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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."'"
This news was announced October 2. I checked the Swedish news papers who are very accurate when it comes to Noble prize awards (it's a Swedish prize after all).
On October 3, they will announce the winner(s) in physics, followed by chemistry the day after. Prize in economy, October 9.
Full Tilt
Here's the schedule for future announcements: http://nobelprize.org/prize_announcements/
Unfortunately its not that simple. The "central dogma" of DNA --> RNA --> Protein has been steadily added to over the past 20 years. Mechanisms such as RNAi have been added to a growing list of different regulatory levels, from transcription to translation, alternative splicing, to protein modifications, to chromatin density...etc. Discoveries like RNAi continually show us that our "programming language" is much more complex than feeding instructions on a paper tape.
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.
The "cloverleaf," or cross shape which is indicative of tRNA is only its secondary structure- the 3D form it assumes in vivo looks more like an "L" shape, as seen here.
"FDA staff reviewers expressed concern about the number of patients who were left out of the study because they died."
This isn't quite correct... The phenomenon identified by Jorgenson et al. was cosupression... What they actually did was transfer an extra copy of the gene (DNA) for chalcone synthase into the petunia. What wasn't known until some years later is that this actually is based on the same mechanism as what happens in RNA interference. Essentially, the overproduction of the chalcone synthase is recognized by the plant, and a second strand of RNA is made, this then leads to the chalcone synthase mRNA being chopped up. For quite some time cosupression was a mystery and it wasn't immediately clear that it was the same thing as RNAi.
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.
It seems that DNA is the 'paper tape' component of the genetic Turing machine. mRNA seems to be the data bus and RNA interference is the ALU.
In the "Genetic Turing Machine" the 'tape' is comprised of DNA, RNA (in various forms), and proteins; the 'head' is mostly protein and RNA; and the FSM involves DNA, RNA, and protein. Oh, with some other crap, like metals, sprinkled throughout. Information is encoded in DNA and various other epigenetic systems (about which we know very little at this point). Reading and writing from/to this 'tape' is accomplished with mechanisms built from proteins and RNA, proteins whose production is regulated by other proteins and various forms of RNA.
There is no similarity in the fundamental workings of biological systems and computers, except perhaps (depending how you feel about the Church-Turing thesis) their computability power.
Computer metaphors are generally useless, whether you are trying to explain computers using cars, or humans using computers.
Oh, but reducing our bodies to algorithms is simple - all you have to do is model the physicals properties of all the atoms that comprise the body. It's simply a matter of processing power.
sic transit gloria mundi
You know what?
It doesn't matter. You and anyone else in the world can believe what you want, it is how it is and belief won't change it.
RNAi explained in a very clear way.t ml
http://www.pbs.org/wgbh/nova/sciencenow/3210/02.h
Left-under is the video
"The test of the morality of a society is what it does for it's children." -Dietrich Bonhoeffer
Do you mean to say that viruses could be introduced into an organism to change DNA? If so would it be possible for there to be something like inheritance where genetic characteristics propogate directly between organisms rather than through reproduction?
I am not entirely clear what you are asking but there are cases where children express phenotypes controlled by the mother's DNA. In some species of snail, the direction of the child's shell rotation is controlled by the mother's genes.
It's called horizontal gene transfer, and it's more common than you think.