The New World of Genes
The modern biology of genetics is one of the
most favoured research fields these days. To judge by the public discussion, however, you
would think it only had to do with clones, changing human beings, or risks to the natural
world. These speculations make everything appear threatening, while obscuring genetic
engineering’s true possibilities. The point of departure for genetic engineering is
that the hereditary molecules (DNA) of all organisms are made of the same four components.
It is only their sequence that decides what an organism will look like and how it will
function. These four components that make up the hereditary molecule are to be found in
both animals and plants. With the knowledge we have today, this is not surprising, because
life on earth can be traced back to a common origin. So nature’s concept of using a
combination of only four components in the hereditary molecule to store the information on
the structure and function of an organism can be found in all organisms. This universal
property of the hereditary molecule has led to the idea of taking certain component
sequences (i.e. certain genes) from one organism and inserting them into another. Once
there, these foreign genes are read and the appropriate substances manufactured according
to instructions. This opens up two options: first, if an organism is suffering from an
illness because of a missing gene, this can be "repaired" by inserting the
appropriate foreign gene; second, a gene can be inserted to alter the functions of an
organism’s cells for quite different reasons. The first possibility – gene
therapy – has remained an illusion up to now: the systems in a highly developed
organism are too complicated for any quick successes here. The other variant is easier to
put into practice. If the human gene for insulin production is introduced into certain
bacteria, for example, the latter will begin to produce insulin. In this way the insulin
can be manufactured for medical purposes in a bioreactor. Today, many such projects have
been successfully implemented. By introducing foreign genes into the milk gland cells of
sheep, medicines can be literally milked. Another idea is to use plants as bio-factories.
They offer several advantages over genetically changed bacteria, yeasts or animal cells.
Genetically altered tobacco plants, for example, grow quickly, are easy to process –
and are more economical as bioreactors than animal cells. Grown on a large scale, foreign
proteins needed as pharmaceutical active substances can be produced within their cells.
The work being conducted in genetic engineering is far too diverse to be described in a
short article. Furthermore, more and more new questions crop up as we penetrate further
into the world of genes. That is the exciting thing about the research. However, it has to
be accepted that the decoding of the human genome has not yielded very much. Knowing the
combination of the four components in a gene says little about its effect. The new
challenge lies in finding out what happens when the decoded genes are read off and
proteins are manufactured according to their instructions in a cell. These proteins
combine to form new molecule complexes that carry out very specific tasks in the
biochemical processes within the cell. The aim of this proteom research is to find out
more about the interaction of the proteins; perhaps we can unravel another of life’s
secrets in this way. Furthermore, stem cells offer an undreamt-of potential for
discovering more about how life functions. In such cells, the hereditary molecule is still
willing and able to take on all possible tasks: in other words, these cells are not yet
specialized. In the future, when brought into contact with nerve cells or muscle cells,
perhaps they can be transformed in such a targeted way that they can replace damaged brain
or heart-muscle cells. These are only a few examples of the exciting prospects that
genetic engineering is opening up.
(Courtesy: Deustchland Magazine,
Embassy of Germany) |
