scholarly journals ‘2A-like’ and ‘shifty heptamer’ motifs in penaeid shrimp infectious myonecrosis virus, a monosegmented double-stranded RNA virus

2007 ◽  
Vol 88 (4) ◽  
pp. 1315-1318 ◽  
Author(s):  
Max L. Nibert

Penaeid shrimp infectious myonecrosis virus (IMNV) is a monosegmented double-stranded RNA virus that forms icosahedral virions and is tentatively assigned to the family Totiviridae. New examinations of the IMNV genome sequence revealed features not noted in the original report. These features include (i) two encoded ‘2A-like’ motifs, which are likely involved in open reading frame (ORF) 1 polyprotein ‘cleavage’; (ii) a 199 nt overlap between the end of ORF1 in frame 1 and the start of ORF2 in frame 3; and (iii) a ‘shifty heptamer’ motif and predicted RNA pseudoknot in the region of ORF1–ORF2 overlap, which probably allow ORF2 to be translated as a fusion with ORF1 by −1 ribosomal frameshifting. Features (ii) and (iii) bring the predicted ORF2 coding strategy of IMNV more in line with that of its closest phylogenetic relative, Giardia lamblia virus, as well as with that of several other members of the family Totiviridae including Saccharomyces cerevisiae virus L-A.

Viruses ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 654 ◽  
Author(s):  
Harry G. Ngoveni ◽  
Antoinette van Schalkwyk ◽  
J.J. Otto Koekemoer

Intragenic recombination has been described in various RNA viruses as a mechanism to increase genetic diversity, resulting in increased virulence, expanded host range, or adaptability to a changing environment. Orbiviruses are no exception to this, with intragenic recombination previously detected in the type species, bluetongue virus (BTV). African horse sickness virus (AHSV) is a double-stranded RNA virus belonging to the Oribivirus genus in the family Reoviridae. Genetic recombination through reassortment has been described in AHSV, but not through homologous intragenic recombination. The influence of the latter on the evolution of AHSV was investigated by analyzing the complete genomes of more than 100 viruses to identify evidence of recombination. Segment-1, segment-6, segment-7, and segment-10 showed evidence of intragenic recombination, yet only one (Segment-10) of these events was manifested in subsequent lineages. The other three hybrid segments were as a result of recombination between field isolates and the vaccine derived live attenuated viruses (ALVs).


2018 ◽  
Vol 6 (8) ◽  
Author(s):  
Hao He ◽  
Xiaoguang Chen ◽  
Pengfei Li ◽  
Dewen Qiu ◽  
Lihua Guo

ABSTRACT We describe here a double-stranded RNA mycovirus, termed Fusarium graminearum alternavirus 1 (FgAV1/AH11), from the isolate AH11 of the phytopathogenic fungus F. graminearum . Phylogenetic analysis showed that FgAV1/AH11 belongs to a newly proposed family, Alternaviridae . This is the first report of a mycovirus in the family Alternaviridae that infects F. graminearum .


2018 ◽  
Vol 2018 ◽  
pp. 1-26 ◽  
Author(s):  
Antonio Puccetti ◽  
Daniele Saverino ◽  
Roberta Opri ◽  
Oretta Gabrielli ◽  
Giovanna Zanoni ◽  
...  

Rotavirus is a double-stranded RNA virus belonging to the family of Reoviridae. The virus is transmitted by the faecal-oral route and infects intestinal cells causing gastroenteritis. Rotaviruses are the main cause of severe acute diarrhoea in children less than 5 years of age worldwide. In our previous work we have shown a link between rotavirus infection and celiac disease. Nonceliac gluten sensitivity (NCGS) is emerging as new clinical entity lacking specific diagnostic biomarkers which has been reported to occur in 6–10% of the population. Clinical manifestations include gastrointestinal and/or extraintestinal symptoms which recede with gluten withdrawal. The pathogenesis of the disease is still unknown. Aim of this work is to clarify some aspects of its pathogenesis using a gene array approach. Our results suggest that NCGS may have an autoimmune origin. This is based both on gene expression data (i.e., TH17-interferon signatures) and on the presence of TH17 cells and of serological markers of autoimmunity in NCGS. Our results also indicate a possible involvement of rotavirus infection in the pathogenesis of nonceliac gluten sensitivity similarly to what we have previously shown in celiac disease.


2000 ◽  
Vol 74 (7) ◽  
pp. 3156-3165 ◽  
Author(s):  
Richard Molenkamp ◽  
Babette C. D. Rozier ◽  
Sophie Greve ◽  
Willy J. M. Spaan ◽  
Eric J. Snijder

ABSTRACT Equine arteritis virus (EAV), the type member of the family Arteriviridae, is a single-stranded RNA virus with a positive-stranded genome of approximately 13 kb. EAV uses a discontinuous transcription mechanism to produce a nested set of six subgenomic mRNAs from which its structural genes are expressed. We have generated the first documented arterivirus defective interfering (DI) RNAs by serial undiluted passaging of a wild-type EAV stock in BHK-21 cells. A cDNA copy of the smallest DI RNA (5.6 kb) was cloned. Upon transfection into EAV-infected BHK-21 cells, transcripts derived from this clone (pEDI) were replicated and packaged. Sequencing of pEDI revealed that the DI RNA was composed of three segments of the EAV genome (nucleotides 1 to 1057, 1388 to 1684, and 8530 to 12704) which were fused in frame with respect to the replicase reading frame. Remarkably, this DI RNA has retained all of the sequences encoding the structural proteins. By insertion of the chloramphenicol acetyltransferase reporter gene in the DI RNA genome, we were able to delimitate the sequences required for replication/DI-based transcription and packaging of EAV DI RNAs and to reduce the maximal size of a replication-competent EAV DI RNA to approximately 3 kb.


2016 ◽  
Vol 4 (2) ◽  
Author(s):  
Alexander L. Greninger ◽  
Keith R. Jerome

We report the draft genome sequence of goose dicistrovirus assembled from the filtered feces of a Canadian goose from South Lake Union in Seattle, Washington. The 9.1-kb dicistronic RNA virus falls within the familyDicistroviridae; however, it shares <33% translated amino acid sequence within the nonstructural open reading frame (ORF) from aparavirus or cripavirus.


2000 ◽  
Vol 74 (13) ◽  
pp. 5788-5795 ◽  
Author(s):  
Nikolai V. Khramtsov ◽  
Steve J. Upton

ABSTRACT RNA polymerase complexes were purified from Cryptosporidium parvum, a parasitic protozoan known to infect many species of mammals including humans. Western blot analysis revealed the association of the complexes with two different proteins, encoded by large and small segments of viral double-stranded RNAs. Each complex was found to contain only double-stranded RNA, both double- and single-stranded RNA, or only single-stranded RNA. Maximum RNA-dependent RNA polymerase activity was observed within the complexes containing both double- and single-stranded RNAs. These complexes possessed both transcriptase and replicase polymerase activities. Virus-like particles with a diameter of 31 nm were copurified with RNA polymerase complexes, and buoyant density and polymerase studies suggest that C. parvum harbors a putative double-stranded RNA virus which separately encapsidates the large and small RNA segments. The mechanism of replication and other characteristics of this virus are similar to those of the viruses of the family Partitiviridae, previously identified only in fungi and plants.


Sign in / Sign up

Export Citation Format

Share Document