By Professor Nigel Brown FRSB, President of the Society for General Microbiology. 
The abbreviation GMO means Genetically-Modified Organism and these can be plants, animals or microorganisms. They are made by adding new genetic material to an organism. The genetic material is DNA, often obtained from a very different organism or chemically synthesised. In either case it is often referred to as ‘foreign DNA’, as it does not occur naturally in the species. Genetic modification in this strict sense is not to be confused with mutation, which occurs naturally within a species. Mutations are small changes to the genetic material which may change the characteristics of an organism, and on which plant and animal breeding have depended for millennia.
Some of the very first GMOs were bacteria into which the DNA coding for human insulin had been introduced and these were used by pharmaceutical companies to produce large amounts of insulin to treat diabetics. The GM bacteria didn’t leave the factory, only the insulin did. Medically-important products made this way, such as insulin and human growth hormone, have generally been more acceptable to the public than GM crops, as it is the purified product rather than the GMO that is used. However, for GM crops, the plant itself is used as food or animal feed and is grown outside. This has led to fervent debate on the acceptability of GM.
Many people are wary of eating an ‘unnatural’ crop containing foreign DNA. The most heated debates have occurred around two crops. One is Roundup-ready soya which contains DNA making it resistant to the herbicide Roundup™ (glyphosate), so that Roundup™ can be used to kill weeds that compete with the crop. US-grown GM soya is now so widely distributed that several UK supermarkets stated in 2013 that they could not guarantee that meat and poultry was raised on non-GM animal feed. Some people are concerned that a single company has a stranglehold on this technology and can make farmers dependent on it, whereas others worry about the foreign DNA appearing in pollen and being transferred to native plants. In the USA, Roundup-ready varieties of maize, soybean, oilseed rape, cotton, sugar beet and alfalfa are grown commercially.
The second crop is the so-called ‘Golden Rice’. In areas of the world where rice is the main staple food, more than 250,000 children a year go blind due to vitamin A deficiency, and many die. Having GM rice produce vitamin A in the grain is a potential solution. Although Golden Rice was produced by a company, Syngenta, it is now freely available through a charity, but concerns about GMOs mean it is not yet in commercial production.
In 2014 the European Commission agreed that it was for each country to decide for itself whether or not to grow genetically-modified (GM) crops. The UK* will permit this, but France, Germany, Austria, Hungary, Greece and Luxembourg have banned the growth of GM maize. [*This was written prior to developments in the UK. For more information on this see the Royal Society of Biology website.]
Part two, coming soon, will focus on the desirability and safety of GM technology.
Professor Brown FRSB is writing an article each month for The Bridge, a local magazine delivered to every home in the villages of Corsley and Chapmanslade in Wiltshire.
The Royal Society of Biology is sponsoring these articles through our regional grant scheme, which supports locally focussed activity.
Find out about the work of the UK Plant Science Federation, a special interest group of the Royal Society of Biology.