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Molecular cloning of polyoma virus DNA in Escherichia coli: plasmid vector system
Abstract:
A series of recombinant plasmids containing polyoma virus (PY) DNA were constructed, and their biological activity was evaluated in mice and in cultured mouse cells. While all of the recombinants studied contain the complete, potentially infectious viral DNA, in no case was the intact recombinant PY-plasmid DNA, or live Escherichia coli containing the recombinant plasmids, capable of inducing PY infection of mice, either by feeding or by parenteral injection.
Insights
Recombinant polyoma virus (PY) DNA in plasmids did not cause PY infection in mice, even when administered orally or by injection. Live bacteria with these plasmids were also unable to induce infection, indicating a lack of infectivity.
Area of Science:
- Molecular Biology
- Virology
- Genetics
Background:
- Polyoma virus (PY) is a DNA tumor virus known to infect rodents.
- Recombinant DNA technology allows for the manipulation and study of viral genomes.
- Understanding the infectivity of modified viral DNA is crucial for assessing potential risks and applications.
Purpose of the Study:
- To construct recombinant plasmids containing polyoma virus (PY) DNA.
- To evaluate the biological activity and infectivity of these recombinant plasmids in vivo (mice) and in vitro (cultured mouse cells).
- To determine if intact recombinant PY-plasmid DNA or live bacteria harboring these plasmids can induce PY infection.
Main Methods:
- Construction of recombinant plasmids incorporating complete polyoma virus (PY) DNA.
- Administration of intact recombinant PY-plasmid DNA to mice via feeding and parenteral injection.
- Administration of live Escherichia coli containing the recombinant plasmids to mice via feeding and parenteral injection.
- In vitro studies using cultured mouse cells to assess viral activity.
Main Results:
- All constructed recombinant plasmids contained complete, potentially infectious polyoma virus (PY) DNA.
- Neither the intact recombinant PY-plasmid DNA nor live Escherichia coli containing the plasmids induced PY infection in mice through feeding or parenteral injection.
- The study did not detail results from cultured mouse cells but focused on the lack of infectivity in vivo.
Conclusions:
- Complete polyoma virus (PY) DNA within recombinant plasmids, or within live E. coli, is not infectious in mice under the tested conditions.
- The integrity or delivery method of the recombinant DNA appears to prevent the induction of polyoma virus (PY) infection.
- Further research may be needed to explore the specific mechanisms underlying this lack of infectivity.