Do You Really Want Tailored Genesp

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So what exactly is genetic engineering? About five years ago biologists developed techniques to make in the test tube novel combinations of genes from different sources.

(A gene is a segment of a molecule called DNA which determines the structure of a particular element of the cell or which governs some cellular process).

These new combinations of genes could be reintroduced into a living bacterial cell and perpetuated indefinitely as the cell divided.

The process of genetic recombination occurs naturally in sexual reproduction when genes from each parent are linked to form a different permutation in the offspring.

However, taking recombination away from the cell and putting it in the test tube allows for the first time the breaking down of the barriers which prevent the joining of genes between different species.

'Clone' In practice this means that any gene from any source, whether plant or animal,including man-may be isolated and incorporated into a bacterium which may then reproduce to give enormous numbers of identical cells each containing the foreign gene-or so-called 'clone' The foreign gene may give the bacterium new and perhaps useful properties, for instance, the power to synthesise a drug or a vaccine.

What are the benefits?

The scientific advantages of genetic manipulation have already given a new and powerful thrust to advancing the study of the living cell at its most basic level.

Genes form the vehicle by which all the information required for the building and functioning of the organism is passed on from celi to cell and from generation to generation.

Genes also control the working of the cell in its second by second and hour by hour existence.

The microscope enabled scientists to explain the structure and working of whole tissues and bodies by allowing the study of their isolated parts -the cells.

Benefit

Now the ability to insert a gene in a bacterium and grow it as a clone allows biologists to examine in fine detail the structure and functioning of a single gene separate from its millions of neighbours.

Medicine will benefit by being given new techniques to first detect, later understand and ultimately correct inherited diseases caused by malformed genes-such as cystic fibrosis, sickle cell anaemia and haemophilia.

In addition genetic engineering holds up the promise of a cheaper and purer source of drugs which have been up to now difficult, expensive and time-consuming to produce.

These include hormones such as insulin which is used to treat diabetics, and vaccines used to innoculate against diseases.

More interestingly the new techniques will allow the manufacture of a whole new range of therapeutic biological products which have to date proved impossible to make including perhaps an antibiotic active against virus infections.

But the diversity of new commodities need not stop at charmaceutical preparations.

Strains of bacteria will be ailor-made to manufacture emirely novel and potent insec=cides, plant hormones, selec-