Looking for DNA beyond Earth. . . Mars?


Looking for DNA within the solar system will, at first, be performed robotically. Thus our intrepid explorers who wish to analyze samples of Mars, Europa, or even Enceladus, must come up with ways to assure that the samples do not decompose (or degrade because of radiation). The traditional means for teasing out DNA samples is based upon Sanger methodology. The method has been a mainstay of molecular biology for the last 35 years. It is now in a “third generation” of development; the use of semiconductor technology has automated its use to the point of using a small initial sample and non-spectral means of analysis. The following piece is drawn from current suggestions that a 2-year mission to Mars may make use of “third generation” Sanger technology to search for DNA under the Martian surface. See endnote **

TECHNOLOGICAL BREAKTHROUGH IN BIOMOLECULAR SCIENCES—DNA (nucleotides) & Proteins (amino acids) Sequence

First generation Sanger technology aimed to determine the sequence of nucleotides in a DNA sample—Dr. Fred Sanger received his 2nd Nobel in Chemistry for the development of the technique. And, his 1st Nobel in Chemistry was given to him for his determination of the amino acid sequence of insulin. Although one may argue that determining the order in which individual molecules occur in a large macro-molecule (e.g. insulin or a DNA sample) may be similar to lopping offing individual units from a long chain. If one were to read his public lectures for each prize, one senses a great deal of reverence and humility. It is a sense of being in the presence of “holiness.” I am not referring to the man but the process of understanding intimate machinery of life, itself. The advancement that the technology gave to mankind is in many ways like walking on the moon for the first time. The direction of humanity was forever changed.

If one looks at each individual technique, each may be viewed from the perspective of an analytical genius. It is in many ways like the invention of the wheel—without which many more inventions could not have come.

(I will leave the analytical details in the Nobel speeches to the intrepid souls who absolutely love chemistry:

http://www.nobelprize.org/nobel_prizes/chemistry/laureates/1958/sanger-lecture.pdf

http://www.nobelprize.org/nobel_prizes/chemistry/laureates/1980/sanger-lecture.pdf )

WHERE DO WE LOOK FOR MARTIAN DNA SAMPLES?

Mars, from all appearances, has a barren surface with a hint of flowing land shapes. Under the surface of Mars is where the answers may lie. The question that all of us need (and want) to know is, how deep do we “drill” into the Martian surface? The standing answer seems to be about 6 to 9 feet or 2 to 3 meters. That is the estimate given by Dr. Chris McKay at NASA Ames. Drilling technology can be readily developed by the engineers at JPL—their template is Antarctica. The surfaces are similar enough by the most conservative estimates.

In a recent Q & A session by Dr. McKay at S.A.G.A.Net.org (the Blue Marble Institute), he reasons that portions of the Martian surface seem to be “dotted” by clay-like patches. It is at those patches (where water also seems to have flowed) that a lot of curiosity is currently directed.

URL Link to Blue Marble Institute Youtube vid:

http://www.youtube.com/watch?feature=player_detailpage&v=F5DSpkLwEo4&list=PLE3A89xLsMeRLr9s5nTjJapXC2-LKBIqL

WHAT IS THE CURRENT TECHNOLOGY OF WHICH I PREVIOULSY MENTIONED? IN A NUTSHELL . . . .

The major drawback in the lab use of Sanger technology is its tediousness—the macromolecules of proteins and DNA are exceedingly complex. The second generation breakthrough of Sanger technology is automation—while the third generation is the miniaturization that semi-conductors can afford. Thus what may have taken a lab tech a large laboratory—could be performed on a rover equipped a drill and “lab-on-a-semiconductor-chip.”

By illustration-à

Source URL: http://web2.clarkson.edu/projects/nanobird/2.4.php

REFERENCES:

Blazej, R. G., Kumaresan, P., & Mathies, R. a. (2006). Microfabricated bioprocessor for integrated nanoliter-scale Sanger DNA sequencing. Proceedings of the National Academy of Sciences of the United States of America, 103(19), 7240–5. doi:10.1073/pnas.0602476103

**Carr, C. E., Rowedder, H., Lui, C. S., Zlatkovsky, I., Papalias, C. W., Bolander, J., Myers, J. W., et al. (2013). Radiation Resistance of Sequencing Chips for in situ Life Detection. Astrobiology, 13(6), 560–569. doi:10.1089/ast.2012.0923

Lecture, Nobel. (1958). The chemistry of insulin. Fredrick Sanger

Metzker, M. L. (2005). Emerging technologies in DNA sequencing. Genome research, 15(12), 1767–76. doi:10.1101/gr.3770505

Rothberg, J. M., Hinz, W., Rearick, T. M., Schultz, J., Mileski, W., Davey, M., Leamon, J. H., et al. (2011). An integrated semiconductor device enabling non-optical genome sequencing. Nature, 475(7356), 348–52. doi:10.1038/nature10242

Sanger, F. (1980). Determination of nucleotide sequences in DNA. Bioscience reports, 24(4-5), 237–53. doi:10.1007/s10540-005-2733-8

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4 thoughts on “Looking for DNA beyond Earth. . . Mars?

  1. Baldscientist

    Isn’t this absolutely exciting? I believe that if there is life in our solar system it will most likely be related to us. If that is true, it should be possible to detect DNA and like molecules. That said, the excitement would be amplified if we find detectable DNA, but with a twist, like a different nucleotide base or sugar, etc. These are interesting times indeed….

    Reply
  2. Torbjörn Larsson, OM

    My concern is that known potential pathways for abiogenesis are competitive with estimates of transpermia rates AFAIK, even in the special case of a sterilizing Earth-Moon impactor. And if other life is indigenous, it is most likely RNA based at the root as our cells were. I’m not at all confident all biospheres would evolve some stabler genetic material or that RNA metabolism would evolve to DNA specifically (but I’m no chemist, just astrobiology interested).

    I would rather see an enzymatic or antibody chip detecting minute traces of RNA, DNA and other molecular relatives. If they go the Sanger route, they should at least include an optional reverse transcriptase pre-step.

    Reply
  3. Torbjörn Larsson, OM

    Strike “stabler”, I meant a material that has less copy errors and is easier to repair. So yes, such a material would evolve at the time cells diversified to take on boundary environments as archaea (low energy specialists) did. Then keeping traits stable, protected from the great lateral gene transfer melting pot of large scale selective sweeps and with low enough copy and repair error, would be necessary.

    Remains to see if all such pathways would evolve DNA specifically.

    Reply

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