Applications of gene technology: current and future

Biotechnology Australia ceased operations on 30 June 2008. The information on this website has been archived and is no longer updated.

Current applications

Agriculture – pest-resistant cotton

Cotton is a valuable crop in Australia, worth about $1.7 billion a year. The cotton industry is also the biggest user of insecticides, spending up to $125 million a year to protect the crop from insect attack.

To address the problem of insects and simultaneously reduce chemical use, CSIRO and the company Monsanto developed a genetically modified cotton variety known as Ingard®. Ingard® contains a gene making it resistant to one of cotton's major enemies - the Helicoverpa caterpillar. The inserted gene produces a protein that kills the caterpillar when it eats the leaves.

This gene is taken from a naturally-occurring soil bacterium known as Bacillus thuringiensis or Bt for short. There are many, slightly different, protein toxins produced by different types of Bt. These Bt toxins affect different groups of insects. For example, one toxin affects only butterflies and moths but not other insects. The correct choice of toxin means that Bt genes can be used to protect against the specific insect groups that affect a particular area or type of crop. No Bt toxins affect vertebrates or humans, and this is one reason why Bt pesticide sprays – consisting of the unmodified bacteria – are often used by organic farmers.

Insects, however, are notorious for their ability to develop resistance to toxins. The Bt toxins are unlikely to be an exception. The Bt sprays used in organic farming expose insect populations temporarily to the toxin, but the genetically modified plant produces the toxin continuously, increasing the exposure of the insect population and therefore increasing the speed with which resistance could develop. There are strategies to minimise the likelihood of resistance. One approach is to plant ‘refuges’ of non-GM unsprayed cotton or other plants, near the GM plant, in which the insect pests can breed freely, diluting out any resistance genes in the insect population.

Ingard® cotton was first approved for commercial use in Australia in 1996. According to the CSIRO and the Co-operative Research Centre for Australian Cotton, farmers growing the modified cotton used an average of 50% less chemical insecticide than for conventional varieties, with results varying between different farms. In the 2000-2001 growing season, Ingard® cotton was planted across 165 000 hectares Australia-wide.

Since the creation of Ingard®, cotton varieties that are both pest-resistant and herbicide-tolerant have also become commercially available in Australia. One such strain of cotton is known as RoundUp Ready Ingard® cotton and was developed by the CSIRO in conjunction with Monsanto. It was first made commercially available in the 2000-2001 growing season. As well as containing a gene for Bt toxin, this type of cotton is also resistant to the herbicide glyphosate, sold as RoundUp. This was to allow farmers to spray the herbicide over their crop, killing weeds but leaving the cotton plants unaffected. There are concerns that such uses of gene technology encourage extra use of herbicides. (Often, the herbicides are manufactured by the same company – or a related company – to the one that makes the GM variety of cotton.)

Ingard® has now been superseded by Bollgard® II that contains two different Bt toxin genes. It is thought that the chance of the Helicoverpa developing resistance to both Bt toxins simultaneously is extremely low. Up to 80% of the cotton grown in Australia will be genetically modified in the 2004-2005 season.

Genetically modified food

Australia approved the use of genetically modified yeasts and bacteria for the production of cheeses and wine some years ago.

The following products from genetically modified crops are also used in foods on sale in Australia:

• cotton seed oil (including oil produced from Australian Bt cotton), used in edible oils and margarines;
• soybeans, used in soy-based products and ingredients in processed foods such as bread, pastries, snack foods and edible oil products;
• canola oil, in edible oils, fried foods and snack foods;
• corn, in corn oil, flour and sugar and in snack foods, fried foods and confectionery;
• potatoes, in processed products such as snack foods; and
• sugar beet, used as sugar in some processed foods.

All of the above, except cotton seed oil, are sourced from overseas. There are currently no genetically modified fresh fruit, vegetables, or meat sold in Australia.

Most of these foods are currently being produced by crops that have been modified to improve their agricultural qualities – for example, pest-resistant and herbicide-tolerant crops. Many people feel that foods developed in the future using gene technology will focus more on benefits for consumers, such as added nutritional value. One example of this type of crop in ‘Golden rice’. Golden rice has been genetically modified to increase Vitamin A available in the diet, which is lacking in the diets of many people for whom rice is a staple food. Although originally developed some years ago, Golden rice is not being grown commercially at this time.

Food Standards Australia New Zealand (FSANZ) is responsible for food safety in Australia, including the safety of genetically modified foods. For more information on the FSANZ safety assessment process for GM foods, see Biotechnology Australia Fact Sheet 2 - Biotechnology and Food, or visit the FSANZ website - www.foodstandards.gov.au.

Pharmaceuticals  - The story of insulin

Insulin is a hormone that is made in the pancreas to control blood sugar levels. It enables cells to take up sugar molecules from the bloodstream, thereby providing cells with nourishment. In people suffering from type I diabetes, the pancreas does not produce enough insulin. Injected insulin can help regulate blood sugar levels in those who have diabetes.

In the past, scientists used pancreatic extracts from pigs to produce insulin for the treatment of human diabetes. But in 1982, genetic engineers were able to insert the DNA code for human insulin into bacteria and direct the bacteria to produce this valuable protein. Nearly all insulin used for treating diabetes in Australia is now synthesised this way. It is cheaper than using animal-derived insulin, and provides a supply of insulin in quantities not available from animals. Importantly, it is easier to avoid contamination of the insulin by factors such as viruses or other proteins, and it overcomes the problem of occasional allergies to animal insulin.

Scientists can now alter the genes of micro-organisms to produce commercial quantities of a range of other pharmaceuticals. These include new antibiotics; plasminogen, which dissolves blood clots that can cause heart attack or strokes; human growth hormone to treat some forms of dwarfism, as well as to promote healing of wounds, burns and fractures; and vaccines against diseases, such as Hepatitis B. Pharmaceuticals in Australia are regulated by the Therapeutic Goods Administration (TGA).

Somatic cell gene therapy

Somatic cell gene therapy is being researched and trialled through a number of techniques, the most common of which involves the use of a gene carrier or “vector”. The vector is often a defective virus which carries a gene into cells with the aim of integrating the gene into the patient’s own DNA. Once there, the introduced gene would continue to function for a long period of time.  Another promising technique involves the removal and genetic manipulation of some body cells (such as bone marrow cells) and their re-implantation into the individual, in order to overcome a particular disease. The function of the introduced gene is to produce a protein or enzyme that the patient would otherwise be lacking. The genetic changes affect only certain cells within the individual being treated and are not passed on to successive generations.

Gene therapy has exciting possibilities for treatment of diseases such as types of cancer (for example leukaemia) and degenerative diseases such as Parkinson's disease. However, this is a very complex area of research complicated by the fact that many common diseases are caused by multiple genes and environmental factors. This technique is currently in the research and trial stage, but not yet available as a general medical treatment.

Gene therapy research in Australia is tightly regulated, and proposals for gene therapy research undergo a process of review and approval. This involves a Human Research Ethics Committee (HREC), the NHMRC’s Gene and Related Therapies Research Advisory Panel (GTRAP), the Therapeutic Goods Administration (TGA), and Institutional Biosafety Committee (IBC), and when relevant, the Gene Technology Regulator. For more detailed information on the regulation of gene therapy research in Australia, please visit the NHMRC website (www.nhmrc.gov.au).

Risk and new technologies

Most new technologies involve risk. For example, electricity is delivered to our homes in a form that is easily lethal and many deaths from its misuse have occurred. Car, train and airline travel are all potentially dangerous, and are therefore regulated to minimise risk while keeping their benefits.

Genetic engineering involves potential risks too. For this reason, there are strict regulatory systems in place in Australia to regulate gene technology.

As mentioned earlier, Food Standards Australia New Zealand (FSANZ) is responsible for food standards in Australia and New Zealand, including standards for genetically modified food.

The Office of the Gene Technology Regulator (OGTR) is a Australian government regulatory agency located within the Health and Ageing portfolio. The Gene Technology Act 2000 (Cth) established the Gene Technology Regulator to be responsible for a national scheme to regulate genetically modified organisms (GMOs).

For more information on the regulatory regime for genetically modified organisms, visit the OGTR website at www.ogtr.gov.au, or phone the OGTR hotline on 1800 181 030.

Future prospects

Environmental protection

Researchers are developing genetic engineering techniques to combat the problem of industrial pollution. Oil slicks could be controlled by genetically engineered bacteria that feed on oil efficiently and exclusively. Other micro-organisms may also be used to break down pesticides, herbicides and chemical waste.

Human applications

Germline gene therapy is more controversial than somatic cell gene therapy. It is illegal to undertake any germline gene therapy research or development in Australia under the Prohibition of Human Cloning Act 2002 (Cth).  Germline gene therapy would involve making genetic changes that are passed on to the person's offspring. For example, many inherited diseases - such as haemophilia - are carried through generations by a particular gene. These genes are now being identified. As genetic technologies advance, the prospect is emerging that such genes could be eliminated not only from an individual's DNA, but also from the DNA passed to his or her children.

Application of germline therapies is still many years off and will be the subject of significant public debate and review by medical authorities before any use. In particular, many people have concerns about the safety and ethics of changes that will be carried to subsequent generations, and these concerns will probably be the subject of future public enquiries by relevant authorities.

So called ‘Pharma’ crops are plants that have been engineered to express useful therapeutic proteins or drugs, making their production far cheaper and easier. There have been concerns about the risks such crops would pose for food production, if there is not total separation of Pharma from normal crops. For this reason, it is likely that Pharma crops may be restricted to plant species not normally grown for food.

Cloning of animals is controversial. It has been developed mainly for potential animal production purposes.   It involves the use of a technique called somatic cell nuclear transfer.   A recent incident involving the commercial cloning of a pet cat generated much criticism in view of the fact that there are so many abandoned pets without homes.

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