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Genetic Engineering


 
written by Chris Schubert on April 18, 2003 | forum profile | contact me
number of views: 76728 |   printable version (text) (PDF)



Nuclear DNA
Nuclear DNA
Credit: Unknown
It is clear that to terraform we will need the help of different forms of lichen and bacteria, but here at Redcolony.com it has never been clearly set which organisms should be present to help terraforming. When trying to decide we must look at the organism’s traits, and make sure it has the attributes that are needed to survive in the harsh Martian Climate. Some may be more equipped then others, that is where the role of Genetic Engineering comes into play. Using different techniques we can manipulate an organisms DNA to have the traits of another, by doing this several times to the same host, we can create what seems to be a “super-organism.”

BACTERIA:

There are many different species of bacteria, some good some bad, but there are only a few of them have the traits that we are looking for to help us terraform. First we must make sure that the new “super-bacteria” has the ability to survive on Mars. Mars itself is cold, dry, windy, and radiation pours through the thin atmosphere, we must make sure that the bacteria that we release can stand against all of these things.

Lets look at some different types of bacteria:

Chroococcidiopsis caldariorum - This bacteria is the most desiccation-resistant cyanobacterium and is the sole photosynthetic organism in very arid climates. It has been found in Indonesia hot springs, marine and hypersaline areas, nitrate caves, and extreme arid deserts worldwide. Its traits can be used on Mars because of its desiccation-resistance (resistant against dryness), and its tolerance to high salinities. Also in some cases fast growing strains have been discovered. It is also partially the main reason of changing Earth’s anoxic (Lack of oxygen) atmosphere into an oxygen rich one. The same could be done on Mars.

Deinococcus radiodurans - This bacteria is resistant to very high levels of UV radiation. It has very high DNA repair mechanisms. If a culture was exposed to 1.5 Mrad of radiation it would display a reduction in size of genomic DNA fragments corresponding to approximately 100 double stranded breaks, but typically, most prokaryotic and eukaryotic organisms cannot tolerate more than 5 double stranded breaks per genome without reduced survival. Remarkably within 8 to 10 hours the D. radioduran’s genetic fragment lengths are the same size as fragment lengths in untreated cells. This means that within this time interval the bacteria had restored itself back to normal with little or no reduction in survival of the cells. This trait can be used on Mars to protect our new “super-bacteria” from harsh cosmic radiation.

T. ferooxidan - This bacteria can be found in mines. It survives by using the energy it receives when it oxidizes iron. We can use this trait in two different ways. This trait we will use to create a genetic on/off switch , which I will explain later, and the other is to use it for a chemosynthetic organism.

HOST:

Now that we have identified the bacteria with the traits that we need it is time to choose a host organism. There are several ways of choosing a host, most of which depend on the form of Genetic Engineering we will be using. In my opinion the most efficient ways are Electroporation, and the Plasmid-Vector Transfer method.

Electroporation - This is the easiest and most efficient way to Genetically Engineer in my opinion, mainly because this technique can be used on most organisms. Because of this we can use any one of our choice organisms as a host. So the choice needs to be carefully decided, because we want the most equipped organism to be the host, and this would have to be the Chroococcidiopsis caldariorum since it is photosynthetic. A new idea has occurred to me that instead of combining all of the traits into one, we can make many different versions of our super-bacteria, each having a different application, a different purpose.

Plasmid-Vector Transfer method - A host cell for a genetically engineered bacterium using the Plasmid-Vector transfer method must be easy to handle and propagate, should be available as a wide variety of genetically defined strains, and should accept a wide range of vectors. (A DNA molecule that is capable of replication in a host organism, and can act as a carrier molecule for construction of recombinant DNA.) The bacterium that fits all of these requirements is Escherichia coli or better known as just E. coli. It is a very simple organism and is used most often for genetic engineering.

GENETIC ENGINEERING PROCESS:

After the long hard process of using restriction enzymes and DNA lisage, we can separate the specific genes from the organisms depicting the traits we want to include in the super organism, here are the processes for Electroporation and the Plasmid-Vector transfer methods.

Electroporation - This process is fairly simple, even more so then to its counter-part Chemoporation. To genetically engineer a bacteria using Electroporation, we need to introduce the cell to a weak electric current. First we suspend say the Chroococcidiopsis caldariorum cell in a solution of the DNA fragments making up the gene we want to implement into it, say in this instance the very efficient and very fast DNA repair and resistance to radiation trait of the D. Radioduran. When the weak electric current is introduced to the cell and the solution it is in, it make tiny pores in the cell wall, allowing the genes to flow into the cell and implement themselves into the hosts genes. So the Chroococcidiopsis caldariorum now has the radiation resistance of the D. Radioduran. We repeat this process with this new Chroococcidiopsis caldariorum and add all the traits of the different organisms.

Plasmid-Vector Transfer - This process is a little more complicated. Because the Chroococcidiopsis caldariorum doesn’t have any suitable plasmid vectors it can not be used as a host as in the Electroporation. So we will use the previously discussed E. Coli. It has many different plasmid vectors that we can choose to use, the best is any member of the pUC family. This plasmid as an area where the DNA fragments of the gene we want can be inserted and make recombinant DNA production much faster. These vectors are then accepted into the cell and the cell nuclease where they implement themselves among the hosts DNA. We do this for several times to get all of the traits we need into the E. Coli.

Now whether by Electroporation or the Plasmid-Vector Transfer methods, we have our super bacteria with the traits of all of the different bacterium.

THE SUPER-BACTERIUM AND THEIR APPLICATIONS:

I planned to have different versions of the super-bacteria, so that it can have many different applications. If we were to overload one bacteria with all of the genes, then one bacteria’s trait could interfere with another’s. Here are a list of the different applications for the super-bacterium and what traits they will have.

Basic Bacteria - These versions do not do any complicated processes.

Oxygen - Uses the D. radioduran’s trait to protect itself from radiation. Uses the photosynthetic properties of C. caldariorum, and also its high salinity resistance.

This version of the super-bacteria is a simple photosynthetic one. It will help lichen (Coming Soon) change the CO2 into O2.

The Genetic on/off Switch - There have been studies advocated by NASA that show that cells actually have skeletons hereafter called cytoskeletons. Now, through one experiment the attached very very small metallic beads to things called integrins, when they introduced a magnetic field to the cell the beads pulled the integrins to align with the field. As they did the integrins in turn pulled on the cytoskeleton pulling in different directions. Now as this happens, as the cytoskeleton becomes taught, certain genetic operations take place. Does anyone see where I am going with this?

This discovery has a huge impact on Genetic Terraforming. This can be taken advantage of, if we “program” our bacteria to perform a certain Terraforming operation if the cytoskeleton is taught, then this opens the door for a Genetic on/off switch.

We use the gene or a form of the gene form T. ferrooxidan, to oxidize iron from the regolith, now as this happened our bacteria will secrete an enzyme that bonds it with the iron. Soon a lot of iron will build up on the cell. Now at that point we introduce to our bacteria, a magnetic field. This will pull on the iron, pulling on the integrins, which in turn pull the cytoskeleton taught; this starts the genetic operation that is some Terraforming technique such as producing a certain gas for example.

So, let us take also for example that we have enough of the gas that is being made by the bacteria. To stop the production all we simply do is flip the switch to the magnetic field, the cytoskeleton relaxes and the genetic operation stops. Terraforming at the flick of a switch.

This bacteria would of course have the radiation resistance of D. Radioduran and the high salinity and drought resistance of Chroococcidiopsis.

LICHEN - Coming soon…

Works Cited:

1) http://www.ictp.trieste.it/~chelaf/ss10.html
2) http://deinococcus.allbio.org/
3) http://thiobacillus.allbio.org/
4) http://www.nasa.gov/vision/earth/livingthings/19jun_cytoskeletons.html
5) Introduction to Genetic Engineering-Desmond S.T. Nicholl

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