What is Genetic Engineering?

Genetic engineering is an umbrella term which can cover a wide range of ways of changing the genetic material, "the DNA code" in a living organism. This code contains all the information, stored in a long chain chemical molecule, which determines the nature of the organism, "whether it is an amoeba, a pine tree, a robin, an octopus, a cow or a human being" and which characterises the particular individual. Apart from identical twins, your detailed genetic make-up is unique to you. Individual genes are particular sections of this chain, spaced out along it, which determine the characteristics and functions of our body. Defects of individual genes can cause a malfunction in the metabolism of the body, and are the roots of many "genetic" diseases.

Genetic mapping

Our understanding of our genetic makeup is being greatly expanded by a systemmatic mapping process known as the Human Genome Project, carried out internationally with enormous commercial and government funding. Smaller projects are also drawing the genetic map of pigs, chickens and some other organisms. As this work proceeds, individual genes are being identified for various functions and especially for medical conditions. Sometimes it appears that a single gene is responsible, for example in cystic fibrosis, but most conditions seem to be caused by more complex sets of factors, both genetic and environmental. We should make an important distinction between a gene which causes a condition outright, and one that gives one a susceptibilty to it, but which requires other factors to be present as well for the condition to develop. The ability to detect such genes now means we can use the tests for screening, especially pre-natally. This raises some important ethical questions, as we shall see. Screeing for various diseases is not, strictly speaking, the same thing as manipulating or "engineering" them. Some people feel "engineering" is an inappropriate term, with connotations of cold mechanics rather than living things, but it does reflect that manipulating genes has in some cases become a relatively common laboratory technique. We should also put it in context, that genetic engineering has been performed for centuries in animals and plants by selective breeding. This enhances particular genetic traits based on outward appearance, by choosing, for example, which boars to mate which sows to develop, over many generations, leaner pig meat.

Genetic manipulation

From the early beginnings in the 1970's, however, it has now become possible to manipulate specific genes at a molecular level, using laboratory procedures on material taken from living organisms, which can be replaced in the organism, or put into a different one. It can be likened to taking a long, thin garment with a constantly varying pattern along its length, snipping out a section of pattern (an individual gene), modifying it and putting it back, or putting in a section with a different pattern (gene) taken from another garment. In principle, this ought to be much more specific than selective breeding, but the uptake of the relevant modified gene is often quite low, particularly in animals. It also allows the creation of "transgenic" organisms, where a short section of genetic material from an unrelated species can be introduced into another (N.B. a transgenic animal does not mean a 50-50 mixture!).

Some Uses of Genetic Engineering

But why should we do this manipulation, be it within or across species? The purposes of doing genetic engineering are many and various. A range of them are listed below. These include :

    :to repair a genetic "defect" (as with the current early trials of gene therapy in humans)

    :to enhance an effect already natural to that organism and to increase its growth rate.

    :to increase resistance to disease or external damage from anything in its natural environment.

    :to enable animal or plant, to do something it would not normally do.

    :getting a micro-organism to produce human insulin for diabetics, or a sheep to produce a human blood-clotting protein in her milk.

    :getting a tomato to ripen without going squashy, this can be done simply by taking one of its own genes, turning its "pattern" upside down and putting it back again!



Cloning often gets referred to in the same breath as genetic engineering, but it is not really the same. In genetic engineering, one or two genes are typically changed from amongst perhaps 100,000. Cloning essentially copies the entire genetic complement of a nucleus or a cell, depending on which method is used.

Some Wider Questions about Genetic Engineering

The list above simply gives some ideas of what is or might be technically possible. It says nothing of whether it is ethically or socially desirable. Hand in hand with the technology must go an ethical evaluation. Early trials with growth enhanced pigs revealed disastrous side-effects for the animal. Do we need non-squashy tomatoes? But would it be wrong not to develop a means of producing a vital human therapeutic protein in sheep's milk, if we knew how? Should we develop armies of super warriors,like the warrior in the the movie the Fifth Element, who had addition genes to make her super human? Should we develop super genius's that may consider everyone else inferior to them, and make the rest of us thier slaves? Maybe some one will clone an army of himself, and tried to take over the world. I leave you with these thoughts, is this furture science, or science fiction?

Couple wants man best friend cloned::