The Biggest Piece Of DNA Ever Made

An anonymous reader writes "Forbes has a story on 'the biggest piece of artificial DNA ever made'. The real story is that companies are racing to produce longer and longer DNA fragments to serve the growing science of synthetic biology." From the article: "On a piece of DNA as long as the one made for Microbia, ten or more genes may be present. By studying more than one gene at once, researchers hope to get a better picture of how they work in concert to produce an organism. Another advantage: These stretches can also be made to contain all the DNA letters that occur between genes. Scientists once thought of that stuff as junk, but many now believe it may regulate how the genes work or provide some other function."

Comments

Genetic sentence

[Rob T Firefly]

These stretches can also be made to contain all the DNA letters that occur between genes.

Such gene patterns have also been found in the quick brown foxes which jump over lazy dogs.

"junk" DNA

[Scrameustache]

Ah, "junk" in biology.
There was a piece of the brain that was once thought of as "junk", or "filler", until it was removed by a zealous neurosurgeon during an operation in that region of the brain of his patient. The patient unexpectedly lost the ability to learn new things (as in Memento)... Now we know.
The pancreas was once though to serve simply as a support structure for the more obvious organs...
Beware the tendency of the very litterate to dismiss that which they do not understand, it's simple hubris.

My not-supported-by-resasearch-of-any-kind take on "junk" DNA?
I think it's stored evolution.
DNA that isn't expressed, but stored in a way that it can mutate for generations and generations before being randomly reactivated, cueing natural selection. That would result in a simple mutation (only the reactivation of a chunk of stored DNA) with not-so-simple results from generations of stored changes.

Re:"junk" DNA

[timster]

Yes, and 25 years from now we will all rue the day when surgeons thought they could extract the Zombification Prevention Organ with impunity, as if it were a mere "appendix".

Re:"junk" DNA

[DarthStrydre]

In soviet Russia, your children can be breast fed by you.

However odd it may be, human males have the ability to breastfeed, though since pregnancy is impossible, most people do not realize it. Granted, I am not sure the feasability or usefulness, but it is physiologically possible in certain cases.

http://en.wikipedia.org/wiki/Male_lactation for a start to your research, and the end of mine.

Re:"junk" DNA

[ultramk]

The argument you're making isn't a new one, but the main piece of evidence against it is pretty compelling. "Genetic drift" is a phenomena where over time, random mutations add up to change areas of DNA. The thing is, if the DNA in an area is used for something that is important to keep the organism alive (or gives some sort of reproductive advantage), it can't take too many changes or the organism will die (or not be able to reproduce, very much the same thing from an evolutionary standpoint). So you get some areas where there are lots of changes, and areas where there are essentially no changes.

Picture it this way, you have a fleet of 500 Geo Metros starting out in Kuwait City, with direction to drive north to Turkey through Iraq. The whole time, guys with AK47's are taking pot shots at them (random mutations). For the ones who get all the way to Turkey, you'll find that none of them have sustained major damage to their engines/coolant systems/drivetrain/tires (because if they had, they wouldn't have made it this far). This is one way of identifying what's important to the functioning of the organism. You can drive without windows or an air conditioner, but without a transmission you're screwed.

Beware the tendency of the uneducated to assume that people who devote their lives to a subject haven't considered the most basic of possibilities. It's simple hubris.

m-

Size Matters?

[DavidV]

A friend once got told size doesn't matter, it's what you do with your DNA. Yeah..it was a friend...nothing to do with me. I'm lucky if I don't trip over my DNA.

Re:27000 "letters" long?

[yourOneManArmy]

Are they creating a string, or DNA?

Strings... of DNA, obviously.

DNA myDNA = new DNA(new String(char(DNA.ADENINE) + char(DNA.CYTOSINE) ...

Biggest Ball of Twine...

[Anonymous Coward]

You know, I bet if we unravelled that sucker,
It'd roll all the way down to Fargo, North Dakota
'Cause it's the biggest DNA in Minnesota
I'm talkin' 'bout the biggest DNA in Minnesota

- with apologies to Weird Al Yankovic, Biggest Ball of Twine in Minnesota

exons/introns

[smellsofbikes]

>Scientists once thought of that stuff as junk, but many now believe it may regulate how the genes work or provide some other function.

To clarify: a stretch of DNA that actually gets turned into RNA and thence into proteins is an exon, and the DNA that lives between exons is called an intron. It's been known for a long time that there are sequences before an exon that control it: regulators, promotors, and repressors, that are activated or deactivated by proteins binding to them during DNA reading, and in some cases there are sections of DNA that are processed into RNA, that help stabilize the RNA and are then clipped out before the RNA becomes protein, so they also have a function. (This is part of the reason that making insulin artificially has been tricky: you can't just stick the DNA into a bacterium and have it crank out insulin because the DNA is in a couple sections and requires post-processing.)

Also, many of the introns contain echoes of old sequences that used to be useful way back when, and aren't anymore, or bits of viruses that integrated into the genome hundreds or thousands of generations ago and are now widely spread in the population, and some intron bits are designed to facilitate shuffling of chunks of DNA into different orders for proteins that come in a wide variety of flavors with the same start and end sequences. Antibodies, for instance, have long, consistent, identical start and end chunks with wildly variable center chunks. (Think of a key, with differing teeth to fit various locks, but the same end piece, to fit your hand. Likewise an antibody has a hypervariable section that, for each antibody, can adhere to precisely one antigen, and a nonvariable section that signals passing cells that it has/hasn't found any of that antigen.)

Getting to go play around and make any set of repressor/promoter sequences and change the distances between them is a really nice tool, and being able to make massive sequences like this, helps play with gene interactions and with massive proteins like antibodies. Think of this as the beginnings of the transition from transistors to integrated chips, or maybe it'd be more apt to say from single computers to the beginnings of networks.

Re:The longest piece of DNA was made by God.

[studpuppy]

hmmm... the temptation to respond "I knew God, sir. I was friends with God. And let me tell you, sir... you are no God" is pretty darn high at this moment.

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All references to God, a deity or higher power, or any aspect of the so-called theory of evolution are not meant as an endorsement or denial of any particular religious belief, save Scientology. After all, I read L. Ron's other books and I didn't believe any of them either...