From ACLARK@plant.uoguelph.ca Sun Jul 25 13:26:31 1999 Date: Sun, 25 Jul 1999 10:21:27 EST From: "E. Ann Clark, Associate Professor" To: sanet-mg@ces.ncsu.edu Subject: Re: GE primer (was: easier to swallow?) Beth: yes, I'm increasingly convinced that it really is the process, and not the product, that is suspect. Understand that I am no expert on this, my field is pasture and grazing management, so I am repeating what I've been told or have read. The issue is the presumption (some might say arrogance or even ignorance) that genes can be identified as having causal influences on some trait, such that they can be snipped out, zipped in, and presto-chango, no more problems with pest X or disease Y (or, for that matter, diabetes, overly tall or fat people, retarded people, or otherwise objectionable people). Ah, what a world. What power. What delicious arrogance. The author of The Prince must be proud. The reality, which I think will become increasingly "real" as our friends at "M" actually try to commercialize multi-genic trait products, is that genes interact. I mean, "really" interact, and often in ways that are unintended and unpredictable. The very notion of an independent "snip-zip-able" gene is actually a product of faulty, outdated science - yet this notion is the foundation of commercial GE today. Our pals in the life science companies (another misnomer) have gotten away with it so far because they are working with single gene traits, and often, genes which already exist in a given species. So, what is being inserted is another copy of the same gene but with very slight changes in it - so the plant can sometimes be "fooled" into letting it be. Understand that plant cells have fantastically elaborate processes for constantly inspecting chromosome integrity, ever alert to detecting abnormalities and either excising them or silencing them. See Mae Wan Ho's very readable book Genetic Engineering: Dream or Nightmare for a much more authoritative take on this. Understand also that "order matters" - that is to say, the particular place that a given transgene lands on a given chromosome influences its expression. And both of the methods used by GE breeders to insert transgenes are entirely random. They have no way (yet) of ensuring that the transgene(s) goes into a particular chromosome, let alone, at a particular insertion point. So, they just make zillions of attempts, and then expend enormous effort to screen out the maladapted individuals from the cases where genes have successfully inserted. But the point is, what will happen when the introduced genes are interacting not just "one-on-many" but "several-on-many"? The potential for unintended side effects will be massively increased, given that it is the interactions that determine the product - not a single gene. And be clear, that the above phenomenon pertains whether the transgenes come from within or without the host species. Case in point is the Arabidopsis example discussed earlier on this list. Find a naturally occurring mutation (in Arabidopsis) which confers herbicide resistance (chlorosulfuron, I think), pull it out and make it into a transgene, and then blast it back into other individuals (non mutant) of the same species. What happens? Transformed individuals express not just chlorosulfuron resistance, but are also changed from selfing to outcrossing species. In its natural state, Arabidopsis has 0.3% outcrossing. In transformed individuals, outcrossing increases to a range of degrees (up to 10%, if memory serves), depending on "where" in the chromosomes the transgenes insert. And this is all in the same species. So, I am increasingly convinced that it is the process that is dysfunctional and indefensible - not just the products (the latter is the industry position). Ann ACLARK@plant.uoguelph.ca Dr. E. Ann Clark Associate Professor Crop Science University of Guelph Guelph, ON N1G 2W1 Phone: 519-824-4120 Ext. 2508 FAX: 519 763-8933 http://www.oac.uoguelph.ca/www/CRSC/faculty/eac.htm To Unsubscribe: Email majordomo@ces.ncsu.edu with the command "unsubscribe sanet-mg". If you receive the digest format, use the command "unsubscribe sanet-mg-digest". To Subscribe to Digest: Email majordomo@ces.ncsu.edu with the command "subscribe sanet-mg-digest". All messages to sanet-mg are archived at: http://www.sare.org/san/htdocs/hypermail