Re: CULT - Genetic Engineering

--- In iris-talk@egroups.com, Bill Shear <wshear@e...> wrote:
> The worries expressed about the genetic engineering of corn are 
unlikely to
> effect irises in the ways Walter (with tongue in cheek so far he 
might bite
> it off) worried about.
> 
> The engineered corn has had a gene inserted from the bacterium 
Bacillus
> thuringensis ("Bt"), which we have long used as a pesticide.  Bt 
produces a
> protien toxin that attacks the guts of a range of insect pests.  
Different
> strains of the bacterium can be used to kill cabbage worms, corn 
borers,
> corn earworms, and even Japanese beetles (but this is not the same 
as milky
> spore disease).
> 
> The nutritional value of the corn is unchanged and so far as we 
know, Bt
> toxin is not directly harmful to either animals or humans.
> 
> However, there are two possible concerns.  The Bt toxin is 
structurally
> similar to the protien which is responsible for some serious food 
allergies
> (such as those to peanuts, which can be rapidly fatal in sensitive
> individuals), though there are no known cases of reactions by 
humans to Bt
> toxin.  It is likely that the toxin is destroyed by cooking or at 
least
> altered to the point that it would not provoke a reaction.  The 
toxin does
> not pass through animals that are fed the engineered corn, but is 
broken
> down in their digestive systems.  Nevertheless, thorough testing 
would be
> needed before the corn could be ajudged safe for human consumption.
> 
> The second concern is that by exposing large pest populations to 
the Bt
> toxin, we could hasten the development of resistance to it, and 
thus lose a
> valuable adjunct in the battle against insect pests.
> 
> Advantages, of course, are many.  The greatest from an environmental
> standpoint is that farmers can use much less of the more dangerous
> pesticides and still produce lots of good clean corn.
> 
> Some people are concerned about lateral gene transfer, the movement 
of
> genes from one species to another, possibly carried by viruses that 
can
> infect multiple hosts.  This might not be such a problem with Bt in 
corn,
> but engineered cotton with herbicide resistance could allow the
> herbicide-resistance gene to enter populations of weeds.  We don't 
know of
> any viruses that infect both humans (or any vertebrate) and plants.
> 
> The Law of Unintended Consequences is still not much heeded by 
industrial
> researchers, despite some disasterous failures.  On the other side 
we have
> irresponsible panic-mongers who decry any attempt to improve food 
yields by
> "unnatural" methods, whatever that means.  The two groups tend to 
balance
> off somewhat and eventually we get a usable solution.....
> 
> 
> Bill Shear
> Department of Biology
> Hampden-Sydney College
> Hampden-Sydney VA 23943
> (804)223-6172
> FAX (804)223-6374
> email<wshear@e...>
> Moderating e-lists:
> Coleus at http://www.egroups.com/community/coleus
> Opiliones at http://www.egroups.com/community/opiliones
> Myriapod at http://www.egroups.com/community/myriapod


Hi, Bill,

Thanks for your well-reasoned info on genetic engineering.  And the 
message on the limitations to our understanding.

Your iris book has been well-recommended to me also, and I'll be 
ordering it from AIS as soon as I have two nickles to rub together.  
What I may not understand in it, I will still need to know.

Interesting articles in the Sept. TALL TALK, also recommended and new 
sub.  By next spring, I hope to know a little, at least, of what I 
should to launch my hybridizing project.

Patricia Brooks, new kid on the block


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