Putting Genetic Engineering in Context

 The Unintended Effects of Genetic Engineering

A Project of The Nature Institute

Dr. Craig Holdrege, Director


Executive Summary

“The frequently heard claim that genetic manipulation of organisms is a ‘precise science’ without dramatic risks can no longer be made or will be recognized as dishonest. The unintended effects of genetic engineering are extensive and wildly unpredictable. They have been documented in more than thirty-five different species of plants and animals, including humans. The evidence for their occurrence, while mostly buried in the technical literature, is not disputable, or even particularly controversial.  It’s simply not widely known.”                                    

The Facts

1) When DNA is taken from one species and genetically into another species (or when the DNA of a single organism is genetically engineered), the physiology and the behavior of the genetically altered organism are affected in unexpected and unpredictable ways.

2) The quality of the food and feed produced from genetically engineered seed is affected in unexpected and unpredictable ways.

3) Animals and humans who eat genetically engineered food and feed are affected in unpredictable and harmful ways.

4) The man-made genetic code contained within genetically engineered seed is passed on to future generations. Unlike a horse and a donkey, which, when mated, produce offspring that are sterile (mules) – genetically engineered seed reproduces itself, generation after generation.

 The Unintended Effects of Genetic Engineering

Alfalfa:  Plant height and flowering were altered in alfalfa genetically engineered to reduce lignin content.

Alfalfa:  Genetically engineered alfalfa with corn transgenes for anthocyanin (red-purple pigment) production was not visibly altered or changed dependent on light and temperature conditions.

Apple:  Apples genetically engineered to over-express a fruit-ripening enzyme lacked flowers and had malformed stomata and altered composition of cell walls.

Aspen Trees: Innate immunity is affected in aspen trees genetically engineered for insect-resistance.

Bacteria:  Genetically engineered root nodule bacteria with Bt transgene tended to displace non-manipulated bacteria in legume root nodules.

Barley:  Genetically engineered barley plants over-expressing a zinc transport protein had smaller seeds and did not accumulate more zinc when grown in zinc-deficient soil.

Barley:  Genetically engineered barley with the transgene for a heat-stable enzyme showed highly variable levels of the enzyme, an anomalous distribution of expression in the grain, and dramatically reduced weight of individual grains.

Barley:  Difficulties were encountered when trying to genetically engineer human collagen in barley.

Barley:  A group of genetically engineered barley plants expressing the bar selectable marker gene did not produce viable offspring.

Bees:  Genetically engineered sugarbeet production alters population densities of some arthropods, significantly reducing the number of bees and butterflies in sugarbeet fields.

Bees:  Fewer wild bees were observed in genetically engineered canola fields.

Bentgrass:  Spread of herbicide-resistance from genetically engineered creeping bentgrass into the wild.

Birch Trees:  Genetically engineered birch trees expressing an antifungal enzyme from sugarbeets showed increased susceptibility to leaf spot disease in the field.

Butterflies:  Monarch butterfly larvae exposed to anthers from genetically engineered corn ate less and gained less weight.

Canola:  Transgenes that have escaped from genetically engineered canola can persist in the wild.

Canola:  Herbicide-resistant canola volunteers were still detected after ten years of stringent control.

Canola:  Conventional, certified canola seedlots were contaminated with genetically engineered seeds.

Canola:  Genetically engineered canola plants over-expressing a bacterial phytoene synthase gene also had a reduced level of chlorophyll, changed structure of plastids, changed composition of fatty acids, and delayed germination.

Canola: Experimental cross-pollination between genetically engineered herbicide-resistant canola and wild filed mustard led to highly fertile, herbicide-resistant wild field mustard.

Cotton:  Genetically engineered cotton showed decreased ability to kill cotton bollworm larvae during flower development and flowering.

Cotton:  Cotton plants and seeds expressing Bt toxin were found in non-Bt refuges.

Cotton:  Insect-resistant, genetically engineered cotton was more susceptible to fungal disease than its parent line.

Corn:  Genetically engineered corn varieties matured more slowly and had on average lower grain yield and higher grain moisture content than conventional varieties.

Corn:  Genetically engineered corn had changed lipid composition in stems; also, lipid composition in soil was altered, and soil respiration was reduced.

Corn:  The transgenic sequences of some genetically engineered corn plants have changed since they were approved.

Dandelions:  Dandelions genetically engineered to have compound leaves showed irregular leaf form and did not flower.

Humans:  Transgenic DNA from glyphosate-resistant soybeans was detected in the intestinal flora of humans.

Fish:  Tilapia fish engineered for transgenic expression of growth hormone had deformed heads and backs, atrophied gonads, and lower mineral content.

Flowers:  Single-site integration of foreign DNA into arabidopsis showed rearrangements and deletions of both plant DNA and foreign DNA.

Flowers:  Unintended changes in gene expression were observed in arabidopsis plants engineered for resistance to the herbicide glufosinate.

Flowers:  Over expression of phytoene synthase gene in arabidopsis resulted in delayed germination, increased levels of chlorophyll, and changes in relative levels of carotenoids.

Insects:  Byproducts from genetically engineered corn affected stream insects.

Mice:  Diet containing genetically engineered soybeans affected the nuclei of liver cells in mice.

Oats:  Insertion of transgenes in oats resulted in modification of both the transgenic construct and host DNA.

Peas:  Peas engineered to be weevil-resistant elicited immune reactions in mice.

Pea:  Peas engineered to be weevil-resistant had lowered starch digestibility when fed to chickens and pigs.

Pig:  Genetically engineered pigs with elevated levels of growth hormone were infertile, pre-diabetic, and experienced joint problems.

Pig:  Genetically engineered pigs expressing bovine growth hormone had lower appetites, enlarged organs, gastric ulcers, and other health problems.

Pig:  Transgenic expression of a mouse milk protein impaired mammary development and function in pigs.

Pig:  Sheep growth hormone expression was highly variable in genetically engineered pigs, whose bodies had more protein and water and less fat.

Pineapple:  Pineapple plants genetically engineered with transgenes for fungus and herbicide resistance had altered biochemical make-up.

Potato: Genetically engineered potatoes with altered sugar metabolism had changed levels of many metabolites, some not thought to be associated with sugar metabolism.

Potato:  Potatoes genetically engineered to store inulin had higher alkaloid content.

Potato: Potatoes genetically engineered to store more starch stored less starch.

Potato: Genetically engineered potatoes with transgene for virus resistance were variably resistant, and some lines without the target gene nevertheless became highly resistant.

Potato:  Potatoes genetically engineered for insect-resistance had less foliage and altered levels of leaf-glycoalkaloids.

Rice:  Genes escaped from cultivated genetically engineered rice to its weedy and wild relatives.

Rice:  Genetically engineered rice showed signs of dwarfism and other abnormalities.

Rice:  Rice genetically engineered with a disease-resistance gene activated the oxidative-stress response.

Salmon:  Genetically engineered coho salmon expressing growth hormone had enlarged heads, reduced viability, and accelerated development of their life cycle.

Salmon:  Genetically engineered atlantic salmon expressing transgenic growth hormone experienced numerous changes to their cardiorespiratory system.

Salmon:  Coho salmon genetically engineered for transgenic expression of growth hormone led to a narrower body, more red muscle mass, and smaller white muscle fibers.

Salmon:  Coho salmon genetically engineered for transgenic expression of growth hormone were more aggressive predators in simulated natural environments.

Sheep:  Sheep genetically engineered for transgenic expression of growth hormone had increased incidence of reproductive problems and premature death.

Sheep:  Genetically engineered sheep had unusually high morbidity and expressed a milk-specific protein in their spleen, liver, and other organs.

Soybean: Genetically engineered soybean plants were shorter, with less chlorophyll, lower weight, and increased susceptibility to stem-splitting at high temperatures.

Soybean:  Root colonization of genetically engineered soybeans by pathogenic Fusarium fungi increased with glyphosate application.

Sunflower:  Wild sunflowers genetically engineered with transgene for Bt toxin produced more seeds than normal wild sunflowers.

Sugarbeet:  Genetically engineered sugar beets became more susceptible to root rot when sprayed with glyphosate.

Sugarcane:  Genetically engineered sugarcane plantswith lectin transgene for stem borer resistance showed altered growth.

Sugarcane:  Sugarcane engineered to reduce polyphenol oxidase (PPO) activity had greater PPO activity, even without the transgene.

Tobacco:   Discoloration and DNA rearrangements were observed in genetically engineered tobacco plants expressing HIV proteins.

Tobacco:  Genetically engineered tobacco with resistance to bleaching herbicides had altered composition of carotenoids.

Tomato:  Genetically engineered tomatoes had altered levels of at least fifteen other substances.

Tomato:  Genetically engineered tomatoes altered with a marker gene construct showed significant changes in morphological and physiological characteristics.

Tomato:  Genetically engineered tomato plants over expressing phytoene synthase gene were stunted in growth.

Weeds:   Increased planting of genetically engineered crops and application of glyphosate causes increase in glyphosate-resistant weed species.

Wheat:  Genetically engineered wheat transformed with a high-molecular-weight glutenin gene showed irregular expression of glutenin and changed its expression levels over subsequent generations.

Wheat: Genetically engineered spring wheat with scab-resistance transgene was non scab-resistant and showed localized death of leaf tissue.

Wheat: Genetically engineered wheat outcrosses more often than conventional wheat of the same varieties.

Wheat:  Genetically engineered wheat expressing transgenic glutenin shows reduction in yield, varying production of glutenin, and altered morphology.


2 thoughts on “Putting Genetic Engineering in Context

  1. I realize it’s a ton more work, but I would have loved if you’d have just listed the studies or articles your facts come from below this article.

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