scholarly journals Open reading frame L1 of Marek's disease herpesvirus is not essential for in vitro and in vivo virus replication and establishment of latency.

1998 ◽  
Vol 79 (4) ◽  
pp. 841-849 ◽  
Author(s):  
K A Schat ◽  
B J Hooft van Iddekinge ◽  
G Koch ◽  
P H O'Connell ◽  
H Boerrigter
2007 ◽  
Vol 88 (11) ◽  
pp. 2941-2951 ◽  
Author(s):  
Mohammad M. Ahasan ◽  
Clive Sweet

Murine cytomegalovirus mutant Rc29, with a premature stop codon mutation in the m29 open reading frame (ORF), produced no apparent phenotype in cell culture or following infection of BALB/c mice. In contrast, a similar mutant virus, Rc29.1, with a premature stop codon mutation in its m29.1 ORF, showed reduced virus yields (2–3 log10 p.f.u. ml−1) in tissue culture. Mutant virus yields in BALB/c mice were delayed, reduced (∼1 log10 p.f.u. per tissue) and persisted less well in salivary glands compared with wild-type (wt) and revertant (Rv29.1) virus. In severe combined immunodeficiency mice, Rc29.1 virus showed delayed and reduced replication initially in all tissues (liver, spleen, kidneys, heart, lung and salivary glands). This delayed death until 31 days post-infection (p.i.) compared with wt (23 days p.i.) but at death virus yields were similar to wt. m29 gene transcription was initiated at early times post-infection, while production of a transcript from ORF m29.1 in the presence of cycloheximide indicated that it was an immediate-early gene. ORFs m29.1 and M28 are expressed from a bicistronic message, which is spliced infrequently. However, it is likely that each ORF expresses its own protein, as antiserum derived in rabbits to the m29.1 protein expressed in bacteria from the m29.1 ORF detected only one protein in Western blot analysis of the size predicted for the m29.1 protein. Our results suggest that neither ORF is essential for virus replication but m29.1 is important for optimal viral growth in vitro and in vivo.


1998 ◽  
Vol 72 (8) ◽  
pp. 6956-6959 ◽  
Author(s):  
Hong-Wu Xin ◽  
Liang-Hui Ji ◽  
Simon W. Scott ◽  
Robert H. Symons ◽  
Shou-Wei Ding

ABSTRACT We found that RNA 2 of the four ilarviruses sequenced to date encodes an additional conserved open reading frame (ORF), 2b, that overlaps the 3′ end of the previously known ORF, 2a. A novel RNA species of 851 nucleotides was found to accumulate to high levels in plants infected with spinach latent virus (SpLV). Further analysis showed that RNA 4A is a subgenomic RNA of RNA 2 and encodes all of ORF 2b. Moreover, a protein species of the size expected for SpLV ORF 2b was translated in vitro from the RNA 4A-containing virion RNAs. The data support the suggestion that the SpLV 2b protein is translated in vivo. The 2b gene of ilarviruses, which is not encoded by alfamoviruses and bromoviruses, shares several features with the previously reported cucumovirus 2b gene; however, their encoded proteins share no detectable sequence similarities. The evolutionary origin of the 2b gene is discussed.


1999 ◽  
Vol 1 (18) ◽  
pp. 1-16 ◽  
Author(s):  
Shahid Jameel

Hepatitis E virus (HEV) infection results in hepatitis E, an acute and self-limited disease. The virus is transmitted in a faecal–oral manner and is a major cause of viral hepatitis in much of the developing world, where it causes rampant sporadic infections and large epidemics. A curious feature of hepatitis E is the unusually high rates of mortality that are observed in pregnant women, in whom the disease is exacerbated by the development of fulminant liver disease. In the absence of viable in vitro propagation systems, several geographical isolates of HEV have been maintained in vivo in nonhuman primates and, subsequently, the viral genome has been cloned and sequenced. HEV has been classified provisionally into a separate family known as the HEV-like viruses, which has at least four recognised genotypes, but has only a single serotype. The viral genome is a positive-stranded (+)RNA of ~7.5 kb and encodes at least three proteins. Open reading frame 1 (ORF1) encodes the viral nonstructural polyprotein, which has domains that are homologous to some of the replication and processing enzymes found in other +RNA viruses. The HEV protein itself remains poorly characterised. The protein encoded by open reading frame 2 (ORF2) is the major HEV capsid protein, and the protein encoded by open reading frame 3 (ORF3) appears to be involved in virus–host interactions. Several questions related to the biology, epidemiology and pathogenesis of HEV remain unanswered; the progress of a few of these is reviewed here.


FEBS Letters ◽  
1983 ◽  
Vol 164 (2) ◽  
pp. 355-360 ◽  
Author(s):  
Paula A. Kiberstis ◽  
Antonello Pessi ◽  
Eric Atherton ◽  
Richard Jackson ◽  
Tony Hunter ◽  
...  

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