Publications by authors named "Ashley Byrne"

Accurate detection and quantification of mRNA isoforms from nanopore long-read sequencing remains challenged by technical noise, particularly in single cells. To address this, we introduce Isosceles, a computational toolkit that outperforms other methods in isoform detection sensitivity and quantification accuracy across single-cell, pseudo-bulk and bulk resolution levels, as demonstrated using synthetic and biologically-derived datasets. Here we show Isosceles improves the fidelity of single-cell transcriptome quantification at the isoform-level, and enables flexible downstream analysis.

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  • Single-cell RNA sequencing typically uses short-read technology, which struggles to fully analyze RNA isoforms; long-read sequencing can detect these isoforms but has challenges like lower throughput and errors.
  • The new method developed, called Single-cell Targeted Isoform Long-Read Sequencing (scTaILoR-seq), captures over a thousand targeted genes, enhancing the number of useful transcripts by 29 times.
  • By applying scTaILoR-seq, researchers successfully analyzed RNA isoforms from ovarian cancer samples, uncovering 10,796 transcriptomes and revealing how genetic variations relate to different transcript structures in single cells.
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Animal regeneration involves coordinated responses across cell types throughout the animal body. In endosymbiotic animals, whether and how symbionts react to host injury and how cellular responses are integrated across species remain unexplored. Here, we study the acoel Convolutriloba longifissura, which hosts symbiotic Tetraselmis sp.

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  • Altered myeloid inflammation and lymphopenia are key characteristics of severe infections, particularly in patients with acute lung injuries from SARS-CoV-2.
  • The upregulated EN-RAGE gene program found in airway and blood myeloid cells is linked to increased clinical severity, predicting outcomes like mechanical ventilation and mortality.
  • IL-6 was identified as a major factor driving myeloid dysfunction, and blocking its signaling with tocilizumab effectively normalized EN-RAGE gene expression and improved T cell function in clinical trials.
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In this manuscript, we introduce and benchmark Mandalorion v4.1 for the identification and quantification of full-length transcriptome sequencing reads. It further improves upon the already strong performance of Mandalorion v3.

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Spatial transcriptomics extends single-cell RNA sequencing (scRNA-seq) by providing spatial context for cell type identification and analysis. Imaging-based spatial technologies such as multiplexed error-robust fluorescence in situ hybridization (MERFISH) can achieve single-cell resolution, directly mapping single-cell identities to spatial positions. MERFISH produces a different data type than scRNA-seq, and a technical comparison between the two modalities is necessary to ascertain how to best integrate them.

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Molecular characterization of cell types using single-cell transcriptome sequencing is revolutionizing cell biology and enabling new insights into the physiology of human organs. We created a human reference atlas comprising nearly 500,000 cells from 24 different tissues and organs, many from the same donor. This atlas enabled molecular characterization of more than 400 cell types, their distribution across tissues, and tissue-specific variation in gene expression.

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The immunological features that distinguish COVID-19-associated acute respiratory distress syndrome (ARDS) from other causes of ARDS are incompletely understood. Here, we report the results of comparative lower respiratory tract transcriptional profiling of tracheal aspirate from 52 critically ill patients with ARDS from COVID-19 or from other etiologies, as well as controls without ARDS. In contrast to a "cytokine storm," we observe reduced proinflammatory gene expression in COVID-19 ARDS when compared to ARDS due to other causes.

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  • Autoantibodies against type I interferons (IFNs) are present in some patients with critical COVID-19, affecting 19% of those with critical disease and 6% of severe cases, but not in moderate cases.
  • Analysis of over 600,000 immune cells from patients showed that those with critical disease had a lack of IFN-stimulated responses, particularly in dendritic cells, which produced these autoantibodies.
  • There was also increased expression of the LAIR1 receptor on monocytes, which inversely correlated with the immune response, suggesting that both autoantibodies and LAIR1 contribute to immune suppression in critical COVID-19.
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Secondary bacterial infections, including ventilator-associated pneumonia (VAP), lead to worse clinical outcomes and increased mortality following viral respiratory infections including in patients with coronavirus disease 2019 (COVID-19). Using a combination of tracheal aspirate bulk and single-cell RNA sequencing (scRNA-seq) we assessed lower respiratory tract immune responses and microbiome dynamics in 28 COVID-19 patients, 15 of whom developed VAP, and eight critically ill uninfected controls. Two days before VAP onset we observed a transcriptional signature of bacterial infection.

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The Andean bear is the only extant member of the Tremarctine subfamily and the only extant ursid species to inhabit South America. Here, we present an annotated de novo assembly of a nuclear genome from a captive-born female Andean bear, Mischief, generated using a combination of short and long DNA and RNA reads. Our final assembly has a length of 2.

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  • Secondary bacterial infections like ventilator-associated pneumonia (VAP) worsen outcomes for COVID-19 patients, increasing mortality rates.
  • A study of 23 COVID-19 patients, some of whom developed VAP, revealed immune response changes and bacterial infection signs occurring days to weeks before VAP onset.
  • The research indicates that COVID-19 patients who eventually get VAP have weakened immune defenses against bacteria, potentially leading to secondary infections.
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  • Type I interferon (IFN-I) autoantibodies were detected in 19% of critical COVID-19 patients, 6% of severe cases, and none in moderate cases, indicating a higher prevalence in more severe infections.
  • A study analyzing over 600,000 blood cells from various groups revealed that critical COVID-19 patients have an impaired IFN-I stimulated gene (ISG-I) response, particularly in myeloid cells.
  • There is a notable inverse relationship between an inhibitory receptor (LAIR-1) and ISG-I expression, suggesting that this suppressed response may contribute to the severity of COVID-19 through multiple mechanisms.
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  • The protein-coding gene neuro-oncological ventral antigen 1 (NOVA1) is crucial for brain development and differs between modern humans and our extinct relatives, the Neanderthals and Denisovans.
  • Researchers used genome editing to introduce an ancient version of this gene into modern human cells and studied its effects on brain organoids.
  • The archaic version of NOVA1 slowed neural development and changed the complexity and electrical properties of the organoids, suggesting that human-specific changes to this gene may have influenced our evolution.
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We performed comparative lower respiratory tract transcriptional profiling of 52 critically ill patients with the acute respiratory distress syndrome (ARDS) from COVID-19 or from other etiologies, as well as controls without ARDS. In contrast to a cytokine storm, we observed reduced proinflammatory gene expression in COVID-19 ARDS when compared to ARDS due to other causes. COVID-19 ARDS was characterized by a dysregulated host response with increased PTEN signaling and elevated expression of genes with non-canonical roles in inflammation and immunity that were predicted to be modulated by dexamethasone and granulocyte colony stimulating factor.

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  • Bacterial symbionts help their host organisms by providing useful functions, but their own genes can get weaker over time when they depend too much on their hosts.
  • In marine environments, some bacteria can still share genes with others, which helps keep their abilities strong even when they mostly rely on one host.
  • Scientists studied different types of bacteria living with clams to see how they pass on genes and found that those that mainly passed genes vertically (from parent to offspring) had weaker genomes, while those that could share genes with other bacteria were healthier and had more variations.
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The liver is a key regulator of systemic energy homeostasis whose proper function is dependent on the circadian clock. Here, we show that livers deficient in the oscillator component JARID1a exhibit a dysregulation of genes involved in energy metabolism. Importantly, we find that mice that lack hepatic JARID1a have decreased lean body mass, decreased respiratory exchange ratios, faster production of ketones, and increased glucose production in response to fasting.

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  • The human immune system needs a variety of special proteins and genes to protect us from diseases.
  • To help with things like organ transplants, it's important to know which HLA genes people have.
  • Researchers used a new method to accurately study millions of gene sequences, which will help in understanding our immune systems better without needing to already know about the genetic differences.
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Pumas are the most widely distributed felid in the Western Hemisphere. Increasingly, however, human persecution and habitat loss are isolating puma populations. To explore the genomic consequences of this isolation, we assemble a draft puma genome and a geographically broad panel of resequenced individuals.

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Long-read sequencing holds great potential for transcriptome analysis because it offers researchers an affordable method to annotate the transcriptomes of non-model organisms. This, in turn, will greatly benefit future work on less-researched organisms like unicellular eukaryotes that cannot rely on large consortia to generate these transcriptome annotations. However, to realize this potential, several remaining molecular and computational challenges will have to be overcome.

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Transcriptome studies evaluating whole blood and tissues are often confounded by overrepresentation of highly abundant transcripts. These abundant transcripts are problematic, as they compete with and prevent the detection of rare RNA transcripts, obscuring their biological importance. This issue is more pronounced when using long-read sequencing technologies for isoform-level transcriptome analysis, as they have relatively lower throughput compared to short-read sequencers.

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Objectives: The aim of this investigation was to evaluate whether the use of a provisional implant-supported crown improves the final esthetic outcome of implant crowns that are placed within esthetic sites.

Materials And Methods: Twenty endosseous implants were inserted in sites 13 to 23 (FDI) in 20 patients. Following the reopening procedure, a randomization process assigned them to either cohort group 1: a provisional phase with soft tissue conditioning using the "dynamic compression technique" or cohort group 2: without a provisional phase.

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High-throughput short-read sequencing has revolutionized how transcriptomes are quantified and annotated. However, while Illumina short-read sequencers can be used to analyze entire transcriptomes down to the level of individual splicing events with great accuracy, they fall short of analyzing how these individual events are combined into complete RNA transcript isoforms. Because of this shortfall, long-distance information is required to complement short-read sequencing to analyze transcriptomes on the level of full-length RNA transcript isoforms.

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Chromosomal inversions are widely thought to be favored by natural selection because they suppress recombination between alleles that have higher fitness on the same genetic background or in similar environments. Nonetheless, few selected alleles have been characterized at the molecular level. Gene expression profiling provides a powerful way to identify functionally important variation associated with inversions and suggests candidate phenotypes.

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