change the dna of a living organism, then get it to express changes?
Just a little thought experiment. But lets say you wanted to go about changing the dna of a living organism and getting it to actually express this change without actually killing it. And i’m not talking about something like changing the color of its skin or eye color. I mean really messing the thing up (new organs, new limbs, increasing size of body parts). In short making it do things that its god given genes would never let it do. I’ve heard of making gene modifications in embryos and gamete cells and then having the changes expressed when the organism is born. I guess a good example of this would be those zebra fish they made fluorescent (http://en.wikipedia.org/wiki/Glofish#Early_development). I can see how its possible to actually change the dna of a mature organism (microinjection, plasmids, that sort of thing) but how can they be made to express these traits (proteins, stem cells, cancers?). So are there any ideas on how could you get zebra fish to glow or hamsters to grow gills while they are still alive without actually killing the bastards?
well i was thinking you change the things dna (recombination or w/e technique) then you sorta induce the growth or change you want by introducing stem cells and getting a blastema or tumor or something to grow with the body. I didn’t think about it but you might be right about the fish. Even though they aren’t normally neon its still just a replacement of a gene they already have, not the introducing of a new slot for a different gene.
i guess the stem cells would have to have the changes as well.
4 Responses
Smoorthy
09 Feb 2010
Duke O
09 Feb 2010
It’s called cancer. 
I know what you’re getting at and no, limbs, internal organs and such are signaled for during development, which only happens once. The reason they could make fluorescent zebra fish is because that’s a simple fluorescent protein, you just insert the gene into the fish’s DNA and it will begin to produce it like any other protein. Wholesale changes to a mature organism is just not possible, unless you could induce a secondary developmental phase like butterflies.
Willian
09 Feb 2010
Not really, at least not with the technology we have at the moment
You would have to change the DNA in the ALL body, in every single cell.
Because you change the DNA of offsprings before they are born it makes it easier.
Honestly would you need to understand more about Genetics for me to discuss it deeper with you.
In the case that they make animals glow(and they have done that with MANY kinds of animals already) they dont really CHANGE the organs, they only add a small gene to something that will not make much difference but will add the protein that glows.
We still have not much idea how the dna designs a all organ in an organism.
It could be possible perhaps in the future that using a virus we could genetically modify adult organisms, but that is risky cause if this virus mutate and becomes infectious and pathogenic we are in big trouble!
Waspy
09 Feb 2010
In order for this to be done, you need to know the genome of the particular animal or insect. Once you now every aspect of there genome, you can then modify the DNA. Simple things of base modifications. like you change the amino acid of Serine to histine.
so for the glowing fish. The scientist realized that this part of the Genome was in control of doing a glowing effect. They would replicate this part of the DNA to the Fishes’ original DNA.
the problem. It requires numerals trials. You would be lucky to actually get one stable product.
Its possible to cause changes in mature organisms that cause them to express different genes or change certain aspects of their body. However, this is not often done because its much easier to cause changes in organisms in their embryonic stages so that the mature organism’s cells will have derived from those cells.
In reality it depends on what exactly you are trying to do. There are also different possible solutions for certain problems. So suppose you wanted to make somebody grow an extra limb, an arm for example. This would be very complicated because limb growth is different from organ growth. Limb growth occurs in embryos via the seeding and development of a limb "field," the field tells the cells in which direction to grow out and how far to grow. Thus in an adult organism, if you were to replicate this limb field environment, it may be possible to grow an extra limb in a mature organism. This would involve flooding the area with the appropriate amounts of countless transcription factors (the levels present during development) which would signal the cells in the area to develop a limb field, then a limb bud, and finally cause a limb to grow. This is actually how animals such as salamanders and lizards regenerate their tails and parts of their limbs when they are torn off.
All in all the obstacles that prevent humans from having regenerative or over-generative abilities that other lower animals (and plants) possess can be analogized to a pc security issue. For instance in an older version of Windows, say Windows 98, certain viruses will invade and disrupt the computer, however in Windows Vista, these same viruses will not affect the system because of upgraded (more advanced) security, however these security enhancements come at a cost, certain features such as networking devices or even installing programs are made more difficult in Windows Vista because of the security barriers that are meant to prevent viruses and malware.
With todays technology, many things are possible, but many things are also still difficult. Ten years ago it took over a year to sequence the human genome, now it would take a couple of weeks, and it could be done using a 100th of the amount of machinery (given today’s technology). As scientific research unveils the functions of more genes, proteins, transcription factors, etc… and as robotic technology becomes more advanced, it will definitely be possible to regenerate lost limbs, tissues, and cells. Maybe it will even be possible to easily carry out adult somatic cell/tissue reprogramming.