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Highlights ? Genome segments, dsRNA2 and 3, of Pyrus pyrifolia cryptic virus (PpCV) were analyzed. ? Phylogenetic analysis on two capsid proteins shows PpCV belongs to Deltapartitivirus . ? PpCV is thought to be tripartite. Abstra...
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Highlights ? Genome segments, dsRNA2 and 3, of Pyrus pyrifolia cryptic virus (PpCV) were analyzed. ? Phylogenetic analysis on two capsid proteins shows PpCV belongs to Deltapartitivirus . ? PpCV is thought to be tripartite. Abstract According to previous studies, three double-stranded (ds) RNA molecules (dsRNA1, 2, and 3) detected in Japanese pear are transmitted to the next generation with high frequency through both ovules and pollen. Nucleotide sequence analysis of dsRNA1-encoding RNA-dependent RNA polymerase (RdRp) has suggested that these dsRNAs are related to a cryptovirus named Pyrus pyrifolia cryptic virus (PpCV). In this study, purified dsRNA prepared from a PpCV-infected Japanese pear cultivar was subjected to next-generation deep sequencing. This sequencing generated two de novo assembled contigs corresponding to dsRNA2 and 3, with BLAST analysis of the predicted amino acid sequences indicating homology to capsid proteins (CPs) of the cryptoviruses persimmon cryptic virus and Sinapis alba cryptic virus 1, respectively. Relationships between the two contigs and dsRNA2 and 3 were confirmed by northern blot hybridization with probes generated using primers designed from the assembled contigs. Rapid amplification of cDNA ends analyses of 5′- and 3′-terminal sequences of dsRNA2 and 3 revealed that these two dsRNAs consist of 1523 and 1481 bp, respectively. The 5′-terminal sequences (AGAAUUUC) of dsRNA1, 2 and 3 were found to be conserved. Phylogenetic analysis of deduced amino acid sequences of the two CP-like variants indicated that PpCV belongs to Deltapartitivirus ( Partitiviridae ). Our results imply that PpCV is tri-segmented.
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This paper presents the experimental results that were obtained by implementing the payload of a cryptovirus on the Microsoft Windows platform. The attack is based entirely on the Microsoft Cryptographic API and the needed API cal...
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This paper presents the experimental results that were obtained by implementing the payload of a cryptovirus on the Microsoft Windows platform. The attack is based entirely on the Microsoft Cryptographic API and the needed API calls are covered in detail. More specifically, it is shown that by using eight types of API calls and 72 lines of C code, the payload can hybrid encrypt sensitive data and hold it hostage. Benchmarks are also given. A novel countermeasure against cryptoviral extortion attacks is shown that forces the API caller to demonstrate that an authorized party can recover the asymmetrically encrypted data.
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Through the application of next generation sequencing, in synergy with conventional cloning of DOP-PCR fragments, two double-stranded RNA (dsRNA) molecules of about 1.5 kbp in size were isolated from leaf tissue of a Japanese pers...
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Through the application of next generation sequencing, in synergy with conventional cloning of DOP-PCR fragments, two double-stranded RNA (dsRNA) molecules of about 1.5 kbp in size were isolated from leaf tissue of a Japanese persimmon (accession SSPI) from Apulia (southern Italy) showing veinlets necrosis. High-throughput sequencing allowed whole genome sequence assembly, yielding a 1,577 and a 1,491 bp contigs identified as dsRNA-1 and dsRNA-2 of a previously undescribed virus, provisionally named as Persimmon cryptic virus (PeCV). In silico analysis showed that both dsRNA fragments were monocistronic and comprised the RNA-dependent RNA polymerase (RdRp) and the capsid protein (CP) genes, respectively. Phylogenetic reconstruction revealed a close relationship of these dsRNAs with those of cryptoviruses described in woody and herbaceous hosts, recently gathered in genus Deltapartitivirus. Virus-specific primers for RT-PCR, designed in the CP cistron, detected viral RNAs also in symptomless persimmon trees sampled from the same geographical area of SSPI, thus proving that PeCV infection may be fairly common and presumably latent.
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Phylogenetic analyses have prompted a taxonomic reorganization of family Partitiviridae (encapsidated, bisegmented dsRNA viruses that infect plants, fungi, or protozoa), the focus of this review. After a brief introduction to part...
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Phylogenetic analyses have prompted a taxonomic reorganization of family Partitiviridae (encapsidated, bisegmented dsRNA viruses that infect plants, fungi, or protozoa), the focus of this review. After a brief introduction to partitiviruses, the taxonomic changes are discussed, including replacement of former genera Partitivirus, Alphacryptovirus, and Betacryptovirus, with new genera Alphapartitivirus, Betapartitivirus, Gammapartitivirus, and Deltapartitivirus, as well as redistribution of species among these new genera. To round out the review, other recent progress of note in partitivirus research is summarized, including discoveries of novel partitivirus sequences by metagenomic approaches and mining of sequence databases, determinations of fungal partitivirus particle structures, demonstrations of fungal partitivirus transmission to new fungal host species, evidence for other aspects of partitivirus host interactions and host effects, and identification of other fungal or plant viruses with some similarities to partitiviruses. Some outstanding questions are also discussed. (C) 2014 Elsevier B.V. All rights reserved.
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