Can you swap a cell's DNA for pure DNA in cloning?

[Jarfi]

In cloning, they replace the cells nucleus, but what if you only have pure dna, could you somehow, switch it for the cells own dna?

 

[Ygggdrasil]

This has been done for bacteria. Scientists have synthesized the DNA for one species of Mycoplasma, and replaced the DNA from a different species of Mycoplasma with the synthetic DNA. They then showed that the DNA replacement causes the bacterium with the synthetic DNA to behave like the Mycoplasma species from which its DNA came and not the Mycoplasma species that is hosting the DNA. It may be possible to use similar techniques in other types of organisms, but this has not been demonstrated yet.

For more information see the following physics forum discussion: https://www.physicsforums.com/showthread.php?t=404603

 

[Pyaemia4]

I've heard of the studies described above, but I would imagine this would be much more difficult, if not close to impossible, to do with a eukaryotic cell since we would be talking about several chromosomes packaged with histones, etc. instead of a single bacterial chromosome. I'm not sure if any groups have tried to do something similar.

 

[Ygggdrasil]

There is a group trying to rewrite the yeast genome that has so far succeeded in replacing two chromosome arms with re-engineered versions (see citation and New Scientist article below). Of course, yeast are a single-celled organism, whereas the situation might be more complex with multicellular organisms. In multicellular organisms, cells are specialized and epigenetic changes to the genome are very important for determining cell fate. It is uncertain whether incorporation of synthetic DNAs into these organisms much more difficult (it is worth noting that such epigenetic regulation happens in yeast, too, so maybe the cell is able to epigenetically program the synthetic DNA just fine).

Dymond et al. 2011. Synthetic chromosome arms function in yeast and generate phenotypic diversity by design. Nature 477:471 http://dx.doi.org/10.1038/nature10403
New Scientist summary on the above study: http://www.newscientist.com/article/dn20909-synthetic-yeast-will-evolve-on-command.html

 

[nmz787]

In cloning, they replace the cells nucleus, but what if you only have pure dna, could you somehow, switch it for the cells own dna?

In short, yes.

In prokaryotic cells (DNA in cytoplasm) this has been done with the M. mycoides genome at JCVI.

Eukaryotic cells (DNA in nucleus) generally have more regulation, so swapping the native DNA for synthetic might work, but the expression of it might not be as expected due to lack of associated regulatory proteins.

That said, transforming eukaryotes with naked DNA might be perfectly fine, but I'm less experienced with eukaryotic genomics than I am with prokaryotic genomics.

http://www.nature.com/scitable/topi...g-in-prokaryotes-the-circular-chromosome-9113