What is genetic engineering?

Genetic engineering is the term given to the manipulation in the laboratory of the genetic code of a living organism t plant or animal. The main applications put forward by its proponents are in the areas of food and medicine. To understand the main features of genetic engineering t and the enormous risks posed t it is necessary to have at least a basic understanding of what the genetic code (also known as the DNA) is, and how it functions in a living organism.

What is the DNA, or the genetic code?

A comprehensive understanding of the DNA requires a background in quantum physics, chemistry, and molecular biology. It is possible, however, to describe in a few sentences some of the most important features and qualities of the DNA molecule. In this article, I would like to portray some of these qualities, in layman's language, highlighting some of the features that are often left out of the picture when genetic engineering is being defined.

Simply speaking, the DNA is the code of all life. It is a very long molecular structure, consisting of a string of units or genes that encode all the information regarding the structure and functioning of a living organism for its entire lifespan, as well as the biological information that is passed on from one generation to the next. Human DNA is arranged as complex double helix, coiled on itself, with of the order of 100,000 genes, as well as substantial lengths of the DNA about which very little is known so far. Human DNA is arranged in 23 pairs of chromosomes, and although the DNA of all living organisms consists of the same four fundamental molecular units, there is a huge variety in terms of the length and shape of DNA from one species to another. Only in the case of extremely rudimentary organisms, such as bacteria, has the sequence of genes in the DNA been completely deciphered, although even here its functioning is far from being completely understood.

The functioning of DNA

The DNA expresses itself through a complex set of processes. These allow the DNA to create the proteins that are at the basis of the multitude of structures and functions in the body. The DNA is "read" or "transcribed", a process which involves specific genes for each specific function. Also involved are other sections of the DNA which switch the gene on or off. (This includes genes known as "promoters" and "operators", as well as molecular complexes called "repressors" and "inducers", which are associated to specific sections of the DNA.) Although this may seem highly technical, these concepts are crucial in understanding why genetic engineering is so hazardous.

A final point on the structure and functioning of DNA. It is often represented as a chain of units, into or out of which sections can be inserted at will, rather like computer chips or spare parts in a car. In reality, it is a beautiful, elegant, and highly complex quantum- mechanical structure, whose configuration and properties are only understood to a meagre degree. This is a very important, but rarely noted, point, since any infinitesimal change to the DNA at any point will change its properties throughout its length, in ways that no scientist could possibly predict.

The elements of genetic engineering

Genetic engineering involves taking bits of DNA from one species, and putting it into the DNA of another, in order to mimic certain desired characteristics.

Contrary to the promotional literature, genetic engineering is not the natural extension of natural breeding or natural selection. Where in nature do we find DNA from a fish, a scorpion, a spider, a virus or bacterium, an animal, or even human DNA, introducing itself into the DNA of a vegetable? Yet these are all examples of the types of genetic transplants that have already been done. Of equal or even greater concern is the fact that highly active genetic parasites are used to implant the new genes (transgenes) in the DNA of the target species. These are derived from viruses that can cause cancer and other diseases, and are themselves engineered to be active in a wide range of host DNA environments (unlike most viruses, which can survive and multiply only in a limited range of species).

Another myth to be dispelled is that laboratory techniques are perfectly precise, enabling the new gene to be inserted in an exact location in the DNA. This is far from the case. The precision is akin to attaching a string of words on to a brick, throwing it through the library window, and expecting it to lodge in a precise position in a poem in a particular book. Literally thousands of experiments are usually performed before a gene implant performs properly. Even then, there may be one or many unpredictable and uncontrollable secondary effects.

There are two important reasons for this. First, the inserted gene must interrupt the natural sequence of the DNA. Secondly, as pointed out earlier, even the smallest modification will inevitably result in completely unpredictable changes in the form and structure of the DNA on the quantum-mechanical level.

The use of bits and pieces of DNA from viruses and bacteria, crucial to the technology, is also of potentially dire consequence. The control sections for the new gene (promoters, repressors, etc) are much cruder in their operation than for "natural" genes. Therefore they may switch the new gene on or off in an unpredictable manner, leading again to side-effects that could turn up at any time in the future. This aspect of the technology also means that natural barriers that stop DNA hopping from one species to another no longer apply. The highly virulent components (from viruses and bacteria) of the inserted genes could transfer to other plant species, to animals, and to our own DNA, leading to new diseases in plants, animals and humans, or mutations of a completely unpredictable nature.

There are a number of other technicalities that should be mentioned for completeness, and which are described in the articles referred to below.

HOWEVER IT MUST BE EMPHASISED THAT THOSE CURRENTLY INVOLVED IN GENE TECHNOLOGY HAVE NO GUARANTEES AGAINST THESE EFFECTS OCCURRING.

Misadventures so far

Already, in the brief history of genetic engineering, there have been more than enough "mistakes" to show that we should call a halt to the introduction of new modified products. Some examples:

Toxicity: a food supplement, which had been manufactured by a process using a genetically engineered enzyme, killed 37 people and permanently disabled 1,500 more.

Allergies: soybean containing a brazil nut gene was found to create allergic reactions (which can of course be fatal). Fortunately, this problem was found at the research phase and this soybean was not marketed. (Soybean is a component of 60% of processed foods.)

Damaging effects through ingesting modified products: bees consuming pollen from genetically modified plants suffered from impaired sense of smell and had shortened lifespan. DNA is difficult to destroy; it survives boiling, and ingested DNA can survive the digestive process. From there it can pass into the bloodstream and into other cells. Possibilities include genetic disturbances, including cancer.

Changed hormone levels and altered milk content: cows eating genetically engineered soybeans showed increased fat content in their milk. This was probably related to increased plant oestrogen, which can also affect humans, especially children (The USA company, Genetic ID, can detect the presence of as little as 1 in 10,000 modified soybeans.) In another case, the use of genetically engineered Bovine Growth Hormone (BST) created sickness in cattle and unhealthy milk.

Uncontrolled gene transfer to other species: modified oil-seed rape is closely related to wild plant species. The modified genes have been shown to be transferred to the wild species through pollen. This can lead to:

The development of superweeds: that are resistant to herbicides. Evidence of this has already been observed, and the creation of new super-viruses.

Build up of antibiotic resistance: this is already a rapidly-growing problem in medicine, leading to the emergence of super-diseases, that are virtually untreatable. Many genetically modified plants carry antibiotic-resistant genes.

Loss of biodiversity: the range of crop seed species is restricted and the use of herbicides curtails wild plant species.

Loss of food quality: there is already evidence of poor quality in some modified foods, eg soft, easily damaged fruits.

Crop failure and unexpected results: failure of a genetically modified cotton crop; the unexpected and unpredictable change in colour of modified petunias.

Proliferation of crops that are dependent on high input of chemicals: a designer feature of many crops is their dependence on fertilizers and pesticides. (Incidentally, these crops are also singularly unsuitable for developing countries, for whom genetically engineered foods are held as the long-awaited saviour.)

Increased pollution of food and water supply: the increased use of chemicals is a hazard for our food and water.

Pollution of the soil with transgenes: this has already been observed in soil fungi and bacteria.

Ethical concerns: there are many issues here, eg religious and vegetarian, when animal and human genes are found in plants and other animals.

Considering that genetically engineered foods have been around for such a short time, these are surely enough examples to show that we must call a halt to such dangerous experimentation with the code of life. Many foodstuffs, ingredients, and processing substances are already subject to genetic engineering; many more are on the way. The need for a moratorium is urgent. There are no good reasons why such an untried technology, subject to such a range of lethal hazards, should be rushed on to the market.

Labelling is not adequate t it is a tacit admission that either the technology is acceptable, which clearly it is not, or that commercial forces have conquered common sense and prudence regarding the future of life itself. There can be no product recall for genetic transformations t once released into the environment, these mutations will be around as long as life survives on earth. There is a saying "If you violate Natural Law, Natural Law will violate you." To avoid the proliferation of such dangerous technologies, it is our collective responsibility to ensure that life, including science and technology, is lived in tune with Natural Law.

© Dr Geoffrey Clements, November 1997