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In theory, yes, by using retroviral vectors that infect a wide range of cells in a wide range of tissue types. Problem is, most such vectors target fairly specific cell types.
Retrovirus vectors are the agent most commonly used to insert, or change, genes in multi-cellular organisms. They are the agent used for the retroviral based flu vaccine. Also, there have been some other gene therapies developed on retroviral vectors. The problem with them as disease treatment agents is that they are finite; that is, the immune system eventually clears them, and any cells with altered DNA are eventually lost due to normal tissue turn over. So, the "cure" is not permanent.
And, of course, mutagens can impact and alter DNA on a cell by cell basis. And, several environmental toxicants are now known to exert an "epigenetic" effect on DNA. Exposure to these after birth leads, especially during early development, to a change in DNA structure in many or all cells. The change is not a mutation. Rather, it is a change in DNA Methylation or histone phosphorylation, that alters gene expression. This epigenetic mechanism is now recognized as one of the primary ways that environmental substances may cause disease later in life.
Yes, but on a cell by cell basis, not all of it together. A cell (and all of its mitotically cloned descendents) can be altered randomly with mutagenic radiation or chemicals, and it can be altered scientifically with various enzymes that can lyse it and remove, substitute or add genes.
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Sure, mutations. Many caused by exposure to carcinogens.
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October 31st, 2009 at 11:31 am
Thanks for your comments. i will be writing more soon.