|Pacheco Tobin, Juan|
|Rieder, Aida - Elizabeth|
Submitted to: Archives of Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/22/2008
Publication Date: 3/14/2009
Citation: Piccone, M.E., Pauszek, S.J., Pacheco Tobin, J., Rieder, A.E., Kramer, E., Rodriguez, L.L. 2009. Molecular Characterization of a Foot-and-Mouth Disease Virus (FMDV) Containing a 57-Nucleotide Insertion in the 3' Untranslated Region (3'UTR). Archives of Virology. 154:671-676. Interpretive Summary: Foot-and-mouth disease virus (FMDV) is one of the most important pathogens of livestock worldwide. Despite the basic research done so far, very little is known about the role of the individual viral proteins or elements of the viral RNA on the course of the disease in the main natural hosts (cattle and swine). The viral RNA codes for a single protein and is flanked at each end (5’ and 3’ respectively) by untranslated regions (UTR) of about 1200 and 90 nucleotides respectively. The 5’ UTR contains important genetic elements involved in virus translation and replication; while the 3’ UTR is believed to be essential for virus replication. In an effort to evaluate the role of the latter region on FMDV virulence, we constructed a mutant virus containing a 57-nucleotide insertion in the 3’UTR of the viral RNA. The effect of the insertion was evaluated on virus growth in cells and virulence in cattle. The mutant virus grew at a slightly slower rate than but eventually, reached similar titers as the wild type virus in infected cell lines. No defects in protein synthesis or replication were observed. Moreover, when inoculated in cattle via aerosolization, the mutant virus caused disease similar to that observed after WT virus infection. Computer modeling of the viral RNA showed that the mutation did not change the main conformation of the 3’UTR. These results revealed that the 3’UTR can tolerate insertion of foreign sequences that do not disrupt essential signals required for virus replication. This information will be useful to better understand viral pathogenesis and also help in our research on vaccine development.
Technical Abstract: A foot-and-mouth disease virus (FMDV) virus containing a 57 nt insertion in the 3’ untranslated region (3’UTR) was generated by a transposon (tn) mediated mutagenesis. Characterization of the mutant virus (A24-3’UTR8110) revealed no significant differences in virus growth, translation efficiency and virulence in cattle compared to the A24 wild-type (WT) virus. RNA modeling showed that the structures predicted in the 3’UTR were not affected by the tn insertion. These results revealed that the 3’UTR can tolerate foreign sequences that do not disrupt essential signals required for virus replication.