Biology subjects

Hui, X.

Publications and source records attributed to Hui, X..

9 recordsLinked to original sources

bioRxiv2026

CardioChrom Reconstructs the Human Cardiac Virtual Epigenome from Single-Nucleus Transcriptomes

Background: Matched epigenomic profiling remains scarce in human heart failure, limiting regulatory interpretation of single-nucleus ribonucleic acid (RNA) sequencing data. We developed CardioChrom, a cardiac-specialized framework that reconstructs chromatin accessibility, histone H3 lysine 27 acetylation (H3K27ac), and histone H3 lysine 27 trimethylation (H3K27me3) from single-nucleus RNA profiles. Methods: CardioChrom was developed using same-nucleus human heart datasets jointly measuring RNA with chromatin accessibility by assay for transposase-accessible chromatin (ATAC), H3K27ac, or H3K27me3, with donor-separated development and leave-one-cell-type-out testing. Frozen models were evaluated in 10-donor and 23-sample external human heart cohorts. Histone reconstruction was benchmarked against measured profiles and a Transformer. The models were then applied without refitting to an RNA-only cohort of 43 donors with heart failure with preserved ejection fraction (HFpEF). Results: Across unseen cardiac cell types, CardioChrom increased area under the precision-recall curve by 0.0109 relative to within-cell-type RNA shuffling in 11 of 12 cell types and increased area under the receiver operating characteristic curve by 0.0179 in all 12. CardioChrom exceeded controls in both external cohorts and matched or exceeded the Transformer across 6 prespecified histone metrics. In HFpEF, 3,581 donor-level pathway-layer associations met global false discovery rate, sex-adjustment, and leave-one-donor-out robustness criteria. Endothelial cells showed prominent reconstructed histone-associated changes involving coagulation, inflammation, hypoxia, and profibrotic signaling. Von Willebrand factor expression and its reconstructed regulatory states were consistently reduced, and all 6 linked candidate cis-regulatory elements were classified as repressed. Motif-supported TF-cCRE-gene hypotheses were generated in endothelial cells and fibroblasts. Conclusions: CardioChrom extends RNA-only human heart failure cohorts toward cell-type-resolved virtual epigenomic and regulatory analysis while distinguishing predictions from direct measurements.

bioinformatics↗

bioRxiv2024

Evolution of Salmonella Chromosomes and Its Influence on Gene Expression and Chromosomal Conformation

Salmonella is one of the most important bacterial pathogens in the world, causing an estimated 120 million infections each year. There is considerable diversity, with [~]2,600 serovars, but it remains unclear how the genomes have evolved as the species and subspecies of Salmonella differentiate. Here, we have reconstructed the ancient orthologous chromosomes of each major Salmonella lineage and traced their evolutionary process. In total, 911 rearrangement events were identified, with 64% of events occurring in a locus-specific way. Using RNA sequencing and multi-strain association analysis, we demonstrate that genetic rearrangements have a significant effect on gene expression across Salmonella lineages. Moreover, we perform chromosome conformation capture (3C) sequencing analysis, which demonstrates large variations for the organization of ter chromosomal interaction domains among Salmonella lineages. In conclusion, our work delineates the evolutionary trajectory of Salmonella chromosomes, and demonstrates the influence of rearrangements on gene expression profiles and chromosomal conformation. ImportanceThis study reconstructed the ancient orthologous chromosomes of the Salmonella genus, species and well-recognized subspecies, by which the trajectory of gene flow caused by genetic rearrangements was delineated chronologically. The rearrangements show apparent hotspot distribution property and are enriched with genes important for bacterial fitness. Correlation analysis further disclosed the general influence of the rearrangements on gene expression and the organization and conformation of chromosome interaction domains. The results provide new insights on the evolution of Salmonella chromosomes, especially the genetic rearrangements and their epigenetic consequences.

microbiology↗

bioRxiv2023

CentIER: accurate centromere identification for plant genomes with sequence specificity information

Centromere identification is one of the important problems in genomics, providing a foundation for the studies of centromeres in aspects of composition, functionality, evolution, inheritance, and variation. The existing wet-experiment-based method is costly and time-consuming, while the bioinformatic method can only detect tandem repeats losing non-repetitive sequence regions in the centromere. To address these shortcomings, we introduce a new pipeline, CentIER, for the automatic and accurate identification and annotation of centromere regions by taking advantage of the sequence specificity information. CentIER only requires users to input the genomic sequence, and then it can partition the centromeric region from a chromosome, identify tandem repeat monomers, annotate retrotransposons, and ultimately output visualized results. By referencing the experimentally determined centromere regions, it was discovered that the predictive accuracy of centromere recognition by CentIER exceeded 90%. Following the evaluation of CentIERs accuracy, it was applied to investigate the sequence and distribution characteristics of centromeric retrotransposons and tandem repeat sequences of different species, providing insights into these traits in monocotyledonous and dicotyledonous plants.

bioinformatics↗

bioRxiv2023

Comprehensive Assessment of Eleven de novo HiFi Assemblers on Complex Eukaryotic Genomes and Metagenomes

BackgroundPacific Bioscience HiFi sequencing technology generates long reads (>10 kbp) with very high accuracy (less than 0.01% sequencing error). While several de novo assembly tools are available for HiFi reads, there are no comprehensive studies on the evaluation of these assemblers. ResultsWe evaluated the performance of eleven de novo HiFi assemblers on (i) real data for three eukaryotic genomes, (ii) 34 synthetic datasets with different ploidy, sequencing coverage levels, heterozygosity rates and sequencing error rates, (iii) one real metagenomic dataset, and (iv) five synthetic metagenomic datasets with different composition abundance and heterozygosity rates. The nine assemblers were evaluated using QUAST (Quality Assessment Tool) and BUSCO (Benchmarking Universal Single-Copy Ortholog). We also used several additional criteria, namely, completion rate, single-copy completion rate, duplicated completion rate, average proportion of largest category, average distance difference, quality value, run-time and memory utilization. On complex eukaryotic genomes, Hifiasm had a clear advantage over the other assemblers in all tested experiments. On synthetic datasets, Hifiasm, HiCanu, and HiFlye performed equally well. Shasta and Peregrine had good performance across varying ploidy, but required high computational resources. On metagenomic datasets, Hifiasm-meta demonstrated a clear advantage over other assemblers. ConclusionWe carried out a comprehensive benchmarking study of commonly used assemblers on complex eukaryotic genomes and metagenomes. Our study will help the research community to choose the most appropriate assembler for their data and identify possible improvements in assembly algorithms.

genomics↗

bioRxiv2021

T1SEstacker: A tri-layer stacking model effectively predicts bacterial type 1 secreted proteins based on C-terminal non-RTX-motif sequence features

The proteins secreted through type 1 secretion systems often play important roles in pathogenicity of various gram-negative bacteria. However, the type 1 secretion mechanism remains unknown. In this research, we observed the sequence features of RTX proteins, a major class of type 1 secreted substrates. We found striking non-RTX-motif amino acid composition patterns at the C-termini, most typically exemplified by the enriched [FLI][VAI] at the most C-terminal two positions. Machine-learning models, including deep-learning models, were trained using these sequence-based non-RTX-motif features, and further combined into a tri-layer stacking model, T1SEstacker, which predicted the RTX proteins accurately, with a 5-fold cross-validated sensitivity of ~0.89 at the specificity of ~0.94. Besides substrates with RTX motifs, T1SEstacker can also well distinguish non-RTX-motif type 1 secreted proteins, further suggesting their potential existence of common secretion signals. In summary, we made comprehensive sequence analysis on the type 1 secreted RTX proteins, identified common sequence-based features at the C-termini, and developed a stacking model that can predict type 1 secreted proteins accurately.

microbiology↗

bioRxiv2020

Quantify the requirements to achieve grain Zn biofortification of high-yield wheat on calcareous soils

The solution to address global human Zn deficiency is Zn biofortification of staple food crops, aimed at high grain Zn concentration as well as high yield. However, the desired high grain Zn concentration above 40 mg kg-1 is rarely observed for high-yield wheat on worldwide calcareous soils, due to inadequate Zn uptake or Zn distribution to grain. The present study aims to investigate how much Zn uptake or distribution is adequate to achieve the Zn.t of high-yield wheat on calcareous soils with low available Zn ([~] 0.5 mg kg-1). Of the 123 cultivars tested in a three-year field experiment, 19 high-yield cultivars were identified with similar yields around 7.0 t ha-1 and various grain Zn concentrations from 9.3 to 26.7 mg kg-1. The adequate Zn distribution to grain was defined from the view of Zn biofortification, as the situation where the Zn distribution to grain (Zn harvest index) increased to the observed maximum of [~] 91.0% and the Zn concentration of vegetative parts (straw Zn concentration) decreased to the observed minimum of [~] 1.5 mg kg-1 (Zn.m). Under the assumed condition of adequate Zn distribution to grain ([~] 91.0%), all the extra Zn above Zn.m was remobilized from straw to grain and the grain Zn concentration would be increased to its highest attainable level, which was 14.5 [~] 31.3 mg kg-1 for the 19 high-yield cultivars but still lower than 40 mg kg-1. Thus, even with the adequate Zn distribution to grain, the current Zn uptake is still not adequate and needs to be increased to 308 g ha-1 or higher to achieve Zn.t for high-yield wheat (7.0 t ha-1) on low-Zn calcareous soils. Besides, the established method here can also provide the priority measures and quantitative guidelines to achieve Zn biofortification in other wheat production regions.

plant biology↗

bioRxiv2020

SARS-CoV-2 neutralizing serum antibodies in cats: a serological investigation

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first reported in Wuhan, China, and rapidly spread worldwide. Previous studies suggested cat could be a potential susceptible animal of SARS-CoV-2. Here, we investigated the infection of SARS-CoV-2 in cats by detecting specific serum antibodies. A cohort of serum samples were collected from cats in Wuhan, including 102 sampled after COVID-19 outbreak, and 39 prior to the outbreak. 15 of 102 (14.7%) cat sera collected after the outbreak were positive for the receptor binding domain (RBD) of SARS-CoV-2 by indirect enzyme linked immunosorbent assay (ELISA). Among the positive samples, 11 had SARS-CoV-2 neutralizing antibodies with a titer ranging from 1/20 to 1/1080. No serological cross-reactivity was detected between the SARS-CoV-2 and type I or II feline infectious peritonitis virus (FIPV). Our data demonstrates that SARS-CoV-2 has infected cat population in Wuhan during the outbreak.

microbiology↗

bioRxiv2019

Title: Risk factors for postoperative meningitis after microsurgery for vestibular schwannoma

OBJECTIVEMeningitis after microsurgery for vestibular schwannoma (VS) is a severe complication and result in high morbidity. But few studies have focused on meningitis after VS surgery alone. The purpose of this study was to identify the risk factors for meningitis after VS surgery.\n\nMETHODSWe undertook a retrospective analysis of all VS patients, who underwent microsurgery of VS and at least live for 7 days after surgery, between 1st June 2015 and 30st November 2018 at West China Hospital of Sichuan University. Univariate and multivariate analyses were performed to identify the risk factors for postoperative meningitis (POM).\n\nRESULTSWe collected 410 patients, 27 of whom had POM. Through univariate analysis, hydrocephalus (p=0. 018), Koos grade IV (p=0.04), The operative duration (> 3 hours p=0.03) and intraoperative bleeding volume ([≥] 400ml p=0. 02) were significantly correlated to POM. Multivariate analysis showed that Koos grade IV (p=0.04; OR=3.19; 95% CI 1.032-3.190), operation duration (> 3 hours p=0.03 OR= 7.927; 95% CI 1.043-60.265), and intraoperative bleeding volume ([≥] 400ml p=0.02; OR=2.551; 95% CI 1.112-5.850) are the independent influencing factors of POM.\n\nCONCLUSIONSKoos grade IV, the duration of operation, and the amount of bleeding were identified as independent risk factors for POM after microsurgery of VS. POM caused a prolonged hospital stay.

neuroscience↗

bioRxiv2016

Identification of new bacterial type III secreted effectors with a recursive Hidden Markov Model profile-alignment strategy

To identify new bacterial type III secreted effectors is computationally a big challenge. At least a dozen machine learning algorithms have been developed, but so far have only achieved limited success. Sequence similarity appears important for biologists but is frequently neglected by algorithm developers for effector prediction, although large success was achieved in the field with this strategy a decade ago. In this study, we propose a recursive sequence alignment strategy with Hidden Markov Models, to comprehensively find homologs of known YopJ/P full-length proteins, effector domains and N-terminal signal sequences. Using this method, we identified 155 different YopJ/P-family effectors and 59 proteins with YopJ/P N-terminal signal sequences from 27 genera and more than 70 species. Among these genera, we also identified one type III secretion system (T3SS) from Uliginosibacterium and two T3SSs from Rhizobacter for the first time. Higher conservation of effector domains, N-terminal fusion of signal sequences to other effectors, and the exchange of N-terminal signal sequences between different effector proteins were frequently observed for YopJ/P-family proteins. This made it feasible to identify new effectors based on separate similarity screening for the N-terminal signal peptides and the effector domains of known effectors. This method can also be applied to search for homologues of other known T3SS effectors.

bioinformatics↗