SC - Evolution of food-genetics of food

[Rachel Holliday]

Right I'm going to answer generally to some of the points raised.

1. In the UK Organic food is certified by the Soil Association which states
that no ingredients can be used that have been genetically modified.
2. Most food is now labelled to say whether it contains GM food, although
this is voluntary public demand has forced the issue.
3. The evidence both for and against GM food is slight and requires a
greater degree of testing.
4. Transplanting genes can have a huge effect on the biology of a plant.
Trying to explain this might take some time but here is a brief cut down
version.  Genes are controlled by "switches" which are specific both to the
species and tissue type.  To transplant a gene from another species the gene
has to be joined to a switch.  However these switches are not necessarily
tissue specific so the gene will be expressed throughout the plant (animal -
although we are not there yet for food anyway).  Because this processes
necessitates the use of a switch that is already present in the plant is can
have a knock-on effect disrupting the expression of other genes and hence
chaining the biological profile.  Just as in a human the presence of a
protein at too high a concentration can be detrimental (see various hormone
conditions) the same can be true of a plant.  The whole system could
potentially be thrown out of balance.  The way the switches work is by
signalling molecules binding to them.  If many new copies of a switch are
introduced it will dilute out the signal to the "normal" switches and gene
expression levels are disrupted.

The problem with GM food lies in it being an untested field.  It is
extremely difficult to measure the change in expression of endogenous genes
upon the introduction of a recombinant gene and so we cannot tell what the
side effects may be.  The whole process really started in bacteria which are
much more simple having only one cell and one chromosome.  A world away from
a plant!

If anyone want to ask me anything about this matter, I hold a degree in the
subject, please feel free to contact me.

Thanks to the person who looked up the Nature article it saved me the
trouble!

Rachel
http://www.homeusers.prestel.co.uk/witchwood/
ICQ: 64354245