Genetically Modified Foods is dealt with in US Patent No. 7,049,483 Transgenic bioluminescent plants which states as follows
The present invention relates to the use of bioluminescent mechanisms to create transgenic plants that glow in the dark. Although this may be done with any plant, it is generally not preferable to use the present invention with crops. Bioluminescing takes from a plant's energy that could otherwise be used to grow fruit or vegetables. Also, there is a significant amount of controversy relating to genetically modified foods. The general public would probably be reluctant to consume food that glows in the dark. However, despite these drawbacks, there are foreseeable advantages to luminescent crops. Crops capable of producing light facilitate night-time harvesting. Once harvested, they would eventually cease to glow. Assuming that the general public's aversion to genetically modified foods is overcome, this could aid farmers. They could harvest their crops at anytime, including during the cooler evening hours.
It is preferred that common house and landscaping plants be used for the present invention. The present invention enhances the aesthetic qualities of landscape vegetation. The present invention also reduces light pollution and overall energy use. Because the plants themselves illuminate their surroundings, there is no need for landscape lighting and the number of light posts and outdoor lights may be reduced. The softer light of bioluminescence provides for less light pollution than other outdoor lighting. In addition, replacing standard outdoor lighting with bioluminescent plants will result in decreased power usage. This results in a cleaner environment and lower utility bills.
In order to facilitate bioluminescence in plants, at least two genes must be added to the plants. The first is a luciferase enzyme, and the second is a luciferin, the substrate of luciferase. There are many different types of luciferase found in nature. Different luciferases have different luciferins as their substrates. Luciferins are for the most part not interchangeable with other types of luciferase. For example, a firefly luciferase will not induce bioluminescence when exposed to a jellyfish luciferin.
Luciferases and corresponding luciferin have been found in firefly, jellyfish and sea life that live in the bottom of the ocean. For years, they have been used by scientists to study gene regulation and expression in a variety of organisms. Luciferases serve as excellent marker genes because of the ease with which their expression may be detected. Luciferins tend to be complex organic compounds that are oxidized by luciferases. As luciferins are typically not polypeptides, they are produced by complex metabolic pathways. Many of these luciferin catabolic pathways have yet to be elucidated but are believed to require the interaction of several enzymes.
In current genetic expression assays involving bioluminescence, a luciferase gene is spliced downstream from a promoter region to be studied. This recombinant DNA is then inserted into a vector which is subsequently used to transform plant, animal or bacterial cells, depending on a variety of circumstances known to those skilled in the art. The luciferase gene either will or will not be expressed as determined by the promoter region being studied. The cells are then lysed in a bioluminescence buffer and the proper luciferin is added. Emission spectra are then measured. If the sample luminesces it means that the promoter region has induced expression. Those skilled in the art will appreciate that these are common gene expression assays.
Until recently, methods of in vivo production of luciferins were unknown. This is why cells must be lysed and luciferin is then added to them. Typically, luciferins are either organically synthesized or purified from an organism that produces them. This has made luciferins expensive. It has also meant that bioluminescent activity has not been susceptible to transgenic insertion into other organisms. Recently, however, as disclosed in U.S. Pat. No. 5,741,668 to Ward et al., the metabolic pathway for the formation of a luciferin, coelenterrazine has been elucidated.
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