RNA May 'Run' Genetic Coding

leonbrooks writes "First a Stanford Medicine Magazine article speaks about RNA 'produced by plants that turn genes on and off', and now a Science Magazine issue says 'For a long time, RNA has lived in the shadow of its more famous chemical cousin DNA and of the proteins that supposedly took over RNA's functions in the transition from the 'RNA world' to the modern one. The shadow cast has been so deep that a whole universe [of RNA] has remained hidden from view, until recently' and speaks of 'an order of magnitude more transcripts than genes', suggesting that more actual coding is done through RNA than DNA. Is everything we know about genetics off-base? (no pun intended)"

Comments

I suspect so but didnt know for sure

[taj]

RNA is the hardest to work with in the laboratory. It just fall to pieces. When I was working with DNA/RNA/protien it was just really hard to work with RNA.

so DNA->RNA->Protein

We could work with DNA we could work with most protiens. RNA? no way. well sortof but.. no way.

So DNA and Protein do play major rolls no doubt. but we could not get an angle on the RNA. 1990's tech.

Re:I suspect so but didnt know for sure

[TCQuad]

RNA breaks down without RNase. Physically, RNA is much less stable than DNA purely becuase it is not double stranded (in most cases).

Actually, the 2'-hydroxyl (the difference between deoxyribonucleic acid and ribonucleic acid) is a more significant problem. DNA is not hydrolyzable because it lacks any remaining hyroxyl groups (they're busy making the backbone bonds between the bases), while the sugar backbone in RNA can be hydrolyzed by base (base like NaOH, not like A, C, G, T, U...), cutting the single RNA into two pieces.

Slashdot science reporting

[dancingmad]

For a long time, RNA has lived in the shadow of its more famous chemical cousin DNA

What is this? Maybe during the OJ Simpson trial, but for anyone that's taken an intro bio course, that's bunk. RNA is a huge part of the entire thing...there are organisms that rely on RNA as their primary genetic material.

Once again, Slashdot, if you're going to post science news, have someone as an editor that knows some basic science!

RAM and disk drives

[idlake]

until recently' and speaks of 'an order of magnitude more transcripts than genes', suggesting that more actual coding is done through RNA than DNA.

No, that's not what it suggests. The coding is still done (almost) exclusively through DNA; we know that because we can synthesize DNA (and DNA only) from scratch and have it work.

What they are talking about is that RNA isn't just a short-lived intermediate in the cell, but has many other functions. That's been known for several decades, although people are only now slowly waking up to how important and widespread those functions are.

As a rough analogy, you can think of DNA as the disk drive of a cell and RNA as its RAM. The disk drive contains all the information you need to boot, but RAM is where most of the action happens, and a lot of stuff on disk is copied into RAM, often several times.

Re:mRNA is fascinating stuff...

[RyanFenton]

Nah - iRNA is a subset of mRNA (see your link), which is all a subset of RNA. mRNA is so fascinating to me because of the ranges of messages that can be sent, and what all those interactions really mean. So far it seems that various kinds of mRNA, not just iRNA can be used ultimately to manipulate DNA on and off to help us see what the whole of DNA ultimately can functionally mean.

Again, I'm just a layman on the issues - and find it deeply fascinating in terms of the pure science of it.

Ryan Fenton

Re:This brings up a good question

[Alain Williams]

It is years since I read that book, but AFIR it is as much about ''how we did it'' as the science. The science in the book is still correct today, but remember that much more has been discovered since that ''enhances'' what they knew at the time.

Do read it, it is a good book.

Or they watch Canadian TV and saw ReGenesis

[msobkow]

This DNA/RNA combination sounds familiar if you're in Canada and caught the first couple of episodes of ReGenesis.

One of the plotlines of the show deals with a genetically engineered combination of Camel Pox (bacteria/DNA) and Ebola (virus/RNA). Trust the brilliant researchers to claim it as their own "new" idea instead of crediting science fiction...

Re:oh good lord

[Maset]

WHAT?

silencing RNAs work by binding to mRNA (creating double stranded RNA) so that normal translation (mRNA -> protein) cannot happen.

The destruction of RNA from siRNA (or RNAi as is being touted) is due to the cell's normal defenses to fight viriii and creating essentially an immune response.

So much for intelligent design

[The Fun Guy]

Not at all a well-designed, efficient and elegant system, it looks instead like the genetics is the most convoluted Rube Goldberg style mess you could imagine. To make a gene work you first express the DNA as mRNA, then edit the mRNA to remove to bits you didn't want in the first place, then reassmeble the parts you did. Except that some of that "non-coding" mRNA is used for spacing the "coding" mRNA.

To turn a gene off, you don't just turn it off... you turn another gene on that makes a piece of interfering RNA that binds to some of the mRNA from the first gene. The second gene is controlled in the same way, maybe as a positive feedback from the first gene maybe as a negative feedback, maybe under the control of some other gene, which may or may not have the same promoter region. Layers on top of layers on top of layers of interlocking control systems.....

Little bits and pieces of RNA, recycled and reused, adapted from their former functions to serve some new function, forming a hugely complex interlocking mess that somehow functions. This is like a typewriter constructed from a couple of staplers, a telephone and a box of paperclips.

So, since inefficient, cumbersome and inelegant spaghetti code-type machinery is at the heart of every mammalian cell, that pretty much drives a stake in the heart of any thought that this was a product of rational design, right?