Biology subjects

Ou, X.

Publications and source records attributed to Ou, X..

5 recordsLinked to original sources

bioRxiv2021

Genetic loci of the R. anatipestifer serotype discovered by Pan-GWAS and its application for the development of a multiplex PCR serotyping method

The disease caused by Riemerella anatipestifer (R. anatipestifer) causes large economic losses to the global duck industry every year. Serotype-related genomic variation (such as in O-antigen and capsular polysaccharide gene clusters) has been widely used for the serotyping in many gram-negative bacteria. To date, there have been few studies focused on genetic basis of serotypes in R. anatipestifer. Here, we used pan-genome-wide association studies (Pan-GWAS) to identify the serotype-specific genetic loci of 38 R. anatipestifers strain. Analyses of the loci of 11 serotypes showed that the loci could be well mapped with the serotypes of the corresponding strains. We constructed the knockout strain for the wzy gene at the locus, and the results showed that the mutant lost the agglutination characteristics to positive antisera. Based on the of Pan-GWAS results, we developed a multiple PCR method to identify serotypes 1, 2, and 11 of R. anatipestifer. Our study provides a precedent for systematically analysing the genetic basis of the R anatipestifer serotypes and establishing a complete serotyping system in the future. HighlightsO_LIR. anatipestifer serotype-specific locus was identified by Pan-GWAS for the first time. C_LIO_LIMolecular serotyping multiplex PCR was developed based on O-antigen biosynthesis gene clusters C_LI

genomics↗

bioRxiv2021

Single-Cell Profiling Resolved Transcriptional Alterations and Lineage Dynamics of Subventricular Zone after Mild Traumatic Brain Injury

Mild traumatic brain injury (mTBI) is the most common form of brain trauma caused by physical impact. The subventricular zone (SVZ) is a neurogenetic niche that contributes to homeostasis and repair after brain injury. It is particularly challenging to fully elucidate the molecular alterations in the SVZ occurring in response to injury due to its cell diversity and the complex network. In this study, we aimed to address this issue using a novel transcriptomic technique- unbiased single-cell RNA sequencing. We resolved previous unknown cell subpopulations harbored in the niche, and uncovered cell type-specific alterations in gene expression, enriched pathways, and cell-cell crosstalk following mTBI. Notably, we also report novel lineage trajectories and molecular hallmarks that govern neurogenesis. This study dissects the delicate transcriptome changes of individual cell types as well as the reprogramming process of cells in the SVZ niche after mTBI, and our findings are expected to facilitate the development of therapeutic interventions or diagnostic tests for mTBI.

neuroscience↗

bioRxiv2020

The Rhinolophus affinis bat ACE2 and multiple animal orthologs are functional receptors for bat coronavirus RaTG13 and SARS-CoV-2

Bat coronavirus (CoV) RaTG13 shares the highest genome sequence identity with SARS-CoV-2 among all known coronaviruses, and also uses human angiotensin converting enzyme 2 (hACE2) for virus entry. Thus, SARS-CoV-2 is thought to have originated from bat. However, whether SARS-CoV-2 emerged from bats directly or through an intermediate host remains elusive. Here, we found that Rhinolophus affinis bat ACE2 (RaACE2) is an entry receptor for both SARS-CoV-2 and RaTG13, although RaACE2 binding to the receptor binding domain (RBD) of SARS-CoV-2 is markedly weaker than that of hACE2. We further evaluated the receptor activities of ACE2s from additional 16 diverse animal species for RaTG13, SARS-CoV, and SARS-CoV-2 in terms of S protein binding, membrane fusion, and pseudovirus entry. We found that the RaTG13 spike (S) protein is significantly less fusogenic than SARS-CoV and SARS-CoV-2, and seven out of sixteen different ACE2s function as entry receptors for all three viruses, indicating that all three viruses might have broad host rages. Of note, RaTG13 S pseudovirions can use mouse, but not pangolin ACE2, for virus entry, whereas SARS-CoV-2 S pseudovirions can use pangolin, but limited for mouse, ACE2s enter cells. Mutagenesis analysis revealed that residues 484 and 498 in RaTG13 and SARS-CoV-2 S proteins play critical roles in recognition of mouse and human ACE2. Finally, two polymorphous Rhinolophous sinicus bat ACE2s showed different susceptibilities to virus entry by RaTG13 and SARS-CoV-2 S pseudovirions, suggesting possible coevolution. Our results offer better understanding of the mechanism of coronavirus entry, host range, and virus-host coevolution.

microbiology↗

bioRxiv2020

Live poultry feeding and trading network and the transmission of avian influenza A(H5N6) virus in a large city in China, 2014-2015

To understand clearly the mechanism of H5N6 transmission, the role of a live poultry feeding and trading network should be explored deeply. However, there is little data to show the network in an area. In this study, we performed a field epidemiological investigation to collect the numbers of farms, wholesale markets, and live poultry retail markets, and the numbers of purchased (from where) and sold (to where) live birds in Changsha City, China in 2014. We also collected samples from the network in the city from January 2014 to March 2015, including the LPMs visited by the patient known to be infected with A(H5N6) virus, and sequenced the genomes of 10 A(H5N6) viral strains isolated from these environmental samples, to determine the source of virus that infected the patient reported in Changsha. Additionally, we collected and analyzed A(H5N6) virus genome sequence isolated from humans, poultry, and LPMs registered in National Center for Biotechnology Information (NCBI; NIH, Bethesda, MD, USA) 14, to determine the source of other human infections with A(H5N6) virus reported in China. Changsha City in China has a large live poultry feeding and trading network (LPFTN) which had 665 farms, 5 wholesale markets, and 223 live poultry retail markets in 2014. The network covered nine provinces and purchased and sold more than 150000 live birds every day. About 840 environmental samples collected from the LPFTN network from January 2014 to March 2015. About 8.45% (71/840) environmental samples were shown to be positive for N6 and 10 full genome sequences of H5N6 virus were analyzed. We performed phylogenetic analyses and virus characterization, which demonstrated that the H5N6 viral strains isolated from Chinese patients were closely related to those isolated from the poultry and environmental samples obtained from the LPFTN network. This indicates that the network with a large volume of live poultry provides a platform for the transmission of H5N6, and provides an infectious pool which makes the people in high risk. ImportanceAvian influenza A(H5N6) virus is an emerging threat to public health. With several human cases reported in recent years, it has become a dominant avian influenza virus (AIV) subtype in China. Live poultry feeding and trading network (LPFTN) contributes to the presence of novel AIV. By a field epidemiological investigation in the complex LPFTN in Changsha, we demonstrated that the H5N6 viral strains isolated from Chinese patients were closely related to those isolated from the poultry and environmental samples obtained from the network, suggesting the LPFTN with a large volume of live poultry provides a platform for the transmission of H5N6 and creates an infectious pool which makes people in high risk. Considering the wide circulation and dynamic reassortment of this highly pathogenic avian influenza H5N6 virus, it should be carefully monitored in poultry and humans due to the pandemic potential.

molecular biology↗

bioRxiv2020

Tracing two causative SNPs reveals SARS-CoV-2 transmission in North America population

During the COVID-19 pandemic, precisely tracing the route of the SARS-CoV-2 transmission in human population remains challenging. Because this RNA virus can mutate massively without a specifically tracing maker. Herein, using a geographic stratified genome-wide association study (GWAS) of 2599 full-genome sequences, we identified that two SNPs (i.e., 1059.C>T and 25563.G>T) of linkage disequilibrium were presented in approximately half of North America SARS-CoV-2 population (p = 2.44 x 10-212 and p = 2.98 x 10-261), resulting two missense mutations (i.e., Thr 265 Ile and Gln 57 His) in ORF1ab and ORF3a, respectively. Interestingly, these two SNPs exclusively occurred in the North America dominated clade 1, accumulated during mid to late March, 2020. We did not find any of these two SNPs by retrospectively tracing the two SNPs in bat and pangolin related SARS-CoV-2 and human SARS-CoV-2 from the first epicenter Wuhan or other regions of China mainland. This suggested that the SARS-CoV-2 population of Chinese mainland were different from the prevalent strains of North America. Time-dependently, we found that these two SNPs first occurred in Europe SARS-CoV-2 (26-Feb-2020) which was 3 days early than the occurring date of North America isolates and 17 days early for Asia isolates (Taiwan China dominated). Collectively, this population genetic analysis highlights a well-confidential transmission route of the North America isolates and the two SNPs we newly identified are possibly novel diagnosable or druggable targets for surveillance and treatment.

microbiology↗