The Synthetic Revolution in Biology

Oct. 18, 2013

By Medical Discovery News

Synthetic biology sounds like an oxymoron. One word means artificial while the other means natural. Put together, what those two words really mean is a combination of biology and engineering that will allow scientists to harness biological processes for human use. Imagine genetic engineering and biotechnology on steroids.

In short, synthetic biology aims to manipulate cells or their components to achieve a certain result, such as advancing human health, producing energy, manufacturing products, producing food, or protecting the environment. There are plenty of applications for synthetic biology in many important fields. Scientists want to create cells with new and unique properties that are programmed to fulfill a directed purpose. For example, these engineered cells might be programmed to synthesize new biofuels.

One practical example of the promise of synthetic biology is directed at malaria, a disease caused by a single-celled parasite called Plasmodium that has been killing humans throughout our recorded history. Today, it infects 250 million people worldwide each year and is the No. 1 killer of children under five.

Malaria is currently treated by a group of drugs that are derived from artemisinin, such as artseunate, artemether, and dihydroartemisinin. Artemisinin is a compound from the sweet wormwood plant, which was used as a natural remedy for centuries in China. The downside is that this plant must grow for up to 1.5 years before it can be harvested for drug production. Of course, the normal variables of agriculture – rain, sunlight, soil content, labor – also mean that the supply of sweet wormwood fluctuates. Combined with the expensive manufacturing process, the result is that not everyone who is infected with malaria can be treated.

Synthetic biology has the power to change that. Recently, the World Health Organization gave pharmaceutical giant Sanofi approval to produce artemisinin using a genetically modified form of a yeast called Saccharomyces cervesiae. Several genes are inserted into the yeast’s genome to alter its metabolic pathways to produce a precursor to artemisinin. This has turned a simple organism into a “one-cell factory” for a new source of artemisinin.

Now, it will only take three months to produce artemisinin for antimalarial drugs. It will also insure a steady supply and greatly increases the amount that can be produced at one time. About 25 tons were produced in 2013 and that is expected to double next year. And if that weren’t good enough already, each dose of the yeast-produced artemisinin will only cost 25 cents.

Critics of synthetic biology fear a Frankensteinian world of potentially dangerous biological creations. In that regard, the United States government is drafting guidelines and regulations for this new field. With proper care and funding, synthetic biology will yield many new advances to improve lives as it reaches it potential in the future.  

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Biological Control of Mosquitoes

By Medical Discovery News

Jan. 28, 2012

Biological Control of Mosquitoes

Late at night, many people hear the mosquito truck spraying insecticides to control the mosquito population in their neighborhood. Imagine that truck releasing genetically modified mosquitoes instead, ones that can kill off their natural born, disease-carrying twin.

That’s already happened on Grand Cayman Island and in Malaysia where the local mosquito carries the dengue fever virus. In both locations, modified male mosquitoes were released into the environment. These mosquitoes carry a self-destruct gene that they pass on to their offspring when modified males mate with wild females, and these offspring die before becoming adults.

On Grand Cayman Island, where they have aedes aegypti, a mosquito that carries and transmits the dengue fever virus, for every natural male 10 modified male mosquitoes were released, or three million modified mosquitoes total. This way a wild female is more likely to mate with a modified male thereby producing self-destructing offspring. In just four months, the entire mosquito population in the test area was reduced by 80 percent, according to the study led by Hilary Rankin of the Liverpool School of Tropical Medicine.

The second approach is really clever. Scientists discovered that mosquitoes infected with a bacterium called Wolbachia pipientis become resistant to the dengue fever virus. They not only become resistant themselves, but pass these intracellular bacteria to their offspring, making them resistant as well.

During a recent field study in northern Australia by the country’s Monash University, scientists released a comparatively small number of 10 to 20,000 Wolbachia-infected mosquitoes weekly for 10 weeks. Six weeks after the final release, all the mosquitoes in the area that were sampled were infected. This means at least in the test area, the risk of people getting dengue fever from mosquitoes should have declined.

Scientists have done further studies with Wolbachia-infected mosquitoes and found they may also be effective in controlling the spread of other deadly viruses and parasites such as malaria. Since malaria kills more people in the world than any other infectious disease, this approach may have a huge impact.

While exciting and humanitarian, this approach faces some tough opposition. A number of groups are against modified insects because there’s no way to tell what impact they would have on the local ecology. They wonder if modified mosquitoes would be better at survival and grow to unmanageable numbers, or if the modified mosquitoes could cause a collapse of the mosquito population and affect the population of animals or insects that feed on them.

Groups against modified mosquitoes also criticize companies and government agencies that allow field tests without appropriate oversight, claiming the tests are done in secret without an opportunity for scientists and the public to comment.

While their concerns are legitimate, scientists will undoubtedly continue trying to make them more effective because of modified mosquitoes’ life saving potential.

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