SO WHAT ARE WE REALLY CREATING?
I TELL MY CELLS WHAT I WANT!
YOU CAN TOO
Google Groups : sci.bio.evolution: "Usually with a nice little creature called Agrobacterium tumefaciens. This
actually inserts a portion of its genome into a plant it infects, causing
the cells to become cancerious and, cleverly, to secrete a substance known
as octopine, which very few organisms can use a carbon source. Agrobacterium
is of course one of the few, so it enjoys a monopoly food supply.
By removing the tumour and octopine genes from the transfer DNA, and
inserting a gene of interest, we can genetically engineer plants, with a
certain amount of hassle getting the transformed cells to regenerate into
whole plants.
(If you are wondering how to genetically engineer Agrobacterium, that is
relatively easy. The DNA is on a plasmid which the bacteria can be induced
to take up with minimal hassles, for genetic engineering).
The problem is we don't know how to control the site of integration, and it
may be that DNA which has integrated is less stable than other DNA. Also for
technical reasons the DNA needs an antibiotic resistance marker gene. There
are new protocols for getting these out of the released plants, but they add
cost to the engineering procedure. There is a theoretical possibility of
these antibiotic resistance genes getting into bacteria. However the genes
originally came from the bacterial gene pool anyway, so it is not really a
very serious concern to most scientists, though the media have jumped on it
because genetically engineered superbug make a nice story. "
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