scholarly journals Tracking infection dynamics at single-cell level reveals highly resolved expression programs of a large virus infecting algal blooms

2019 ◽  
Author(s):  
Chuan Ku ◽  
Uri Sheyn ◽  
Arnau Sebé-Pedrós ◽  
Shifra Ben-Dor ◽  
Daniella Schatz ◽  
...  

AbstractNucleocytoplasmic large DNA viruses have the largest genomes among all viruses and infect diverse eukaryotes across various ecosystems, but their expression regulation and infection strategies are not well understood. We profiled single-cell transcriptomes of the worldwide-distributed microalga Emiliania huxleyi and its specific coccolithovirus responsible for massive bloom demise. Heterogeneity in viral transcript levels detected among single cells was used to reconstruct the viral transcriptional trajectory and to map cells along a continuum of infection states. This enabled identification of novel viral genetic programs, which are composed of five kinetic classes with distinct promoter elements. The infection substantially changed the host transcriptome, causing rapid shutdown of protein-encoding nuclear transcripts at the onset of infection, while the plastid and mitochondrial transcriptomes persisted to mid- and late stages, respectively. Single-cell transcriptomics thereby opens the way for tracking host-pathogen infection dynamics at high resolution within microbial communities in the marine environment.

2020 ◽  
Vol 6 (21) ◽  
pp. eaba4137 ◽  
Author(s):  
Chuan Ku ◽  
Uri Sheyn ◽  
Arnau Sebé-Pedrós ◽  
Shifra Ben-Dor ◽  
Daniella Schatz ◽  
...  

The discovery of giant viruses infecting eukaryotes from diverse ecosystems has revolutionized our understanding of the evolution of viruses and their impact on protist biology, yet knowledge on their replication strategies and transcriptome regulation remains limited. Here, we profile single-cell transcriptomes of the globally distributed microalga Emiliania huxleyi and its specific giant virus during infection. We detected profound heterogeneity in viral transcript levels among individual cells. Clustering single cells based on viral expression profiles enabled reconstruction of the viral transcriptional trajectory. Reordering cells along this path unfolded highly resolved viral genetic programs composed of genes with distinct promoter elements that orchestrate sequential expression. Exploring host transcriptome dynamics across the viral infection states revealed rapid and selective shutdown of protein-encoding nuclear transcripts, while the plastid and mitochondrial transcriptomes persisted into later stages. Single-cell RNA-seq opens a new avenue to unravel the life cycle of giant viruses and their unique hijacking strategies.


2020 ◽  
Author(s):  
Seung Won Jung ◽  
Joonsang Park ◽  
Junsoo Kang ◽  
Hyun-Jung Kim ◽  
Hyung Min Joo ◽  
...  

Abstract Background: Characterising ecological relationships between viruses, bacteria, and phytoplankton in the ocean are critical to understanding the ecosystem, yet these relationships are infrequently investigated together. To understand the dynamics of microbial communities and environmental factors in harmful algal blooms (HABs), we examined the environmental factors and microbial communities during Akashiwo sanguinea HABs in the Jangmok coastal waters of South Korea by metagenomics. Results: Specific bacterial communities showed synergistic and antagonistic relationships with A. sanguinea bloom. Endoparasitic dinoflagellate Amoebophrya sp. 1 controlled the bloom dynamics, as an increase in their abundance was correlated with HAB decline. In the nucleocytoplasmic large DNA viruses, abundance of Pandoraviridae increased following an increase in HAB. Operational taxonomic units and environmental factors associated with A. sanguinea were also visualized by network analysis: A. sanguinea-Amoebophrya sp. 1 (r=0.81, Time-lag: 2 day) and A. sanguinea-Pandoravirus dulcis (0.64, 0 day) relationships showed close association. A. sanguinea-dissolved organic carbon and -dissolved inorganic phosphorus relationships were also very closely correlated (each 0 day time-lag, respectively). Conclusions: Microbial communities and the environment dynamically and complexly changed in A. sanguinea bloom, and a rapid turnover of microorganisms could respond to ecological interactions. A. sanguinea bloom dramatically changes the environments through their exudation of dissolved carbohydrates by autotrophic processes, followed by changes in microbial communities involving host-specific viruses, bacteria, and parasitoids. Thus, microbial communities in HAB ecology are composed of various organisms and they interact in a complex way. Therefore, to interpret their ecosystem, the complex reactions among various microorganisms should be studied rather than studying a simple 1:1 reaction, such as a prey-predator interaction.


2021 ◽  
Vol 91 (3) ◽  
pp. 510
Author(s):  
Т.Э. Кулешова ◽  
Н.Р. Галль ◽  
А.С. Галушко ◽  
Г.Г. Панова

The paper describes electrogenic features of the plant-microbial fuel cell (PMFC) with various assembling of single cells into a battery. The operation of a single cell and two variants of electric circuit organization: parallel and series connection of PMFC, have been experimentally studied and compared. A potential difference, ~ 70 mV, was measured for a cell without a plant, which disappears with time. This supports the significant role of the plant in PMFC; we put forward a hypothesis of diffusion EMF production by the root system with the participation of electrogenic chemoorganoterotrophic microorganisms. It has been shown that the mean bioelectric potential generated by a single cell is 170 mV. It is increased by only 1.5 times in a series connection of 3 fuel cells. Load current increase is also observed for parallel connection of 3 PMFC, but also only by 1.5 times, and only in the late stages of the plant growth. It is likely that the sum of flowing currents and generated voltages affects the electrogenic reactions in each individual plant and microorganisms in each PMFC and thereby trigger some compensation mechanisms decreasing electrogenic plant features.


Author(s):  
Gunnar Zimmermann ◽  
Richard Chapman

Abstract Dual beam FIBSEM systems invite the use of innovative techniques to localize IC fails both electrically and physically. For electrical localization, we present a quick and reliable in-situ FIBSEM technique to deposit probe pads with very low parasitic leakage (Ipara < 4E-11A at 3V). The probe pads were Pt, deposited with ion beam assistance, on top of highly insulating SiOx, deposited with electron beam assistance. The buried plate (n-Band), p-well, wordline and bitline of a failing and a good 0.2 μm technology DRAM single cell were contacted. Both cells shared the same wordline for direct comparison of cell characteristics. Through this technique we electrically isolated the fail to a single cell by detecting leakage between the polysilicon wordline gate and the cell diffusion. For physical localization, we present a completely in-situ FIBSEM technique that combines ion milling, XeF2 staining and SEM imaging. With this technique, the electrically isolated fail was found to be a hole in the gate oxide at the bad cell.


2021 ◽  
Vol 12 (11) ◽  
pp. 4111-4118
Author(s):  
Qi Zhang ◽  
Yunlong Shao ◽  
Boye Li ◽  
Yuanyuan Wu ◽  
Jingying Dong ◽  
...  

We achieved the low-damage spatial puncture of single cells at specific visual points with an accuracy of <65 nm.


2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Bhupinder Pal ◽  
Yunshun Chen ◽  
Michael J. G. Milevskiy ◽  
François Vaillant ◽  
Lexie Prokopuk ◽  
...  

Abstract Background Heterogeneity within the mouse mammary epithelium and potential lineage relationships have been recently explored by single-cell RNA profiling. To further understand how cellular diversity changes during mammary ontogeny, we profiled single cells from nine different developmental stages spanning late embryogenesis, early postnatal, prepuberty, adult, mid-pregnancy, late-pregnancy, and post-involution, as well as the transcriptomes of micro-dissected terminal end buds (TEBs) and subtending ducts during puberty. Methods The single cell transcriptomes of 132,599 mammary epithelial cells from 9 different developmental stages were determined on the 10x Genomics Chromium platform, and integrative analyses were performed to compare specific time points. Results The mammary rudiment at E18.5 closely aligned with the basal lineage, while prepubertal epithelial cells exhibited lineage segregation but to a less differentiated state than their adult counterparts. Comparison of micro-dissected TEBs versus ducts showed that luminal cells within TEBs harbored intermediate expression profiles. Ductal basal cells exhibited increased chromatin accessibility of luminal genes compared to their TEB counterparts suggesting that lineage-specific chromatin is established within the subtending ducts during puberty. An integrative analysis of five stages spanning the pregnancy cycle revealed distinct stage-specific profiles and the presence of cycling basal, mixed-lineage, and 'late' alveolar intermediates in pregnancy. Moreover, a number of intermediates were uncovered along the basal-luminal progenitor cell axis, suggesting a continuum of alveolar-restricted progenitor states. Conclusions This extended single cell transcriptome atlas of mouse mammary epithelial cells provides the most complete coverage for mammary epithelial cells during morphogenesis to date. Together with chromatin accessibility analysis of TEB structures, it represents a valuable framework for understanding developmental decisions within the mouse mammary gland.


2021 ◽  
Vol 7 (8) ◽  
pp. eabe3610
Author(s):  
Conor J. Kearney ◽  
Stephin J. Vervoort ◽  
Kelly M. Ramsbottom ◽  
Izabela Todorovski ◽  
Emily J. Lelliott ◽  
...  

Multimodal single-cell RNA sequencing enables the precise mapping of transcriptional and phenotypic features of cellular differentiation states but does not allow for simultaneous integration of critical posttranslational modification data. Here, we describe SUrface-protein Glycan And RNA-seq (SUGAR-seq), a method that enables detection and analysis of N-linked glycosylation, extracellular epitopes, and the transcriptome at the single-cell level. Integrated SUGAR-seq and glycoproteome analysis identified tumor-infiltrating T cells with unique surface glycan properties that report their epigenetic and functional state.


Author(s):  
Martin Philpott ◽  
Jonathan Watson ◽  
Anjan Thakurta ◽  
Tom Brown ◽  
Tom Brown ◽  
...  

AbstractHere we describe single-cell corrected long-read sequencing (scCOLOR-seq), which enables error correction of barcode and unique molecular identifier oligonucleotide sequences and permits standalone cDNA nanopore sequencing of single cells. Barcodes and unique molecular identifiers are synthesized using dimeric nucleotide building blocks that allow error detection. We illustrate the use of the method for evaluating barcode assignment accuracy, differential isoform usage in myeloma cell lines, and fusion transcript detection in a sarcoma cell line.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xingjian Zhang ◽  
Trevor Chan ◽  
Michael Mak

AbstractCancer cell metastasis is a major factor in cancer-related mortality. During the process of metastasis, cancer cells exhibit migratory phenotypes and invade through pores in the dense extracellular matrix. However, the characterization of morphological and subcellular features of cells in similar migratory phenotypes and the effects of geometric confinement on cell morphodynamics are not well understood. Here, we investigate the phenotypes of highly aggressive MDA-MB-231 cells in single cell and cell doublet (an initial and simplified collective state) forms in confined microenvironments. We group phenotypically similar single cells and cell doublets and characterize related morphological and subcellular features. We further detect two distinct migratory phenotypes, fluctuating and non-fluctuating, within the fast migrating single cell group. In addition, we demonstrate an increase in the number of protrusions formed at the leading edge of cells after invasion through geometric confinement. Finally, we track the short and long term effects of varied degrees of confinement on protrusion formation. Overall, our findings elucidate the underlying morphological and subcellular features associated with different single cell and cell doublet phenotypes and the impact of invasion through confined geometry on cell behavior.


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