Scientists synthesise a working biological entity for the first time
using genetic code as the recipe and carbon-containing chemicals as the ingredients, researchers have recently recreated the polio virus. The feat is significant, as it is for the first time that a working biological entity has been synthesised. Moreover, the achievement is a step towards creating life in laboratories -- though viruses are not considered as living organisms, they are said to be alive because of their capability to replicate themselves.
The experiment, funded by the Pentagon as part of a programme to develop biowarfare counter-measures, was carried out by Eckard Wimmer of the State University of New York, usa, and his colleagues. Their task was very comprehensive, as the polio virus is little more than a microscopic protein shell that just carries rna, a chemical cousin of dna. The researchers made the code of this rna as the basis of their endeavour. Since rna is not very feasible for experiments due to its unstable nature, the researchers first made a dna version of the rna code by using laboratory-made custom snippets of dna material. They first assembled the shorter dna segments into a full-length genome and, thereafter, used an enzyme that turns dna into rna to make a working copy of the polio virus's natural rna code.
When placed in a dish with appropriate chemicals and enzymes, the rna pieces acted naturally -- they made their duplicates, and also started producing proteins, including those into which the new rna became spontaneously packaged. The result was countless functional polio viruses that caused the disease when injected into mice. This shows that living beings are a result of chemical and physical reactions.
The feat proves that even if all the polio viruses in the world were destroyed, it would be easily possible to resurrect the disease. According to the researchers, the synthesis method could be applied to other viral diseases. "We feel this could be used for just about anything, including smallpox," Wimmer says. This raises the worrying possibility of bioterrorists using the method to recreate devastating diseases. In the wake of such a scenario, Wimmer asserts that governments should monitor what chunks of dna are being ordered from commercial sources. "Our work makes a safer world because it puts out notice that we have to cope up with the new danger from bioterrorism," he says.
According to him, an increasing ability to build viruses would allow scientists to intensify research about many difficult diseases. For example, the influenza virus that caused the global pandemic of 1918 has still not been isolated and dissected. But once its genetic sequence is known, it can perhaps be recreated for study.
Also, scientists may someday want to resurrect disease organisms that have been exterminated, seeking new weapons against diseases. "There is a possibility that you could change the genome structure to get a milder virus for use as a vaccine," says Wimmer. In fact during their experiments, when the researchers introduced a few changes into polio's genome, they found that the changes weakened the virus. "We discovered that the virus became less virulent," says Wimmer. However, the feat does not pave way to create new viruses. "No one has been able to invent a virus as it's too complicated ," reveals Wimmer.
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