Biology subjects

Wan, Y.

Publications and source records attributed to Wan, Y..

At least 91 records · Page 5Linked to original sources

bioRxiv2021

Subcellular dynamics studies reveal how tissue-specific distribution patterns of iron are established in developing wheat grains

Understanding iron trafficking in plants is key to enhancing the nutritional quality of crops. Due to the difficulty of imaging iron in transit, little is known about iron translocation and distribution in developing seeds. A novel approach, combining 57Fe isotope labelling and NanoSIMS, was used to visualize iron translocation dynamics at the subcellular level in wheat grain, Triticum aestivum L. We were able to track the main route of iron from maternal tissues to the embryo through different cell types. Further evidence for this route was provided by genetically diverting iron into storage vacuoles, as confirmed by histological staining and TEM-EDS. Virtually all iron was found in intracellular bodies, indicating symplastic rather than apoplastic transport. Aleurone cells contained a new type of iron body, highly enriched in 57Fe, and most likely represents iron-nicotianamine being delivered to phytate globoids. Correlation with tissue-specific gene expression provides an updated model of iron homeostasis in cereal grains with relevance for future biofortification efforts.

plant biology↗

bioRxiv2021

SiCEP3, a C-terminally encoded peptides from Setaria italica, promotes ABA import and signaling pathway

C-terminally encoded peptides (CEPs) are small peptides, typically post-translationally modified, and highly conserved in many species. CEPs are known to play roles in inhibition of plant growth and regulation of development, but the mechanisms are not well understood. In this study, we searched for CEP peptides in foxtail millet (Setaria italica). The 14 peptides we identified are divided into two subfamilies. The transcripts of most SiCEPs were more abundant in roots than in other tissues. SiCEP3, SiCEP4, and SiCEP5 were also expressed at high levels in panicles. Moreover, expression of all SiCEPs was induced by biotic stress and phytohormones. SiCEP3 overexpression and application of biosynthetic SiCEP3 both inhibited the growth of seedlings. In the presence of ABA, growth inhibition and ABA content of seedlings increased with the concentration of SiCEP3. Transcripts encoding two ABA transporters and one ABA receptor were induced by SiCEP3, ABA, and the two in combination. Further analysis revealed that SiCEP3 promoted ABA transport via NRT1.2 and ABCG40. In addition, SiCEP3, ABA, or the combination inhibited the kinase activities of CEP receptors CEPR1/2. Taken together, our results indicated that the CEP-CEPR module mediates ABA signaling by regulating ABCG40, NRT1.2, and PYL4 in planta. HighlightSiCEP3, a C-terminally encoded peptide, can promote ABA import and signaling pathway by inhibiting the kinase activity of its receptors under abiotic stress in Setaria italica.

cell biology↗

bioRxiv2021

Comprehensive mapping of SARS-CoV-2 interactions in vivo reveals functional virus-host interactions

SARS-CoV-2 has emerged as a major threat to global public health, resulting in global societal and economic disruptions. Here, we investigate the intramolecular and intermolecular RNA interactions of wildtype (WT) and a mutant ({Delta}382) SARS-CoV-2 virus in cells using high throughput structure probing on Illumina and Nanopore platforms. We identified twelve potentially functional structural elements within the SARS-CoV-2 genome, observed that identical sequences can fold into divergent structures on different subgenomic RNAs, and that WT and {Delta}382 virus genomes can fold differently. Proximity ligation sequencing experiments identified hundreds of intramolecular and intermolecular pair-wise interactions within the virus genome and between virus and host RNAs. SARS-CoV-2 binds strongly to mitochondrial and small nucleolar RNAs and is extensively 2-O-methylated. 2-O-methylation sites in the virus genome are enriched in the untranslated regions and are associated with increased pair-wise interactions. SARS-CoV-2 infection results in a global decrease of 2-O-methylation sites on host mRNAs, suggesting that binding to snoRNAs could be a pro-viral mechanism to sequester methylation machinery from host RNAs towards the virus genome. Collectively, these studies deepen our understanding of the molecular basis of SARS-CoV-2 pathogenicity, cellular factors important during infection and provide a platform for targeted therapy.

genomics↗

bioRxiv2020

TIPS: Trajectory Inference of Pathway Significance through Pseudotime Comparison for Functional Assessment of single-cell RNAseq Data

Recent advances in bioinformatics analyses have led to the development of novel tools enabling the capture and trajectory mapping of single-cell RNA sequencing (scRNAseq) data. However, there is a lack of methods to assess the contributions of biological pathways and transcription factors to an overall developmental trajectory mapped from scRNAseq data. In this manuscript, we present a simplified approach for trajectory inference of pathway significance (TIPS) that leverages existing knowledgebases of functional pathways and transcription factor targets to enable further mechanistic insights into a biological process. TIPS returns both the key pathways whose changes are associated with the process of interest, as well as the individual genes that best reflect these changes. TIPS also provides insight into the relative timing of pathway changes, as well as a suite of visualizations to enable simplified data interpretation of scRNAseq libraries generated using a wide range of techniques. The TIPS package can be run through either a web server, or downloaded as a user-friendly GUI run in R, and may serve as a useful tool to help biologists perform deeper functional analyses and visualization of their single-cell and/or large cohort RNAseq data.

bioinformatics↗

bioRxiv2020

The Development of a Novel Nanobody Therapeutic for SARS-CoV-2

Combating the COVID-19 pandemic requires potent and low-cost therapeutics. We identified a novel series of single-domain antibodies (i.e., nanobody), Nanosota-1, from a camelid nanobody phage display library. Structural data showed that Nanosota-1 bound to the oft-hidden receptor-binding domain (RBD) of SARS-CoV-2 spike protein, blocking out viral receptor ACE2. The lead drug possessing an Fc tag (Nanosota-1C-Fc) bound to SARS-CoV-2 RBD with a Kd of 15.7picomolar ([~]3000 times more tightly than ACE2 did) and inhibited SARS-CoV-2 infection with an ND50 of 0.16microgram/milliliter ([~]6000 times more potently than ACE2 did). Administered at a single dose, Nanosota-1C-Fc demonstrated preventive and therapeutic efficacy in hamsters subjected to SARS-CoV-2 infection. Unlike conventional antibody drugs, Nanosota-1C-Fc was produced at high yields in bacteria and had exceptional thermostability. Pharmacokinetic analysis of Nanosota-1C-Fc documented a greater than 10-day in vivo half-life efficacy and high tissue bioavailability. Nanosota-1C-Fc is a potentially effective and realistic solution to the COVID-19 pandemic. Impact statementPotent and low-cost Nanosota-1 drugs block SARS-CoV-2 infections both in vitro and in vivo and act both preventively and therapeutically.

microbiology↗

bioRxiv2020

A potent neutralizing nanobody against SARS-CoV-2 with inhaled delivery potential

The outbreak of COVID-19 has emerged as a global pandemic. The unprecedented scale and severity call for rapid development of effective prophylactics or therapeutics. We here reported Nanobody (Nb) phage display libraries derived from four camels immunized with the SARS-CoV-2 spike receptor-binding domain (RBD), from which 381 Nbs were identified to recognize SARS-CoV-2-RBD. Furthermore, seven Nbs were shown to block interaction of human angiotensin converting enzyme 2 (ACE2) with SARS-CoV-2-RBD-variants, bat-SL-CoV-WIV1-RBD and SARS-CoV-1-RBD. Among the seven candidates, Nb11-59 exhibited the highest activity against authentic SARS-CoV-2 with ND50 of 0.55 g/mL. Nb11-59 can be produced on a large-scale in Pichia pastoris, with 20 g/L titer and 99.36% purity. It also showed good stability profile, and nebulization did not impact its stability. Overall, Nb11-59 might be a promising prophylactic and therapeutic molecule against COVID-19, especially through inhalation delivery. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=154 SRC="FIGDIR/small/242867v2_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@e4434org.highwire.dtl.DTLVardef@9fee79org.highwire.dtl.DTLVardef@1e15bb1org.highwire.dtl.DTLVardef@4adb0c_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2020

Direct RNA sequencing reveals structural differences between transcript isoforms

The ability to correctly assign structure information to an individual transcript in a continuous and phased manner is critical to understanding RNA function. RNA structure play important roles in every step of an RNAs lifecycle, however current short-read high throughput RNA structure mapping strategies are long, complex and cannot assign unique structures to individual gene-linked isoforms in shared sequences. To address these limitations, we present an approach that combines structure probing with SHAPE-like compound NAI-N3, nanopore direct RNA sequencing, and one-class support vector machines to detect secondary structures on near full-length RNAs (PORE-cupine). PORE-cupine provides rapid, direct, accurate and robust structure information along known RNAs and recapitulates global structural features in human embryonic stem cells. The majority of gene-linked isoforms showed structural differences in shared sequences both local and distal to the alternative splice site, highlighting the importance of long-read sequencing for phasing of structures. Structural differences between gene-linked isoforms are associated with differential translation efficiencies globally, highlighting the role of structure as a pervasive mechanism for regulating isoform-specific gene expression inside cells.

biochemistry↗

bioRxiv2020

A GRAB sensor reveals activity-dependent non-vesicular somatodendritic adenosine release

The purinergic signaling molecule adenosine (Ado) modulates many physiological and pathological brain functions,but its spatiotemporal release dynamics in the brain remains largely unknown. We developed a genetically encoded GPCR-Activation-Based Ado sensor (GRABAdo) in which Ado-induced changes in the human A2A receptor are reflected by fluorescence increases. This GRABAdo revealed that neuronal activity-induced extracellular Ado elevation was due to direct Ado release from somatodendritic regions of the neuron, requiring calcium influx through L-type calcium channels, rather than the degradation of extracellular ATP. The Ado release was slow ([~]30 s) and depended on equilibrative nucleoside transporters (ENTs) rather than conventional vesicular release mechanisms. Thus, GRABAdo reveals an activity-dependent slow Ado release from somatodendritic region of the neuron, potentially serving modulating functions as a retrograde signal.

neuroscience↗

bioRxiv2020

scSTATseq: Diminishing Technical Dropout Enables Core Transcriptome Recovery and Comprehensive Single-cell Trajectory Mapping

The advent of single-cell RNA sequencing has provided illuminating information on complex systems. However, large numbers of genes tend to be scarcely detected in common scRNAseq approaches due to technical dropout. Although bioinformatics approaches have been developed to approximate true expression profiles, assess the dropout events on single-cell transcriptomes is still consequently challenging. In this report, we present a new plate-based method for scRNAseq that relies on Tn5 transposase to tagment cDNA following second strand synthesis. By utilizing pre-amplification tagmentation step, scSTATseq libraries are insulated against technical dropout, allowing for detailed analysis of gene-gene co-expression relationships and mapping of pathway trajectories. The entire scSTATseq library construction workflow can be completed in 7 hours, and recover transcriptome information on up to 8,000 protein-coding genes. Investigation of osteoclast differentiation using this workflow allowed us to identify novel markers of interest such as Rab15. Overall, scSTATseq is an efficient and economical method for scRNAseq that compares favorably with existing workflows.

genomics↗

bioRxiv2020

The dominance hierarchy of the female Yunnan snub-nosed monkeys (Rhinopithecus bieti)

Dominance hierarchies are common in social mammals, especially primates. The formation of social hierarchies is conducive to solving the problem of the allocation of scarce resources among individuals. From August 2015 to July 2016, we observed a wild, provisioned Yunnan snub-nosed monkey (Rhinopithecus bieti) group at Xiangguqing in Baimaxueshan National Nature Reserve, Yunnan Province, China. Aggressive and submissive behaviors were used to investigate dominance hierarchies between female individuals in the same one-male unit (OMU), and the grooming reciprocity index was used to detect reciprocal relationships between these females within the OMU. The results showed that loose social hierarchies exist among the females in each OMU, and more dominant individuals have higher grooming incomes. These results are consistent with the aggressive-submissive hypothesis and the resource control hypothesis.

animal behavior and cognition↗

bioRxiv2020

Evidence of the Recombinant Origin and Ongoing Mutations in Severe Acute Respiratory Syndrome 2 (SARS-COV-2)

The recent global outbreak of viral pneumonia designated as Coronavirus Disease 2019 (COVID-19) by coronavirus (SARS-CoV-2) has threatened global public health and urged to investigate its source. Whole genome analysis of SARS-CoV-2 revealed ~96% genomic similarity with bat CoV (RaTG13) and clustered together in phylogenetic tree. Furthermore, RaTGl3 also showed 97.43% spike protein similarity with SARS-CoV-2 suggesting that RaTGl3 is the closest strain. However, RBD and key amino acid residues supposed to be crucial for human-to-human and cross-species transmission are homologues between SARS-CoV-2 and pangolin CoVs. These results from our analysis suggest that SARS-CoV-2 is a recombinant virus of bat and pangolin CoVs. Moreover, this study also reports mutations in coding regions of 125 SARS-CoV-2 genomes signifying its aptitude for evolution. In short, our findings propose that homologous recombination has been occurred between bat and pangolin CoVs that triggered cross-species transmission and emergence of SARS-CoV-2, and, during the ongoing outbreak, SARS-CoV-2 is still evolving for its adaptability.

microbiology↗

bioRxiv2020

GeneMates: an R package for Detecting Horizontal Gene Co-transfer between Bacteria Using Gene-gene Associations Controlled for Population Structure

Antimicrobial resistance (AMR) in bacteria has been a global threat to public health for decades. A well-known driving force for the emergence, evolution and dissemination of genetic AMR determinants in bacterial populations is horizontal gene transfer, which is frequently mediated by mobile genetic elements (MGEs). Some MGEs can capture, maintain, and rearrange multiple AMR genes in a donor bacterium before moving them into recipients, giving rise to a phenomenon called horizontal gene co-transfer (HGcoT). This physical linkage or co-localisation between mobile AMR genes is of particular concern because it facilitates rapid dissemination of multidrug resistance within and across bacterial populations, providing opportunities for co-selection of AMR genes and limiting our therapeutic options. The study of HGcoT can be benefited from large-scale whole-genome sequencing (WGS) data, however, by far most published studies of HGcoT only consider simple co-occurrence measures, which can be confounded by strong bacterial population structure due to clonal reproduction, leading to spurious associations. To address this issue, we present GeneMates, an R package implementing a network approach to identification of HGcoT using WGS data. The package enables users to test for associations between presence-absence of bacterial genes using univariate linear mixed models controlling for population structure based on core-genome variation. Furthermore, when physical distances between genes of interest are measurable in bacterial genomes, users can evaluate distance consistency to further support their inference of putative horizontally co-transferred genes, whose co-occurrence cannot be completely explained by the population structure. We demonstrate how this package can be used to identify co-transferred AMR genes and recover known MGEs from Escherichia coli and Salmonella Typhimurium WGS data. GeneMates is accessible at github.com/wanyuac/GeneMates.

genomics↗

bioRxiv2019

A novel vaccine targeting the viral protease cleavage sites protects Mauritian cynomolgus macaques against vaginal SIVmac251 infection

After over three decades of research, an effective anti-HIV vaccine remains elusive. Unconventional and novel vaccine strategies are needed. Here, we report that a vaccine focusing the immune response on the sequences surrounding the 12 viral protease cleavage sites (PCSs) provides greater than 80% protection of Mauritian cynomolgus macaques (MCMs) against repeated intravaginal SIVmac251 challenges. The PCS-specific T cell responses are correlated with vaccine efficacy. The PCS vaccine does not induce immune activation and inflammation known to be associated with increased susceptibility to HIV infection. Machine learning analyses revealed that the immune environment generated by the PCS vaccine predicts vaccine efficacy. Our study demonstrates for the first time that a novel vaccine which targets viral maturation, but lacks full Env and Gag proteins as immunogens, can prevent intravaginal infection in a highly stringent NHP/SIV challenge model. Targeting HIV maturation thus offers a novel approach to developing an effective HIV vaccine. One Sentence SummaryThe anti-PCS T cell responses and the immune environment induced by the novel PCS vaccine are key correlates of vaccine efficacy

microbiology↗

bioRxiv2019

The Manganese Salt (MnJ) Functions as A Potent Universal Adjuvant

Aluminum adjuvants have been used for a century in various vaccines due to its ability to potentiate humoral immunity and safety records since 1920s. Manganese is an essential micronutrient required for diverse biological activities in cells. We previously found that Mn2+ is a strong type I-interferon stimulator activating the cGAS-STING pathway. Herein we report that a colloidal manganese salt (MnJ) is a potent adjuvant to induce both humoral and cellular immune responses, particularly CTL activation. When administrated intranasally, MnJ was also a strong mucosal adjuvant, inducing high levels of IgA antibodies. MnJ strongly promoted dendritic cell maturation and antigen-specific T cell activation. Interestingly, IL-1/-18 induction and release by Mn2+-activated ASC-mediated inflammasomes were not observed. MnJ showed great adjuvant effects to all tested antigens including inactivated viruses, recombinant proteins and peptides by either intramuscular or intranasal immunization. These findings may have implications in developing potent but safe Mn2+-containing vaccines.

immunology↗

bioRxiv2019

Lung tumour cell-derived exosomes promote the expansion of MDSC through miR-21a/PDCD4/IL-6/STAT3 pathway

The percentage of MDSC population in peripheral blood is significantly increased in lung cancer patients. The accumulation of MDSC contributes to the development of a tumour-associated immune suppressive environment. But the mechanism mediating MDSC accumulation in lung cancer patients is elusive. We found that exosomes from Lewis lung cancer cells (LLC-Exo) can be taken up by the mice bone marrow cells and then promote MDSC expansion, which enhance tumour growth. Mechanistically, during the induction of MDSC from the bone marrow cells, miR-21a from LLC-Exo can stimulate BM cells to produce more IL-6 by inhibiting pdcd4 expression post-transcriptionally. Autocrine IL-6 induces tyrosine 705(Y705) of STAT3 to be phosphorylated during MDSC expansion. LLC-Exo with miR-21a deletion lost its ability to stimulate IL-6 production, STAT3 activation and MDSC expansion. These results demonstrate that lung cancer cell-derived exosomes promote functional MDSC expansion through activation of miR-21a/PDCD4/IL-6/STAT3 pathway.

cancer biology↗

bioRxiv2019

Clinical diagnosis of single-gene disorders and chromosomal abnormalities based on BGISEQ-500 platform

Most of the variation in the human genome is a single nucleotide variation (SNV) based on a single base or small fragment insertions and deletions and genomic copy number variation (CNV). Both types of mutations are involved in many human diseases. Such diseases often have complex clinical symptoms and difficult clinical diagnosis, so an effective detection method is needed to help clinical diagnosis and prevent birth defects. With the development of sequencing technology, the method of chip capture combined with high-throughput sequencing has been extensively used because of its high throughput, high accuracy, high speed and low cost. This study designed a chip that captures the coding region of 3043 genes associated with 4013 monogenic diseases. In addition, 148 chromosomal abnormalities can be identified by setting targets in specific regions. Compared with the whole exon chip, the chip can detect 4013 monogenic diseases and 148 chromosomal abnormalities at a lower cost, including SNV, intra-gene CNV and genomic copy number variation. This study utilized a strategy of combining the BGISEQ500 sequencing platform with the chip to identify 102 disease-associated mutations in 63 patients, 69 of which were new mutations. The evaluation test results also show that this combination complies with the requirements of clinical testing and has good clinical application value.

genomics↗

bioRxiv2019

A Pandas complex adapted for piRNA-guided transposon silencing

The repression of transposons by the Piwi-interacting RNA (piRNA) pathway is essential to protect animal germ cells. In Drosophila ovaries, Panoramix (Panx) enforces transcriptional silencing by binding to the target-engaged Piwi-piRNA complex, although the precise mechanisms by which this occurs remain elusive. Here, we show that Panx functions together with a germline specific paralogue of a nuclear export factor, dNxf2, and its cofactor dNxt1 (p15), as a ternary complex to suppress transposon expression. Structural and functional analyses demonstrate that dNxf2 binds Panx via its UBA domain, which plays an important role in transposon silencing. Unexpectedly, dNxf2 interacts directly with dNxf1 (TAP), a general nuclear export factor. As a result, dNxf2 prevents dNxf1 from binding to the FG repeats of the nuclear pore complex, a process required for proper RNA export. Transient tethering of dNxf2 to nascent transcripts leads to their nuclear retention. Therefore, we propose that dNxf2 may function as a Pandas (Panoramix-dNxf2 dependent TAP/p15 silencing) complex, which counteracts the canonical RNA exporting machinery and restricts transposons to the nuclear peripheries. Our findings may have broader implications for understanding how RNA metabolism modulates epigenetic gene silencing and heterochromatin formation.

molecular biology↗

bioRxiv2019

Genome-wide Associations of Flavivirus Capsid Proteins

Dengue virus (DENV) and Zika virus (ZIKV) are both positive sense single-stranded RNA viruses. They are packaged within the virion with a capsid (C) protein to form the nucleocapsid. Based on cryo-electron microscopy imaging, the nucleocapsid has been described as lacking symmetry, whilst there is distinguishable separation of the C proteins from the viral RNA (vRNA) genome. Here, to elucidate the architecture of the nucleocapsid of DENV serotype 2 and ZIKV, we used a nuclease digestion assay and next-generation sequencing to map the respective vRNA genome wide association with the C protein in vitro. The C protein exhibited non-uniform binding along the vRNA, and as C protein concentration increased, the normalized read counts also increased. A saturation point of 1:100 (vRNA:C protein monomers) was found, and binding regions showed variable saturation patterns. We also observed that C protein had a preference for G-rich sequences for both viruses. Taken together, we demonstrate that the DENV 2 and ZIKV C proteins bind vRNA in a non-uniform manner with distinct patterns of association.\n\nSingificance StatementOur study demonstrates that flavivirus capsid proteins associate with the viral genome at specific sites rather than in a uniform manner as commonly expected. We estimate the number of capsid proteins binding to a single genomic RNA. We proceed to locate the capsid binding sites along the viral genomes of Dengue and Zika viruses. We characterize the binding sites in terms of affinity and analyze the nucleotide composition and sequence motifs at binding sites. We cross-reference binding sites against SHAPE reactivity data corresponding to local RNA secondary structure, which allows us to identify structural motifs of capsid binding sites. As capsid proteins are essential for viral packaging, these interactions may form attractive targets for therapeutic intervention.

genomics↗