Thread: changing genetic-code

hello!this might be a dumb question, but whatever, here it goes :P. If someone changes a blood-cell genetic code, it will multiply himself normally, and it will multiply with the new genes, is it possible for itto reach every cell and change it, so every cell in our body has the "altered" genetic code? for example, is it possible to change my genetic code? like manipulating the genes of a normal person, so it "transforms" and becames the new creature?

thanks, and again, sorry if its messy or an ignorant question.

Khazar

I'm not too sure, but i don't think so. For example, if you could 'alter' the genetic code of a blood cell (you mean like a white blood cell yes? (remember platelets and red blood cells don't have DNA, i'm not sure about white blood cells)) it would only divide into other blood cells (also i don't think that blood cells do replicate via mitosis as they are usually produced from stem cells in bone marrow), so its genetic information would only be passed onto these specific blood cells. So as for every cell in the body, including nerve cells / neurons and such - i don't think so (- a blood cell doesn't [divide] to produce a neuron). :? I hope i've helped.

Oh and don't worry your question is neither ignorant nor messy :-D .

Like elhermoso said, red blood cells are derived from bone marrow and don't contain a nucleus, thus not being cells that replicate via mitosis. So, any genetic change in red blood cells won't acoomplish much... If you gave it a nucleus with genetic material it would destroy its function as a red blood cell. As for white blood cells, they may produce new white blood cells, but nothing else, so the genetic change would be very widespread, and once a leukocyte (white blood cell) had new genetic info, it would cease to be itself, and possibly just die, not passing any genetic changes along.

As for any non-blood cell, I would guess that genetic changes would only be carried over to the same type of cells, so the change would not be body-wide. Also, with different genetics a cell would probably produce different surface carbohydrates and proteins and such, and may very well, since it's no longer a normal body cell, be recognized as an intruder in the body and killed off by the immune system. So yeah, I don't think genetic changes in that way are feasible, and if they're feasible, they're probably not useful.

If you think about it, there are probably very few cases where you would actually want to change every single copy of a gene in every single cell in your body. If you want to make a change that causes you to have stronger bones, why make the change in cell types that do not contribute to bone creation or maintenance? If you want to make a change that makes you smarter, why make changes in cells that are not in your nervous system and brain? Etc. And, if you want to pass the change on to your offspring, you just need to change the gene in your germ cells.

Virus technology is being used to try and achieve such a thing. If you're interested in it, you should look it up. I think there was also another thread on the subject a while ago.

first of all, let me thank you all for your replys and answers .
So i see a blood cell wouldn´t work, but (following paralith) if i change a bone cell, it could affect the whole bone?(same goes to muscle, nerve,etc.?)
If so, Which cells would you have to manipulate so that, for example, an arm grows from your back? when your being formed, if all cells have the same DNA, how do they know where to stop and how to form themselves, so you get your shape and variety of cells instead of being just a ball, filled with the same cells?(this is another question, but related to the topic :P)
thanks

I was only trying to point out that it may be unnecessary to make wholesale changes to your body's genes, not that changing the genes in bones or any other type of cells would be particularly easy. If your goal is to seed the change in a few cells and have it proliferate from there, then you have a few limitations.

First, it needs to be a tissue/cell type that actively regenerates; many of the cells in your nervous system, for example, were generated when you were a fetus, will never divide and form more cells, and if it dies - well, you're pretty much screwed, cuz it ain't growin back. Seeding a genetic change in this kind of cell will do nothing but change that particular cell. Your skin, however, changes itself over quite regularly.

Second, you need to seed the change in enough cells so that, eventually, all the cells in that tissue will have the change. Obviously, one adult skin cell is not going to be the mother cell that eventually divides and forms ALL the cells in ALL of your skin. There are lots of cells all dividing and replicating at the same time across the tissue. You'd probably have to seed the genetic change in several different places all along the tissue, and even then there's still be a good chance that there will be patches of cells here and there that escaped the change and continued to make copies of their unchanged selves.

As you can see, it's not simple. And all this is assuming that we have the technology to make the change in the first place, and that there are no detrimental side effects that might, for example, kill all the cells with that changed gene, etc.

I can kind of address your questions about growing an arm from your back and embryonic development together. Included in your genetic code are specific genes that are only active during specific stages of development, that order and arrange the differentiating cells correctly. Some of these genes are turned on by other developmental events - for example, if one layer of cells touches another layer of cells, this physical contact can set off a specific gene cascade, so that instructions specific to that situation are followed. Other genes have their expression controlled depending on the position of the cell within the growing fetus, etc. There is a whole field of study on embryological development that you can look up if you're interested.

Now, the overall formation of limbs and digits are controlled by a certain set of genes called HOX genes. Scientists have found that relatively simple on/off manipulations of these genes can start a gene expression cascade that results or more or less limbs, with more or less joints/digits etc. However, for these limbs to actually function, they have to be integrated correctly into the rest of the body - they have to grow at the right time and the right place, to have skeletal support and the correct musculature etc. When you see pictures on the internet of cows and sheep with extra legs hanging off their butts, it was probably from some kind of HOX gene mutation - but, cows and sheep did not evolve to have legs on their butts, so these extra limbs just hang there. So it is possible that with some HOX gene manipulation you could get something of an arm sprouting out of your back - but it probably wouldn't be functional or complete.

All cells have same DNA but their activation differ from cell to cell. This starts from the time development the process called differentiation which begins with gastrulation.
It like specific messages are sent which governs the dna in expressing itself. For e.g in skin cell melanin is more activated than in our intestinal or other cells.
We can manipulate our genetic str. not genetic code. Our system would mostly follow the same codeof dna to rna to ptn.
New genes can be inserted, particular genes expression can also be manipulated in fact a gene can be knocked out which leads to specific changes. That's how gene therapy works.
About growing arm from back, well its possible but for that we have to know first what set of genes need to manipulated and which cells should be our target. But such manipulation could be lethal and in current technology manipulating a large set of genes is quite difficult.
In Drosophila and some other lower organisms such experiments have been done by manipulating their HOX genes in which legs grow from their head and etc.
But human have much more complex genome and its difficult to get such human volunteers. Even trying planning exp. on human could set the ethical group against you.

Originally Posted by madhumita

All cells have same DNA but their activation differ from cell to cell. This starts from the time development the process called differentiation which begins with gastrulation.
It like specific messages are sent which governs the dna in expressing itself. For e.g in skin cell melanin is more activated than in our intestinal or other cells.
We can manipulate our genetic str. not genetic code. Our system would mostly follow the same codeof dna to rna to ptn.
New genes can be inserted, particular genes expression can also be manipulated in fact a gene can be knocked out which leads to specific changes. That's how gene therapy works.
About growing arm from back, well its possible but for that we have to know first what set of genes need to manipulated and which cells should be our target. But such manipulation could be lethal and in current technology manipulating a large set of genes is quite difficult.
In Drosophila and some other lower organisms such experiments have been done by manipulating their HOX genes in which legs grow from their head and etc.
But human have much more complex genome and its difficult to get such human volunteers. Even trying planning exp. on human could set the ethical group against you.

Also, and an important point we often lose sight of: when HOX genes are manipulated ('knocked out' frequently) the results are seen in the descendants - it is a germ line change, not a somatic line change.

If you wanted to take an adult human being and change his actual genetic structure such that he grew a hand out of his back, the task would be stupendously difficult. I think that's partly paralith's point.

Originally Posted by sunshinewarrio

If you wanted to take an adult human being and change his actual genetic structure such that he grew a hand out of his back, the task would be stupendously difficult. I think that's partly paralith's point.

It would be impossible. Growing a hand on an adult arm is already stupendously difficult, as in currently impossible.

Theoretically it could be done, because some vertebrate species actually do it.


Now...what about growing a hand on someone's back if you could change the genetic code of a fertilized egg?

Also impossible!!!

Extremities grow at a certain location. And this isn't on your back! You could swap identities of front and hind extremity. That would be feasible. Or grow extra limbs on the sides of your body.

The shit is that they will lack complete functionality because there is no hip or shoulder to attach too!