Science China Life Sciences

The endomembrane reticulum (ER) is largely reorganized by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 ORF3a and membrane (M) protein expression affects ER-derived structures including cubic membrane and double membrane vesicles in coronavirus-infected cells; however, the molecular mechanisms underlying ER remodeling remain unclear. We introduced a "plug and playable" proximity labeling tool (TurboID-GBP) for interactome mapping of GFP-tagged SARS-CoV-2 ORF3a and M proteins. Through mass spectrometric identification of the biotinylated lysine residue (K+226 Da) on the viral proteins using Spot-TurboID workflow, 117 and 191 proteins were robustly determined as ORF3a and M interactomes, respectively, and many, including RNF5 (E3 ubiquitin ligase), overlap with the mitochondrial-associated membrane (MAM) proteome. RNF5 expression was correlated to ORF3a ubiquitination. MAM formation and secreted proteome profiles were largely affected by ORF3a expression. Thus, SARS-CoV-2 may utilize MAM as a viral assembly site, suggesting novel anti-viral treatment strategies for blocking viral replication in host cells. HighlightsO_LISARS-CoV-2 proteins ORF3a and M alter endoplasmic reticulum proteome profile C_LIO_LIORF3a affects mitochondrial-associated membrane formation C_LIO_LISARS-CoV-2 may utilize mitochondrial-associated membrane as viral assembly site C_LIO_LIORF3a and M interactome proteins may serve as targets for COVID-19 treatment C_LI eTOC BlurbER remodelling by SARS-CoV-2 ORF3a and M protein

The outbreak of the novel coronavirus disease, COVID-19, originating from Wuhan, China in early December, has infected more than 70,000 people in China and other countries and has caused more than 2,000 deaths. As the disease continues to spread, the biomedical society urgently began identifying effective approaches to prevent further outbreaks. Through rigorous epidemiological analysis, we characterized the fast transmission of COVID-19 with a basic reproductive number 5.6 and proved a sole zoonotic source to originate in Wuhan. No changes in transmission have been noted across generations. By evaluating different control strategies through predictive modeling and Monte carlo simulations, a comprehensive quarantine in hospitals and quarantine stations has been found to be the most effective approach. Government action to immediately enforce this quarantine is highly recommended.

The novel coronavirus (2019-nCoV) appeared in Wuhan in late 2019 have infected 34,598 people, and killed 723 among them until 8th February 2020. The new virus has spread to at least 316 cities (until 1st February 2020) in China. We used the traffic flow data from Baidu Map, and number of air passengers who left Wuhan from 1st January to 26th January, to quantify the potential infectious people. We developed multiple linear models with local population and air passengers as predicted variables to explain the variance of confirmed cases in every city across China. We found the contribution of air passengers from Wuhan was decreasing gradually, but the effect of local population was increasing, indicating the trend of local transmission. However, the increase of local transmission is slow during the early stage of novel coronavirus, due to the super strict control measures carried out by government agents and communities.

Seasonal spermatogenesis in fish is driven by spermatogonial stem cells (SSCs), which undergo a complex cellular process to differentiate into mature sperm. In this study, we characterized spermatogenesis in the large yellow croaker (Larimichthys crocea), a marine fish of significant commercial value, based on a high-resolution single-cell RNA-seq atlas of testicular cells from three distinct developmental stages- juvenile, adult differentiating and regressed testes. We detailed continuous developmental trajectory of spermatogenic cells, from spermatogonia to spermatids, elucidating the molecular events involved in spermatogenesis. We uncovered dynamic heterogeneity in cellular compositions throughout the annual reproductive cycle, accompanied by strong molecular signatures within specific testicular cells. Notably, we identified a distinct population of SSCs and observed a critical metabolic transition from glycolysis to oxidative phosphorylation, enhancing our understanding of the biochemical and molecular characteristics of SSCs. Additionally, we elucidated the interactions between somatic cells and spermatogonia, illuminating the mechanisms that regulate SSCs development. Overall, this work enhances our understanding of spermatogenesis in seasonal breeding teleost and provides essential insights for the further conservation and culture of SSCs. Summary statementOur study reveals new insights into the development of spermatogonial stem cells (SSCs), potentially impacting further conservation and culture of SSCs in teleost.

The trimeric spike protein (S) mediates host-cell entry and membrane fusion of SARS-CoV-2. S protein is highly glycosylated, whereas its O-glycosylation is still poorly understood. Herein, we site-specifically examine the O-glycosylation of S protein through a mass spectrometric approach with HCD-triggered-ETD model. We identify 15 high-confidence O-glycosites and at least 10 distinct O-glycan structures on S protein. Peptide microarray assays prove that human ppGalNAc-T6 actively participates in O-glycosylation of S protein. Importantly, the upregulation of ppGalNAc-T6 expression can profoundly enhance the O-glycosylation level by generating new O-glycosites and increasing both O-glycan heterogeneity and intensities. Further molecular dynamics simulations reveal that the O-glycosylation on the protomer-interface regions, which are mainly modified by ppGalNAc-T6, can potentially stabilize the trimeric S protein structure. Our work provides deep molecular insights of how viral infection harnesses the host O-glycosyltransferases to dynamically regulate the O-glycosylation level of the viral envelope protein responsible for membrane fusion.

Ancient DNA advances have reported the complex genetic history of Eurasians, but how the knowledge of ancient subsistence strategy shifts and population movements influenced the fine-scale paternal genetic structure in East Asia has not been assessed. Here, we reported one integrated Y-chromosome genomic database of 15,530 people, including 1753 ancient people and newly-reported 919 individuals genotyped using our recently-developed targeted sequencing YHSeqY3000 panel, to explore Chinese genomic diversity, population evolutionary tracts and their genetic formation mechanism. We identified four major ancient technological innovations and population movements that shaped the landscape of Chinese paternal lineages. First, the expansion of millet farmers and early East Asians from the Yellow River Basin carrying the major O2/D subclades promoted the formation of the Sino-Tibetan peoples major composition and accelerated the Tibetan Plateaus permanent occupation. Second, rice farmers dispersal from the Yangtze River Valley carrying O1 and some sublineages of O2 contributed significantly to Tai-Kadai, Austronesian, Hmong-Mien, Austroasiatic people and southern Han Chinese. Third, Siberian-related paternal lineages of Q and C originated and boomed from Neolithic hunter-gatherers from the Mongolian Plateau and the Amur River Basin and significantly influenced the gene pools of northern Chinese. Fourth, western Eurasian-derived J, G and R lineages initially spread with Yamnaya steppe pastoralists and other proto-Indo-European people and further widely dispersed via the trans-Eurasian cultural communication along the Eurasian Steppe and the ancient Silk Road, remaining genetic trajectories in northwestern Chinese. Our work provided comprehensive modern and ancient genetic evidence to illuminate the impact of population interaction from the ancient farmer or herder-based societies on the genetic diversity patterns of modern people, revised our understandings of ancestral sources of Chinese paternal lineages, underscored the scientific imperative of the large-scale genomic resources of dense spatiotemporal underrepresented sampling populations to understand human evolutionary history.

PIWI-interacting RNAs (piRNAs) are critical for transposon silencing and genome integrity, as well as gene expression regulation and antiviral immunity in metazoans, yet the molecular mechanisms governing their biogenesis remain incompletely understood. The participation of the splicing-associated process in piRNA biogenesis has been emphasized in multiple species, but the key factors and mechanisms remain elusive. Here, we identified SUGP1 (SURP and G-Patch Domain Containing 1) in BmE (a unique model cell system with a complete piRNA biogenesis pathway) as a key splicing factor that functions in piRNA biogenesis. Through CRISPR-Cas9-mediated gene knockdown in cultured cells combined with RNA-seq, small RNA-seq, and IP-mass spectrometry (IP-MS), our results reveal that SUGP1 deficiency disrupts piRNA accumulation, alters mature piRNA length distributions, and activates transposon expression. Immunofluorescence and Western blot (WB) analyses further demonstrate that SUGP1 interacts with Y-box protein (YBP), which is key regulators of RNA metabolism. Functional validation in Drosophila SUGP1-RNAi lines highlights evolutionary conserved and species-specific roles of SUGP1 in piRNA maturation. Collectively, our data uncover a dual role for silkworm SUGP1 in coordinating YBP-dependent piRNA biogenesis, thus elucidating a novel mechanistic framework for piRNA pathway regulation. Our work also underscores the silkworm as a unique model for studying non-canonical piRNA biogenesis mechanisms, with implications for treating transposon dysregulation-linked diseases. Author summaryDisruption of piRNA synthesis leads to abnormal consequences such as transposon de-repression, posing a significant threat to genomic stability. It is therefore essential to in-depth analysis of the piRNA biosynthetic mechanism. Previous studies have highlighted the involvement of splicing-related processes in piRNA biosynthesis, yet key factors and mechanisms remain poorly understood. This study employed the silkworm cell system, which possesses a complete piRNA biosynthetic pathway. Utilizing CRISPR-Cas9-mediated gene knockout technology combined with RNA sequencing, small RNA sequencing, and immunoprecipitation-mass spectrometry (IP-MS), we discovered that SUGP1 deficiency disrupts piRNA accumulation, alters the length distribution of mature piRNAs, and activates transposon expression. Furthermore, immunofluorescence and Western blot analyses confirmed an interaction between SUGP1 and Y-box proteins (YBPs), key regulators of RNA metabolism. Functional validation using Drosophila SUGP1-RNAi lines revealed that SUGP1 plays dual roles in piRNA maturation. Our study reveals that the silkworm scissor-related factor SUGP1 has dual functions in coordinating YBP-dependent piRNA biosynthesis.

The outbreak of coronavirus disease 2019 (COVID-19) which originated in Wuhan, China, constitutes a public health emergency of international concern with a very high risk of spread and impact at the global level. We developed data-driven susceptible-exposed-infectious-quarantine-recovered (SEIQR) models to simulate the epidemic with the interventions of social distancing and epicenter lockdown. Population migration data combined with officially reported data were used to estimate model parameters, and then calculated the daily exported infected individuals by estimating the daily infected ratio and daily susceptible population size. As of Jan 01, 2020, the estimated initial number of latently infected individuals was 380.1 (95%-CI: 379.8[~]381.0). With 30 days of substantial social distancing, the reproductive number in Wuhan and Hubei was reduced from 2.2 (95%-CI: 1.4[~]3.9) to 1.58 (95%-CI: 1.34[~]2.07), and in other provinces from 2.56 (95%-CI: 2.43[~]2.63) to 1.65 (95%-CI: 1.56[~]1.76). We found that earlier intervention of social distancing could significantly limit the epidemic in mainland China. The number of infections could be reduced up to 98.9%, and the number of deaths could be reduced by up to 99.3% as of Feb 23, 2020. However, earlier epicenter lockdown would partially neutralize this favorable effect. Because it would cause in situ deteriorating, which overwhelms the improvement out of the epicenter. To minimize the epidemic size and death, stepwise implementation of social distancing in the epicenter city first, then in the province, and later the whole nation without the epicenter lockdown would be practical and cost-effective.

Microalgae are highly efficient photosynthetic organisms that hold enormous potential as sources of renewable energy. In particular, Chlorella pyrenoidosa displays a rapid growth rate, high tolerance to light, and high lipid content, making it especially valuable for applications such as flue gas CO2 fixation, biofuel production, and nutritional extracts. In order to unveil its full potential, it is necessary to characterize its subcellular architecture. Here, we achieved three-dimensional (3D) visualization of the architectures of C. pyrenoidosa cells, by combining focused ion beam scanning electron microscopy (FIB/SEM), cryo-FIB milling, and cryo-electron tomography (cryo-ET). These high-resolution images bring to light intricate features of intact organelles, including thylakoid membranes, pyrenoid, starch granules, mitochondria, nucleus, lipid droplets and vacuoles, as well as the fine architectures within the chloroplast, including the concave-convex pyrenoid, plastoglobules, thylakoid tips, and convergence zones. Significantly, comparative analysis of wild-type and nuclear-irradiated mutagenic strains determined that cell volume and surface area of mutant cells have increased substantially to 2.2-fold and 1.7-fold, respectively, consistent with up-regulation of the enzyme Rubisco and enhanced photosynthetic metabolic processes. Moreover, quantitative analysis established that the thylakoid membrane width in mutant cells increased to 1.3-fold, while the membrane gap decreased to 0.8-fold, possibly contributing to the higher biomass growth rate of mutant cells. Our work reveals the first 3D subcellular architectures of C. pyrenoidosa cell and provides a structural framework for unlocking the higher growth rate in microalgae relevant to a wide range of industrial applications.

In mammals, the transcription of transposable elements (TEs) is important for maintaining early embryonic development. Here, we systematically analyzed the expression characteristics of TE-derived transcripts in early embryos by constructing a database of TEs and transcriptome data from goats and using it to study the function of endogenous retroviruses (ERVs) in regulating early embryo development. We found that ERV1 made up the highest proportion of TE sequences and exhibited a stage-specific expression pattern during early embryonic development. Among ERV elements, ERV1 had the potential to encode the Gag protein domain to form virus-like particles (VLPs) in early goat embryos. Knockdown of ERV1_1_574 significantly reduced the embryo development rate and the number of trophoblast cells (P< 0.05). Transcriptome sequencing analysis of morula embryos showed that ERV1_1_574 mainly regulated the expression of genes related to embryo compaction and trophoblast cell differentiation, such as CX43 and CDX2. In summary, we found that ERV1 expression was essential for early embryonic development in goats through regulation of trophoblast cell differentiation.

In the context of public health, asymptomatic carriers of respiratory infectious diseases are considered a hidden yet critical factor in the transmission of infection and represent a key target for efforts to mitigate disease spread. To contribute a unique genomic resource to the SARS-CoV-2 research community, we collected SARS-CoV-2-positive samples from asymptomatic individuals at the SB Coronavirus Inspection Center Corp. during the COVID-19 pandemic in Japan and conducted a comprehensive analysis of their viral genomes. Using Illumina COVIDSeq technology, we successfully generated 8,266 SARS-CoV-2 genome assemblies, all of which have been made publicly available to facilitate further research. In this report, we summarize our efforts to collect SARS-CoV-2-positive samples from asymptomatic individuals and highlight the key features and accessibility of this genomic dataset.

Viral recombination can rapidly generate new variants and influence outbreak severity. Currently, a method to track viral recombination events at high genomic resolution during natural transmission remains unavailable. Here we describe a novel linkage disequilibrium method and the first report of viral recombination events over time by using single nucleotide polymorphisms (SNPs) as natural genetic markers. Combined with phylogenetic data, we analyzed mpox virus (MPXV) Ib genome during 2023-2025 outbreak and found that 71 recombination events among Ib genomes, yielding a recombination frequency (Rf) and rate of 0.16%/kbp and 0.11%/kbp/year, respectively. Phylogenetic time analysis also shows that recombination began as early as December 23, 2023. Rf of MPXV Ib is 8.8-fold lower compared to vaccinia virus (1.5%/kbp) in vitro. Recombination and linkage hotspots are enriched at both inverted terminal repeat and variable regions of MPXV Ib genome. Our data not only reports the first Rf and rate of natural human transmission in the poxvirus family but also provides a powerful genomic surveillance tool for better understanding transmission and evolution of any viral outbreak globally.

Nucleotide-binding leucine-rich repeat (NLR) immune receptor genes are of significant value in disease resistance breeding and the control of viral diseases. Soybean mosaic virus (SMV) poses a serious threat to soybean production and the Rsv1 locus in soybean cultivar Suweon 97 confers broad-spectrum resistance against SMV strains G1 to G7; however, this locus harbors no fewer than 18 NLR genes, and thus the broad-spectrum antiviral mechanisms underlying the Rsv1 locus remain poorly understood to date. Here, we established a rapid and highly efficient screening system for cloning NLR genes from soybean Rsv1 locus and identified a broad-spectrum antiviral NLR gene 13g184900 from this highly complicated locus. The NLR encoded by 13g184900 can recognize viral P3 protein from all SMV strains (G1-G7) and another potyvirus Bean common mosaic virus (BCMV). The coiled-coil (CC) domain of this NLR directly interacts with viral P3 protein. Additionally, we showed that this NLR originated from wild soybean accession in East China and has been introduced into several soybean cultivars during domestication. Collectively, we developed a high-throughput screening system for identifying NLR genes in soybean and our study provides new mechanistic perspective on how the Rsv1 locus mediates the broad-spectrum resistance to all SMV G1-G7 strains.

The authors have withdrawn this manuscript because the experiment was badly designed and the results could not be repeated. Therefore, the authors do not wish this work to be cited as reference for the project.

The authors have withdrawn their manuscript because the authors need to re-organize the data and writing, meanwhile more experimental evidence from more RNA-seq replications, immunofluorescence assay and in vivo knock-down assays will be added to support the viewpoints. In this preprint, only one individual of decolonized mussel was employed for transcriptome sequencing while combined data from single cell transcriptomics with in situ hybridization is not enough convincing to draw some of the conclusion. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.

Aedes albopictus shows a rapid global expansion and dramatic vectorial capacity for various arboviruses. Mosquitoes display distinct sexual dimorphisms, only adult females consume blood meals to complete ovarian follicle development. Therefore, cyclic reproduction in female mosquitoes serves as a foundation for the transmission of numerous disease-causing pathogens. Aedes have an expansion of the piRNA biogenesis genes, indicated that piRNA may play multiple functional roles in mosquitoes. Although the antiviral function of piRNA pathway in mosquitoes has been extensively studied, the role of piRNAs in mosquito reproduction remain to be further understood. In the present study, we first profiled the characteristics of sex-biased piRNAs in adult Ae.albopictus. Then, we identified a female biased piRNA (Aalpi18529) in adult females, that was highly expressed in ovaries at blood feeding-dependent termination, and depended on PIWI5 and ago3 mediated biogenesis. Aalpi18529 overexpression suppressed ovarian development, and reduced fertility and fecundity in adult females post-bloodmeal. Furthermore, we demonstrated that Aalpi18529 can effectively repress its direct target, growth arrest and DNA-damage-inducible protein 45a (GADD45A), and eventually regulates ovarian development via the Gadd45a-mediated JNK-dependent nurse cell apoptosis pathway. Our study is the first to report an endogenous piRNA, which trigger silencing of an important protein-coding gene by posttranscriptional regulation in mosquitoes, expanding our current understanding of the important and multiple roles of piRNAs in biological processes in Ae. albopictus. Author SummaryHere, we conducted high throughput piRNA sequencing and comprehensive analysis of piRNA sex-based expression profiles in adult females and males of Aedes albopictus. Based on several established universal tools for research, we demonstrate an ovary-enriched endogenous piRNA, Aalpi-18529, is involved in the regulation of the apoptosis of nurse cells during vitellogenesis via the GADD45A/phosphorylated JNK (pJNK) axis and ultimately affects ovarian development. In general, uncovering the biological functions of sex-biased piRNAs in Aedes albopictus will enhance the understanding of piRNA roles in mosquito Sexual dimorphism (SD) and will provide provide more information about the high reproductive capacity of Aedes albopictus, which is essential to find alternative control strategies. Classification: Research Reports

The COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has overwhelmed many health systems globally. Here, we aim to identify biological markers and associated biological processes of COVID-19 using a bioinformatics approach to elucidate their potential pathogenesis. The gene expression profile of the GSE152418 dataset was originally produced by using the high-throughput Illumina NovaSeq 6000. Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) and Gene Ontology (GO) enrichment analyses were applied to identify functional categories and biochemical pathways. KEGG and GO results suggested that biological pathways such as "Cancer pathways" and "Insulin pathways" were mostly affected in the development of COVID-19. Moreover, we identified several genes including EP300, CREBBP, and POLR2A were involved in the virus activities in COVID-19 patients. We further predicted that some inhibitors may have the potential to block the SARS-CoV-2 infection based on the L1000FWD analysis. Therefore, our study provides further insights into the underlying pathogenesis of COVID-19.

Metagenomics could detect SARS-CoV-2 in all eight nasopharyngeal/throat swabs with high/low viral loads, and rhinovirus in a co-infected patient. The sequenced viruses belonged to lineage B1. Because metagenomics could detect novel pathogen and co-infection, and generate sequence data for epidemiological investigation, it is an attractive approach for infectious-disease diagnosis.

Profiling and comparing the performance of current widely used DNA targeting CRISPR systems provide the basic information for the gene-editing toolkit and can be a useful resource for this field. Herein we made a parallel comparison between the recently reported miniature Cas12f1 and the widely used Cas12a and Cas9 nucleases in mammalian cells. The results revealed that as a CRISPRa activator, Un1Cas12f1 could induce gene expression with a comparable level to these of Cas12a and Cas9, while as a cleaving editor, Cas12f1 exhibited similar properties to Cas12a, like high specificity and dominantly induced deletions over insertions, but with less activity. In contrast, wild-type SpCas9 showed the highest activity, lowest specificity, and induced balanced deletions over insertions. Thus, Cas12f1 is recommended for gene-activation-based applications, Cas12a is for therapy applications, and wild-type Cas9 is for in vitro and animal investigations. The comparison provided the editing properties of current widely used DNA-targeting CRISPR systems for the gene-editing field.

As reported previously, exosomes have significant impacts on the physiological and pathological state in vivo. Exosomes have been extensively studied as a drug delivery carrier and some exosomes drugs have been undergoing clinical research. The mechanisms of exosome production, transport, and secretion remain to be studied in depth. Thus, here, we developed a novel CRISPR-UMI-based gene screening system, with which we can reveal the exosomes biogenesis, transport, and uptake mechanisms on a genome-wide scale. This system consists of two parts: one is a gene knockout component; the other part is a unique molecular identifiers (UMI) labeling component that can label the exosomes produced by the knockout cells, in which each sgRNA corresponds to a specific UMI. In this way, by detecting the UMI loaded in the exosomes, we can trace the knockout gene. In this study, we first verified the function of each component using plasmids and lentiviruses respectively. Next, we simulated the infection of cells with lentiviral libraries using a single lentivirus to validate the functionality of the screening system. Finally, we constructed a CRISPR-UMI-based library targeting 15 genes (genes with clear effects on exosomes biogenesis) to further validate the reliability of the screening system. The development of this screening system is of indispensable importance for the in-depth study of the mechanisms of exosome production and secretion, as well as for the improvement of exosomes production and the advancement of exosomes industrialization.