Genetically modified organism or GMO is the term applied to an animal, plant, or bacterium that has, through genetic recombination technology, had a gene(s) from either the same species or a different species introduced into its genome. This organism may also be known as genetically engineered or transgenic. The gene (or transgene) extracted from one organism and introduced into another is made up of DNA (deoxyribonucleic acid); this DNA will code for the expression (or production) of a specific protein(s). Within cells, proteins carry out most of the chemical functions necessary for life and are what allow organisms to express unique traits.

 

Genetic recombination technology is used to create genetically modified food crops, because of a sought-after economic, environmental, or humanitarian benefit that results from the expression of a novel trait. With the technology to develop GMOs in place, the scientist is limited by his/her ability to locate genes that will confer desired traits, such as pest resistance or herbicide tolerance, which may then be transferred into the plant of choice.

 

The modern techniques employed by the genetic engineer of a GM food crop create more precise changes than the types of recombination events that occur in nature. In nature, genetic changes in plants occur spontaneously and result in a random transfer of genes within the same or closely related species. Traditional plant breeding will create plants that possess some beneficial trait(s) among closely related species, however unwanted genes may also transfer with those that confer the desired characteristics. Modern genetic engineering technology allows scientists to control the transfer of genes between both related and unrelated species into the cells of a plant (or other organism).

 

Scientists will utilize many of the same molecular methods to create, isolate, and purify DNA for gene transfer that are used to determine if and in what quantity a GMO is present in both raw and finished food products. Polymerase chain reaction (PCR) is used to produce large amounts of a specific DNA fragment (or gene) to be inserted into the target organism. Gel electrophoresis is used to separate molecules produced in the PCR. Next, DNA can be lifted from the gel in a technique called blotting. Restriction enzymes are used to cut DNA in a specific and known location and then DNA ligase will rejoin the DNA after being cut. In this way, the exact DNA sequence of the gene may be extracted, multiplied, purified, and transferred into the target organism.

 

Scientists use a variety of techniques to introduce a transgene into a plant cell; in one method the DNA can be coated onto tiny metal particles that are then shot into the cell. Alternatively, scientists can add the gene to a non-pathogenic bacterium´s DNA, and the bacterium can then transport the gene directly into the plant cell. Often bacteria in the Agrobacterium family are used for this purpose, as they naturally possess the ability to infect plant cells. Plants have the capacity to develop from a single cell of an adult plant. Tissue culture techniques are used to encourage the growth of modified plant cells into a whole plant. The regenerated plant will then produce seed containing the transgene, and these modified or engineered seeds may then be used like conventional seeds.