I have a question and I would be very pleased if someone could satisfy my curiosity.
I know it may seem silly to some of you, but I was wondering, we all have our own DNA. But, what happens if someone gets a transplant? what happens if he gets a bone marrow transplant? Does he have 2 DNA's?
Sorry, if this is silly. It's been in my mind for a few days.
Biology is not my subject, so I may have misunderstood some things.
Thank you!!

I wondered something like that when there was that business a while ago about some US undertakers replacing dead people's bones with plastic plumbing pipes, and selling off body parts to tissue labs for grafts and suchlike. If you'd had a double-arm transplant like the man in the news today and you were in a CSI situation, would it mess up their forensic results? I'm not a scientist, so maybe I'm thinking silly things too!

I seem to remember reading a fiction book which had an element of this in it...I think it was a Jodi Picoult novel, but I can't remember which one...I'll have a snoop along my bookshelf when I have a spare moment and see if I can find it for you!

I think it's a great question!

The answer is yes you have 2 DNA's

Basically whenever you have any form of transplant like a bone marrow transplant the tissue put into the body will contain different DNA to that of the recipient. As a result the recipient becomes a Chimera meaning they have double DNA. However the DNA from the donor and recipient will not merge to form a 'super DNA' they will remain separate entities. The whole reasons things like bone marrow transplants work is because the donor's DNA is able to replace the fault that is caused by the recipient's DNA resulting in diseases such as leukaemia. So if you have a bone marrow transplant your body's cells remain your own however your blood cells would have a mixture of your DNA and the donor's DNA.

hope this helps 8-)

Thank you!
That's very interesting! Having 2 DNAs....wow!!!

Yes, very interesting, thanks Tricky!! A nice future storyline for the CSI scriptwriters maybe.

There are at least 14 real human chimeras documented; formed from the fusion of two individually fertilized eggs. Kind of the opposite of twins. Some of their organs have the DNA of one egg; some of the other. It has even been suggested that autoimmune diseases actually spring from this kind of chimerism.

This is a review in New Scientist of the phenomenon:

http://environment.newscientist.com/article/mg18024215.100