I think its called a retro virus or something? Whats happened with that?

no, a retro virus has enzymes to transcibe RNA into DNA, the opposite of what we would usually expect.

I don't understand what you're trying to ask in the original post. Nor how e-coli's answer addresses it (though he's entirely correct).

I don't understand what you're trying to ask in the original post. Nor how e-coli's answer addresses it (though he's entirely correct).

 

He obviously thinks that a retrovirus does something that is does not do.

Oh what I was trying to ask was if there was DNA and then there was engineered DNA could a retrovirus write over the original DNA with the engineered DNA?

i believe that you might be talking about retroviral gene vectors?

 

retroviruses invade cells, and then stick their genomes into the host genome, which then has some extra (viral) genes.

 

in retroviral gene vectors, the viral genes are replased with (insert gene of choice here), and then packaged into viral capsids/envelopes in the lab.

 

these genetically modified retroviruses will then invade cells, and stick their genomes (which now consist of (insert gene of choice here)) into the host cell's genome; et voila, you have now stuck a new gene into an organism's genome.

 

sorta like lambda phage, but designed to work on eukaryotes?

If this process defined some type of logical progression, it would be a speedy path for early evolution.