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Volume 60 (2010)
- Issue 2 Pages 143-
- Issue 1 Pages 3-
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Volume 60, Issue 2
Displaying 1-10 of 10 articles from this issue
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Reviews
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Masayuki HORIE, Keizo TOMONAGA2010 Volume 60 Issue 2 Pages 143-154
Published: December 25, 2010
Released on J-STAGE: September 01, 2011
JOURNAL FREE ACCESSApproximately 8% of our genome is made up of endogenous retroviral elements. Endogenous retrovirus is a fossil record of ancient retrovirus infection and, therefore, gives important insights into the evolutional relationship between retroviruses and their hosts. On the other hand, until recently, it has been believed that no endogenous non-retroviral viruses exist in animal genomes. We lately discovered endogenous elements homologous to the nucleoprotein of bornaviruses, a negative-strand RNA virus, in the genomes of many mammalian species, including humans. We also demonstrated that mRNA of extant mammalian bornavirus, Borna disease virus, is reverse-transcribed and integrated into the host genome DNA. These findings provided novel insights not only into the interaction between RNA viruses and their hosts, but also into the mechanism underlying the gain of novelty in mammalian genomes. In this review, we will briefly summarize our recent knowledge about endogenous bornavirus elements and also introduce some recent discoveries regarding endogenous elements of non-retroviral viruses in vertebrate genomes.View full abstractDownload PDF (1533K) -
Noriko YAMAGISHI, Nobuyuki YOSHIKAWA2010 Volume 60 Issue 2 Pages 155-162
Published: December 25, 2010
Released on J-STAGE: September 01, 2011
JOURNAL FREE ACCESSVirus-induced gene silencing (VIGS) is a technology that exploits an RNA-mediated antivirus defense mechanism in plants and has been shown to have great potential in plant reverse genetics. When the virus vector carries sequences of plant genes, virus infection triggers VIGS that results in the degradation of endogenous mRNAs homologous to the plant genes. The system is well established in Nicotiana benthamiana and several reliable VIGS vectors have been developed for other plant species including important agricultural crops. Here, we describe the use of VIGS technology to determine gene function and plant virus vectors for induction of VIGS in plants.View full abstractDownload PDF (1413K) -
Sotaro CHIBA, Hideki KONDO, Satoko KANEMATSU, Nobuhiro SUZUKI2010 Volume 60 Issue 2 Pages 163-176
Published: December 25, 2010
Released on J-STAGE: September 01, 2011
JOURNAL FREE ACCESSViruses are widespread in all major groups of fungi. The transmission of fungal viruses occurs intracellularly during cell division, sporogenesis, and cell fusion. They apparently lack an extracellular route for infection. Recent searches of the collections of field fungal isolates have detected an increasing number of novel viruses and lead to discoveries of novel genome organizations, expression strategies and virion structures. Those findings enhanced our understanding of virus diversity and evolution. The majority of fungal viruses have dsRNA genomes packaged in spherical particles, while ssRNA mycoviruses, possessing or lacking the ability to form particles, have increasingly been reported. This review article discusses the current status of mycovirus studies and virocontorl (biocontrol) of phytopathogenic fungi using viruses that infect them and reduce their virulence. Selected examples of virocontrol-associated systems include the chestnut/chestnut blight/hypovirus and fruit trees/ white root rot fungus/ mycoviruses. Natural dissemination and artificial introduction of hypovirulent fungal strains efficiently contributed to virocontrol of chestnut blight in European forests. Attempts to control white root rot with hypovirulence-conferring mycoviruses are now being made in Japan.View full abstractDownload PDF (2550K) -
Teruo SANO2010 Volume 60 Issue 2 Pages 177-186
Published: December 25, 2010
Released on J-STAGE: September 01, 2011
JOURNAL FREE ACCESSViroids are autonomously replicating, small single-stranded circular RNA pathogens that cause diseases in infected, susceptible plants. They are non-coding RNA replicon which replicate depending on host transcriptional machinery and develop disease symptoms through interactions with cellular components of the host. The small size and unique molecular structure of viroid RNA makes them an attractive system to analyze molecular features responsible for pathogenesis, RNA transport, or molecular evolution and adaptation to specific host species. Here we show the latest progress in viroid research on new disease epidemics, molecular evolution and host adaptation, and pathogenesis in relation to viroid-induced RNA silencing.View full abstractDownload PDF (796K)
Special Issue : Herpesviruses
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Yasushi KAWAGUCHI2010 Volume 60 Issue 2 Pages 187-196
Published: December 25, 2010
Released on J-STAGE: September 01, 2011
JOURNAL FREE ACCESSHerpes simplex virus (HSV), the prototype of the herpesvirus family, causes a variety of diseases in human. In this review, I focus on the molecular mechanism of HSV infection including recent advance on this research field.View full abstractDownload PDF (1047K) -
Kyosuke KANAI, Souichi YAMADA, Naoki INOUE2010 Volume 60 Issue 2 Pages 197-208
Published: December 25, 2010
Released on J-STAGE: September 01, 2011
JOURNAL FREE ACCESSVaricella-zoster virus (VZV) causes varicella in primary infection and zoster after reactivation from latency. Both herpes simplex virus (HSV) and VZV are classified into the same alpha-herpesvirus subfamily. Although most VZV genes have their HSV homologs, VZV has many unique biological characteristics. In this review, we summarized recent studies on 1) animal models for VZV infection and outcomes from studies using the models, including 2) viral dissemination processes from respiratory mucosa, T cells, to skin, 3) cellular receptors for VZV entry, 4) functions of viral genes required uniquely for in vivo growth and for establishment of latency, 5) host immune responses and viral immune evasion mechanisms, and 6) varicella vaccine and anti-VZV drugs.View full abstractDownload PDF (1016K) -
Isao KOSUGI2010 Volume 60 Issue 2 Pages 209-220
Published: December 25, 2010
Released on J-STAGE: September 01, 2011
JOURNAL FREE ACCESSHuman cytomegalovirus (HCMV) is a ubiquitous beta human herpesvirus type 5. Compared to other human herpesviruses, HCMV is the largest, with a genome of ~235 kb containing ~250 ORFs with the potential to encode proteins. Usually, HCMV asymptomatically infects the host during childhood, and establishes life-long latency. The infection is life-threatening for infants and immunocompromised individuals, because of direct cytopathicity by viral replication, causing systemic organ injuries. Intrauterine infection occasionally causes microcephaly, sensorineural hearing loss and mental retardation. HCMV genome contains a number of accessory genes. Most of them are engaged in immune evasion or inhibition of cell death, possibly, resulting in a symbiosis between virus and host. CD34-positive myeloid progenitor cells are considered as a site of latency. However, the molecular mechanisms by which HCMV establishes and maintains latency and reactivates remain poorly understood. Recently in Japan, the decline of maternal HCMV seropositivity may increase the risk of intrauterine infection. It needs to immediately establish the protection against transplacental HCMV infection, such as a new type of neutralizing antibody or vaccine, which effectively interferes viral entry specific to endothelial and epithelial cells. Furthermore, HCMV infection might be considered as the most important factor for driving immune senescence in the elderly.View full abstractDownload PDF (1393K) -
Huamin TANG, Tomohiko SADAOKA, Yasuko MORI2010 Volume 60 Issue 2 Pages 221-236
Published: December 25, 2010
Released on J-STAGE: September 01, 2011
JOURNAL FREE ACCESShuman herpesvirus 6 ( HHV-6) is the major causative agent of exanthem subitum which is one of popular diseases in infant, and establishes latent infections in adults of more than 90%.
Recently, the encephalitis caused by reactivated- HHV-6 has been shown in patients after transplantation. In addition, the relationship HHV-6 and drug-induced hypersensitivity syndrome has also been reported.
human herpesvirus 7 (HHV-7) was isolated from the stimulated-peripheral blood lymphocytes of a healthy individual, and also causes exanthema subitum. Both viruses are related viruses which belong to betaherpesvirus subfamily, and replicate and produce progeny viruses in T cells.View full abstractDownload PDF (662K) -
Harutaka KATANO2010 Volume 60 Issue 2 Pages 237-246
Published: December 25, 2010
Released on J-STAGE: September 01, 2011
JOURNAL FREE ACCESSEpstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV or human herpesvirus 8, HHV-8) are members of gamma-herpes virus family. Both viruses infect to B cells and cause malignancies such as lymphoma. Since EBV and HHV-8 are so-called 'oncovirus', their oncogenecities have been focused in the researches on EBV and KSHV for a long time. EBV was discovered in 1964, whereas KSHV was identified in 1994. However, KSHV was analyzed rapidly in these fifteen years. One of the recent progresses in the research on EBV and KSHV is that virus-encoded small RNAs were identified in their genomes and characterized. EBV is the first human virus in whose genome microRNA was identified. The oncogenecity of EBV and KSHV remains unclear. Here, I discuss the pathogenesis by EBV and KSHV with special reference to recent progress in this field.View full abstractDownload PDF (277K)
Topics
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Hiroomi AKASHI2010 Volume 60 Issue 2 Pages 249-246
Published: December 25, 2010
Released on J-STAGE: September 01, 2011
JOURNAL FREE ACCESSFoot-and-mouth disease caused by Foot-and-mouth disease virus (FMDV) is a severe and acute vesicular disease of cloven-hoofed animals including cattle, pigs, sheep and goats. As FMDV is highly contagious and causes productivity losses among infected animals, outbreaks of the disease are a primary animal health concern worldwide. In April, 2010, the disease reoccurred in Miyazaki prefecture in 10 years. Compared to the outbreak in 2000 in which no infection among pigs was observed, a total of 292 infected farms have been involved in this outbreak, and infected animals (37,412 cattle, 42 water buffalos, 174,132 pigs, 14 goats, and 8 sheep) were culled and buried. Vaccination was decided to reduce the speed of virus spreading. Finally a total of 76,756 heads of vaccinated animals were also slaughtered. The outbreak has continued for 2.5 months, and the ban on animal movements have been eased 3 months after the first occurrence. As several factors for disease spreading have been rumored, I would like to note this point and discuss future preventive measures.View full abstractDownload PDF (1537K)
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