[Genecks]

Through various gene knock-in and knock-outs, could a microorganism, such as Eschericia coli, turn into another microorganism, such as Staphylococcus aureus?

This post has been edited by Genecks: 14 January 2010 - 11:23 PM

[CharonY]

Nope. You still need the correct cellular background. DNA is only half of the equation. What is potentially feasible is to change the 16S rRNA to resemble another species (though of course it would only trick 16s based taxonomy). It is possible that it would not interfere with cellular processes too much. I may be wrong, though.

This post has been edited by CharonY: 15 January 2010 - 05:57 PM

[Genecks]

Here is something close I found out asking a bunch of people:
http://en.wikipedia....ma_laboratorium

I suspect it's related.

Here is this, too:
http://www.sciencema...bstract/1151721

Title: Complete Chemical Synthesis, Assembly, and Cloning of a Mycoplasma genitalium Genome

Abstract part:

Quote

...which were all cloned as bacterial artificial chromosomes in Escherichia coli. Most of these intermediate clones were sequenced, and clones of all four 1/4 genomes with the correct sequence were identified. The complete synthetic genome was assembled by transformation-associated recombination cloning in the yeast Saccharomyces cerevisiae, then isolated and sequenced.

This does not seem to fit what I'm looking for. However, it seems similar.
I will say, however, that I think a large amount of knowledge about developmental microbiology might help accomplish the goal.

This post has been edited by Genecks: 15 January 2010 - 10:56 PM

[CharonY]

There is no branch like developmental microbiology. You are thinking either bacterial genetics or physiology. Basically it was the believe and hope that you could get bacteria to do whatever you like with genetic manipulations. E.g. nitrogen fixing E. coli. While certain manipulations are clearly feasible the big changes, e.g. allowing a bacterium to take over the role of another in a completely unrelated environment is still out of reach. Venter's attempt at an "artificial" organism is proof of that. The genome was a re-arranged Mycoplasma genome and was re-integrated into a Mycoplasma cell.
And this beast is simple.

[Genecks]

Well, wouldn't the idea of various knock-ins and KOs over several generations mean that the prokaryote being transmuted would have that cellular background and be a viable, living, working microorganism? The genes would code for things to be made. Those things then support the cell's ability to live and sustain life. And from there, continually add/delete genes until the desire phentoypic qualities are observed?

Or would I be better off using a phylogenetic tree to see who the distant cousins are and then use them as model organisms of developmental transmutation?

Why should the rRNA matter so much? I'm not too knowledgeable about bacterial genetics, though. Would the binding signals be different?

This post has been edited by Genecks: 16 January 2010 - 03:05 AM

[Mr Skeptic]

Well, I can't think of any reason it definitely wouldn't work. However, the genetic code is just one portion of the story. The code is meaningless without the physiology to interpret it. If any of it were different, you could end up with some difference that just won't go away by changing the genes, or with a non-viable organism.

I'm pretty sure it would work for similar organisms. But it would be difficult, and what would be the point? Proof of principle?

[Genecks]

No, the thing would be actually synthesizing impractical to obtain microorganisms.
I'm always for proof of principle, though.
We can do it with viruses.

[Mr Skeptic]

Viruses do not do their own transcription nor post-translational modifications -- they depend on the host for that. The only thing that might prevent it for viruses is viability, and even so they could be helped out. But a bacteria interprets its own code, and from its code makes itself. If the interpretation of the code were to change, then there might not be a way to switch out the genes part by part and end up with the correct physiology.

A computer analogy may be helpful. There is a programming language called C, which is human readable but be turned into a binary before a computer can run it. It uses a program called a compiler, and this process is called compiling. It converts the human readable C code into a binary program, though in the process can add optimizations and such -- so not a word for word translation. The compiler itself is a binary program. The code for the compiler is written in C, and uses the C compiler to compile it into the compiler program.

In that analogy, the compiler acts as the cell, and the C code as the DNA. As the cell forms itself from the information in the DNA, the compiler forms itself from the C code. Neither is a direct translation -- the cell has post-translational modifications -- can have chaperonins to modify how proteins fold, and to the proteins can add sugar groups or other things. Likewise, the compiler can add optimizations, and in some cases the rules of the C code allow for ambiguities, which the compiler chooses how to interpret.

Of course, the compiler's purpose is to convert C code in general into the binary form; coding itself is just a special case -- whereas the cell is only supposed to make itself. So, you'd think that it would be easier to get a specific compiler by inputting certain C code than it would be to get a specific bacterium by inputting certain DNA.

However, people have considered the computer side of this analogy. A theoretical virus was proposed that would infect the C compiler, and insert itself into new compilers. As I understand it, there would be no way to get rid of it, not by compiling a new compiler anyhow.