RNA Interference Leads To Nobel Prize
gollum123 writes "The Nobel Prize for medicine has been awarded to two US scientists who discovered a phenomenon called RNA interference, which regulates the expression of genes. From the article: 'The breakthrough has also given scientists the ability to systematically test the functions of all human genes. [...] The Nobel citation, issued by Sweden's Karolinska Institute, said: "This year's Nobel Laureates have discovered a fundamental mechanism for controlling the flow of genetic information."'"
DNA doesn't tell you the whole story. A developing zygote doesn't respond only to its own genetic makeup, but also to prepackaged mRNA signals from the parents, whose DNA differs from that of the zygote. The zygote's environment and packaging determines its phenotype as much as its own DNA does in the early stages of development. Viruses that convert RNA to DNA show that the messaging isn't one-way and that DNA can be reprogrammed on the fly. It is this adaptability that makes living things so adaptable and diverse. If DNA was merely a static instruction set, the diversity and complexity of life we see today wouldn't be possible.
Ever since the 1920's, scientists knew that DNA was the inheritable component that held the genes. They also knew that protein was the actual workhorse, the microscopic machines that accomplished cellular processes. Eventually, they elucidated that DNA copies itself into RNA, which is then converted into protein. Watson and Crick determined the structure of DNA, and proposed the mechanism for conversion of DNA to RNA.
Since Watson and Crick's time, we have been using the Central Dogma of Molecular Biology:
DNA -> RNA -> protein
Increase the amount of DNA? That means more protein. Increase the amount of RNA? That means more protein.
The big question in biology is now: given that there is usually just one gene for each protein, why do you have drastically different amounts of protein?
What these guys show is that the Dogma really isn't entirely true. Sometimes you can add certain RNAs and make *less* protein. Moreover, they showed that this mechanism was conserved in organisms ranging from yeast to microscopic worms, to humans. In other words, small RNA molecules not only directed the synthesis of protein, they actually could be used to suppress it. An entirely new level of cellular regulation was elucidated.
But to be quite honest, that wasn't the reason they won the Nobel Prize. It is for the experimental implications. Back before RNAi, if I were studying My Favorite Gene, the classical way to do it would be either to find a small molecule inhibitor (very difficult and expensive to find one) or to genetically modify cells to stop making it (also very time consuming and difficult). Now, with RNAi, I have a third, very fast method. Simply construct RNAi using a pretty standardized cookbook, order it online for around $100, and stick it in the cells. See what happens. Experiments that used to take months to years and cost thousands of dollars could now be done in a few days for a few hundred dollars.
I'll put it in terms you guys can probably understand. Research without RNAi is like debugging without a debugger. Yeah, you can do it, but it's often time-consuming and confusing.