with the conventional pegylated interferon alfa-2b. This study together with previous Phase 2 data validated ropeginterferon alfa-2b to be a new treatment option for chronic hepatitis C genotype 2.
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Many synaptic proteins form biological condensates via liquid-liquid phase separation (LLPS). Synaptopathy, a key feature of autism spectrum disorders (ASD), is likely relevant to the impaired phase separation and/or transition of ASD-linked synaptic proteins. Here, we report that LLPS and zinc-induced liquid-to-gel phase transition regulate the synaptic distribution and protein-protein interaction of cortactin-binding protein 2 (CTTNBP2), an ASD-linked protein. CTTNBP2 forms self-assembled condensates through its C-terminal intrinsically disordered region and facilitates SHANK3 co-condensation at dendritic spines. Zinc binds the N-terminal coiled-coil region of CTTNBP2, promoting higher-order assemblies. Consequently, it leads to reduce CTTNBP2 mobility and enhance the stability and synaptic retention of CTTNBP2 condensates. Moreover, ASD-linked mutations alter condensate formation and synaptic retention of CTTNBP2 and impair mouse social behaviors, which are all ameliorated by zinc supplementation. Our study suggests the relevance of condensate formation and zinc-induced phase transition to the synaptic distribution and function of ASD-linked proteins.
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Trastorno Autístico , Animales , Trastorno Autístico/genética , Ratones , Proteínas de Microfilamentos/metabolismo , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Conducta Social , Zinc/metabolismoRESUMEN
Taiwanofungus camphoratus mushrooms are a complementary and alternative medicine for hangovers, cancer, hypertension, obesity, diabetes, and inflammation. Though Taiwanofungus camphoratus has attracted considerable biotechnological and pharmacological attention, neither classical genetic nor genomic approaches have been properly established for it. We isolated four sexually competent monokaryons from two T. camphoratus dikaryons used for the commercial cultivation of orange-red (HC1) and milky-white (SN1) mushrooms, respectively. We also sequenced, annotated, and comparatively analyzed high-quality and chromosome-level genome sequences of these four monokaryons. These genomic resources represent a valuable basis for understanding the biology, evolution, and secondary metabolite biosynthesis of this economically important mushrooms. We demonstrate that T. camphoratus has a tetrapolar mating system and that HC1 and SN1 represent two intraspecies isolates displaying karyotypic variation. Compared with several edible mushroom model organisms, T. camphoratus underwent a significant contraction in the gene family and individual gene numbers, most notably for plant, fungal, and bacterial cell-wall-degrading enzymes, explaining why T. camphoratus mushrooms are rare in natural environments, are difficult and time-consuming to artificially cultivate, and are susceptible to fungal and bacterial infections. Our results lay the foundation for an in-depth T. camphoratus study, including precise genetic manipulation, improvements to mushroom fruiting, and synthetic biology applications for producing natural medicinal products. IMPORTANCETaiwanofungus camphoratus (Tc) is a basidiomycete fungus that causes brown heart rot of the aromatic tree Cinnamomum kanehirae. The Tc fruiting bodies have been used to treat hangovers, abdominal pain, diarrhea, hypertension, and other diseases first by aboriginal Taiwanese and later by people in many countries. To establish classical genetic and genomic approaches for this economically important medicinal mushroom, we first isolated and characterized four sexually competent monokaryons from two dikaryons wildly used for commercial production of Tc mushrooms. We applied PacBio single molecule, real-time sequencing technology to determine the near-completed genome sequences of four monokaryons. These telomere-to-telomere and gapless haploid genome sequences reveal all genomic variants needed to be studied and discovered, including centromeres, telomeres, retrotransposons, mating type loci, biosynthetic, and metabolic gene clusters. Substantial interspecies diversities are also discovered between Tc and several other mushroom model organisms, including Agrocybe aegerita, Coprinopsis cinerea, and Schizophyllum commune, and Ganoderma lucidum.
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Cromosomas , Genómica , Polyporales/genética , Polyporales/metabolismo , Secuenciación Completa del Genoma , Agaricales , Basidiomycota , Cuerpos Fructíferos de los Hongos/genética , Humanos , Micelio , Metabolismo Secundario/genética , Análisis de Secuencia de ADN , TranscriptomaRESUMEN
AIMS: Ropeginterferon alfa-2b is a novel, long-acting pegylated interferon alfa-2b. We aimed to evaluate its safety, pharmacokinetics (PK) and pharmacodynamics (PD). METHODS: Thirty-six subjects received single subcutaneous injection of ropeginterferon alfa-2b at doses ranging from 24 to 270 µg, and 12 subjects received pegylated IFN alfa-2a subcutaneously at 180 µg. Primary endpoints were safety/PK profiles of ropeginterferon alfa-2b, while secondary endpoints were to compare PK/PD parameters with pegylated IFN alfa-2a. RESULTS: Adverse events in ropeginterferon alfa-2b and pegylated IFN alfa-2a groups were similar, and most of them were mild or moderate. Mean Cmax increased from 1.78 to 24.84 ng/mL along with the dose escalations in ropeginterferon alfa-2b groups and was 12.95 ng/mL for pegylated IFN alfa-2a. At 180 µg, ropeginterferon alfa-2b showed statistically significant Cmax geometric mean ratio (1.76; P = .0275). Mean Tmax ranged from 74.52 to 115.69 h for ropeginterferon alfa-2b groups, and was 84.25 h for pegylated IFN alfa-2a. Mean AUC0-t increased from 372.3 to 6258 ngâ¢h/mL with the dose escalations in the ropeginterferon alfa-2b groups, while for pegylated IFN alfa-2a it was found to be 2706 ngâ¢h/mL in pegylated IFN alfa-2a. For neopterin and 2',5'-oligoadenylate synthase, mean Emax , Tmax and AUC0-t of ropeginterferon alfa-2b were similar to those of pegylated IFNα-2a at 180 µg. CONCLUSION: Ropeginterferon alfa-2b up to 270 µg was safe and well tolerated. The PK/PD parameters of ropeginterferon alfa-2b showed increase in dose-response. Ropeginterferon alfa-2b had higher drug exposures and showed similar safety profile when compared to pegylated IFN alfa-2a at the same dose level.
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Antivirales , Interferón-alfa , Antivirales/efectos adversos , Humanos , Interferón alfa-2/efectos adversos , Interferón-alfa/efectos adversos , Polietilenglicoles/efectos adversos , Proteínas Recombinantes/efectos adversosRESUMEN
Trichoderma spp. represent one of the most important fungal genera to mankind and in natural environments. The genus harbors prolific producers of wood-decaying enzymes, biocontrol agents against plant pathogens, plant-growth-promoting biofertilizers, as well as model organisms for studying fungal-plant-plant pathogen interactions. Pursuing highly accurate, contiguous, and chromosome-level reference genomes has become a primary goal of fungal research communities. Here, we report the chromosome-level genomic sequences and whole-genome annotation data sets of four strains used as biocontrol agents or biofertilizers (Trichoderma virens Gv29-8, Trichoderma virens FT-333, Trichoderma asperellum FT-101, and Trichoderma atroviride P1). Our results provide comprehensive categorization, correct positioning, and evolutionary detail of both nuclear and mitochondrial genomes, including telomeres, AT-rich blocks, centromeres, transposons, mating-type loci, nuclear-encoded mitochondrial sequences, as well as many new secondary metabolic and carbohydrate-active enzyme gene clusters. We have also identified evolutionarily conserved core genes contributing to plant-fungal interactions, as well as variations potentially linked to key behavioral traits such as sex, genome defense, secondary metabolism, and mycoparasitism. The genomic resources we provide herein significantly extend our knowledge not only of this economically important fungal genus, but also fungal evolution and basic biology in general. IMPORTANCE Telomere-to-telomere and gapless reference genome assemblies are necessary to ensure that all genomic variants are studied and discovered, including centromeres, telomeres, AT-rich blocks, mating type loci, biosynthetic, and metabolic gene clusters. Here, we applied long-range sequencing technologies to determine the near-completed genome sequences of four widely used biocontrol agents or biofertilizers: Trichoderma virens Gv29-8 and FT-333, Trichoderma asperellum FT-101, and Trichoderma atroviride P1. Like those of three Trichoderma reesei wild isolates [QM6a, CBS999.97(MAT1-1) and CBS999.97(MAT1-2)] we reported previously, these four biocontrol agent genomes each contain seven nuclear chromosomes and a circular mitochondrial genome. Substantial intraspecies and intragenus diversities are also discovered, including single nucleotide polymorphisms, chromosome shuffling, as well as genomic relics derived from historical transposition events and repeat-induced point (RIP) mutations.
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Agentes de Control Biológico/química , Genoma Fúngico , Trichoderma/crecimiento & desarrollo , Trichoderma/genética , Evolución Molecular , Fertilizantes/análisis , Variación Genética , Filogenia , Plantas/microbiología , Metabolismo Secundario , Trichoderma/clasificación , Trichoderma/metabolismoRESUMEN
Toll-like receptor (TLR) signaling is critical for defense against pathogenic infection, as well as for modulating tissue development. Activation of different TLRs triggers common inflammatory responses such as cytokine induction. Here, we reveal differential impacts of TLR3 and TLR7 signaling on transcriptomic profiles in bone marrow-derived macrophages (BMDMs). Apart from self-regulation, TLR3, but not TLR7, induced expression of other TLRs, suggesting that TLR3 activation globally enhances innate immunity. Moreover, we observed diverse influences of TLR3 and TLR7 signaling on genes involved in methylation, caspase and autophagy pathways. We compared endogenous TLR3 and TLR7 by using CRISPR/Cas9 technology to knock in a dual Myc-HA tag at the 3' ends of mouse Tlr3 and Tlr7. Using anti-HA antibodies to detect endogenous tagged TLR3 and TLR7, we found that both TLRs display differential tissue expression and posttranslational modifications. C-terminal tagging did not impair TLR3 activity. However, it disrupted the interaction between TLR7 and myeloid differentiation primary response 88 (MYD88), the Tir domain-containing adaptor of TLR7, which blocked its downstream signaling necessary to trigger cytokine and chemokine expression. Our study demonstrates different properties for TLR3 and TLR7, and also provides useful mouse models for further investigation of these two RNA-sensing TLRs.
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Epítopos/metabolismo , Macrófagos/metabolismo , Glicoproteínas de Membrana/fisiología , Neuronas/metabolismo , Receptor Toll-Like 3/fisiología , Receptor Toll-Like 7/fisiología , Animales , Quimiocinas/metabolismo , Citocinas/metabolismo , Epítopos/inmunología , Femenino , Perfilación de la Expresión Génica , Inmunidad Innata , Macrófagos/inmunología , Masculino , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , Factor 88 de Diferenciación Mieloide/metabolismo , Factor 88 de Diferenciación Mieloide/fisiología , Transducción de Señal , Receptor Toll-Like 3/genética , Receptor Toll-Like 3/metabolismo , Receptor Toll-Like 7/genética , Receptor Toll-Like 7/metabolismoRESUMEN
Most eukaryotes possess two RecA-like recombinases (ubiquitous Rad51 and meiosis-specific Dmc1) to promote interhomolog recombination during meiosis. However, some eukaryotes have lost Dmc1. Given that mammalian and yeast Saccharomyces cerevisiae (Sc) Dmc1 have been shown to stabilize recombination intermediates containing mismatches better than Rad51, we used the Pezizomycotina filamentous fungus Trichoderma reesei to address if and how Rad51-only eukaryotes conduct interhomolog recombination in zygotes with high sequence heterogeneity. We applied multidisciplinary approaches (next- and third-generation sequencing technology, genetics, cytology, bioinformatics, biochemistry, and single-molecule biophysics) to show that T. reesei Rad51 (TrRad51) is indispensable for interhomolog recombination during meiosis and, like ScDmc1, TrRad51 possesses better mismatch tolerance than ScRad51 during homologous recombination. Our results also indicate that the ancestral TrRad51 evolved to acquire ScDmc1-like properties by creating multiple structural variations, including via amino acid residues in the L1 and L2 DNA-binding loops.
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Proteínas de Ciclo Celular/metabolismo , Proteínas de Unión al ADN/metabolismo , Proteínas Fúngicas/metabolismo , Genoma Fúngico , Recombinación Homóloga , Hypocreales/metabolismo , Meiosis , Recombinasa Rad51/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Ciclo Celular/genética , ADN de Cadena Simple , Proteínas de Unión al ADN/genética , Proteínas Fúngicas/genética , Hypocreales/genética , Recombinasa Rad51/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genéticaRESUMEN
The RecA-family recombinase Rad51 is the central player in homologous recombination (HR), the faithful pathway for repairing DNA double-strand breaks (DSBs) during both mitosis and meiosis. The behavior of Rad51 protein in vivo is fine-tuned via posttranslational modifications conducted by multiple protein kinases in response to cell cycle cues and DNA lesions. Unrepaired DSBs and ssDNA also activate Mec1ATR and Tel1ATM family kinases to initiate the DNA damage response (DDR) that safeguards genomic integrity. Defects in HR and DDR trigger genome instability and result in cancer predisposition, infertility, developmental defects, neurological diseases or premature aging. Intriguingly, yeast Mec1ATR- and Tel1ATM-dependent phosphorylation promotes Rad51 protein stability during DDR, revealing how Mec1ATR can alleviate proteotoxic stress. Moreover, Mec1ATR- and Tel1ATM-dependent phosphorylation also occurs on DDR-unrelated proteins, suggesting that Mec1ATR and Tel1ATM have a DDR-independent function in protein homeostasis. In this minireview, we first describe how human and budding yeast Rad51 are phosphorylated by multiple protein kinases at different positions to promote homology-directed DNA repair and recombination (HDRR). Then, we discuss recent findings showing that intrinsic structural disorder and Mec1ATR/Tel1ATM-dependent phosphorylation are coordinated in yeast Rad51 to regulate both HR and protein homeostasis.
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Péptidos y Proteínas de Señalización Intracelular/genética , Proteínas Serina-Treonina Quinasas/genética , Recombinasa Rad51/genética , Proteínas de Saccharomyces cerevisiae/genética , Daño del ADN/genética , Homeostasis/genética , Recombinación Homóloga/genética , Humanos , Meiosis/genética , Mitosis/genética , Saccharomyces cerevisiae/genéticaRESUMEN
Single-molecule real-time (SMRT) sequencing developed by Pacific BioSciences (PacBio) offers three major advantages compared to second-generation sequencing: long read length and high consensus accuracy, and a low degree of bias. Together with high sequencing coverage, these advantages overcome the difficulty of sequencing genomic regions such as long AT-rich islands and repeated regions (e.g., ribosomal DNA) in the genome of Trichoderma reesei QM6a. Herein, we describe a protocol for preparing high-quality, high molecular weight genomic DNA for PacBio long-read sequencing, de novo assembly and streamlined annotation of the QM6a genome.
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Genoma Fúngico , Hypocreales/genética , Anotación de Secuencia Molecular , Análisis de Secuencia de ADN/métodos , Programas Informáticos , ADN de Hongos/aislamiento & purificación , Peso Molecular , ARN de Hongos/aislamiento & purificación , Reproducibilidad de los ResultadosRESUMEN
TSETA (Third-generation Sequencing to Enable Tetrad Analysis) is a fungus-centric software pipeline that utilizes chromosome-level sequence assembly for genome-wide and single-nucleotide-resolution mapping of single-nucleotide polymorphisms (SNPs), meiotic recombination products, illegitimate mutations (IMs) and repeat-induced point (RIP) mutations. It utilizes a newly invented algorithm (i.e., BLASTN-guided sectional MAFFT) to perform fast, accurate, and low-cost multiple genome sequence alignments. This new algorithm outcompetes next-generation sequencing (NGS)-based variant-calling approaches for accurate and comprehensive identification of single-nucleotide variants (SNVs) and insertion/deletion mutations (Indels) among the near-complete genome sequences of any two or more intraspecific strains, as well as sequences before and after meiosis, with single-nucleotide precision. TSETA also has a powerful tool for the visualization of the results from the scale of the chromosomal landscape to individual nucleotides. The data output files are user-friendly for researchers and students lacking computational expertise to analyze and reason about data and evidence.
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Biología Computacional/métodos , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Meiosis/genética , Mutación Puntual/genética , Polimorfismo de Nucleótido Simple/genética , Recombinación Genética/genética , Programas Informáticos , Algoritmos , Secuencia de Bases , Marcadores GenéticosRESUMEN
Highly toxic DNA double-strand breaks (DSBs) readily trigger the DNA damage response (DDR) in cells, which delays cell cycle progression to ensure proper DSB repair. In Saccharomyces cerevisiae, mitotic S phase (20-30 min) is lengthened upon DNA damage. During meiosis, Spo11-induced DSB onset and repair lasts up to 5 h. We report that the NH2-terminal domain (NTD; residues 1-66) of Rad51 has dual functions for repairing DSBs during vegetative growth and meiosis. Firstly, Rad51-NTD exhibits autonomous expression-enhancing activity for high-level production of native Rad51 and when fused to exogenous ß-galactosidase in vivo. Secondly, Rad51-NTD is an S/T-Q cluster domain (SCD) harboring three putative Mec1/Tel1 target sites. Mec1/Tel1-dependent phosphorylation antagonizes the proteasomal degradation pathway, increasing the half-life of Rad51 from â¼30 min to ≥180 min. Our results evidence a direct link between homologous recombination and DDR modulated by Rad51 homeostasis.
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Roturas del ADN de Doble Cadena , Endodesoxirribonucleasas/genética , Meiosis/genética , Recombinasa Rad51/genética , Proteínas de Saccharomyces cerevisiae/genética , Daño del ADN/genética , Reparación del ADN/genética , Proteínas de Unión al ADN/genética , Regulación Fúngica de la Expresión Génica/genética , Péptidos y Proteínas de Señalización Intracelular/genética , Fosforilación/genética , Complejo de la Endopetidasa Proteasomal/genética , Dominios Proteicos/genética , Proteínas Serina-Treonina Quinasas/genética , Proteolisis , Saccharomyces cerevisiae/genética , beta-Galactosidasa/genéticaRESUMEN
In Drosophila, the deposition of the germ plasm at the posterior pole of the oocyte is essential for the abdomen and germ cell formation during embryogenesis. To assemble the germ plasm, oskar (osk) mRNA, produced by nurse cells, should be localized and anchored on the posterior cortex of the oocyte. Processing bodies (P-bodies) are cytoplasmic RNA granules responsible for the 5'-3' mRNA degradation. Evidence suggests that the components of P-bodies, such as Drosophila decapping protein 1 and Ge-1, are involved in the posterior localization of osk. However, whether the decapping core enzyme, Drosophila decapping protein 2 (dDcp2), is also involved remains unclear. Herein, we generated a dDcp2 null allele and showed that dDcp2 was required for the posterior localization of germ plasm components including osk. dDcp2 was distributed on the oocyte cortex and was localized posterior to the osk. In the posterior pole of dDcp2 mutant oocytes, osk was mislocalized and colocalized with F-actin detached from the cortex; moreover, considerably fewer F-actin projections were observed. Using the F-actin cosedimentation assay, we proved that dDcp2 interacted with F-actin through its middle region. In conclusion, our findings explored a novel function of dDcp2 in assisting osk localization by modulating the formation of F-actin projections on the posterior cortex.
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Actinas/metabolismo , Proteínas de Drosophila/genética , Drosophila melanogaster/embriología , Desarrollo Embrionario/genética , Animales , Drosophila melanogaster/genética , Oocitos/citología , Isoformas de Proteínas/genética , Estabilidad del ARN/fisiología , ARN Mensajero/genética , ARN Mensajero/metabolismoRESUMEN
Generation of new genetic diversity by crossover (CO) and non-crossover (NCO) is a fundamental process in eukaryotes. Fungi have played critical roles in studying this process because they permit tetrad analysis, which has been used by geneticists for several decades to determine meiotic recombination products. New genetic variations can also be generated in zygotes via illegitimate mutation (IM) and repeat-induced point mutation (RIP). RIP is a genome defense mechanism for preventing harmful expansion of transposable elements or duplicated sequences in filamentous fungi. Although the exact mechanism of RIP is unknown, the C:G to T:A mutations might result from DNA cytosine methylation. A comprehensive approach for understanding the molecular mechanisms underlying these important processes is to perform high-throughput mapping of CO, NCO, RIP and IM in zygotes bearing large numbers of heterozygous variant markers. To this aim, we developed 'TSETA', a versatile and user-friendly pipeline that utilizes high-quality and chromosome-level genome sequences involved in a single meiotic event of the industrial workhorse fungus Trichoderma reesei. TSETA not only can be applied to most sexual eukaryotes for genome-wide tetrad analysis, it also outcompetes most currently used methods for calling out single nucleotide polymorphisms between two or more intraspecies strains or isolates.
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The neuronal innate immune system recognizes endogenous danger signals and regulates neuronal development and function. Toll-like receptor 7 (TLR7), one of the TLRs that trigger innate immune responses in neurons, controls neuronal morphology. To further assess the function of TLR7 in the brain, we applied next generation sequencing to investigate the effect of Tlr7 deletion on gene expression in hippocampal and cortical mixed cultures and on mouse behaviors. Since previous in vivo study suggested that TLR7 is more critical for neuronal morphology at earlier developmental stages, we analyzed two time-points (4 and 18 DIV) to represent young and mature neurons, respectively. At 4 DIV, Tlr7 KO neurons exhibited reduced expression of genes involved in neuronal development, synaptic organization and activity and behaviors. Some of these Tlr7-regulated genes are also associated with multiple neurological and neuropsychiatric diseases. TLR7-regulated transcriptomic profiles differed at 18 DIV. Apart from neuronal genes, genes related to glial cell development and differentiation became sensitive to Tlr7 deletion at 18 DIV. Moreover, Tlr7 KO mice exhibited altered behaviors in terms of anxiety, aggression, olfaction and contextual fear memory. Electrophysiological analysis further showed an impairment of long-term potentiation in Tlr7 KO hippocampus. Taken together, these results indicate that TLR7 regulates neural development and brain function, even in the absence of infectious or pathogenic molecules. Our findings strengthen evidence for the role of the neuronal innate immune system in fine-tuning neuronal morphology and activity and implicate it in neuropsychiatric disorders.
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Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Memoria/fisiología , Receptor Toll-Like 7/genética , Receptor Toll-Like 7/metabolismo , Agresión/fisiología , Animales , Ansiedad/metabolismo , Conducta Animal/fisiología , Depresión/metabolismo , Miedo/fisiología , Hipocampo/metabolismo , Potenciación a Largo Plazo/fisiología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Neurogénesis , Neuroglía/fisiología , Neuronas/fisiología , Olfato/genética , Olfato/fisiología , TranscriptomaRESUMEN
Burkholderia sp. strain WAC0059 was isolated from a fruiting body of the medicinal fungus Antrodia cinnamomea collected in Taiwan. Here, we report the draft genome sequence of this bacterium to facilitate the investigation of its biology.