China
Africa
Explore chapters and articles related to this topic
Other Double-Stranded DNA Viruses
Published in Paul Pumpens, Peter Pushko, Philippe Le Mercier, Virus-Like Particles, 2022
Paul Pumpens, Peter Pushko, Philippe Le Mercier
This next order of giant viruses included 3 families, namely Ascoviridae, Iridoviridae, and Marseilleviridae; 2 subfamilies; 10 genera; and 30 species altogether. The virions of the members of the Iridoviridae family, as reviewed by the latest ICTV report (Chinchar et al. 2017), are nonenveloped, 150–200 nm in diameter; the principal component of their capsids is the major capsid protein of 48 kDa. The genome is represented by a linear, double-stranded, circularly permuted, terminally redundant DNA of 103–220 kb, encoding 92–211 proteins. Chilo iridescent virus (CIV) from the Invertebrate iridescent virus 6 species of the Iridovirus genus serves as a reference strain of the Iridoviridae family. The CIV virion structure is shown in Figure 5.8 in comparison with that of the previously described PBCV-1 and Melbournevirus (MelV) from the Marseilleviridae family. The first electron cryomicroscopy structure of CIV was presented by Yan et al. (2000) in parallel with the PBCV-1 structure. Later, Yan et al. (2009) resolved the CIV structure to 13 Å, when a homology model of P50, the CIV major capsid protein (MCP), was built based on its aa sequence and the structure of the homologous PBCV-1 Vp54 MCP.
Torovirus
Published in Dongyou Liu, Handbook of Foodborne Diseases, 2018
Ziton Abdulrida Ighewish Al-Khafaji, Ghanim Aboud Al-Mola
Viroplasms are electronic dense cytoplasmic inclusions where viral replication and assembly take place. They are produced by nucleocytoplasmic large DNA viruses (NCLDV) like Poxviridae, Asfarviridae, and Iridoviridae, dsRNA viruses like Reoviridae and ssRNA(-) viruses like Filoviridae [40].
The roles of epidermal growth factor receptor in viral infections
Published in Growth Factors, 2022
Infectious spleen and kidney necrosis virus (ISKNV) is a member of family Iridoviridae that infects more than 50 species fishes. It comprises of a single linear, double-stranded DNA enclosed by icosahedral capsid. Outbreak of ISNNV causes serious economic losses in aquaculture industry. A recent study by Niu et al. (2021) has reported that EGFR mediates endocytosis of ISKNV in vitro and in vivo. Treatment of gefitinib inhibits ISKNV entry to Chinese perch brain (CPB) cells by suppressing EGFR/PI3K pathway and viral-induced cytoskeleton rearrangement (Figure 2(h)). In the in vivo study using largemounth bass, gefitinib inhibited ISKNV infection and diminished pathogenicity as evidenced by lower degree of hyperaemia and bleeding in spleen and liver (Niu et al. 2021).
Exploitation of receptor tyrosine kinases by viral-encoded growth factors
Published in Growth Factors, 2018
The evidence is increasing that viruses can interact with RTKs, modulating their activity so as to increase virus entry into cells, to promote viral replication and to enhance dissemination of the virus within the host or in the environment. Viruses achieve this through various mechanisms, including the manipulation of RTK expression, RTK dimerization and signalling, or RTK endocytosis and recycling. This review will concentrate on the VEGFR, EGFR, FGFR ligands produced by members of the large DNA virus families, namely the Poxviridae, Iridoviridae and Baculoviridae. We will describe the genetic diversity amongst virus-derived growth factors and the mechanisms by which exploitation of RTKs enhances virus survival. We will then highlight how viral ligands provide valuable tools to further understanding of RTK signalling and function in their vertebrate or invertebrate hosts.
The gut virome in Irritable Bowel Syndrome differs from that of controls
Published in Gut Microbes, 2021
S. Coughlan, A. Das, E. O’Herlihy, F. Shanahan, P.W. O’Toole, I.B. Jeffery
Of classified clusters, the most abundant families were those of the tailed bacteriophage viruses Siphoviridae (27.7%), Myoviridae (13%), and Podoviridae (8.9%) respectively, which are all in the Caudovirales order, in agreement with previous studies of the gut virome in healthy and disease cohorts (Table S3).17–21,24,26,27 The 4th most abundant family (6%) was the Mimiviridae family, whose members infect amoebae and protists, and whose member Mimivirus has been previously noted as a potentially dubious taxonomic classification in a study of the gut virome in ulcerative colitis.24,28 This led us to examine the confidence of the taxonomic classifications in more detail. Examination of the percentage identity and percentage coverage for each protein sequence aligned to the hit protein used for taxonomic assignment (percentage query cover) revealed a wide distribution of both scores for each family indicating that many of the classifications (Figure 1 and Figure S4) were based on low scores. While families in the Caudovirales order had high-scoring hits present, scores for most other families, including Mimiviridae were low indicating that the family-level classification was not reliable. Except for Mimiviridae, all other families with low scoring hits had very low abundances (<0.2% of total abundance at VC level and <0.6% at contig level; Tables S3 & S4, Figure 1). Ascoviridae, Iridoviridae, Marseilleviridae, Pithoviridae, and Poxviridae, all families of nucleocytoplasmic large dsDNA viruses (NCLDVs; proposed order Megavirales29) of eukaryotes had mainly low scoring hits (Figure 1) and were present in very low abundances (Figure 1; Table S1). Furthermore, Pithoviridae viruses have a diameter of 500 nm, which is larger than the 450 nm filter used to remove non-viral material in this study (Methods), and so would not be expected in our sequence data.30 Some Mimivirdae genomes are less than 450 nm and so could legitimately be present in our data. However, taxonomic assignments to families without the presence of high scoring hits or with low abundance are likely not as reliable as those for Caudovirales.