Thoughts on Craig Venter’s Synthetic Cell

On May 10 ScienceExpress published on-line Craig Venter’s Creation of a Bacterial Cell Controlled by a Chemically Synthesized Genome. A talk by Venter given last year at TED.com is a good introduction to the work.

Venter’s achievement is remarkable and embodies two critical accomplishments–first, the use of a chemically (vs. biologically) synthesized chromosome. Venter’s chromosome had never seen a cell prior to its “booting up” in the new host. Of course, the sequence was based on a known bacterial chromosome, but contained modified genes to distinguish it from the host cell and with “watermarks” (more on that later).

The second accomplishment is that the synthesized chromosome was inserted into a host cell (with different DNA from a different species). The system was engineered so that the original host cell DNA would be destroyed and that the new chemically synthesized chromosome would be preserved. This happened and the cell was transformed to function according to the new “program”, the new synthesized chromosome.

This is a remarkable achievement and paves the way to all sorts of future experiments. In principle, however, this is merely a large-scale and chromosome level version of already existing recombinant DNA technology. Venter calls this a “synthetic cell” and at this point I consider this to be mostly hype. Future experiments may result in something that could be called a “synthetic cell”, but for now this is an already existing cell transformed by a chromosome replacement. Thus, the ethical implications of this seem minimal to me.

The ScienceExpress paper notes:

Phenotypic effects of the recipient cytoplasm are diluted with protein turnover and as cells carrying only the transplanted genome replicate. Following transplantation and replication on a plate to form a colony (>30 divisions or >109 fold dilution), progeny will not contain any protein molecules that were present in the original recipient cell. This was previously demonstrated when we first described genome transplantation. The properties of the cells controlled by the assembled genome are expected to be the same as if the whole cell had been produced synthetically (the DNA software builds its own hardware).

Thus within 30 generations, the proteins of the bacterium have been completely determined by the new chromosome. Presumably this would eventually be true of cellular components synthesized by these proteins.

Starting off with a living bacterial cell (even if the DNA has been destroyed) limits the claim of “synthetic cell.” Again, I’m not in the least trying to minimize Venter’s accomplishment, but he started with a living system and synthesized a chromosome that used the same genetic code as the starting living system. I will wait for “booting” the DNA without a starting living system before I apply the moniker “synthetic cell.” That seems a bit more difficult. Since the entire chromosome is synthesized, why not alter the genetic code, i.e. change the aminoacyl-tRNA synthetases so that there is a completely novel relationship between the DNA and amino acid sequences. At first glance this would require booting from scratch, without the presence of the pre-existing living cell, but accomplishing this would be a convincing proof of concept.

Questions have arisen about such experiments in eukaryotes. Could we regenerate a Neanderthal, or a woolly mammoth, or a Tasmanian wolf (organisms for which the code exists “digitally”)? Epigenetic factors in the fertilized egg into which the synthesized chromosome was “booted” would influence development at first. (Think about the chimp with human DNA in Michael Crichton’s Next). But, if it is true that the original epigenetic factors are diluted after a number of generations as in the bacterial case, then perhaps we would end up with something very close to the organism originally coded for by the synthesized DNA. No control exists, however, so we will never know if we have the real Neanderthal or just something very close.

In the TED video Venter comments on the success of this project as showing that via genome acquisition and incorporation, fast and large-scale evolution is demonstrated. Indeed, Mycoplasma capricolum evolved into Mycoplasma mycoides in one generation (or at most 30 generations).

Venter’s watermark is fascinating, and I think somewhat relevant to the intelligent design debate. Venter’s synthetic chromosome spells out the following “words” in some sections of the coded proteins using the one-letter codes of the amino acids coded for by the synthesized gene:

VENTERINSTITVTE
CRAIGVENTER
HAMSMITH
CINDIANDCLYDE
GLASSANDCLYDE

Without overly simplifying the ID argument, it has often struck me that if God wanted to give us a definitive proof of His hand in Creation he could have done such a thing by writing out a message in English (or whatever language you like) using the one letter amino acid codes. (Think about Sagan’s Contact and the message encoded in the digits of pi.) How does the ID argument fare even here? Are these “watermarks,” which we know are intelligently designed, detectable?

7 comments to Thoughts on Craig Venter’s Synthetic Cell

  • Douglas Hayworth

    Hey Terry,
    Thanks for the quick summary and commentary. I haven’t had the chance to read any of these news stories yet, so I was wondering what “synthetic cell” really meant. As you say, it’s a noteworthy accomplishment, but it’s hardly the same as constructing an entire set and arrangement of genes from scratch and inserting them into a synthetic, membrane-bound structure made of something truly novel.
    Doug

  • Wayne Dawson

    Terry,

    Thank you for posting this.  I also had the feeling that this claim of “creating life”, which appeared throughout the main media outlets, was largely hype.  It is obviously a milestone in engineering in that we can build sequences of that level of length, accuracy and sophistication.  However, in the creativity department, it is largely about as original as copying all the letters out of a book, rearranging the order of a few inconsequential sections, borrowing some a historical context section from another book, and adding a few original letters at the end, and then calling it an original composition.   It does take real skill to know what not to do in complex systems like that, and it takes genuine skill to build all the necessary modules.  All that that should be clear, but it was largely overdone to call it “creating life” with all the pictures of God and Adam. 

    On the other hand, it is the first time that we (humans) have generated the material itself without the aid of plasmids and, therefore, it does mean that we would be able to design bacteria to synthsize far more complex and important pharmaceuticals.  Of course, even with this rudimentary knowledge of how to build simple cells from scratch, we have the potential to do lots of evil as well as good not so far down the road either.  

    On your last point:
    “…..[I]t has often struck me that if God wanted to give us a definitive proof of His hand in Creation he could have done such a thing by writing out a message in English (or whatever language you like) using the one letter amino acid codes. (Think about Sagan’s Contact and the message encoded in the digits of pi.) How does the ID argument fare even here? Are these “watermarks,” which we know are intelligently designed, detectable?”

    Us humans like to put our stamp on things.  Even this comment from me has my name on it.  I would guess that I would be offended if someone just copied everything here, rearranged it slightly and reposted it without giving credit.  We seem to want other people to know that  this is my accomplishment, or this is my work, or this is my invention, etc.  Yet there is no one like God, so God does not appear to be interested in asserting his petty authority over the creation (like we humans would).   No matter how we act, without God, we are just trying to grasp at a little eternity with our own frail hands, no matter how apparently humble we try to make our little dramas here in this life. 

    ID is maybe arguing that the engineering complexity of the cell makes it evidence of God.  If it were truly impossible to build a cell and the means unknowable, this might perhaps serve as a valid argument.  In this way, the hype on the “Venture” project is clear.  We are getting there by our own power and our own strength (but still depending on God’s imponderable grace all the way to get there in our civilization, though that, of course, many will  carefully  neglect to mention).   It’s more like this affirms the very sense of the meaning in the story of the Tower of Babyl.   Little by little, we will know many of these things.  Will we also take the responsibility that comes with this knowledge? 

    It has always been faith.

    By Grace we proceed,
    Wayne

  • I’m not sure I would call the accomplishment noteworthy, and would echo some of the remarks in the NY Times article (link below). The transplantation of a genome had already been accomplished, and the only difference here (as near as I can tell) is that the genome in this case was synthesized by human-made machines and not by evolution-made machines. :-)

    But seriously, I think that when Venter says that “this is a philosophical advance as much as a technical advance,” he’s admitting that all he’s done is put some nails into the coffin of vitalism. (Hence the subsequent comment about raising “new questions about the nature of life.”)

    Link: http://www.nytimes.com/2010/05/21/science/21cell.html

    Steve
     

  • Terry M. Gray

    Steve, while I’m no vitalist, I don’t see how Venter’s experiment puts a few more nails in the coffin of vitalism. It seems to me that because he has transformed an already living cell, a vitalist could point to the continuity of the living cell as being key. Do you see it otherwise.

  • Bernie Dehler

    The power of the experiment is this.  As Venter himself once said, we have learned to read DNA, and now we are learning to write.  This is a very exciting step in the advancement/maturity of the human race.

    …Bernie
    (Friend of the ASA)

  • Alexander Coleman

    I work in a Christian High School.  I saw this article published and decided to use it in my semester final exam for Biology class.  I had them read a one page news brief, and then answer questions over it.

    One of the questions I asked them was whether this research was good or bad, and how it might affect us as Christians.  One of my students surprised me with an excellent answer:

    Its good to understand how life works, how it functions, and what causes something to be alive.  We can even create man-made cells that function like normal cells.  But our God did something way beyond that:  Our God created something out of nothing.

  • Bernie Dehler

    RE:
    “Its good to understand how life works, how it functions, and what causes something to be alive.  We can even create man-made cells that function like normal cells.  But our God did something way beyond that:  Our God created something out of nothing.”

    What was that “something made from nothing”… Adam and Eve, or the Big Bang?  If Adam and Eve, then many might say you didn’t teach them correctly about evolution (man from animal).

    Bernie
    (Friend of the ASA)

 

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