Gene diagram

What is genetic modification (GM)?

Genetic modification is the use of modern biotechnology techniques to change the genes of an organism, such as a plant or animal. Find out all the details in this fact sheet.

  • 2 November 2007 | Updated 14 October 2011

 

What is a gene?

All plants and animals are made of billions of tiny cells. Inside each cell is a nucleus that contains DNA. DNA is passed on from one generation to the next and with it all the information to make the organism and keep it functioning.

Genes are made of DNA and, if DNA is like an information library, genes are like individual instruction books. The instructions in genes allow them to make proteins – which are the building bocks of life. They make up the structural parts of the organism and may make other sorts of molecules like starch, oil, fibre, or fat, which are used within the organism.

An organism is mainly made up of proteins or the things proteins make. Genes make up much less than 0.1 per cent of the weight of an organism, but they control everything else.

Diagram showing DNA Diagram showing what a gene is

Genetic modification (GM)

Genetic modification (GM), genetic manipulation (GM) and genetic engineering (GE) all refer to the same thing – the use of modern biotechnology techniques to change the genes of an organism, such as a plant or animal. A genetically modified organism (GMO) is a plant, animal or other organism that has been changed using genetic modification.

Traditional breeding of plants and animals aims to tailor the plant or animal for a certain application. For example, a new crop variety might be bred that is more drought tolerant or resistant to a certain disease. The process of traditional breeding involves finding individuals with favourable traits and crossing them with each other – with the aim that the progeny of the cross will have the favourable traits from both parents. In reality the progeny have a mix of traits, both good and bad from their parents, and it takes a number of breeding cycles to eliminate the negative traits and build on the positive.

The final new plant variety or breed of animal will hopefully just have the desired traits, which it will have inherited from its ancestors along with the associated genes for those traits.  Traditional breeding is a way of harnessing the genetic resources of an organism by breeding out unwanted genes and breeding in desirable genes.

GM breeding is used because it can change the genes of an organism in ways not possible through traditional breeding techniques providing opportunities for new plant varieties and animal breeds.

GM includes using genes from one organism and inserting them into another. For example, insect resistant GM cotton uses a gene from a naturally occurring soil bacterium to provide it with built-in insect protection. The use of insect resistant GM cotton has reduced pesticide use over 80 per cent in Australia.

However, GM does not necessarily mean that a gene from another organism has to be used to create the GMO. GM can mean that the organism’s own genes are changed.

For example, gene silencing turns down the activity of certain genes already within an organism, such as in oilseed crops where it is being used to turn down the production of unhealthy oils. GM is also used for purely research purposes, for example, to discover genes. 

Find out more about Gene Technology & Farming.