| Date: | 2010-05-21 07:43 |
|---|---|
| Author: | Stefano |
| category: | Bioethics, Biology, Chemistry |
| slug: | craig-venter-programs-a-bacterium-from-scratch |
As you probably heard in the news, Craig Venter, the American biologist best known for starting up Celera Genomics and sequencing the human genome, achieved another big success. He created a fully working new bacterium, programming its DNA from scratch.
Like a computer having hardware and software, a bacterium has a set of components that execute the software written in the DNA to create proteins. For quite some time, the strategy was to put small pieces of new DNA into full genomes, so to add a new piece of genetic code to synthesize a new protein, typically a pharmaceutical drug. For example, people with diabetes must periodically use insulin, a small protein which is normally produced by a fully functional pancreas. If the pancreas does not produce insulin, then diabetes arises. A solution is to inject insulin from outside, but this small protein must be produced somehow. The technique used to produce it is the Recombinant DNA: A small piece of DNA specifying the code to produce insulin was inserted into a normal bacterium (Escherichia coli, the same that lives in your gut). The altered bacterium duplicates, and millions and millions of daughter cells now produce the proteins their genetic code specifies for, like they were small chemical laboratories. Since specification for insulin has been introduced in their DNA, these millions cells also produce the precious insulin, which is then extracted, purified and sold for diabetes treatment.
At the Craig Venter Institute, they went further. They didn't add something new to a bacterium. They took all the DNA contained in one, throw it in the dumpster, put another DNA completely designed on a computer, and let it go. This has been done some time ago, but this artificial bacterium was not able to reproduce, until some time ago. Yesterday the paper has been finally published on Science: "Creation of a Bacterial Cell Controlled by a Chemically Synthesized Genome", marking the fact that the hardware (the mechanism that synthesize proteins) can be programmed at will by totally replacing the software (the DNA). In the most superior example of computer programming skills, the JCVI now controls a chemical computer. Venter walks the path of Wohler, once again demonstrating that life has nothing magic, but it is just a chemical system, obeying the rules of chemistry in a fascinating self-sustaining, self-replicating system made of order and chaos.
What are the consequences of this achievement? What can we do with a totally programmable, reproductive chemical laboratory ? Well, it's not that easy. Actually this achievement is great, a milestone that will probably earn Craig Venter the Nobel Prize very soon, but to go from this achievement to practical uses for humankind we are a bit far, although not that much far. Having such control will allow so endless possibilities that are almost difficult to imagine right now in their completeness, but we can start from:
- production of now expensive proteins to cure diseases, similar to the insulin case, reducing the cost and increasing the effectiveness of therapies.
- production of bacterial species able to consume and transform substances that are toxic for us
- bacterial species able to deliver a pharmacological payload near the source of the disease. Today we inject stuff in our body, for example to kill cancer, but we poison every single cell, even the good ones. What if a bacterial species is able to detect and attach to a tumor, and then start producing an anticancer drug right there ?
- production of electricity from biological sources. Take wood or sugar, let bacteria digest it and promote electricity creation (a so-called microbial fuel cell). It's clean, renewable and easy to control. We already do something similar with Biosensors to evaluate the amount of glucose in blood.
- production of biofuels from garbage or pollutant, like used plastic.
- understand how a simple system like a bacterium works will give us the chance to understand more complex systems
Yes, some will probably be scared at the idea of such inane level of control: biological weapons, superbugs... danger! danger!... but if you really stop for a moment, check some history, and think deep, you realize that biological warfare is nothing new: people in the middle ages threw corpses hit by plague beyond castle walls to kill the opponents via biological warfare; humanity does not need to create a powerful bacterium as a weapon: a large amount of them are already available in nature, ready to be harvested, and they could go straight on the tip of some rocket ! Being scared that this new technology could be used by mad, aggressive people as a weapon is not an issue. Again: the biological weapon is already out there, since the very beginning. This is the reason why biological weapon stockpiling and production has been banned since 1972 (Biological Weapon Convention) and only defensive research is allowed and pursued.
In fact, if you think about it, understanding how bacteria work is actually the only way to find effective protection, and not only from human madness...There is a bigger menace out there to be worried about: the pure, crystalline natural cruelty, wiping thousands and thousands of species out with not a blink of compassion since 4 billions years. In 1918, the so called spanish flu wiped out 6% of the world population of that time. Six percent. We humans do not accept this harsh treatment from cruel nature, and we found a way to understand its mechanisms and use them at our own advantage. Our life today is twice as long and many times safer than the life of our ancestors, just 100 years ago: think about living in a world with no anesthesia, no penicillin, no anticancer drugs, no social security or medical assistance, with sounding remedies like skull trepanning, bloodletting, or Hirudotherapy.
Are you really scared of the 21th century ? I'm not.