Biotechnology and Genetics
Farm animals producing life saving medicines in their milk. Fluorescent pets. Crops that synthesize their own pesticides or promise to help vitamin A deficiencies in the developing world. Yep, all real stuff, and all the result of one of the most promising fields in biotechnology: genetic engineering. Transgenic species, GE (genetically engineered) animals, or GMOs (genetically modified organisms) are animals or plants whose genetic makeup has been changed by introducing genes from other species (called transgenes) thus modifying aspects of their form or function. Species manipulated in this way have benefited many fields including agriculture, medicine and industry.
People that suffer from hereditary AT (antithrombin) deficiency do not produce enough antithrombin, a protein in the blood plasma that works as an anticoagulant. During surgery or childbirth, people with this disorder might develop life-threatening blood clots. Under certain medical situations, people suffering from hereditary AT deficiency require replacement antithrombin, usually obtained from human blood plasma. Transgenic goats, however, are able to produce antithrombin in their milk for therapeutic treatment. These goats, bred at GTC Biotherapeutics, have a segment of human DNA coding for antithrombin inserted into their genome. So that this transgene is only expressed in the milk and not in the whole animal, the promoter driving it (basically, the on/off switch for the gene) is from casein – a milk protein. A single goat during a year can produce as much antithrombin as 90,000 blood collections. This is the first product (named ATryn) produced by a genetically engineered animal approved by the U.S. Food and Drug Administration for use in humans (GTC Biotherapeutics, 2010).
A common genetic manipulation in gene studies involves introducing a fluorescent protein derived from the jellyfish Aequorea victoria. The developers of this technique, Osamu Shimomura, Martin Chalfie, and Roger Y. Tsien, won the Nobel Prize in Chemistry in 2008. The technique allows scientists to study when and where genes might be expressed, as the fluorescent "tag" makes their product visible. For example, using fluorescent-labeled virus strain, it is possible to trace how it reproduces and infects new cells. But such technology also has commercial uses. Pretty much any organism could be made fluorescent by inserting this gene, which has since been engineered from its original green color to include red, blue and yellow variants. The Glofish, sold as a pet, is a transgenic fluorescent zebrafish that you can buy and keep at home.
Its likely you've had foods containing some sort of genetically enhanced product. Some varieties of the most common crops in the US are genetically enhanced. Corn, cotton and soybeans have increased productivity, herbicide tolerance and insect and drought protection. "Golden rice" is a variety of Oriza sativa genetically modified to produce beta-carotene (the pre-cursor for vitamin A) in the endosperm (edible part of the grain). By adding two genes to the plant's genome, "golden rice" accumulates this vital chemical. Golden rice was developed to help areas of the world affected by VAD (vitamin A deficiency). VAD is responsible for blindness, amongst other health problems, in children, and approximately 1.5 million deaths a year (Golden Rice Humanitarian Board, 2010). Additional projects underway promise to enhance other major crops and hopefully help with health concerns around the world.
In the future it is likely that genetically engineered organisms will produce vaccines, antibiotics and biofuels, amongst many other needed biological products. This emerging technology, however, has raised many concerns and considerable opposition. Are we interfering with natural evolutionary processes? How safe are products resulting from genetically engineered species? Could there be some unforeseen secondary effects of inserting transgenes? Who owns these species, and how should they be commercialized? As genetic engineering grows and its benefits and drawbacks are further defined, it will be up to you to decide…
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