RESUMO
Western equine encephalitis virus (WEEV) is an arthropod-borne virus (arbovirus) that frequently caused major outbreaks of encephalitis in humans and horses in the early twentieth century, but the frequency of outbreaks has since decreased markedly, and strains of this alphavirus isolated in the past two decades are less virulent in mammals than strains isolated in the 1930s and 1940s1-3. The basis for this phenotypic change in WEEV strains and coincident decrease in epizootic activity (known as viral submergence3) is unclear, as is the possibility of re-emergence of highly virulent strains. Here we identify protocadherin 10 (PCDH10) as a cellular receptor for WEEV. We show that multiple highly virulent ancestral WEEV strains isolated in the 1930s and 1940s, in addition to binding human PCDH10, could also bind very low-density lipoprotein receptor (VLDLR) and apolipoprotein E receptor 2 (ApoER2), which are recognized by another encephalitic alphavirus as receptors4. However, whereas most of the WEEV strains that we examined bind to PCDH10, a contemporary strain has lost the ability to recognize mammalian PCDH10 while retaining the ability to bind avian receptors, suggesting WEEV adaptation to a main reservoir host during enzootic circulation. PCDH10 supports WEEV E2-E1 glycoprotein-mediated infection of primary mouse cortical neurons, and administration of a soluble form of PCDH10 protects mice from lethal WEEV challenge. Our results have implications for the development of medical countermeasures and for risk assessment for re-emerging WEEV strains.
Assuntos
Vírus da Encefalite Equina do Oeste , Especificidade de Hospedeiro , Protocaderinas , Receptores Virais , Animais , Feminino , Humanos , Masculino , Camundongos , Aves/metabolismo , Aves/virologia , Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/virologia , Vírus da Encefalite Equina do Oeste/classificação , Vírus da Encefalite Equina do Oeste/metabolismo , Vírus da Encefalite Equina do Oeste/patogenicidade , Encefalomielite Equina/epidemiologia , Encefalomielite Equina/virologia , Proteínas Relacionadas a Receptor de LDL/metabolismo , Neurônios/metabolismo , Neurônios/virologia , Fenótipo , Protocaderinas/metabolismo , Receptores de LDL/metabolismo , Receptores de LDL/genética , Receptores Virais/metabolismo , Proteínas do Envelope Viral/metabolismo , Zoonoses Virais/epidemiologia , Zoonoses Virais/virologiaRESUMO
Broad-spectrum ß-lactam antibiotic resistance in Staphylococcus aureus is a global healthcare burden1,2. In clinical strains, resistance is largely controlled by BlaR13, a receptor that senses ß-lactams through the acylation of its sensor domain, inducing transmembrane signalling and activation of the cytoplasmic-facing metalloprotease domain4. The metalloprotease domain has a role in BlaI derepression, inducing blaZ (ß-lactamase PC1) and mecA (ß-lactam-resistant cell-wall transpeptidase PBP2a) expression3-7. Here, overcoming hurdles in isolation, we show that BlaR1 cleaves BlaI directly, as necessary for inactivation, with no requirement for additional components as suggested previously8. Cryo-electron microscopy structures of BlaR1-the wild type and an autocleavage-deficient F284A mutant, with or without ß-lactam-reveal a domain-swapped dimer that we suggest is critical to the stabilization of the signalling loops within. BlaR1 undergoes spontaneous autocleavage in cis between Ser283 and Phe284 and we describe the catalytic mechanism and specificity underlying the self and BlaI cleavage. The structures suggest that allosteric signalling emanates from ß-lactam-induced exclusion of the prominent extracellular loop bound competitively in the sensor-domain active site, driving subsequent dynamic motions, including a shift in the sensor towards the membrane and accompanying changes in the zinc metalloprotease domain. We propose that this enhances the expulsion of autocleaved products from the active site, shifting the equilibrium to a state that is permissive of efficient BlaI cleavage. Collectively, this study provides a structure of a two-component signalling receptor that mediates action-in this case, antibiotic resistance-through the direct cleavage of a repressor.
Assuntos
Antibacterianos , Staphylococcus aureus , Resistência beta-Lactâmica , beta-Lactamas , Humanos , Antibacterianos/química , Antibacterianos/farmacologia , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Resistência beta-Lactâmica/efeitos dos fármacos , beta-Lactamas/química , beta-Lactamas/farmacologia , Microscopia Crioeletrônica , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/enzimologia , Staphylococcus aureus/metabolismoRESUMO
BACKGROUND: The Percidae family comprises many fish species of major importance for aquaculture and fisheries. Based on three new chromosome-scale assemblies in Perca fluviatilis, Perca schrenkii, and Sander vitreus along with additional percid fish reference genomes, we provide an evolutionary and comparative genomic analysis of their sex-determination systems. RESULTS: We explored the fate of a duplicated anti-Mullerian hormone receptor type-2 gene (amhr2bY), previously suggested to be the master sex-determining (MSD) gene in P. flavescens. Phylogenetically related and structurally similar amhr2 duplicates (amhr2b) were found in P. schrenkii and Sander lucioperca, potentially dating this duplication event to their last common ancestor around 19-27 Mya. In P. fluviatilis and S. vitreus, this amhr2b duplicate has been likely lost while it was subject to amplification in S. lucioperca. Analyses of the amhr2b locus in P. schrenkii suggest that this duplication could be also male-specific as it is in P. flavescens. In P. fluviatilis, a relatively small (100 kb) non-recombinant sex-determining region (SDR) was characterized on chromosome 18 using population-genomics approaches. This SDR is characterized by many male-specific single-nucleotide variations (SNVs) and no large duplication/insertion event, suggesting that P. fluviatilis has a male heterogametic sex-determination system (XX/XY), generated by allelic diversification. This SDR contains six annotated genes, including three (c18h1orf198, hsdl1, tbc1d32) with higher expression in the testis than in the ovary. CONCLUSIONS: Together, our results provide a new example of the highly dynamic sex chromosome turnover in teleosts and provide new genomic resources for Percidae, including sex-genotyping tools for all three known Perca species.
Assuntos
Evolução Molecular , Processos de Determinação Sexual , Animais , Processos de Determinação Sexual/genética , Masculino , Feminino , Percas/genética , Filogenia , Receptores de Peptídeos/genética , Genoma , Receptores de Fatores de Crescimento Transformadores betaRESUMO
Susumu Ohno proposed that the gene content of the mammalian X Chromosome should remain highly conserved due to dosage compensation. X Chromosome linkage (gene order) conservation is widespread in placental mammals but does not fall within the scope of Ohno's prediction and may be an indirect result of selection on gene content or selection against rearrangements that might disrupt X-Chromosome inactivation (XCI). Previous comparisons between the human and mouse X Chromosome sequences have suggested that although single-copy X Chromosome genes are conserved between species, most ampliconic genes were independently acquired. To better understand the evolutionary and functional constraints on X-linked gene content and linkage conservation in placental mammals, we aligned a new, high-quality, long-read X Chromosome reference assembly from the domestic cat (incorporating 19.3 Mb of targeted BAC clone sequence) to the pig, human, and mouse assemblies. A comprehensive analysis of annotated X-linked orthologs in public databases demonstrated that the majority of ampliconic gene families were present on the ancestral placental X Chromosome. We generated a domestic cat Hi-C contact map from an F1 domestic cat/Asian leopard cat hybrid and demonstrated the formation of the bipartite structure found in primate and rodent inactivated X Chromosomes. Conservation of gene order and recombination patterns is attributable to strong selective constraints on three-dimensional genomic architecture necessary for superloop formation. Species with rearranged X Chromosomes retain the ancestral order and relative spacing of loci critical for superloop formation during XCI, with compensatory inversions evolving to maintain these long-range physical interactions.
Assuntos
Placenta , Cromossomo X , Animais , Gatos/genética , Eutérios/genética , Evolução Molecular , Feminino , Genômica , Camundongos , Gravidez , Suínos , Cromossomo X/genética , Inativação do Cromossomo XRESUMO
Dissymmetrical chiral peropyrenes with electron-rich and electron-deficient aryl substituents in the bay regions were synthesized via iridium-catalyzed C-H activation and alkyne benzannulation. The electronic properties were studied using cyclic and differential pulse voltammetry. The enantiomers were separated and exhibited high glum and gabs values in circularly polarized luminescence (CPL) and circular dichroism (CD), respectively. Variable-temperature NMR experiments were conducted on symmetrical and dissymmetrical chiral peropyrenes to compare the barrier to rotation of the aryl groups in the bay region.
RESUMO
OBJECTIVE: To derive and validate a simple, accurate CPR to predict future independent walking ability after SCI at the bedside that does not rely on motor scores and is predictive for those initially classified in the middle of the SCI severity spectrum. DESIGN: Retrospective cohort study. Binary variables were derived, indicating degrees of sensation to evaluate predictive value of pinprick and light touch variables across dermatomes. The optimal single sensory modality and dermatome was used to derive our CPR, which was validated on an independent dataset. SETTING: Analysis of SCI Model Systems dataset. PARTICIPANTS: Individuals with traumatic SCI. The data of 3679 participants (N=3679) were included with 623 participants comprising the derivation dataset and 3056 comprising the validation dataset. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Self-reported ability to walk both indoors and outdoors. RESULTS: Pinprick testing at S1 over lateral heels, within 31 days of SCI, accurately identified future independent walkers 1 year after SCI. Normal pinprick in both lateral heels provided good prognosis, any pinprick sensation in either lateral heel provided fair prognosis, and no sensation provided poor prognosis. This CPR performed satisfactorily in the middle SCI severity subgroup. CONCLUSIONS: In this large multi-site study, we derived and validated a simple, accurate CPR using only pinprick sensory testing at lateral heels that predicts future independent walking after SCI.
Assuntos
Regras de Decisão Clínica , Traumatismos da Medula Espinal , Humanos , Exame Neurológico , Estudos Retrospectivos , CaminhadaRESUMO
We present the inaugural synthesis of a chiral teropyrene achieved through a four-fold alkyne benzannulation catalyzed by InCl3, resulting in good yields. The product underwent thorough characterization using FT-Raman and FT-IR spectroscopies, demonstrating a close agreement with calculated spectra. X-ray crystallographic analysis unveiled a notable twist in the molecule's backbone, with an end-to-end twist angle of 51°, consistent with computational predictions. Experimentally determined enantiomeric inversion barriers revealed a significant energy barrier of 23â kcal/mol, facilitating the isolation of enantiomers for analysis by circular dichroism (CD) and circularly polarized luminescence (CPL) spectroscopies. These findings mark significant strides in the synthesis and characterization of chiral teropyrenes, offering insights into their structural and spectroscopic properties.
RESUMO
Local adaptation is facilitated by loci clustered in relatively few regions of the genome, termed genomic islands of divergence. The mechanisms that create and maintain these islands and how they contribute to adaptive divergence is an active research topic. Here, we use sockeye salmon as a model to investigate both the mechanisms responsible for creating islands of divergence and the patterns of differentiation at these islands. Previous research suggested that multiple islands contributed to adaptive radiation of sockeye salmon. However, the low-density genomic methods used by these studies made it difficult to fully elucidate the mechanisms responsible for islands and connect genotypes to adaptive variation. We used whole genome resequencing to genotype millions of loci to investigate patterns of genetic variation at islands and the mechanisms that potentially created them. We discovered 64 islands, including 16 clustered in four genomic regions shared between two isolated populations. Characterisation of these four regions suggested that three were likely created by structural variation, while one was created by processes not involving structural variation. All four regions were small (< 600 kb), suggesting low recombination regions do not have to span megabases to be important for adaptive divergence. Differentiation at islands was not consistently associated with established population attributes. In sum, the landscape of adaptive divergence and the mechanisms that create it are complex; this complexity likely helps to facilitate fine-scale local adaptation unique to each population.
RESUMO
Understanding how gene flow influences adaptive divergence is important for predicting adaptive responses. Theoretical studies suggest that when gene flow is high, clustering of adaptive genes in fewer genomic regions would protect adaptive alleles from recombination and thus be selected for, but few studies have tested it with empirical data. Here, we used restriction site-associated sequencing to generate genomic data for six fish species with contrasting life histories from six reaches of the Upper Mississippi River System, USA. We used four differentiation-based outlier tests and three genotype-environment association analyses to define neutral single nucleotide polymorphisms (SNPs) and outlier SNPs that were putatively under selection. We then examined the distribution of outlier SNPs along the genome and investigated whether these SNPs were found in genomic islands of differentiation and inversions. We found that gene flow varied among species, and outlier SNPs were clustered more tightly in species with higher gene flow. The two species with the highest overall FST (0.0303-0.0720) and therefore lowest gene flow showed little evidence of clusters of outlier SNPs, with outlier SNPs in these species spreading uniformly across the genome. In contrast, nearly all outlier SNPs in the species with the lowest FST (0.0003) were found in a single large putative inversion. Two other species with intermediate gene flow (FST ~ 0.0025-0.0050) also showed clustered genomic architectures, with most islands of differentiation clustered on a few chromosomes. Our results provide important empirical evidence to support the hypothesis that increasingly clustered architecture of local adaptation is associated with high gene flow.
Assuntos
Fluxo Gênico , Genética Populacional , Animais , Genômica , Adaptação Fisiológica/genética , Genoma , Peixes/genética , Polimorfismo de Nucleotídeo Único/genéticaRESUMO
BACKGROUND: The human skin contains a diverse microbiome that provides protective functions against environmental pathogens. Studies have demonstrated that bacteriophages modulate bacterial community composition and facilitate the transfer of host-specific genes, potentially influencing host cellular functions. However, little is known about the human skin virome and its role in human health. Especially, how viral-host relationships influence skin microbiome structure and function is poorly understood. RESULTS: Population dynamics and genetic diversity of bacteriophage communities in viral metagenomic data collected from three anatomical skin locations from 60 subjects at five different time points revealed that cutaneous bacteriophage populations are mainly composed of tailed Caudovirales phages that carry auxiliary genes to help improve metabolic remodeling to increase bacterial host fitness through antimicrobial resistance. Sequence variation in the MRSA associated antimicrobial resistance gene, erm(C) was evaluated using targeted sequencing to further confirm the presence of antimicrobial resistance genes in the human virome and to demonstrate how functionality of such genes may influence persistence and in turn stabilization of bacterial host and their functions. CONCLUSIONS: This large temporal study of human skin associated viruses indicates that the human skin virome is associated with auxiliary metabolic genes and antimicrobial resistance genes to help increase bacterial host fitness.
Assuntos
Bacteriófagos , Microbiota , Vírus , Humanos , Viroma , Bacteriófagos/genética , Vírus/genética , Metagenoma , Bactérias/genéticaRESUMO
One of the earliest and most prevalent barriers to successful reproduction is polyspermy, or fertilization of an egg by multiple sperm. To prevent these supernumerary fertilizations, eggs have evolved multiple mechanisms. It has recently been proposed that zinc released by mammalian eggs at fertilization may block additional sperm from entering. Here, we demonstrate that eggs from amphibia and teleost fish also release zinc. Using Xenopus laevis as a model, we document that zinc reversibly blocks fertilization. Finally, we demonstrate that extracellular zinc similarly disrupts early embryonic development in eggs from diverse phyla, including Cnidaria, Echinodermata, and Chordata. Our study reveals that a fundamental strategy protecting human eggs from fertilization by multiple sperm may have evolved more than 650 million years ago.
Assuntos
Fertilização , Oócitos/metabolismo , Zinco/metabolismo , Ambystoma mexicanum , Animais , Feminino , Hidrozoários , Masculino , Strongylocentrotus purpuratus , Xenopus laevis , Peixe-ZebraRESUMO
Inferences made from molecular data support regional stock assessment goals by providing insights into the genetic population dynamics of enigmatic species. Population genomics metrics, such as genetic diversity and population connectivity, serve as useful proxies for species health and stability. Sleeper sharks (genus Somniosus) are ecologically important deep-sea predators, estimated to reach ages of 250 to 300 yr and taking decades to reach sexual maturity. The subgenus Somniosus (Somniosus) is comprised of 3 species: S. pacificus, S. microcephalus, and S. antarcticus. Given the life history strategy of somniosids, they are vulnerable to overfishing and population declines. Further, data to assess the stocks of these species are limited. To address this deficiency, we used the reduced representation library method Restriction-site Associated DNA sequencing (RADseq) to conduct phylogenomic and population genomics analyses, providing novel information for use in stock assessments. Our results strongly support the species status of S. microcephalus (N = 79), but recover S. antarcticus (N = 2) intermixed within the S. pacificus (N = 170) clade. Population genomics analyses reveal genetic homogeneity within S. pacificus and S. microcephalus, and estimates of effective population size were in the hundreds for both species. Kinship analysis identified 2 first-degree relative pairs within our dataset (1 within each species). Our results contribute new information for stock assessments of these uniquely long-lived species by providing the strongest molecular evidence to date for the synonymization of S. antarcticus and S. pacificus, as well as estimating population genomic metrics for each supported species within the Somniosus (Somniosus) subgenus.
Assuntos
Conservação dos Recursos Naturais , Tubarões , Animais , Tubarões/genética , Pesqueiros , EcologiaRESUMO
BACKGROUND AND PURPOSE: Predicting future outdoor walking ability after spinal cord injury (SCI) is important, as this is associated with community engagement and social participation. A clinical prediction rule (CPR) was derived for predicting outdoor walking 1 year after SCI. While promising, this CPR has not been validated, which is necessary to establish its clinical value. The objective of this study was to externally validate the CPR using a multisite dataset. METHODS: This was a retrospective analysis of US SCI Model Systems data from 12 centers. L3 motor score, L5 motor score, and S1 sensory score were used as predictor variables. The dataset was split into testing and training datasets. The testing dataset was used as a holdout dataset to provide an unbiased estimate of prediction performance. The training dataset was used to determine the optimal CPR threshold through a "leave-one-site-out" cross-validation framework. The primary outcome was self-reported outdoor walking ability 1 year after SCI. RESULTS: A total of 3721 participants' data were included. Using the optimal CPR threshold (CPR ≥ 33 threshold value), we were able to predict outdoor walking 1 year with high cross-validated accuracy and prediction performance. For the entire dataset, area under receiver operator characteristic curve was 0.900 (95% confidence interval: 0.890-0.910; P < 0.0001). DISCUSSION AND CONCLUSIONS: The outdoor walking CPR has been externally validated. Future research should conduct a clinical outcomes and cost-benefit impact analysis for implementing this CPR. Our results support that clinicians may use this 3-variable CPR for prediction of future outdoor walking ability.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A411 ).
Assuntos
Traumatismos da Medula Espinal , Caminhada , Humanos , Estudos Retrospectivos , Traumatismos da Medula Espinal/complicaçõesRESUMO
RNA sequencing (RNA-seq) is extensively used to quantify gene expression transcriptome-wide. Although often paired with polyadenylate (poly(A)) selection to enrich for messenger RNA (mRNA), many applications require alternate approaches to counteract the high proportion of ribosomal RNA (rRNA) in total RNA. Recently, digestion using RNaseH and antisense DNA oligomers tiling target rRNAs has emerged as an alternative to commercial rRNA depletion kits. Here, we present a streamlined, more economical RNaseH-mediated rRNA depletion with substantially lower up-front costs, using shorter antisense oligos only sparsely tiled along the target RNA in a 5-min digestion reaction. We introduce a novel Web tool, Oligo-ASST, that simplifies oligo design to target regions with optimal thermodynamic properties, and additionally can generate compact, common oligo pools that simultaneously target divergent RNAs, e.g. across different species. We demonstrate the efficacy of these strategies by generating rRNA-depletion oligos for Xenopus laevis and for zebrafish, which expresses two distinct versions of rRNAs during embryogenesis. The resulting RNA-seq libraries reduce rRNA to <5% of aligned reads, on par with poly(A) selection, and also reveal expression of many non-adenylated RNA species. Oligo-ASST is freely available at https://mtleelab.pitt.edu/oligo to design antisense oligos for any taxon or to target any abundant RNA for depletion.
Assuntos
Biologia Computacional/métodos , Oligodesoxirribonucleotídeos Antissenso/genética , RNA Mensageiro/genética , RNA Ribossômico/genética , RNA/genética , Animais , Sequência de Bases , Feminino , Perfilação da Expressão Gênica/métodos , Internet , Masculino , Oligodesoxirribonucleotídeos Antissenso/metabolismo , Poli A/genética , Poli A/metabolismo , RNA/metabolismo , RNA Mensageiro/metabolismo , RNA Ribossômico/metabolismo , Ribonuclease H/metabolismo , Análise de Sequência de RNA/métodos , Xenopus laevis/embriologia , Xenopus laevis/genética , Peixe-Zebra/embriologia , Peixe-Zebra/genéticaRESUMO
Strata from the Ediacaran Period (635 million to 538 million years ago [Ma]) contain several examples of enigmatic, putative shell-building metazoan fossils. These fossils may provide insight into the evolution and environmental impact of biomineralization on Earth, especially if their biological affinities and modern analogs can be identified. Recently, apparent morphological similarities with extant coralline demosponges have been used to assign a poriferan affinity to Namapoikia rietoogensis, a modular encrusting construction that is found growing between (and on) microbial buildups in Namibia. Here, we present three-dimensional reconstructions of Namapoikia that we use to assess the organism's proposed affinity. Our morphological analyses, which comprise quantitative measurements of thickness, spacing, and connectivity, reveal that Namapoikia produced approximately millimeter-thick meandering and branching/merging sheets. We evaluate this reconstructed morphology in the context of poriferan biology and determine that Namapoikia likely is not a sponge-grade organism.
Assuntos
Fósseis/anatomia & histologia , Animais , Evolução Biológica , Planeta Terra , Meio Ambiente , Fósseis/história , História Antiga , Imageamento Tridimensional , NamíbiaRESUMO
The domestic cat (Felis catus) numbers over 94 million in the USA alone, occupies households as a companion animal, and, like humans, suffers from cancer and common and rare diseases. However, genome-wide sequence variant information is limited for this species. To empower trait analyses, a new cat genome reference assembly was developed from PacBio long sequence reads that significantly improve sequence representation and assembly contiguity. The whole genome sequences of 54 domestic cats were aligned to the reference to identify single nucleotide variants (SNVs) and structural variants (SVs). Across all cats, 16 SNVs predicted to have deleterious impacts and in a singleton state were identified as high priority candidates for causative mutations. One candidate was a stop gain in the tumor suppressor FBXW7. The SNV is found in cats segregating for feline mediastinal lymphoma and is a candidate for inherited cancer susceptibility. SV analysis revealed a complex deletion coupled with a nearby potential duplication event that was shared privately across three unrelated cats with dwarfism and is found within a known dwarfism associated region on cat chromosome B1. This SV interrupted UDP-glucose 6-dehydrogenase (UGDH), a gene involved in the biosynthesis of glycosaminoglycans. Importantly, UGDH has not yet been associated with human dwarfism and should be screened in undiagnosed patients. The new high-quality cat genome reference and the compilation of sequence variation demonstrate the importance of these resources when searching for disease causative alleles in the domestic cat and for identification of feline biomedical models.
Assuntos
Nanismo/genética , Proteína 7 com Repetições F-Box-WD/genética , Genoma/genética , Uridina Difosfato Glucose Desidrogenase/genética , Sequenciamento Completo do Genoma , Alelos , Animais , Gatos , Mapeamento Cromossômico , Predisposição Genética para Doença , Genômica , Humanos , Masculino , Anotação de Sequência Molecular , Filogenia , Polimorfismo de Nucleotídeo Único/genéticaRESUMO
BACKGROUND: Retinoblastoma binding protein 4 (Rbbp4) is a component of transcription regulatory complexes that control cell cycle gene expression. Previous work indicated that Rbbp4 cooperates with the Rb tumor suppressor to block cell cycle entry. Here, we use genetic analysis to examine the interactions of Rbbp4, Rb, and Tp53 in zebrafish neural progenitor cell cycle regulation and survival. RESULTS: Rbbp4 is upregulated across the spectrum of human embryonal and glial brain cancers. Transgenic rescue of rbbp4 mutant embryos shows Rbbp4 is essential for zebrafish neurogenesis. Rbbp4 loss leads to apoptosis and γ-H2AX in the developing brain that is suppressed by tp53 knockdown or maternal zygotic deletion. Mutant retinal neural precursors accumulate in M phase and fail to initiate G0 gene expression. rbbp4; rb1 mutants show an additive effect on the number of M phase cells. In rbbp4 mutants, Tp53 acetylation is detected; however, Rbbp4 overexpression did not rescue DNA damage-induced apoptosis. CONCLUSION: Rbbp4 is necessary for neural progenitor cell cycle progression and initiation of G0 independent of Rb. Tp53-dependent apoptosis in the absence of Rbpb4 correlates with Tp53 acetylation. Together these results suggest that Rbbp4 is required for cell cycle exit and contributes to neural progenitor survival through the regulation of Tp53 acetylation.
Assuntos
Células-Tronco Neurais , Proteína 4 de Ligação ao Retinoblastoma , Proteína Supressora de Tumor p53 , Peixe-Zebra , Acetilação , Animais , Apoptose/genética , Ciclo Celular/genética , Humanos , Células-Tronco Neurais/metabolismo , Proteína 4 de Ligação ao Retinoblastoma/genética , Proteína 4 de Ligação ao Retinoblastoma/metabolismo , Fatores de Transcrição/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , Proteínas de Peixe-ZebraRESUMO
Rat genomic tools have been slower to emerge than for those of humans and mice and have remained less thorough and comprehensive. The arrival of a new and improved rat reference genome, mRatBN7.2, in late 2020 is a welcome event. This assembly, like predecessor rat reference assemblies, is derived from an inbred Brown Norway rat. In this "user" survey we hope to provide other users of this assembly some insight into its characteristics and some assessment of its improvements as well as a few caveats that arise from the unique aspects of this assembly. mRatBN7.2 was generated by the Wellcome Sanger Institute as part of the large Vertebrate Genomes Project. This rat assembly has now joined human, mouse, chicken, and zebrafish in the National Center for Biotechnology Information (NCBI)'s Genome Reference Consortium, which provides ongoing curation of the assembly. Here we examine the technical procedures by which the assembly was created and assess how this assembly constitutes an improvement over its predecessor. We also indicate the technical limitations affecting the assembly, providing illustrations of how these limitations arise and the impact that results for this reference assembly.
Assuntos
Genoma , Peixe-Zebra , Animais , Genoma/genética , Genômica/métodos , Camundongos , RatosRESUMO
Understanding the earliest events of human immunodeficiency virus (HIV) sexual transmission is critical to developing and optimizing HIV prevention strategies. To gain insights into the earliest steps of HIV rectal transmission, including cellular targets, rhesus macaques were intrarectally challenged with a single-round simian immunodeficiency virus (SIV)-based dual reporter that expresses luciferase and near-infrared fluorescent protein 670 (iRFP670) upon productive transduction. The vector was pseudotyped with the HIV-1 envelope JRFL. Regions of tissue containing foci of luminescent transduced cells were identified macroscopically using an in vivo imaging system, and individual transduced cells expressing fluorescent protein were identified and phenotyped microscopically. This system revealed that anal and rectal tissues are both susceptible to transduction 48 h after the rectal challenge. Detailed phenotypic analysis revealed that, on average, 62% of transduced cells are CCR6-positive (CCR6+) T cells-the vast majority of which express RORγT, a Th17 lineage-specific transcription factor. The second most common target cells were immature dendritic cells at 20%. These two cell types were transduced at rates that are four to five times higher than their relative abundances indicate. Our work demonstrates that Th17 T and immature dendritic cells are preferential initial targets of HIV/SIV rectal transmission. IMPORTANCE Men and women who participate in unprotected receptive anal intercourse are at high risk of acquiring HIV. While in vitro data have developed a framework for understanding HIV cell tropism, the initial target cells in the rectal mucosa have not been identified. In this study, we identify these early host cells by using an innovative rhesus macaque rectal challenge model and methodology, which we previously developed. Thus, by shedding light on these early HIV/SIV transmission events, this study provides a specific cellular target for future prevention strategies.
Assuntos
Células Dendríticas/virologia , Infecções por HIV/transmissão , Infecções por HIV/virologia , HIV-1/fisiologia , Reto/virologia , Vírus da Imunodeficiência Símia/fisiologia , Células Th17/virologia , Canal Anal/virologia , Animais , Feminino , Mucosa Intestinal/virologia , Macaca mulatta , Síndrome de Imunodeficiência Adquirida dos Símios/transmissão , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/genética , Replicação ViralRESUMO
We present an erratum to our Letter [Opt. Lett.46, 5360 (2021)10.1364/OL.437936]. This erratum refers to Fig. 3, where a previous version was wrongly uploaded during the final resubmission of the paper. This correction has no influence on the text, the results, and the conclusions of the original Letter.