The Rural Voice, 1988-08, Page 29culture chambers secrete the desired
materials into their growing medium.
The substances are collected, purified,
and used by people. Most of the
processes of modern biotechnology
use techniques like this.
Genetic engineering has also been
around for a long time. Breeds and
varieties of animals and plants have all
been created by controlled breeding.
The characteristics of a breed are
caused by genetic mutations located
on the chromosomes. Because half an
animal's chromosomes are passed on
to its progeny, a controlled breeding
program increases the number of
offspring that possess the mutation.
What is new is the technology of
recombinant DNA. Scientists recently
discovered that genes, which control
all the physical attributes of an animal,
are movable. A segment of genetic
material (DNA) can be snipped out of
one chromosome and added to a
second one. This is an interesting
experimental technique for under-
standing how one gene functions in
isolation, but it also has great commer-
cial implications. If the genes for a
protein such as insulin are located and
put into the DNA of another organism
such as a bacterium, a colony of bac-
teria should be able to produce a good
deal of insulin. The insulin could then
be harvested, purified, and used to
treat diabetics.
It is only since 1971, when bacter-
ial plasmids and restriction enzymes
were discovered, that it has been pos-
sible to combine DNA in any useful
way. Restriction enzymes break DNA
at certain points on the chain, making
it easier to isolate genes. Plasmids are
circles of DNA found in bacteria.
Their exact function is not known, but
they have many properties that make
them ideal for recombination with
other genes. A recombined plasmid
also instructs a bacterial cell to pro-
duce the protein that has been inserted.
The first viable DNA hybrid was
reported in 1973. The research team
used bacteria to bacteria gene transfers
initially, but soon they performed the
first cross -species hybridization by
putting a toad gene into the bacterium
Esherichia coli. Two of the research-
ers that made the fust discoveries
about recombinant DNA, Stanley
Cohen of the Stanford University
School of Medicine and Herbert Boyer
of the University of California School
of Medicine, met in a deli while
attending a conference in 1972. They
discussed the possibilities of putting
human genes into bacteria. In 1974,
Boyer co-founded the world's first
biotechnology company with busi-
nessman Robert Swanson, and the
new era of biotechnology had started.
The new era of biotechnology got
Dr. Phillips is examining
genes of the fruit fly, and
hopes that a Zink between
his work and the cause of
Porcine Stress Syndrome
could someday produce
pigs genetically free
from PSS.
off to a fast start, but has not been as
successful as many people would have
us believe. Stephanie Yanchinski, an
editor at Biotechnology Newswatch
and a biotechnology consultant for the
Financial Times, the Guardian, and
the BBC, wrote about boom and bust
in the biotechnology business in New
Scientist in 1987. At that time, she
said, there were only four commercial
products being produced through
genetic engineering: a human insulin
called Humulin, an animal vaccine
against scours, interferon, and a hu-
man growth hormone called Protropin.
Yanchinski believes that scientists
have ignored two key areas of bio-
technology: how microbes respond
physiologically to the new genes and
to industrial conditions, and how the
structure of a protein is related to its
function. For example, bacteria with a
foreign gene inside them spend more
energy than normal making that
protein. Normal bacteria in the culture
(and there always are some) will
breed faster and eventually take over
the culture. In the case of structure vs.
function, it has been found that bac-
teria like E. coli make human proteins
that are physically different from the
natural ones. This difference makes
the proteins function differently and
also makes them harder to extract
from the cell. It appears that for
biotechnology, the "bio" part was
easy; it is the technology part that is
troublesome.
This is the difference between
pure recombinant DNA research and
applied research. Dr. Phillips, for
example, describes his work as pure
research that might have practical
applications. He is now examining the
genes for the enzymes involved in the
oxygen defence system of the fruit fly
Drosophila. It also happens that a
genetic defect resulting in a failure of
this system is the cause of Porcine
Stress Syndrome (PSS), a fatal con-
dition induced in pigs by increased
levels of stress. He hopes that his
work with the flies will let him under-
stand the relationship between genes
and the oxygen defence syndrome,
and that this knowledge can be applied
to pigs. The result could be a gene
transfer from Drosophila to the em-
bryos of pigs which, with the correct-
ed genetic makeup, should be free
from PSS.
That jump from pure to applied
research is a big one. Pure research is
playing around, changing things, and
learning how they work. There is no
aim except knowledge. Applied
research looks for concrete results,
systems that work perfectly every
time. Dr. Phillips says that the words
"genetic engineering" imply that
scientists know what they are doing,
but this is not necessarily true. Get-
ting a pure research subject to a
practical stage requires many steps
that are either not well understood or
are too difficult.
The path from applied research to
everyday reality is nearly as difficult.
Dr. Phillips notes that there has been a
great deal of talk about "revolution"
and how biotechnology will change
our lives. Yet the impact of biotech-
nology has been less than revolution-
ary. As an example, Dr. Phillips cites
bovine growth hormone, which can be
produced by recombinant DNA
technology. Injected into mature
cattle it will increase milk production
in a well-managed herd by 20 to 40
per cent. But Dr. Phillips says that in
the end that technology will probably
be too expensive and too "high-tech"
to be of value. Other factors to be
considered are what an increase in
AUGUST 1988 27