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DNA, Fifty Years To the Day
An anonymous reader writes "Today being the fiftieth anniversary (April 2, 1953) of the Watson-Crick double-helical, DNA discovery [to quote, 'We wish to put forward a radically different structure...'], there is an interesting tally of completed gene sequences here, and ones still being worked, including the Ames strain of the anthrax bacteria. It also appears that the only lifeforms not using DNA for code storage are a few viruses like the common cold."
Also today a new base pair was found. In addition to TA,AT,GC,CG the EV pair was found.
Scientists are calling this the EVIL PAIR. Finding this in DNA insures that the organism is PURE EVIL.
The first 500 people to request one, will recieve their very own four-assed monkey.
...will it be another fifty years before I can grow a custom pet?
My real spider monkey can't wait that long to meet the world. Oooo AH AH AHHH!!!!
Seriously, happy 50th, DNA!
Compared to war, all other forms of human endeavor shrink to insignificance. God, how I love it. - Gen. George Patton
Let's not forget Rosalind Franklin - the woman who actually took the X-ray photographs of the DNA molecule. Without her, Watson and Crick would not have been able to discern the DNA structure!
have eliminated the troll-genes back then, before it became too late...
Click here for video of the anniversary of the discovery of the structure of DNA. This was taped at Cold Springs Harbor Lab, where Watson is currently the director. Also, you can find their original paper that was published in Nature annoucing the discovery. It's interesting to note that since their discovery of DNA's double-helical structure, neither Watson nor Crick have discovered or published anything significant since then.
In honor of the birthday I'm going to make a a cellular peptide cake with mint frosting ;-)
If you've not read it, The Double Helix is a great book that discusses the discovery from Watson's perspective. He covers his, Franklin's, Crick's, and Linus Paulings's involvement in a very interesting story. It's a short book, and well worth your time.
Watson rips on Franlin pretty hard in the book, but mainly because of personality conflicts. He acknowledges in the end that without her contributions, they wouldn't have achieved the same success.
...they only described it's structure. The discovery of DNA goes back to at least 1929, possibly earlier (depending on which discovery you're looking for.)
1865 - Gregor Mendel shows that heredity is passed in discreet units
1900 - Three scientists independently verify Mendel's work, and formulate the laws of heredity
1909 - Willhelm Johannsen coins the term gene
1911 - Thomas Hunt Morgan shows that chromosomes contain genes
1929 - Phoebus Levin discovers that genes are made up of nucleotides (i.e., genes are made up of DNA)
1943 - William Astbury obtains first X-ray diffraction pictures of DNA
1951 - Rosalind Franklin's X-ray diffraction images show DNA has two different forms, and that it takes the form of a helix
1953 - Watson and Crick formulate their model
Here's a brief NPR review of a recent biography of Rosalind Franklin and a more extensive review in Scientific American which details the theft of data by Watson/Crick/Wilkins.
foldplay your photos won't know what hit them.
Watson and Crick wouldn't have accomplished much without Chargoff's data either. Chargoff recognized that A and T and G and C were in rougly a 1:1 ratio (# purines = # pyrimidines). Watson and Crick would've been screwed without alot of outside help. For example, they couldn't figure out why their model wasn't coming together. A chemist happened to be walking by one day and pointed out that oxygen is found in the keto, rather than enol form and nitrogen was found in the amino rather than the imino form (in living systems). Crick was a physicist and Watson was more of a general biologist.
Oh, I don't know about that. Watson and crick came up with some realizations that were pretty important, even if you NEVER actually saw the molecule.
One of the realizations that they made was that there had to be a minimum of three identification units to code for each amino acid, and that more than three would be wasted. Now that sounds pretty simple, doesn't it? But even if you get to see the molecule, if you don't understand that you need to look at three sequential base pairs (a codon) together, and that you hence need to have the alignment right, then actually seeing the structure of the molecule doesn't get you very far.
For the curious, the reason that they needed a minimum of three base pairs was this:
You have four different ways to get a single base pair. If a single base pair were the functional unit, you could code for a total of four different amino acids. Way too low. With two sequential base pairs, you could code for sixteen. Still too low. If you use three sequential base pairs, you could code for up to 64 distinct amino acids, which more than covers the number of aminos that humans were known to be capable of producing.
steve
Oh, you're not stuck, you're just unable to let go of the onion rings.
Here's a lot more of the story of her work:
Book Talk on "The Dark Lady of DNA..."
[Broadcast on Saturday 29 March 2003]
Listen via Audio on Demand from:
www.abc.net.au/rn/arts/booktalk/audio/booktalk_29
Brenda Maddox on why the young English biophysicist Rosalind Franklin was never to know how vital her own work was to Francis Crick and James Watson's discovery of 'the secret of life.'
The biographer of D.H. Lawrence, W.B. Yeats and Nora Barnacle, James Joyce's wife, Brenda Maddox talks about her life of Rosalind Franklin at the Cheltenham Festival of Literature.
See also:
"The Dark Lady Of DNA"
Author: Brenda Maddox/Rosalind Franklin
Publisher: Harpercollins
If you are interested in learning about the abusive mistreatment of women researchers look no further than The Double Helix.
foldplay your photos won't know what hit them.
This story was also covered in this month's Smithsonian magazine and was a decent read.
Now if they could only create a DNA custom engineered beowulf cluster of atomic supermen...
-1 Overrated (Too many big words for me to comprehend)
Viruses are 'particles' that cannot replicate on their own. They contain genetic material, in the form of either DNA or RNA and this genetic material encodes for proteins important for the life cycle of the virus. When a virus infects a cell, it takes over the host cell machinary to manufacture more viruses. Very few viruses are naked strands of genetic material (DNA or RNA), often they are housed in cages of protein and may or may not have membranes (which they will have stolen from the host cell as they bud out of various host cell membranes).
Except that the link posted in the post is for microbial genomes only. There are a lot of other genomes that have sequenced. NCBI is better place to look for this info.
m e
Here is the *definitive* page for completed genomes:
http://www.ncbi.nih.gov/entrez/query.fcgi?db=Geno
Mad Software: Rantings on Developing So
One could construct a two-tape turing machine that simulates the four combinations; if you're interested in mixing computer science with DNA, check out this paper.
Influenza, measles, mumps and polio are all RNA based viruses.
DNA viruses include herpes and hepatitis. I think HIV is a DNA type but I don't recall offhand.
--- Ban humanity.
DNA is credited to the inception of genetic algorithms. The main idea behind genetic algorithms is the emulatation of natural selection and evolution by means of DNA manipulation. This is accomplished by many DNA manipulation techniques; the two most prominent are crossover, where two different chromosomes swap DNA information, and genetic mutation, where a random [DNA] bit is rotated. If you're interested in genetic algorithms, check out this introduction.
/joeyo
2^5
I was thinking about this very subject the other day.
It seems strange to me that while, in principle, the discovery of the structure of DNA was a wonderful thing, it doesn't seem to have affected the average person's life very much. Far less, it seems, then Dr. Fleming's noticing that bread mold contamination was killing his bacterial cultures.
Perhaps I'm missing something, and understanding the structure of DNA is contributing more than I think. But, it occurs to me that if we could put a man on the moon in about 10 years, we ought to be able to do something more with DNA in 50 years.
I suspect that science has become too bureaucratized and institutionalized to know which end is up anymore.
Sigh.
1. Find obvious article to whore in.
2. Skim the summary.
3. Reply and title your post "In other news..."
4. Take premise of article and twist it into something obviously absurd. Make sure it is not clever, original, or funny in any way.
5. Wait for dull, crackhead moderators with itchy mouse fingers to click it up into the various realms of Funny That Is Not.
I will either be modded down, someone will post another "step" to my list that references responses like mine, or some Anonymous Coward will copy my style as they usually do.
"Sufferin' succotash."
Hmmm ... you might be interested in reading what Brenda Maddox has to say about that in her biography of Rosalind Franklin, "Rosalind Franklin: the Dark Lady of DNA". I'm sorry, but Watson's portrayal of her was at best stupid and insensitive and at worst a cruel deliberate character assasination of someone who was not only dead and could not reply, but had also been a good friend of his in the years following the discovery of DNA's structure.
Maddox's only explanation is that Watson's remarks about Franklin were - whether conciously or unconciously - an attempt to justify the stealing of her results: by portraying her as someone who jealously guarded her data and yet could not interpret it (and nothing could be further from the truth), he thus implied that he was doing science a credit by obtaining her data and making use of it - even if he had to resort to doing it behind her back.
And if you still want to defend The Double Helix, I could also add that the book was refused publication by Watson's University (which was the first publisher he took it to) after a large number of complaints from the other scientists mentioned in it that it was grossly defamatory - not only of Rosalind Franklin but also of almost every other person who featured in the book short of Watson himself!
Pauling did publish a proposed structure for DNA a few weeks before W&C's paper (in fact, it was his publication that drove them to have another shot at model building) - but Pauling's model was attrocious. Like W&C's first attempt, it was a triple helix with the phosphates on the inside, not on the outside (a fact which, incidentally, was demonstrated by Franklin a year before).
But, W&C or Pauling would have certainly figured it out much faster if they had access to her information.
I don't know what you're talking about here - W&C did have access to her data, without her knowledge or permission - and it was the only way they could propose a model. To put it simply, her oft-reprinted photo was the supreme evidence that the B-form of DNA was a helix.
And Rosalind Franklin (and Ray Gosling, her PhD student) were very, very close to solving the structure, not only of the B-form of DNA but also of the dehydrated A-form of the molecule. They had recognised that both forms were a double helix and had come close to recognising the significance of the the Chargraff ratios of base-pairs at the time of W&C's publication. Their only "failing" was that they wanted to make sure that any model they proposed was in fact the correct one by having X-ray crystallographic data to support it. W&C never cared about any of that, and never bothered to check whether their model was accurate. That's why they "figured it out faster"!
Living and non-living are categories imposed by humans and not by a natural law. Categories like this are useful insofar as they provide insight into natural phenomena, but you should avoid taking them so seriously that you descend into theological hair-splitting. Some biologists count viruses as life becaus they can reproduce, other biologists count them as non-life because they don't have a metabolism. It is worthwhile keeping in mind the differences between a virus and say a bacteria, but don't get hung up on the label attached to them. That is largely a matter of fashion.
That is true, the scientific field does not know at the moment where to classify viruses, as living or non-living, it is actually a very heated debate. The problem is, yes, they can reproduce, but they do so in a way that is very unique, and not truly reproduction. Instead of going through mitosis or sexual reproduction, they viruses DNA reproduces within the host cell, using the pieces of the host cell to create the rest of its body and such. Very interesting stuff, and a fun debate with your science teacher! Bring it up in class next time.
I thought viruses used to be considered non-living since they could not reproduce on their own... They hae to use their host's cellular machinary to reproduce.
But perhaps the thinking on this has changed...
RNA has been demonstrated to have enzyme-like properties in many cases, in some cases even being able to cleave itself if spliced properly. There are more than a few organisms storing information on means other than DNA though few do so exclusively. And for those who doubt, Ms. Franklin's work was most certainly pirated by Crick, Watson, and wilkins. Had this same situation occured today, Ms. Franklin could easily have defeated them in court for theft of intellectual property. Crick was a 10th year PhD student whose previous explorations into whale hemoglobin hadn't led to as much as hoped while Watson was a Harvard postdoc looking for his first breakthrough. At least Wilkins already had a working laboratory, but this does not excuse their actions. Without Franklin's picture, it would have been months or years before the structure would be correctly elucidated (remember, people like Linus Pauling were trying models at that time which included 3-part helices with nucleotides sticking away from the phosphate bonds, etc.)
As long as there is a Second Amendment, there will always be a First Amendment.
And who knows, maybe he is a bit more informed about DNA than the originating poster. While a lot of viruses and retroviruses have RNA making up their genome, a lot do in fact have single or double-stranded DNA.