scholarly journals Recent Progress in Torovirus Molecular Biology

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 435
Author(s):  
Makoto Ujike ◽  
Fumihiro Taguchi
Keyword(s):  
Molecular Biology ◽  
Recent Progress ◽  
Reverse Genetics ◽  
Cultured Cells ◽  
Host Adaptation ◽  
Economic Losses ◽  
New Family ◽  
Enteric Diseases ◽  
Long Time ◽  
Medical Importance

Torovirus (ToV) has recently been classified into the new family Tobaniviridae, although it belonged to the Coronavirus (CoV) family historically. ToVs are associated with enteric diseases in animals and humans. In contrast to CoVs, which are recognised as pathogens of veterinary and medical importance, little attention has been paid to ToVs because their infections are usually asymptomatic or not severe; for a long time, only one equine ToV could be propagated in cultured cells. However, bovine ToVs, which predominantly cause diarrhoea in calves, have been detected worldwide, leading to economic losses. Porcine ToVs have also spread globally; although they have not caused serious economic losses, coinfections with other pathogens can exacerbate their symptoms. In addition, frequent inter- or intra-recombination among ToVs can increase pathogenesis or unpredicted host adaptation. These findings have highlighted the importance of ToVs as pathogens and the need for basic ToV research. Here, we review recent progress in the study of ToV molecular biology including reverse genetics, focusing on the similarities and differences between ToVs and CoVs.

scholarly journals Porcine Reproductive and Respiratory Syndrome Virus: Immune Escape and Application of Reverse Genetics in Attenuated Live Vaccine Development

Vaccines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 480
Author(s):  
Honglei Wang ◽  
Yangyang Xu ◽  
Wenhai Feng
Keyword(s):  
Immune Responses ◽  
Reverse Genetics ◽  
Vaccine Development ◽  
Immune Escape ◽  
Rna Virus ◽  
Economic Losses ◽  
Respiratory Syndrome Virus ◽  
Live Vaccines ◽  
Host Immune Responses ◽  
Inactivated Vaccines

Porcine reproductive and respiratory syndrome virus (PRRSV), an RNA virus widely prevalent in pigs, results in significant economic losses worldwide. PRRSV can escape from the host immune response in several processes. Vaccines, including modified live vaccines and inactivated vaccines, are the best available countermeasures against PRRSV infection. However, challenges still exist as the vaccines are not able to induce broad protection. The reason lies in several facts, mainly the variability of PRRSV and the complexity of the interaction between PRRSV and host immune responses, and overcoming these obstacles will require more exploration. Many novel strategies have been proposed to construct more effective vaccines against this evolving and smart virus. In this review, we will describe the mechanisms of how PRRSV induces weak and delayed immune responses, the current vaccines of PRRSV, and the strategies to develop modified live vaccines using reverse genetics systems.

The molecular biology of SRY and its role in sex determination in mammals

1995 ◽  
Vol 7 (4) ◽  
pp. 713 ◽  
Author(s):  
P Koopman
Keyword(s):  
Molecular Biology ◽  
Transgenic Mice ◽  
Sex Determination ◽  
Gene Product ◽  
Mode Of Action ◽  
Recent Progress ◽  
Sry Gene ◽  
Testis Development ◽  
Direct Demonstration

SRY is the gene that initiates the genetic cascade leading to testis development in mammals. Since its discovery in 1990 and the direct demonstration of its male-determining role in transgenic mice, attention has turned to understanding the biochemical mode of action of the SRY gene product, and to the identification of other genes in the sex-determining pathway. Recent progress in these efforts is summarized in this review.

scholarly journals Review of Current Methodological Approaches for Characterizing MicroRNAs in Plants

2009 ◽  
Vol 2009 ◽  
pp. 1-11 ◽  
Author(s):  
Turgay Unver ◽  
Deana M. Namuth-Covert ◽  
Hikmet Budak
Keyword(s):  
Gene Expression ◽  
Molecular Biology ◽  
Reverse Genetics ◽  
Methodological Approach ◽  
Forward Genetics ◽  
Methodological Approaches

Advances in molecular biology have led to some surprising discoveries. One of these includes the complexities of RNA and its role in gene expression. One particular class of RNA called microRNA (miRNA) is the focus of this paper. We will first briefly look at some of the characteristics and biogenesis of miRNA in plant systems. The remainder of the paper will go into details of three different approaches used to identify and study miRNA. These include two reverse genetics approaches: computation (bioinformatics) and experimental, and one rare forward genetics approach. We also will summarize how to measure and quantify miRNAs, and how to detect their possible targets in plants. Strengths and weaknesses of each methodological approach are discussed.

scholarly journals Effects of physical and chemical factors on pseudorabies virus activity in vitro

2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Lang Gong ◽  
Qiwei Deng ◽  
Runda Xu ◽  
Chihai Ji ◽  
Heng Wang ◽  
...  
Keyword(s):  
Pseudorabies Virus ◽  
Irradiation Time ◽  
Biological Characteristics ◽  
Economic Losses ◽  
Multiple Factors ◽  
Alkaline Environments ◽  
Long Time ◽  
Chemical Factors ◽  
Physical And Chemical

Abstract Background Pseudorabies (PR) is latent and can persist in infected sows for a long time, and thus, convalescent sows can carry the virus throughout life, causing severe economic losses to farmers and posing a tremendous challenge to PR prevention and control. Here, to investigate the biological characteristics of pseudorabies virus (PRV), a variety of physical and chemical factors were analyzed under controlled conditions. Results The results showed that a high ambient temperature and dry environment led to faster virus inactivation. PRV had a certain resistance to weakly acidic or alkaline environments and was rapidly inactivated in strongly acidic or alkaline environments. The effect of ultraviolet (UV) radiation on PRV activity primarily depended on the frequency, intensity, and irradiation time of the UV exposure. Exposure to sunlight inactivated PRV via multiple factors, including temperature, sunlight intensity, UV intensity, and environmental humidity, and any shielding from sunlight strongly lowered the killing effect. Conventional disinfectants had a good disinfection effect on PRV. Conclusions The biological characteristics of different PRV strains are variable. Generally, the activity of PRV is affected by multiple factors, which can show both synergy and antagonism. Real-world conditions should be taken into consideration to guide pork production.

scholarly journals Recombinant Lassa Virus Expressing Green Fluorescent Protein as a Tool for High-Throughput Drug Screens and Neutralizing Antibody Assays

Viruses ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 655 ◽  
Author(s):  
Yíngyún Caì ◽  
Masaharu Iwasaki ◽  
Brett Beitzel ◽  
Shuīqìng Yú ◽  
Elena Postnikova ◽  
...  
Keyword(s):  
Green Fluorescent Protein ◽  
High Throughput ◽  
Reverse Genetics ◽  
Fluorescent Protein ◽  
Cultured Cells ◽  
Neutralizing Antibody ◽  
Quantitative Detection ◽  
Lassa Virus ◽  
Wild Type ◽  
Green Fluorescent

Lassa virus (LASV), a mammarenavirus, infects an estimated 100,000–300,000 individuals yearly in western Africa and frequently causes lethal disease. Currently, no LASV-specific antivirals or vaccines are commercially available for prevention or treatment of Lassa fever, the disease caused by LASV. The development of medical countermeasure screening platforms is a crucial step to yield licensable products. Using reverse genetics, we generated a recombinant wild-type LASV (rLASV-WT) and a modified version thereof encoding a cleavable green fluorescent protein (GFP) as a reporter for rapid and quantitative detection of infection (rLASV-GFP). Both rLASV-WT and wild-type LASV exhibited similar growth kinetics in cultured cells, whereas growth of rLASV-GFP was slightly impaired. GFP reporter expression by rLASV-GFP remained stable over several serial passages in Vero cells. Using two well-characterized broad-spectrum antivirals known to inhibit LASV infection, favipiravir and ribavirin, we demonstrate that rLASV-GFP is a suitable screening tool for the identification of LASV infection inhibitors. Building on these findings, we established a rLASV-GFP-based high-throughput drug discovery screen and an rLASV-GFP-based antibody neutralization assay. Both platforms, now available as a standard tool at the IRF-Frederick (an international resource), will accelerate anti-LASV medical countermeasure discovery and reduce costs of antiviral screens in maximum containment laboratories.

scholarly journals Methods of mycobacterial DNA isolation from different biological material: a review

2012 ◽  
Vol 51 (No. 5) ◽  
pp. 180-192 ◽  
Author(s):  
J. Hosek ◽  
P. Svastova ◽  
M. Moravkova ◽  
I. Pavlik ◽  
M. Bartos
Keyword(s):  
Dna Isolation ◽  
Economic Losses ◽  
Human Beings ◽  
Chain Reaction ◽  
Serious Infections ◽  
Biochemical Characterisation ◽  
Long Time ◽  
Polymerase Chain ◽  
Wide Family

Mycobacteria cause serious infections in animals and human beings. Huge economic losses on farms are caused by selected species of this wide family. A high risk of transmission of infection from animal to human exists. The knowledge of exact pathogen characteristics is an important factor which can improve quick and adequate healing. Cultivation and determination of phenotype is still the “gold standard”, but has the disadvantage of taking a long time and also low detection limit. Biochemical characterisation of isolates is not exact, and it is expensive. A more popular method used is the amplification of specific loci by polymerase chain reaction (PCR). For this method, the isolation of sufficient amounts of purified DNA is necessary. In this paper the most frequently used method for DNA isolation from live mycobacterial cells, body fluids, tissues, histological samples and forensic materials are outlined. This paper assists only as guide for these methods, so we describe them briefly.

scholarly journals Recombinant Newcastle Disease Virus (NDV) Expressing Sigma C Protein of Avian Reovirus (ARV) Protects against Both ARV and NDV in Chickens

Pathogens ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 145
Author(s):  
Deep Prakash Saikia ◽  
Kalpana Yadav ◽  
Dinesh C. Pathak ◽  
Narayan Ramamurthy ◽  
Ajai Lawrence D’Silva ◽  
...  
Keyword(s):  
Newcastle Disease ◽  
Reverse Genetics ◽  
Vaccine Candidate ◽  
Economic Losses ◽  
Avian Reovirus ◽  
C Protein ◽  
Challenge Virus ◽  
Virus Shedding ◽  
Recombinant Newcastle Disease Virus

Newcastle disease (ND) and avian reovirus (ARV) infections are a serious threat to the poultry industry, which causes heavy economic losses. The mesogenic NDV strain R2B is commonly used as a booster vaccine in many Asian countries to control the disease. In this seminal work, a recombinant NDV strain R2B expressing the sigma C (σC) gene of ARV (rNDV-R2B-σC) was generated by reverse genetics, characterized in vitro and tested as a bivalent vaccine candidate in chickens. The recombinant rNDV-R2B-σC virus was attenuated as compared to the parent rNDV-R2B virus as revealed by standard pathogenicity assays. The generated vaccine candidate, rNDV-R2B-σC, could induce both humoral and cell mediated immune responses in birds and gave complete protection against virulent NDV and ARV challenges. Post-challenge virus shedding analysis revealed a drastic reduction in NDV shed, as compared to unvaccinated birds.

scholarly journals Non-Performing Loans for Italian Companies: When Time Matters. An Empirical Research on Estimating Probability to Default and Loss Given Default

2020 ◽  
Vol 8 (4) ◽  
pp. 68
Author(s):  
Giuseppe Orlando ◽  
Roberta Pelosi
Keyword(s):  
Risk Taking ◽  
Economic Losses ◽  
Probability Of Default ◽  
Legal Environment ◽  
Loss Given Default ◽  
Recovery System ◽  
Main Driver ◽  
Long Time ◽  
The Subject ◽  
Time Required

Within bank activities, which is normally defined as the joint exercise of savings collection and credit supply, risk-taking is natural, as in many human activities. Among risks related to credit intermediation, credit risk assumes particular importance. It is most simply defined as the potential that a bank borrower or counterparty fails to fulfil correctly at maturity the pecuniary obligations assumed as principal and interest. Whenever this happens, a loan is non-performing. Among the main risk components, the Probability of Default (PD) and the Loss Given Default (LGD) have been the subject of greater interest for research. In this paper, logit model is used to predict both components. Financial ratios are used to estimate the PD. Time of recovery and presence of collateral are used as covariates of the LGD. Here, we confirm that the main driver of economic losses is the bureaucratically encumbered recovery system and the related legal environment. The long time required by Italian bureaucratic procedures, simply put, seems to lower dramatically the chance of recovery from defaulting counterparties.

scholarly journals User-Friendly Reverse Genetics System for Modification of the Right End of Fowl Adenovirus 4 Genome

Viruses ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 301
Author(s):  
Bingyu Yan ◽  
Xiaohui Zou ◽  
Xinglong Liu ◽  
Jiaming Zhao ◽  
Wenfeng Zhang ◽  
...  
Keyword(s):  
Reverse Genetics ◽  
Economic Losses ◽  
Virus Growth ◽  
Recombinant Viruses ◽  
Fowl Adenovirus ◽  
Viral Genes ◽  
Lmh Cells ◽  
Species Specific ◽  
The Right ◽  
User Friendly

A novel fowl adenovirus 4 (FAdV-4) has caused significant economic losses to the poultry industry in China since 2015. We established an easy-to-use reverse genetics system for modification of the whole right and partial left ends of the novel FAdV-4 genome, which worked through cell-free reactions of restriction digestion and Gibson assembly. Three recombinant viruses were constructed to test the assumption that species-specific viral genes of ORF4 and ORF19A might be responsible for the enhanced virulence: viral genes of ORF1, ORF1b and ORF2 were replaced with GFP to generate FAdV4-GFP, ORF4 was replaced with mCherry in FAdV4-GFP to generate FAdV4-GX4C, and ORF19A was deleted in FAdV4-GFP to generate FAdV4-CX19A. Deletion of ORF4 made FAdV4-GX4C form smaller plaques while ORF19A deletion made FAdV4-CX19A form larger ones on chicken LMH cells. Coding sequence (CDS) replacement with reporter mCherry demonstrated that ORF4 had a weak promoter. Survival analysis showed that FAdV4-CX19A-infected chicken embryos survived one more day than FAdV4-GFP- or FAdV4-GX4C-infected ones. The results illustrated that ORF4 and ORF19A were non-essential genes for FAdV-4 replication although deletion of either gene influenced virus growth. This work would help function study of genes on the right end of FAdV-4 genome and facilitate development of attenuated vaccines.

scholarly journals The Cytotoxic Effect of Genistein, a Soybean Isoflavone, against Cultured Tribolium Cells

Insects ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 241 ◽  
Author(s):  
Shingo Kikuta
Keyword(s):  
Cultured Cells ◽  
Lethal Effect ◽  
Soy Flour ◽  
Adult Survival ◽  
Water Control ◽  
Cytotoxic Effects ◽  
Biological Responses ◽  
Long Time ◽  
Development Failure ◽  
Wheat Flours

The red flour beetle Tribolium castaneum is a known pest of various grains and stored-products such as wheat flours; however, T. castaneum feeds on and infests soybean and soy products. For more than 60 years, soy flour has been suggested to be unstable food for Tribolium spp. because it causes larval development failure. However, it remains unknown whether soy flour affects adult beetles. The objective of the present study was to examine the effects of soy flour and its related isoflavones against T. castaneum using an artificial dietary intake assay. Beetles were fed gypsum (a non-digestible compound) mixed with either water (control) or soy flour. Significantly fewer beetles survived after being fed the soy flour treatment. Although the soy isoflavone genistein, a defensive agent and secondary metabolite, decreased the T. castaneum adult survival, it required a long time to have a lethal effect. Therefore, the cytotoxic effects of soy flour, i.e., the rapid biological responses following isoflavone addition, were also examined using a cultured cell line derived from T. castaneum. Both genistin and genistein significantly affected the survival of the cultured cells, although genistein had a stronger lethal effect. This study demonstrated the toxicity of genistein found in soybean against T. castaneum cultured cells within 24 h period. Genistein may be used as an oral toxin biopesticide against T. castaneum.

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