The Experts below are selected from a list of 297 Experts worldwide ranked by ideXlab platform
Masashi Iwanaga - One of the best experts on this subject based on the ideXlab platform.
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Infectious Virions of Bombyx Mori Latent Virus Are Incorporated into Bombyx Mori Nucleopolyhedrovirus Occlusion Bodies.
Viruses, 2019Co-Authors: Keita Tsukui, Chihiro Yagisawa, Shota Fujimoto, Moe Ogawa, Ryuhei Kokusho, Mitsuyoshi Nozawa, Hideki Kawasaki, Susumu Katsuma, Masashi IwanagaAbstract:The Bombyx Mori latent virus (BmLV) belongs to the unassigned plant virus family Tymoviridae and contains a positive-sense, single-stranded RNA genome. BmLV has infected almost all B. Mori-derived cultured cell lines through unknown routes. The source of BmLV infection and the BmLV life cycle are still unknown. Here, we examined the interaction between BmLV and the insect DNA virus Bombyx Mori nucleopolyhedrovirus (BmNPV). Persistent infection with BmLV caused a slight delay in BmNPV propagation, and BmLV propagation was enhanced in B. Mori larvae via co-infection with BmNPV. We also showed that BmLV infectious virions were co-occluded with BmNPV virions into BmNPV occlusion bodies. We propose a new relationship between BmLV and BmNPV.
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Persistent virus in the silkworm cell lines: Bombyx Mori latent virus
Uirusu, 2019Co-Authors: Masashi IwanagaAbstract:Bombyx Mori latent virus (BmLV) is a positive, single-stranded insect RNA virus with a close relationship to plant tymoviruses and currently classified as an "unclassified" tymovirus. BmLV is accumulated at extremely high levels only in cell lines derived from the silkworm, Bombyx Mori, but it does not lead to lethality and establishes persistent infections. It was unknown whether BmLV affects the Baculovirus Expression Vector System using Bombyx Mori nucleopolyhedrovirus, and how BmLV replicates and establishes persistent infections in insect cell lines. In this review, I introduce the discovery of BmLV, the establishment of virus-free cultured cells and the safety aspect of this virus. I also describe that two distinct small RNA-mediated pathways maintain the virus level in BmLV-infected cells, thereby allowing the virus to establish persistent infection. Virus-derived small interfering RNAs (vsiRNAs) and PIWI-interacting RNAs (vpiRNAs) are both produced as the BmLV infection progressed. We revealed that while siRNA pathway functions in both acute and persistent infection of BmLV, piRNA pathway functions only in the persistent infection of this virus.
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Infection studies of nontarget mammalian cell lines with Bombyx Mori macula-like virus.
Journal of virological methods, 2015Co-Authors: Katsuhisa Innami, Hideki Kawasaki, Susumu Katsuma, Takahiro Aizawa, Toshihiro Tsukui, Shigeo Imanishi, Masashi IwanagaAbstract:Bombyx Mori-derived cell lines are generally used for Bombyx Mori nucleopolyhedrovirus (BmNPV)-based baculovirus expression vector system (BEVS). However, almost all of the B. Mori-derived cell lines are persistently infected with Bombyx Mori macula-like virus (BmMLV). In this study, nontarget mammalian cell lines were exposed to BmMLV, and their susceptibility was investigated. Real-time PCR showed that viral RNA in virus-inoculated nine mammalian cell lines decreased sharply at 7 days postinfection. Also, there was no significant effect on cell viability of mammalian cells after inoculation with BmMLV. These findings indicate that mammalian cell lines used in this study are not permissive to BmMLV, and BmMLV contamination might not affect the safety aspect of BmNPV-based BEVS.
Susumu Katsuma - One of the best experts on this subject based on the ideXlab platform.
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Bombyx Mori nucleopolyhedrovirus Bm96 suppresses viral virulence in Bombyx Mori larvae.
Journal of invertebrate pathology, 2020Co-Authors: Hiroyuki Hikida, Ryuhei Kokusho, Noriko Matsuda-imai, Susumu KatsumaAbstract:Abstract Bombyx Mori nucleopolyhedrovirus (BmNPV) is a severe pathogen for the domestic silkworm, Bombyx Mori. BmNPV harbors over 140 protein-coding genes in its 128.4 kilobase pair-long double-stranded genome. However, many BmNPV genes are still uncharacterized. Here we investigated the role of BmNPV Bm96 in both B. Mori cultured cells and larvae. We found that Bm96 is mainly expressed at the late stage of infection and accumulation of Bm96 protein peaks at 24 h post infection (hpi) and declines gradually at 48 hpi in B. Mori cultured cells. Compared with the wild-type viruses, Bm96-deletion viruses exhibited higher viral propagation and fast-killing phenotype in B. Mori larvae. These results strongly suggest that Bm96 negatively regulates the propagation of BmNPV in B. Mori larvae. Furthermore, we observed that larvae infected with Bm96-deletion viruses showed lower locomotory activity at the late stage of infection compared with those infected with the wild-type viruses.
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Infectious Virions of Bombyx Mori Latent Virus Are Incorporated into Bombyx Mori Nucleopolyhedrovirus Occlusion Bodies.
Viruses, 2019Co-Authors: Keita Tsukui, Chihiro Yagisawa, Shota Fujimoto, Moe Ogawa, Ryuhei Kokusho, Mitsuyoshi Nozawa, Hideki Kawasaki, Susumu Katsuma, Masashi IwanagaAbstract:The Bombyx Mori latent virus (BmLV) belongs to the unassigned plant virus family Tymoviridae and contains a positive-sense, single-stranded RNA genome. BmLV has infected almost all B. Mori-derived cultured cell lines through unknown routes. The source of BmLV infection and the BmLV life cycle are still unknown. Here, we examined the interaction between BmLV and the insect DNA virus Bombyx Mori nucleopolyhedrovirus (BmNPV). Persistent infection with BmLV caused a slight delay in BmNPV propagation, and BmLV propagation was enhanced in B. Mori larvae via co-infection with BmNPV. We also showed that BmLV infectious virions were co-occluded with BmNPV virions into BmNPV occlusion bodies. We propose a new relationship between BmLV and BmNPV.
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Infection studies of nontarget mammalian cell lines with Bombyx Mori macula-like virus.
Journal of virological methods, 2015Co-Authors: Katsuhisa Innami, Hideki Kawasaki, Susumu Katsuma, Takahiro Aizawa, Toshihiro Tsukui, Shigeo Imanishi, Masashi IwanagaAbstract:Bombyx Mori-derived cell lines are generally used for Bombyx Mori nucleopolyhedrovirus (BmNPV)-based baculovirus expression vector system (BEVS). However, almost all of the B. Mori-derived cell lines are persistently infected with Bombyx Mori macula-like virus (BmMLV). In this study, nontarget mammalian cell lines were exposed to BmMLV, and their susceptibility was investigated. Real-time PCR showed that viral RNA in virus-inoculated nine mammalian cell lines decreased sharply at 7 days postinfection. Also, there was no significant effect on cell viability of mammalian cells after inoculation with BmMLV. These findings indicate that mammalian cell lines used in this study are not permissive to BmMLV, and BmMLV contamination might not affect the safety aspect of BmNPV-based BEVS.
Keping Chen - One of the best experts on this subject based on the ideXlab platform.
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Discovery of anti-viral molecules and their vital functions in Bombyx Mori.
Journal of invertebrate pathology, 2018Co-Authors: Ye Pan, Yanhua Yang, Feifei Zhu, Zhongjian Guo, Qin Yao, Keping ChenAbstract:The silkworm Bombyx Mori (B. Mori), a lepidopteran model organism, has become an important model for molecular biology researches with its genome completely sequenced. Silkworms confront different types of virus diseases, mainly including those caused by Bombyx Mori nucleopolyhedrovirus (BmNPV), Bombyx Mori densovirus type 1 (BmDNV-1), Bombyx Mori bidesovirus (BmBDV) which was termed as Bombyx Mori densovirus type 2 (BmDNV-2) or Bombyx Mori parvo-like virus (BmPLV) before in sericulture. B. Mori offers excellent models to study the molecular mechanisms of insect innate immune responses to viruses. A variety of molecules and pathways have been identified to be involved in the immune responses in the silkworm to viruses, such as the antimicrobial peptides, prophenoloxidase-activating system, apoptosis, ROS, small RNA and related molecules. Here in this review, we summarize the current research advances in molecules involved in silkworm anti-virus pathways. Moreover, taking BmNPV as an example, we proposed a schematic model of molecules and pathways involved in silkworm immune responses against virus infection. We hope this review can facilitate further study of antiviral mechanisms in silkworm, and provide a reference for virus diseases in other organisms.
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Virus-induced opposite effect on Bombyx Mori gene transcriptions
ISJ-Invertebrate Survival Journal, 2016Co-Authors: Y Yin, Feifei Zhu, Hengchuan Xia, Liang Chen, Keping ChenAbstract:Bombyx Mori bidensovirus (BmBDV) and Bombyx Mori nucleopolyhedrovirus (BmNPV) are serious pathogens of Bombyx Mori. In this study, we reported the changes of transcription level of several immune genes, including bmi, argo, dicer, cap1, cap3 and car, in Bombyx Mori midgut after exposure to BmBDV or BmNPV. Silkworm strains 798 (anti-BmBDV) and 306 (susceptible to BmBDV) were subjected to BmBDV infection, and NB (anti-BmNPV) and HUABA (35) (susceptible to BmNPV) were subjected to BmNPV infection. The results showed that the transcription levels differ largely among different silkworm strains, and that the extent to which the gene transcriptions were affected by the viruses was different. However, both BmNPV and BmBDV viruses can reverse the transcription patterns of these genes when the silkworms were administered with the viruses compared with those control groups. The transcript levels of bmi and dicer were decreased in 798 and 306 strains that were inoculated with BmBDV compared with their respective controls, but were increased in NB and HUABA (35) inoculated with BmNPV. The transcript levels of argo and cap3 were risen in 798, 306 and NB strains when inoculated with their respective viruses, but were decreased in HUABA (35) strain. The transcript levels of cap1 were risen in all silkworm strains, while the levels of car were decreased in 798, 306 and HUABA (35) strains, and increased in NB strain when inoculated with their respective viruses. These findings may contribute to more in-depth understanding on functions of these genes in virus infection and proliferation.
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Cloning and partial characterization of a gene in Bombyx Mori homologous to a human adiponectin receptor.
Acta biochimica Polonica, 2008Co-Authors: Minfeng Zhu, Zhongjian Guo, Qin Yao, Keping Chen, Yong Wang, Huijuan Yin, Huiqin ChenAbstract:In this study, we report the cloning and characteristics of an adiponectin-like receptor gene from Bombyx Mori (BmAdipoR) with highly conserved deduced amino-acid sequences and similar structure to the human adiponectin receptor (AdipoR). Structural analysis of the translated cDNA suggested it encoded a membrane protein with seven transmembrane domains. BmAdipoR was found to be expressed in multiple tissues and highly expressed in Malpighian tubules, fat body and testis. BmNPV (Bombyx Mori nucleopolyhedrovirus) bacmid system combined with confocal microscopy revealed that BmAdipoR was targeted to the cell membrane. We also found that infection with BmNPV did not have an effect on BmAdipoR mRNA quantity in the midgut of susceptible Bombyx Mori strain (306) at 48 h, but BmAdipoR mRNA quantity increased significantly at 72 h. We concluded that BmAdipoR gene was a membrane protein ubiquitously expressed in Bombyx Mori tissues and that its expression was altered by treating with BmNPV.
Li Xu - One of the best experts on this subject based on the ideXlab platform.
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Isolation and identification of a pathogen, Providencia rettgeri, in Bombyx Mori
Journal of Bacteriology Research, 2013Co-Authors: Jiao Zhang, Zhongyuan Shen, Xudong Tang, Li XuAbstract:A Gram-negative, rod-shaped bacterium, SY-1 strain, was isolated from a naturally infected silkworm Bombyx Mori that was suffering from the common infection septicemia. The colony was round, slightly convex, smooth, moist, translucent, regular-edged and milky white on nutrient agar medium. The SY-1 was identified as a putative strain of Providencia rettgeri through its physiological and biochemical properties, and phylogenetic analyses performed using the 16S rRNA gene sequence. The SY-1 was identified as a putative strain of P. rettgeri. This is the first report demonstrating that P. rettgeri is pathogenic to B. Mori. The identification of this strain adds to known kinds of pathogens that cause bacterial septicemia in the silkworm. This study aids the understanding of the prevention and control of the bacterial septicemia pathogens of B. Mori. Key words: Bombyx Mori, bacterial septicemia, pathogen, Providencia.
Boxiong Zhong - One of the best experts on this subject based on the ideXlab platform.
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Transgenic breeding of anti‐Bombyx Mori L. nuclear polyhedrosis virus silkworm Bombyx Mori
Acta biochimica et biophysica Sinica, 2008Co-Authors: Hui-juan Yang, Wei Fan, Hao Wei, Jin-wei Zhang, Zhong-hua Zhou, Jianrong Lin, Nong Ding, Boxiong ZhongAbstract:Silkworm strains resistant to Bombyx Mori L. nuclear polyhedrosis virus were obtained through transgenic experiments. piggyBac transposon with an A3 promoter were randomly inserted into the silkworm, driving the enhanced green fluorescent protein (EGFP) reporter gene into the silkworm genome. Polymerase chain reaction results verified the insertion of the extraneous EGFP gene, and fluorescence microscopy showed that the EGFP was expressed in the midgut tissue. The morbidity ratio of the nuclear polyhedrosis decreased from 90% in the original silkworm strain to 66.7% in the transgenic silkworm strain. Compared with the resistance to the Bombyx Mori L. nuclear polyhedrosis virus in the Qiufeng strain, which is commonly used in the production, there was an increase of 33 centesimal points in the transgenic silkworms. The antivirotic character in the Chunhua×Qiuyue strain, which was bred from a different transgenic family, was about 10 centesimal points higher than that in the Qiufeng×Baiyu, another crossbreed used in production. Our results indicated a good application value of the transposon-inserted mutation in the breeding of antiBmNPV silkworm strain.