What is DNA?

• DNA stands for deoxyribonucleic acid.
• It is the molecule within a cell nucleus that contains the genetic instructions which are required for the function of a cell.

What are genes?

• Genes are segments of DNA that code for proteins which are vital to the development of a cell.
• All living organisms have genes – animals, plants and even microorganisms!
• These genes largely determine the characteristics of the organism.
• Genes are what living organisms pass on to their offspring for the continuation of the species.

did you know?

The first GMOs were bacteria. Today, GM bacteria are used in the synthesis of pharmaceutical proteins, bioremediation etc.

What is genetic modification (GM) and what are GM organisms?

• Genetic modification is a form of technology that involves direct alteration of DNA of an organism.
• An organism which has had its DNA altered by molecular techniques is termed a genetically modified organism (GMO).
• With the advancement of biotechnology, scientists have developed special biochemical scissors and glue which enable them to “cut” and “paste” genes from one living thing to another. The newly introduced DNA brings new characteristics to the resultant GMO.

Going Back in Time – A Brief History of GM

• 1860s: Gregor Mendel, an Austrian monk, analysed pea plants and published his work with an outline of the laws of genetics.
• 1953: Watson and Crick determined the double helix structure of DNA.
• 1973: The first GMOs were bacteria and were the combined efforts of Herbert Boyer and Stanley Cohen from University of California at San Francisco and Stanford University respectively.
• 1986: The United States Food and Drug Administration (US FDA) approved the first vaccine made with GM technology which was against Hepatitis B.
• 1990: The US FDA approved the first food created by GM bacteria – the enzyme chymosin, used in cheese production.
• 1994: The US FDA approved the Flavr Savr tomato, which was genetically modified to have a longer shelf life.

did you know?

Gregor Johann Mendel is known as the “Father of Modern Genetics” for his work on the pea plants.

What are some current efforts in the field of GM?

Golden Rice

• Deficiency in dietary micronutrients such as vitamins and minerals is a key cause of morbidity and mortality in the world, especially among the poor.
• Where the population cannot obtain a diverse, well-balanced diet, specially modified crops have the potential to relieve these deficiencies.
• Golden Rice – rice modified to contain a higher level of β-carotene (pro-vitamin A)
  – could help alleviate incidences of blindness and susceptibility to disease in under-privileged, rice-based societies.

AquAdvantage ® Salmon

• AquAdvantage ® Salmon includes a gene from the Chinook salmon and ocean pout and has the potential to grow to market size twice as fast as conventional salmon.
• Discussions were initiated with the US FDA in 1993 and a formal application submitted in 1995.

What are some of the common genetic modification techniques?

Agrobacterium-mediated

• Agrobacterium tumefaciens is a soil bacterium used commonly in delivering genes into plants.
• A foreign gene is inserted into the Agrobacterium using a ‘cut and paste’ method.
• Plant tissue is incubated with the Agrobacterium to allow the transfer of genes.
• Plant cells which have successfully received the gene can be regenerated into a ‘ GM plant.

Microinjection

• This involves the injection of genetic material directly into a recipient cell
• The recipient cell (usually an egg cell or embryo) will then give rise to a GM organism.

Environmental

• The use of GM technology has the potential to alleviate environmental degradation.
• Certain plants and microorganisms can be genetically modified to produce a biodegradable plastic which could reduce the reliance on non-biodegradable types.
• Phyto- or bioremediation can be carried out by plants or microorganisms respectively. These can be genetically modified to metabolize or store environmental contaminants, such as heavy metals.
• Alternative, cleaner-burning biofuels could potentially be synthesized at a large enough scale from GM plants or microorganisms to limit the negative effects of fossil fuels.

Did you Know?

Polyhydroxybutyrate (PHB) is a biodegradable plastic that can be produced by genetically modifying certain plants such as alfalfa.

Ornamental

• GM technology can also be applied to the ornamental industry
• The manipulation of genes of flowering plants, for example, can give rise to novel flower colours and scents. Other than these decorative changes, ornamental plants can also be modified to have increased disease resistance and shelf life.
• A blue rose, previously thought impossible, has been created by modifying the genome of conventional roses to include the gene responsible for the production of blue pigment.
• The fluorescent GloFish® were obtained by introducing a fluorescence gene to the fish. This gene occurs naturally in marine organisms. Current GloFish® are offspring of the original genetically modified fish and do not require the insertion of the gene.

Food & Feed

• GM technology can be utilized to improve food items such as crops and animals meant for human consumption.
• The most popular trait introduced into crops, since 1996, is herbicide tolerance. This allows crops to survive the herbicides applied for the clearing of weeds.
• Derivatives of GM crops can be included in processed foods. For instance, corn syrup can be obtained from GM corn and soy lecithin from GM soybean. These common ingredients can be found in a wide range of packaged foods.
• GM technology has also been used to modify microorganisms to produce certain food compounds. For example, microorganisms have been modified to produce chymosin, an enzyme used in the cheese-making process.
• As the population increases and becomes more affluent, the demand for meat will likely increase. Livestock would then require a greater amount of feed to meet this demand; GM grain can be used as feed to achieve this aim.

Did you know?

The Flavr Savr tomato was the first GM whole food to be released for sale in the market in 1994. It was sold in the US but later discontinued due to commercial reasons.

Medicine, Pharmaceuticals & Research

• GM technology has the potential to develop novel and more effective ways to treat and research disease. Better, more accurate disease models can be created with the help of transgenic animal models.
• It could also pave the way for more affordable medication. A case in point would be the production of insulin by the genetically modified bacteria E. coli in 1982.
• The production of vaccines could also be aided by GM technology. The first vaccine against human disease developed with GM technology was against Hepatitis B in 1986.
• GM technology could also assist in the discovery of the functions of different genes, in the hope that a greater understanding would precede better treatment.
• For instance, gene therapy has the potential to treat and/or prevent genetic diseases based on altering/ correcting the affected gene.