• The Journal of Natural Sciences
• /
• v.10 no.1
• /
• pp.17-21
• /
• 1998

Numerous chemicals were tasted to show antiviral activity in vitro against tobacco mosaic virus (TMV). With a brief exposure of TMV to 1 N HCl or 1-0.1 N NaOH, Virions and their encapsidated RNAs were degraded completely and rapidly. When TMV was exposed to 0.1 N HCl, the hydrolysis of viral capsid in 5 min after treatment was observed in the 1% agarose gel. Virions and their encapsidated RNAs were not degraded by 0.01N HCl of 0.01N NaOH. These characteristics indicate that a short exposure to optimal concentration of acid or base is of practical value in eliminating infectious virus. The treatment of 50% isopropanol or UV light did not damage in viral integrity or their encapsidated RNAs. Disinfection of the agricultural tools and laboratory equipments using appropriate disinfectants is necessary to prevent cross contamination if farm and laboratory.

• BMB Reports
• /
• v.47 no.6
• /
• pp.330-335
• /
• 2014

Turnip yellow mosaic virus (TYMV) is a spherical plant virus that has a single 6.3 kb positive strand RNA as a genome. In this study, RNA1 sequence of Flock house virus (FHV) was inserted into the TYMV genome to test whether TYMV can accommodate and express another viral entity. In the resulting construct, designated TY-FHV, the FHV RNA1 sequence was expressed as a TYMV subgenomic RNA. Northern analysis of the Nicotiana benthamiana leaves agroinfiltrated with the TY-FHV showed that both genomic and subgenomic FHV RNAs were abundantly produced. This indicates that the FHV RNA1 sequence was correctly expressed and translated to produce a functional FHV replicase. Although these FHV RNAs were not encapsidated, the FHV RNA having a TYMV CP sequence at the 3'-end was efficiently encapsidated. When an eGFP gene was inserted into the B2 ORF of the FHV sequence, a fusion protein of B2-eGFP was produced as expected.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 2003.10a
• /
• pp.4-8
• /
• 2003

Cucumber mosaic virus (CMV) belongs to genus Cucumovirus. The Cucumovirus group contains three distinct members： CMV, Tomato aspermy virus (TAV), and Peanut stunt virus (PSV). The type member, CMV is the most widespread and most studied. CMV is isometric particles about 30 nm in diameter. The genome of CMV is divided into three RNAs. In addition, RNA extracted from virus particles contains a fourth RNA that is a subgenomic RNA generated from RNA3. RNA1 and RNA2 are each encapsidated in separate particles, whereas RNAs3 and 4 are coencapsidated in a third particle. Hence, inoculation by three particles, transmitted either mechanically or by the aphid vector, is required to infect plants.(중략)

• BMB Reports
• /
• v.41 no.10
• /
• pp.739-744
• /
• 2008

Turnip yellow mosaic virus (TYMV) is a positive strand RNA virus that infects mainly Cruciferae plants. In this study, the TYMV genome was modified by inserting an extra subgenomic RNA promoter and a multiple cloning site. This modified TYMV was introduced into Nicotiana benthamiana using a Agrobacterium-mediated T-DNA transfer system (agroinfiltration). When a gene encoding $\beta$-glucuronidase or green fluorescent protein was expressed using this modified TYMV as a vector, replication of the recombinant viruses, especially the virus containing $\beta$-glucuronidase gene, was severely inhibited. The suppression of replication was reduced by co-expression of viral silencing suppressor genes, such as tombusviral p19, closteroviral p21 or potyviral HC-Pro. As expected, two subgenomic RNAs were produced from the recombinant TYMV, where the larger one contained the foreign gene. An RNase protection assay revealed that the recombinant subgenomic RNA was encapsidated as efficiently as the genuine subgenomic RNA.

• Journal of Microbiology
• /
• v.34 no.1
• /
• pp.61-67
• /
• 1996

Double-stranded RNA (dsRNA) viruses and single-stranded RNA(ssRNA) viruses were detected in a strain of Pleurotus mushroom cultivated in a farm. Those fungal virsus were purified in the pH 6.0 or pH 7.2 using CsCI or Cs$_{2}$SO$_{4}$ buoyant density centrifugation. Each viral particles were not completely separated at any trials. However, mushroom bacili-form virus contains a single major nucleic acid with 0.7 Kb ssRNA, which might code for 20 Kd viral capsid protein. The dsRNAs are encapsidatred into spherical-form viruses, whereas ssRNA viral genomes are encapsidated into two different sizes of bacili-form particles. A healthy-looking mushroom also contained some spherical-form viruses with dsRNAs. Laboratory strains of Pleurotus ostreatus and a cultivated strain of P. sajor-caju did not show any viral particles. Mushrooms with specific disease symptoms. however, contained at least four different sizes of spherical-form viruses. Thus, we concluded that a bacilli-form virus case a severe disease symptoms of adnormal on mushroom development.

• Journal of Microbiology and Biotechnology
• /
• v.29 no.11
• /
• pp.1790-1798
• /
• 2019

Flock House virus (FHV), an insect RNA virus, has a bipartite genome. FHV RNA1 can be packaged in turnip yellow mosaic virus (TYMV) as long as the FHV RNA has a TYMV sequence at the 3'-end. The encapsidated FHV RNA1 has four additional nucleotides at the 5'-end. We investigated whether the recombinant FHV RNA1 could replicate in mammalian cells. To address this issue, we prepared in vitro transcribed FHV RNAs that mimicked the recombinant FHV RNA1, and introduced them into baby hamster kidney (BHK) cells. The result showed that the recombinant FHV RNA1 was capable of replication. An eGFP gene inserted into the frame with B2 gene of the FHV RNA1 was also successfully expressed. We also observed that eGFP expression at the protein level was strong at 28℃ but weak at 30℃. Sequence analysis showed that the 3'-ends of the RNA1 and RNA3 replication products were identical to those of the authentic FHV RNAs. This indicates that FHV replicase correctly recognized an internally-located replication signal. In contrast, the 5'-ends of recombinant FHV RNA1 frequently had deletions, indicating random initiation of (+)-strand synthesis.

• Molecules and Cells
• /
• v.25 no.4
• /
• pp.545-552
• /
• 2008

A hepadnaviruses replicates its DNA genome via reverse transcription of an RNA template (pregenomic RNA or pgRNA), which has a cap structure at the 5' end and a poly(A) tail at the 3' end. We have previously shown that the 5' cap is indispensable for encapsidation of the pgRNA. A speculative extension of the above finding is that the cap contributes to encapsidation via its interaction with the poly(A) tail, possibly involving eIF4E-eIF4G-PABP interaction. To test this hypothesis, poly(A)-less pgRNAs were generated via cleavage by a cis-acting hepatitis delta virus ribozyme sequence. We found that accumulation of the poly(A)-less pgRNA was markedly diminished, mostly likely due to its reduced stability. Importantly, however, the remaining poly(A)-less pgRNAs were nonetheless encapsidated and reverse transcribed normally when the reduced stability was taken account. Our finding clearly contradicts the notion that the poly(A) tail has any function in encapsidation and viral reverse transcription.

• Journal of Aquaculture
• /
• v.13 no.1
• /
• pp.21-27
• /
• 2000

The successful gene transfer and transient expression was demonstrated in olive flounder embryos using lipofected sperm. Olive flounder sperm interacted with foregn plasmid DNA encapsidated by positively charged liposome. The maximum plasmid copy number that associated with the sperm was 5 copies/sperm based on the examination of DNA blot assay. The foreign DNA was transferred into fertilized eggs without any adverse effect on fertilization and survival of embryos (P>0.05) and retained in embryos until at least 42 hours with successful expression. The maximal expression was detected in 18 hours after fertilization at 18$^{\cird}C$ and gradually decreased with development of embryo. Most of DNA transferred into embryos persisted extrachromosomally without significant sign of integration or replication.

• Korean Journal of Animal Reproduction
• /
• v.19 no.1
• /
• pp.35-41
• /
• 1995

In this study, we have tested whether the retrovirus vector system is applicable in transgenic cattle production. To overcome low infectivity of currently available retrovirus vector system we have directly microinjected retrovirus-producing cells into the perivitelline space of the day 1.5 embryos. The virus-producing cell line was designed to release replication-defective retrovirus encapsidated with Gibbon ape leukemia virus (GaLV) envelope protein. E. coli LacZ gene was used as a marker gene to facilitate evaluation of the transgene expression and X-gal staining at morula or blastocyst stage resulted in expression of E. coli LacZ gene The results in these experiments were summarized as follows : 1. The lowest concentration of polybrene necessary for efficient virus infection was Sf' g/ml. 2. Development rate from day 1.5 embryos microinjected with virus-producing cells to the morulae /blastocysts was 29%. 3. 21% of the morulae /blastocysts were LacZ+. 4. There was no evidence that the retrovirus-producing cells used in this study produced replication-competent retrovirus.

• Journal of Microbiology
• /
• v.33 no.2
• /
• pp.154-159
• /
• 1995

SH-14, a novel killer strain of Ustilago maydis was isolated in Korea. It has been reported in other papers that the toxin specificity and double-stranded RNA pattern of SH-14 strain were different from other laboratory strains. In this paper, we analyzed the biochemical characteristics of U. maydis SH-14 virus. Three distinctive peaks were isolated from CsCl density gradient, designated as top (T), intermediate (I) and bottom (B) components. We found that the densities of each components, 1.285, 1.408 g/cm$\^$3/, respectively, are very similar to those of other strains. As previously reported by the analysis of dsRNA in each component, the dsRNA segments are separately encapsidated. Capsid protein of SH-14 virus consists of two proteins about 70 Kd shown by SDS-PAGE analysis. Electron microscopic examination of the virus particles revealed that UmV particles are very similar in size and morphology to all isolates as well as all lab-strains. In order to test immunological cross reactivity of UmV, werstern bolt analysis was carriedout with antiserum against A8 virus. All capsid protein had positive reaction against A8 antibody which indicated that UmV are immunologically cross-reactive with all isolates from Korea. The results presented in this paper may show that UmV isolated from SH-14 strain has very similar biochemical characteristics to those of other UmV. However, the difference in the toxin specificity and the molecular weight of toxin protein from the SH-14 strain has us to conclude that U. maydis SH-14 strain is a new killer type.