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Technology
Hopes held high for biotech animals
HOW
A
cloned sheep named Dolly has moved
agriculture one step closer to the
elusive dream of creating and farming
highly productive, disease-resistant animals.
Dolly the Finn
Dorset lamb hit
the headlines in a
by
frenzy of world
Nicole
wide publicity
earlier this year
Baxter,
after researchers
Kondinin Group
at
Edinburgh,
Scotland,
announced they had
unlocked the mystery of using genetic
engineering to clone adult mammals.
But the achievement is only the most
recent example of how various gene
technologies are being used to provide
greater control over animal breeding.
For years scientists across the globe have
tried to answer the question of why some
animals contain ideal characteristics and
others do not.
It is an age-old jigsaw puzzle with many
pieces missing and a substantial amount of
uncertainty. Supporters say the breeding
method will take away this uncertainty and
provide greater control over animal breeding
by using genes from completely unrelated
organisms. But concerns remain and much
needs to be understood before products
reach the market.
ENGINEERING
16
CSIRO
GENETIC
Genetic engineering, a major component
of biotechnology, is the process used to
remove a gene from one organism and insert
it into another.
The technology is not new. Animals have
been selected for genetic superiority and
used for breeding ever since people first
started to domesticate them.
But selective breeding remains slow and
does not allow breeders to separate a single
production trait from one or more
undesirable characteristics. It also fails to
allow genes to be transferred between
species because of the biological barrier that
prevents inter-species breeding.
Genetic engineering, and now cloning,
give scientists a new way to overcome this
barrier, allowing them to introduce genetic
material into animals from completely
unrelated organisms. Animal genes are
going into vegetables, bacterial genes into
food crops and human genes into animals.
But for all its high-tech science, genetic
engineering is no more than a ‘cleaner’ and
‘faster’ road to producing improved animals
or plants — one that supplements rather than
replaces traditional breeding methods.
IT WORKS
Making a change to the way an animal
looks or how it functions depends on genes
and their arrangement within a chemical
called deoxyribonucleic acid (DNA).
DNA is made of four chemical building
blocks which are arranged in pairs and look
like a spiral staircase when viewed under a
high-powered microscope.
These chemical building blocks are the
same for all living things and they provide a
set of instructions which tell a cell how to
make the proteins needed for life.
It is this chemical similarity that makes it
possible to take a gene from one organism
and insert it into another.
Scientists locate a useful gene which can
be removed, manipulated and reinserted into
a new cell where it can operate effectively
and give rise to new animal properties.
All genes are made of two parts — a
portion which contains the information for
the gene product and another part which acts
as a ‘switch’ to determine in what organism
the gene will work and how it will work.
Genetic engineering removes the switches
normally found on a gene and replaces them
with new switches which will tell the gene to
work in a different way.
There are many ways organisms can have
their genes altered and the most common
method for animals is by directly inserting a
gene into the nucleus of a fertilised egg.
Scientists use a very thin glass needle to
inject many copies of the gene into the cell
to increase the chances of the gene being
incorporated into the egg. The altered egg is
then transferred into a recipient mother
where it grows into a normal but genetically
modified animal.
If the introduced gene integrates into the
existing genetic material the resulting
newborn animal will contain the introduced
material in all its cells and this animal is
known as transgenic.
The disadvantage of using this technique
is that its success rate is incredibly low. The
Microinjection of DNA into a sheep embryo
pronucleus 12 hours after fertilisation.
FARMING AHEAD No. 69 - September 1997
technique used to produce Dolly — cloning
— is different. Cloning allows scientists to
fuse cells into eggs emptied of their genetic
material and then grow the embryo inside a
surrogate mother.
One example of the technology’s use in
Australia involves cloning Friesian calves
using embryonic cells.
A Monash
University team has produced and
developed embryos carrying adult DNA.
Their work has resulted in six cloned calves.
Despite this, the process is highly inefficient
— the researchers at the Roslin Institute in
Edinburgh, Scotland, implanted 29 embryos
before one successfully divided. But once
perfected the technology could have a
profound effect on the cattle industry as
breeders and farmers seek to produce calves
with superior characteristics from both the
cow and bull.
Another
technique,
known
as
superovulation, is being used to collect the
thousands of eggs produced in a cow’s
ovaries to expand rare stocks or new breeds
and increase rapidly the rate of genetic
progress.
Normally a cow gives birth to only about
four to six calves in a lifetime, yet produces
more than 75,000 eggs. Down the track it
might be possible for superior egg supplies
to be stored and used to increase control
over developing beef or milk production
herds.
BENEFITS
TO ALL
During the next 10 years there will be
scores of genetically engineered food
products released in what could be a multibillion dollar industry around the world.
The effects of these products will be felt at
every link in the food and fibre chain.
For consumers, the technology could
mean a cleaner environment, a reliable food
supply and more nutritional food products.
Understandably, many consumers are
concerned about feeding antibiotics to food
animals, the presence of drug and hormone
residues in milk, meat and eggs and the
effects of chemicals on the environment.
Already, genetic engineering is addressing
these concerns by producing animals with
in-built disease resistance, improved wool
production, faster growth, whiter wool and
higher protein milk.
For the processing industry, the
technology will allow speedier production of
drugs using animals as bioreactors
(manufacturers of pharmaceuticals), fewer
off-cuts and less spoilage as food products
are transported from the paddock to the
plate. On farms, genetically engineered
animals with in-built resistance to disease
could decrease animal health costs, reduce
environmental hazards and improve animal
production on existing land — vital for
meeting the needs of a growing world
population and conserving the world’s
FARMING AHEAD No. 69 - September 1997
rainforests and animal habitats. Specific
rural applications of animal genetic
engineering include:
• vaccines to improve stock health;
• altering the make-up of milk, meat and
wool;
• breeding disease-resistant animals;
• improved plant digestibility; and
• superior animal production.
To remain competitive, and even survive,
the pressure is on to make additional gains
by increasing animal growth rates and
reducing stock losses from disease.
It is believed genetic engineering will
allow farmers to compete with overseas
competitors, many of which already have
embraced the technology to sustain farm
production.
Supporters claim genetic
engineering has endless possibilities as
farmers strive to overcome the quality and
disease problems unique to Australian
agriculture.
Tender wool, flystrike and
poor quality pastures are major challenges
facing the livestock industries in Australia
but solutions are on the horizon if research
proves successful.
The new cloning technologies pioneered
on Dolly also may mean sheep producers
could clone top lambs and dairy farmers
could clone high production cows, making it
possible to produce more meat and milk
from smaller flocks and herds. But despite
the immense potential of the technology
concerns remain as scientists and consumers
consider the benefits and risks of the new
technology.
ETHICAL
CONCERNS
The cloning of Dolly unleashed a wave of
concern among the community that similar
technology soon would be used to clone
adult humans. In the United States,
President Bill Clinton responded to the
Dolly breakthrough by banning all human
cloning research. But the question must be
raised of whether the work will move
elsewhere, after all, a black market exists for
almost all illegal products available today.
This issue is less clear cut in most Australian
states other than Victoria. In Victoria,
human cloning is prohibited by legislation
on infertility treatment and embryo
experiments. And in states where no
legislation exists, cloning appears to clash
with guidelines prepared by the National
Health and Medical Research Council.
Apart from ethical dilemmas, most of the
concern about animal genetic engineering
surrounds its safety and suitability for
human consumption. The recent push for
agricultural industry groups to become
quality assured has brought to the fore
consumers’ demands for high quality and
safe food.
In many cases genetic engineering will
eliminate the need to administer veterinary
products by creating in-built resistance to
disease in the animal but uncertainty
remains about the possible ill-effects on
human health. Some consumer groups
opposed to the release of modified foods
believe there is no way to ensure modified
products are safe to eat. They claim safety
testing can never provide a complete
guarantee about a product’s safety. For
example, tests extending over three years
may fail to detect harmful effects that
require five years to emerge. Supporters of
the technology refute this claim by arguing
that there are legislative checks and a
substantial time period in place to test
biotech products before their release.
Several countries, including Australia,
have addressed the question of safety, and a
wide range of regulatory regimes currently
operate. These vary from a very liberal
approach in Italy to extremely strict
regulations in Germany, Denmark, Canada,
the United Kingdom, the US and Australia.
In Australia the method of modifying
animals is standardised and a production
process is established. The product is tested
in trials on several animals of varying ages
and different environments and in a range of
locations, and then under ‘natural’
conditions using normal management
practices. In the case of the cattle tick
vaccine more than 18,000 cattle were
vaccinated during the trial period. Added to
the research time are a set of regulatory
checks. These include permission from the
Australian Quarantine and Inspection
Service if any imports of biological products
are to be made and permission from the
Genetic Manipulation Advisory Committee
to manufacture a genetically engineered
product. Finally permission needs to be
obtained from the National Registration
Authority to market the product.
Another concern voiced frequently by
various groups is that gene manipulation
could transfer allergenic properties from the
donor organism to the modified organism.
These fears have been echoed by the
medical community.
One example of this is the epidemic
outbreak of the disease eosinophilia-myalgia
syndrome which arose in the US and other
countries during 1989. The symptoms of the
disease include abnormally high counts of
white blood cells which at the time resulted
in about 1500 cases reported and more than
a dozen deaths. To control muscle pain, the
victims had taken a particular batch of
synthetic L-tryptophan, a harmless amino
acid found naturally in food. It is thought
this batch of L-tryptophan, produced from a
genetically engineered bacteria, became
contaminated.
Supporters of genetic engineering, on the
other hand, argue that many of the proteins
produced by gene expression are common to
a large range of organisms and are unlikely
to trigger allergic reactions. They also claim
these factors are tested for during the
17
Technology
research process and evaluated by various
regulatory checks in each country.
In the case of food additives, unlike whole
foods, strict laws exist where they are
evaluated before use and their presence in a
food is clearly shown on the label. While it is
too early to say whether engineered animals
and their products will produce similar illeffects there is no doubt price and customer
perception will have a big role to play.
LEAN
PIGS SPARK OUTCRY
Perhaps the best example of how customer
perception can affect the success of biotech
foods was when Adelaide-based company,
Bresatec, made moves to slaughter some of its
transgenic pigs for human consumption during
1994. The pigs had been genetically modified
to grow faster when fed a diet high in zinc.
Although the pigs were not deemed unsafe by
the Australian and New Zealand Food
Authority, staff of the Australian Consumers
Association held a demonstration to protest
against the possible slaughtering of the pigs for
human consumption. A company in Corowa,
New South Wales, also protested the move by
refusing to process the pigs at its abattoir.
Bresatec crumbled under the public
pressure, and although free to slaughter the
pigs, it withdrew all plans to do so because it
alledgedly wanted some type of official stamp
of approval from the National Food Authority.
Like other areas within the food and fibre
industry, this event showed how marketing and
consumer perceptions ultimately will decide
the fate of genetically engineered products.
Negative perceptions of genetically
engineered products could decrease market
size until the public understands the merits of
these products and their safety is confirmed.
One suggested solution to allay the safety
fears surrounding genetically engineered foods
is to legislate for mandatory labelling.
Appropriately labelled foods would allow
consumers to choose for themselves whether or
not to accept the risk. Health officials also
could trace the source of any problems more
easily within appropriately labelled products.
TO LABEL
OR NOT TO LABEL
Many manufacturers of biotech foods claim
there is no need to label products because
humans have eaten plant and animal DNA for
millions of years and the introduced material is
no different from its original source.
There is some concern that labelling could
cause consumer alarm, deterring them from
buying a product because they think there is
something wrong with it.
Nonetheless, others argue that appropriate
labelling would help build consumer
understanding, confidence and maintain a vital
and healthy market.
The public does have some right to know
and various surveys within Australia have
confirmed the need for appropriate labelling.
According to a 1994 survey carried out by
the Department of Industry, Science and
Technology, the Australian public broadly
supports the notion of genetic engineering.
The survey showed a vast majority of
Australians would wear clothes made from
genetically engineered cotton (77%) and eat
genetically engineered cooking oil (60%),
tomatoes (61%) and pork (56%). But
respondents wanted products clearly labelled
so they could choose for themselves whether or
not to use them.
In the case of genetically engineered
animals, it is quite likely people will be
impressed with improved meat, milk and fibre
quality of biotech products.
As engineered animals and their products are
released onto the market farmers and
consumers will have to make certain value
judgements on a range of ethical issues and at
times other moral, social or even political
aspects will come into the equation.
The decisions concerning animal genetics
will be difficult and will be overcome only by
extensive education and discussion.
Nevertheless, it is clear genetic engineering
will play a vital role in agriculture of the future.
The research yet required is substantial, longterm and costly, but it is only a matter of time
before transgenic livestock is used successfully
to improve production on Australian farms.
Acknowledgements: Kevin Ward, CSIRO,
and Marion Seymour, Kondinin Group.
But labelling remains one of the most
contentious issues in the area of genetic
engineering and legislation varies according to
individual countries.
Some supermarkets in the UK banned the
sale of genetically engineered foods despite the
presence of labels. Similarly, grocers in
Switzerland have erected signs to inform
customers that food has been modified
genetically because labelling laws have lagged
behind the release of biotech products.
Opponents to mandatory labelling believe
there is no definite line between where
labelling is justified and where it is not. There
have been calls in Australia to label cheese
made from genetically modified organisms,
despite the fact that the cheese itself does not
contain any introduced genetic material.
FARMING AHEAD No. 69 - September 1997
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