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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 721 records · Page 40
All sourcesNASA NTRSDOE OSTI
DOE OSTI2014

Reduced repair capacity of a DNA clustered damage site comprised of 8-oxo-7,8-dihydro-2'-deoxyguanosine and 2-deoxyribonolactone results in an increased mutagenic potential of these lesions

A signature of ionizing radiation is the induction of DNA clustered damaged sites. Non-double strand break (DSB) clustered damage has been shown to compromise the base excision repair pathway, extending the lifetimes of the lesions within the cluster, compared to isolated lesions. This increases the likelihood the lesions persist to replication and thus increasing the mutagenic potential of the lesions within the cluster. Lesions formed by ionizing radiation include 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) and 2-deoxyribonolactone (dL). dL poses an additional challenge to the cell as it is not repaired by the short-patch base excision repair pathway. Here we show recalcitrant dL repair is reflected in mutations observed when DNA containing it and a proximal 8-oxodGuo is replicated in Escherichia coli . 8-oxodGuo in close proximity to dL on the opposing DNA strand results in an enhanced frequency of mutation of the lesions within the cluster and a 20 base sequence flanking the clustered damage site in an E. coli based plasmid assay. In vitro repair of a dL lesion is reduced when compared to the repair of an abasic (AP) site and a tetrahydrofuran (THF), and this is due mainly to a reduction in the activity of polymerase β, leading to retarded FEN1 and ligase 1 activities. This study has given insights in to the biological effects of clusters containing dL.

Cunniffe, Siobhan↗
DOE OSTI2022

Semi-empirical simulation of in-motion radiation detection systems

The Replicative Assessment of Spectroscopic Equipment (RASE) is an open-source software that uses experimental data as the basis to simulate the response of commercial radiation detectors to sources in various situations, particularly in the context of nuclear security and safeguards applications. Dynamic RASE introduces the capability to simulate scenarios where sources and detector are in relative motion. Position-dependent experimentally acquired gamma spectra are ingested by Dynamic RASE to build maps that describe the detector response over all space. These response maps are used to replicate the time-dependent energy spectra collected as sources move on a path near the detector. Here, a Gaussian process is used to build each map, incorporating a novel kernel adapted to the special case of radiation detection. The approach has been validated against experimental data acquired using a NaI-based detector for 137 Cs and 54 Mn sources. The capability to create accurate simulations using either long-dwell static measurements or dynamic pass-by measurements as source data has been demonstrated. Quantitative relative performance, benefits, and shortcomings are discussed.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2026

Using Artificial Soiling to Rank Anti-Soiling Coatings for Arid Climates

A simple method to evaluate (e.g., screen and rank) the performance of coatings that are fully or partially anti-soiling (AS) is lacking within the PV industry. Artificial soiling may be used as a rapid and economical assessment approach, offering an efficient alternative to time-intensive, site-specific field testing. In this study, we present an artificial soiling method to replicate the anti-soiling performance rankings of two groups of coated glass samples supplied by two manufacturers (group C with CA, CP, and CS coatings; group A with AC coating). These are compared to field aging in two climates: semi-arid Lemoore, California over 4 months, and the hot desert in Mesa, Arizona over 7 months. Both field and indoor performance ranking utilize the transmittance ratio, defined as the optical transmittance between a coated sample and an uncoated reference in each group, as an evaluation metric to assess the effectiveness of the artificial soiling approach in replicating field soiling. It is critical to mimic the dominant field meteorological conditions associated with soiling-prone days and vulnerable times of day during the soiling season. Our results reveal that the use of artificial soiling for field performance ranking among coatings strongly depends on the soil type (composition and particle distribution), dust surface density, and prevalent environmental factors (wetting saturation by humidity, dew condensation extent, and prior weathering history of the coating). The similar rank order relative to the field suggests that the artificial soiling approach presented may be used for down-selecting anti-soiling coatings prior to prolonged field validation.

14 SOLAR ENERGY↗
DOE OSTI2013

Sensitivity to methylmercury toxicity is enhanced in oxoguanine glycosylase 1 knockout murine embryonic fibroblasts and is dependent on cellular proliferation capacity

Methylmercury (MeHg) is a persistent environmental contaminant with potent neurotoxic action for which the underlying molecular mechanisms remain to be conclusively delineated. Our objectives herein were twofold: first, to corroborate our previous findings of an increased sensitivity of spontaneously-immortalized oxoguanine glycosylase 1-null (Ogg1{sup −/−}) murine embryonic fibroblasts (MEFs) to MeHg through generation of Simian virus 40 (SV40) large T antigen-immortalized wild-type and Ogg1{sup −/−} MEFs; and second, to determine whether MeHg toxicity is proliferation-dependent. As with the spontaneously-immortalized cells used previously, the SV40 large T antigen-immortalized cells exhibited similar tendencies to undergo MeHg-initiated cell cycle arrest, with increased sensitivity in the Ogg1{sup −/−} MEFs as measured by clonogenic survival and DNA damage. Compared to exponentially growing cells, those seeded at a higher density exhibited compromised proliferation, which proved protective against MeHg-mediated cell cycle arrest and induction of DNA double strand breaks (DSBs), measured by phosphorylation of the core histone H2A variant (H2AX) on serine 139 (γH2AX), and by its functional confirmation by micronucleus assessment. This enhanced sensitivity of Ogg1{sup −/−} MEFs to MeHg toxicity using discrete SV40 immortalization corroborates our previous studies, and suggests a novel role for OGG1 in minimizing MeHg-initiated DNA lesions that trigger replication-associated DSBs. Furthermore, proliferative capacity may determine MeHg toxicity in vivo and in utero. Accordingly, variations in cellular proliferative capacity and interindividual variability in repair activity may modulate the risk of toxicological consequences following MeHg exposure. - Highlights: • SV40 large T antigen-immortalized Ogg1{sup −/−} cells are more sensitive to MeHg. • Sensitivity to MeHg is dependent on cellular proliferation capacity. • OGG1 maintains genomic integrity following MeHg-initiated DNA damage. • OGG1 may limit MeHg-initiated DNA lesions that trigger replication-associated DSBs. • Variations in proliferation and repair activity may modulate toxicological risk.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2022

Efficacy of an inactivated Senecavirus A vaccine in weaned pigs and mature sows

Senecavirus A (SVA), commonly known as Seneca Valley virus (SVV) is a causative agent for vesicular disease in swine. It has been found across the globe including the United States, Brazil, and China. Clinical disease caused by this virus is identical to foot-and-mouth disease virus (FMDV). Since FMDV has the potential to cause severe economic consequences in FMDV-free countries, those countries are on high alert for signs of vesicles in swine and an investigation is performed to rule out the presence of FMDV if observed. In countries where SVA cases have continued to occur, investigations and testing can cause a burden on personnel and resources. The objectives of this study were to test the efficacy of a whole-virus inactivated SVA vaccine against challenge in nursery-aged pigs, mature sows, and to assess the protection of passive maternal immunity generated by immunized dams. Animals were given two doses of the vaccine intramuscularly three weeks apart and challenged intranasally two weeks after the second dose. Non-vaccinated animals challenged with SVA developed clinical signs of disease, replicated virus, and developed a neutralizing antibody response. Vaccinated animals had robust neutralizing titers after two doses; and after challenge, did not develop vesicular disease and had limited rectal shedding. Piglets suckling immunized dams and challenged with SVA at 3–6 days-of-age had neutralizing titers prior to challenge and did not replicate or shed virus. An efficacious vaccine could improve swine welfare and reduce the economic consequences of continued foreign animal disease investigations.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2012

A single amino acid change resulting in loss of fluorescence of eGFP in a viral fusion protein confers fitness and growth advantage to the recombinant vesicular stomatitis virus

Using a recombinant vesicular stomatitis virus encoding eGFP fused in-frame with an essential viral replication protein, the phosphoprotein P, we show that during passage in culture, the virus mutates the nucleotide C289 within eGFP of the fusion protein PeGFP to A or T, resulting in R97S/C amino acid substitution and loss of fluorescence. The resultant non-fluorescent virus exhibits increased fitness and growth advantage over its fluorescent counterpart. The growth advantage of the non-fluorescent virus appears to be due to increased transcription and replication activities of the PeGFP protein carrying the R97S/C substitution. Further, our results show that the R97S/C mutation occurs prior to accumulation of mutations that can result in loss of expression of the gene inserted at the G-L gene junction. These results suggest that fitness gain is more important for the recombinant virus than elimination of expression of the heterologous gene.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

Death-domain associated protein-6 (DAXX) mediated apoptosis in hantavirus infection is counter-balanced by activation of interferon-stimulated nuclear transcription factors

Hantaviruses are negative strand RNA species that replicate predominantly in the cytoplasm. They also activate numerous cellular responses, but their involvement in nuclear processes is yet to be established. Using human umbilical vein endothelial cells (HUVECs), this study investigates the molecular finger-print of nuclear transcription factors during hantavirus infection. The viral-replication-dependent activation of pro-myelocytic leukemia protein (PML) was followed by subsequent localization in nuclear bodies (NBs). PML was also found in close proximity to activated Sp100 nuclear antigen and interferon-stimulated gene 20 kDa protein (ISG-20), but co-localization with death-domain associated protein-6 (DAXX) was not observed. These data demonstrate that hantavirus triggers PML activation and localization in NBs in the absence of DAXX-PLM-NB co-localization. The results suggest that viral infection interferes with DAXX-mediated apoptosis, and expression of interferon-activated Sp100 and ISG-20 proteins may indicate intracellular intrinsic antiviral attempts.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

The RXL motif of the African cassava mosaic virus Rep protein is necessary for rereplication of yeast DNA and viral infection in plants

Geminiviruses, single-stranded DNA plant viruses, encode a replication-initiator protein (Rep) that is indispensable for virus replication. A potential cyclin interaction motif (RXL) in the sequence of African cassava mosaic virus Rep may be an alternative link to cell cycle controls to the known interaction with plant homologs of retinoblastoma protein (pRBR). Mutation of this motif abrogated rereplication in fission yeast induced by expression of wildtype Rep suggesting that Rep interacts via its RXL motif with one or several yeast proteins. The RXL motif is essential for viral infection of Nicotiana benthamiana plants, since mutation of this motif in infectious clones prevented any symptomatic infection. The cell-cycle link (Clink) protein of a nanovirus (faba bean necrotic yellows virus) was investigated that activates the cell cycle by binding via its LXCXE motif to pRBR. Expression of wildtype Clink and a Clink mutant deficient in pRBR-binding did not trigger rereplication in fission yeast. - Highlights: • A potential cyclin interaction motif is conserved in geminivirus Rep proteins. • In ACMV Rep, this motif (RXL) is essential for rereplication of fission yeast DNA. • Mutating RXL abrogated viral infection completely in Nicotiana benthamiana. • Expression of a nanovirus Clink protein in yeast did not induce rereplication. • Plant viruses may have evolved multiple routes to exploit host DNA synthesis.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

The Cucumber leaf spot virus p25 auxiliary replicase protein binds and modifies the endoplasmic reticulum via N-terminal transmembrane domains

Cucumber leaf spot virus (CLSV) is a member of the Aureusvirus genus, family Tombusviridae. The auxiliary replicase of Tombusvirids has been found to localize to endoplasmic reticulum (ER), peroxisomes or mitochondria; however, localization of the auxiliary replicase of aureusviruses has not been determined. We have found that the auxiliary replicase of CLSV (p25) fused to GFP colocalizes with ER and that three predicted transmembrane domains (TMDs) at the N-terminus of p25 are sufficient for targeting, although the second and third TMDs play the most prominent roles. Confocal analysis of CLSV infected 16C plants shows that the ER becomes modified including the formation of punctae at connections between ER tubules and in association with the nucleus. Ultrastructural analysis shows that the cytoplasm contains numerous vesicles which are also found between the perinuclear ER and nuclear membrane. It is proposed that these vesicles correspond to modified ER used as sites for CLSV replication. - Highlights: • The CLSV p25 auxiliary replicase targets the endoplasmic reticulum (ER). • Targeting of CLSV p25 is associated with ER restructuring. • Restructuring of the ER occurs during CLSV infection. • CLSV p25 contains 3 predicted transmembrane domains 2 of which are required for ER targeting. • Vesicles derived from the ER may be sites of CLSV replication.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Functional characterization of Autographa californica multiple nucleopolyhedrovirus gp16 (ac130)

To investigate the function of Autographa californica multiple nucleopolyhedrovirus (AcMNPV) gp16, multiple gp16-knockout and repair mutants were constructed and characterized. No obvious difference in productivity of budded virus, DNA synthesis, late gene expression and morphogenesis was observed between gp16-knockout and repair viruses, but gp16 deletion resulted in six hours of lengthening in ST{sub 50} to the third instar Spodoptera exigua larvae in bioassays. GP16 was fractionated mainly in the light membrane fraction, by subcellular fractionation. A GP16-EGFP fusion protein was predominantly localized close around the nuclear membrane in infected cells, being coincident with formation of the vesicles associated with the nuclear membrane, which hosted nucleocapsids released from the nucleus. These data suggest that gp16 is not required for viral replication, but may be involved in membrane trafficking associated with the envelopment/de-envelopment of budded viruses when they cross over the nuclear membrane and pass through cytoplasm. - Highlights: • gp16 knockout and repair mutants of AcMNPV were constructed and characterized. • AcMNPV gp16 is not essential to virus replication. • Deletion of gp16 resulted in time lengthening to kill S. exigua larvae. • GP16 was localized close around the nuclear membrane of infected cells. • GP16 was fractionated in the light membrane fraction in subcellular fractionation.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Cell migration is another player of the minute virus of mice infection

The parvovirus minute virus of mice, prototype strain (MVMp), preferentially infects and kills cancer cells. This intrinsic MVMp oncotropism may depend in part on the early stages of MVMp infection. To test this hypothesis, we investigated the early events of MVMp infection in mouse LA9 fibroblasts and a highly invasive mouse mammary tumor cell line derived from polyomavirus middle T antigen-mediated transformation. Using a combination of fluorescence and electron microscopy, we found that various parameters of the cell migration process affect MVMp infection. We show that, after binding to the plasma membrane, MVMp particles rapidly cluster at the leading edge of migrating cells, which exhibit higher levels of MVMp uptake than non-motile cells. Moreover, promoting cell migration on a fibronectin matrix increased MVMp infection, and induction of epithelial–mesenchymal transition allowed MVMp replication in non-permissive epithelial cells. Hence, we propose that cell migration influences the early stages of MVMp infection. - Highlights: • We document early steps of MVMp infection. • We report that a fibronectin matrix promotes MVMp infection. • We show that cellular migration plays a role in MVMp uptake. • We show that epithelial–mesenchymal transition allows MVMp replication.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Alterations in the nuclear proteome of HIV-1 infected T-cells

Virus infection of a cell involves the appropriation of host factors and the innate defensive response of the cell. The identification of proteins critical for virus replication may lead to the development of novel, cell-based inhibitors. In this study we mapped the changes in T-cell nuclei during human immunodeficiency virus type 1 (HIV-1) at 20 hpi. Using a stringent data threshold, a total of 13 and 38 unique proteins were identified in infected and uninfected cells, respectively, across all biological replicates. An additional 15 proteins were found to be differentially regulated between infected and control nuclei. STRING analysis identified four clusters of protein–protein interactions in the data set related to nuclear architecture, RNA regulation, cell division, and cell homeostasis. Immunoblot analysis confirmed the differential expression of several proteins in both C8166-45 and Jurkat E6-1 T-cells. These data provide a map of the response in host cell nuclei upon HIV-1 infection. - Highlights: • We identify changes in the expression of nuclear proteins during HIV-1 infection. • 163 nuclear proteins were found differentially regulated during HIV-1 infection. • Bioinformatic analysis identified several nuclear pathways altered by HIV infection. • Candidate factors were validated in two independent cell lines.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Bacterial CRISPR/Cas DNA endonucleases: A revolutionary technology that could dramatically impact viral research and treatment

CRISPR/Cas systems mediate bacterial adaptive immune responses that evolved to protect bacteria from bacteriophage and other horizontally transmitted genetic elements. Several CRISPR/Cas systems exist but the simplest variant, referred to as Type II, has a single effector DNA endonuclease, called Cas9, which is guided to its viral DNA target by two small RNAs, the crRNA and the tracrRNA. Initial efforts to adapt the CRISPR/Cas system for DNA editing in mammalian cells, which focused on the Cas9 protein from Streptococcus pyogenes (Spy), demonstrated that Spy Cas9 can be directed to DNA targets in mammalian cells by tracrRNA:crRNA fusion transcripts called single guide RNAs (sgRNA). Upon binding, Cas9 induces DNA cleavage leading to mutagenesis as a result of error prone non-homologous end joining (NHEJ). Recently, the Spy Cas9 system has been adapted for high throughput screening of genes in human cells for their relevance to a particular phenotype and, more generally, for the targeted inactivation of specific genes, in cell lines and in vivo in a number of model organisms. The latter aim seems likely to be greatly enhanced by the recent development of Cas9 proteins from bacterial species such as Neisseria meningitidis and Staphyloccus aureus that are small enough to be expressed using adeno-associated (AAV)-based vectors that can be readily prepared at very high titers. The evolving Cas9-based DNA editing systems therefore appear likely to not only impact virology by allowing researchers to screen for human genes that affect the replication of pathogenic human viruses of all types but also to derive clonal human cell lines that lack individual gene products that either facilitate or restrict viral replication. Moreover, high titer AAV-based vectors offer the possibility of directly targeting DNA viruses that infect discrete sites in the human body, such as herpes simplex virus and hepatitis B virus, with the hope that the entire population of viral DNA genomes might be destroyed. In conclusion, we believe that the continued rapid evolution of CRISPR/Cas technology will soon have a major, possibly revolutionary, impact on the field of virology. - Highlights: • Bacterial CRISPR/Cas systems can edit specific DNA sequences in mammalian cells. • CRISPR/Cas systems could eliminate latent or persistent DNA viruses in vivo. • CRISPR/Cas could also be used to screen for viral co-factors or restriction factors.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Origins and evolution of viruses of eukaryotes: The ultimate modularity

Viruses and other selfish genetic elements are dominant entities in the biosphere, with respect to both physical abundance and genetic diversity. Various selfish elements parasitize on all cellular life forms. The relative abundances of different classes of viruses are dramatically different between prokaryotes and eukaryotes. In prokaryotes, the great majority of viruses possess double-stranded (ds) DNA genomes, with a substantial minority of single-stranded (ss) DNA viruses and only limited presence of RNA viruses. In contrast, in eukaryotes, RNA viruses account for the majority of the virome diversity although ssDNA and dsDNA viruses are common as well. Phylogenomic analysis yields tangible clues for the origins of major classes of eukaryotic viruses and in particular their likely roots in prokaryotes. Specifically, the ancestral genome of positive-strand RNA viruses of eukaryotes might have been assembled de novo from genes derived from prokaryotic retroelements and bacteria although a primordial origin of this class of viruses cannot be ruled out. Different groups of double-stranded RNA viruses derive either from dsRNA bacteriophages or from positive-strand RNA viruses. The eukaryotic ssDNA viruses apparently evolved via a fusion of genes from prokaryotic rolling circle-replicating plasmids and positive-strand RNA viruses. Different families of eukaryotic dsDNA viruses appear to have originated from specific groups of bacteriophages on at least two independent occasions. Polintons, the largest known eukaryotic transposons, predicted to also form virus particles, most likely, were the evolutionary intermediates between bacterial tectiviruses and several groups of eukaryotic dsDNA viruses including the proposed order “Megavirales” that unites diverse families of large and giant viruses. Strikingly, evolution of all classes of eukaryotic viruses appears to have involved fusion between structural and replicative gene modules derived from different sources along with additional acquisitions of diverse genes. - Highlights: • Eukaryotic virome dramatically differs from the viromes of bacteria and archaea. • Eukaryotic virome is dominated by RNA viruses and retroelements. • All classes of eukaryotic viruses evolved by gene module exchange. • Prokaryotic ancestry is traceable for core gene modules of most eukaryotic viruses. • Evolutionary histories of viruses and transposable elements are tightly linked.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Cocaine promotes both initiation and elongation phase of HIV-1 transcription by activating NF-κB and MSK1 and inducing selective epigenetic modifications at HIV-1 LTR

Cocaine accelerates human immunodeficiency virus (HIV-1) replication by altering specific cell-signaling and epigenetic pathways. We have elucidated the underlying molecular mechanisms through which cocaine exerts its effect in myeloid cells, a major target of HIV-1 in central nervous system (CNS). We demonstrate that cocaine treatment promotes HIV-1 gene expression by activating both nuclear factor-kappa B (NF-ĸB) and mitogen- and stress-activated kinase 1 (MSK1). MSK1 subsequently catalyzes the phosphorylation of histone H3 at serine 10, and p65 subunit of NF-ĸB at 276th serine residue. These modifications enhance the interaction of NF-ĸB with P300 and promote the recruitment of the positive transcription elongation factor b (P-TEFb) to the HIV-1 LTR, supporting the development of an open/relaxed chromatin configuration, and facilitating the initiation and elongation phases of HIV-1 transcription. Results are also confirmed in primary monocyte derived macrophages (MDM). Overall, our study provides detailed insights into cocaine-driven HIV-1 transcription and replication. - Highlights: • Cocaine induces the initiation phase of HIV transcription by activating NF-ĸB. • Cocaine induced NF-ĸB phosphorylation promotes its interaction with P300. • Cocaine enhances the elongation phase of HIV transcription by stimulating MSK1. • Cocaine activated MSK1 catalyzes the phosphorylation of histone H3 at its Ser10. • Cocaine induced H3S10 phosphorylation facilitates the recruitment of P-TEFb at LTR.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Intratracheal exposure of common marmosets to MERS-CoV Jordan-n3/2012 or MERS-CoV EMC/2012 isolates does not result in lethal disease

Middle East Respiratory Syndrome Coronavirus (MERS-CoV) continues to be a threat to human health in the Middle East. Development of countermeasures is ongoing; however, an animal model that faithfully recapitulates human disease has yet to be defined. A recent study indicated that inoculation of common marmosets resulted in inconsistent lethality. Based on these data we sought to compare two isolates of MERS-CoV. We followed disease progression in common marmosets after intratracheal exposure with: MERS-CoV-EMC/2012, MERS-CoV-Jordan-n3/2012, media, or inactivated virus. Our data suggest that common marmosets developed a mild to moderate non-lethal respiratory disease, which was quantifiable by computed tomography (CT), with limited other clinical signs. Based on CT data, clinical data, and virological data, MERS-CoV inoculation of common marmosets results in mild to moderate clinical signs of disease that are likely due to manipulations of the marmoset rather than as a result of robust viral replication. - Highlights: • Common marmosets infected with MERS-EMC and MERS-JOR did not develop lethal disease. • Infected subjects developed transient signs of clinical disease. • CT indicated few differences between the infected and control groups. • Marmosets do not faithfully replicate human MERS pathogenesis.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Visualizing double-stranded RNA distribution and dynamics in living cells by dsRNA binding-dependent fluorescence complementation

Double-stranded RNA (dsRNA) is an important type of RNA that plays essential roles in diverse cellular processes in eukaryotic organisms and a hallmark in infections by positive-sense RNA viruses. Currently, no in vivo technology has been developed for visualizing dsRNA in living cells. Here, we report a dsRNA binding-dependent fluorescence complementation (dRBFC) assay that can be used to efficiently monitor dsRNA distribution and dynamics in vivo. The system consists of two dsRNA-binding proteins, which are fused to the N- and C-terminal halves of the yellow fluorescent protein (YFP). Binding of the two fusion proteins to a common dsRNA brings the split YFP halves in close proximity, leading to the reconstitution of the fluorescence-competent structure and restoration of fluorescence. Using this technique, we were able to visualize the distribution and trafficking of the replicative RNA intermediates of positive-sense RNA viruses in living cells. - Highlights: • A live-cell imaging system was developed for visualizing dsRNA in vivo. • It uses dsRNA binding proteins fused with two halves of a fluorescent protein. • Binding to a common dsRNA enables the reporter to become fluorescent. • The system can efficiently monitor viral RNA replication in living cells.

60 APPLIED LIFE SCIENCES↗