What traits can we modify or create?
The genetic modification of organisms originated with the idea of improving the resistance of crops to certain diseases brought on by the introduction of herbicides. In order to prevent these crops from dying, certain bacteria were introduced to the genes of the crops. The disease-resistant genes that existed in the bacteria were extracted from them and then placed into various crops. Genetic modification of plants is also often done with the intent of adding pest-resistant qualities to plants. This is often done by splicing the genes of a plant with the resistant properties of the bacillus thuringiensis (bt), a bacteria most commonly found in soil (5).
While modifications are still widely done to prevent disease and pests from destroying crops, other uses have been found. Genetic modifications can be used to extend the shelf life of crop items. An example of this can be found by looking at the FlavrSavr tomato, the first crop item available for retail in the United States. In order to improve the shelf life of this crop item the enzyme polygalaturonase was isolated in the genetic sequence. This enzyme is responsible for the ripening and eventual molding of fruit plants. The genetic code for this enzyme was then reversed and placed back into the tomato plants, thus slowing their natural ripening progression (4).
Genetic modifications can also be used to do such things as improve the nutrition of certain crop items and increase their resistance to harsh climates. This has proved especially useful in countries where harsh climates often destroy crops essential for the livelihoods of those who grow them.
Today, the most commonly modified crops around the world include soybeans, wheat, alfalfa, cotton, rice, corn and potatoes (1).
Although genetic modifications are often done with the purpose of improving crops and food items, other uses for GM plants are being explored. For example, bananas that have been injected with the genetic code of hepatitis B will grow and contain the antigen for the virus. It is thought that this antigen can be extracted from the bananas and used to create vaccines for human use (3).
While genetic modifications are most widely done on plants, genetically modifying animals is a growing field. While the process of creating these modified animals is very similar to that of modifying plants, one major difference between the two is that genes are often modified within the embryo of that species of animal. The embryo is then implanted into a female of that species and brought to term (2). These embryos can contain genes from other animals of the same species, different species and even in some cases genes from plants such as algae.
Genetically modified animals are created for a variety of reasons. The most well known reason is for the use of medical research. For example, cats that have been modified with genes from jellyfish and rhesus monkeys, have shown increased resistance again feline HIV (see section "A Case Study on GMOs") . Because feline HIV and human HIV and AIDS are closely related, many believe that a better treatments for these viruses can be created from this research (6).
Animals that have been modified for food are also growing in popularity. For example, researchers in China added human fat and chicken enhancers, that contained the code for creating omega-3 fatty acids, to pig embryos. The pigs born from this combination contained omega-3 fatty acids which are not found normally in pig meat. Omega-3 fatty acids are incredibly good for the human body, thus having new sources for these acids could be beneficial (8). Another, perhaps unexpected, example can be seen by looking at the modification of some dairy cows. In Argentina researchers added human milk proteins to the genes of a dairy cow. The cow was then cloned to create Rosita, the first cow that produces milk that is similar in structure to human breast milk. It is believed that this milk could be used to provide newborn babies the nutrients they may not get if their mother is unable to nurse them (7).
Other uses for genetically modified animals also include exotic pets (for example glowing fish) and disease resistance for other animals.
While modifications are still widely done to prevent disease and pests from destroying crops, other uses have been found. Genetic modifications can be used to extend the shelf life of crop items. An example of this can be found by looking at the FlavrSavr tomato, the first crop item available for retail in the United States. In order to improve the shelf life of this crop item the enzyme polygalaturonase was isolated in the genetic sequence. This enzyme is responsible for the ripening and eventual molding of fruit plants. The genetic code for this enzyme was then reversed and placed back into the tomato plants, thus slowing their natural ripening progression (4).
Genetic modifications can also be used to do such things as improve the nutrition of certain crop items and increase their resistance to harsh climates. This has proved especially useful in countries where harsh climates often destroy crops essential for the livelihoods of those who grow them.
Today, the most commonly modified crops around the world include soybeans, wheat, alfalfa, cotton, rice, corn and potatoes (1).
Although genetic modifications are often done with the purpose of improving crops and food items, other uses for GM plants are being explored. For example, bananas that have been injected with the genetic code of hepatitis B will grow and contain the antigen for the virus. It is thought that this antigen can be extracted from the bananas and used to create vaccines for human use (3).
While genetic modifications are most widely done on plants, genetically modifying animals is a growing field. While the process of creating these modified animals is very similar to that of modifying plants, one major difference between the two is that genes are often modified within the embryo of that species of animal. The embryo is then implanted into a female of that species and brought to term (2). These embryos can contain genes from other animals of the same species, different species and even in some cases genes from plants such as algae.
Genetically modified animals are created for a variety of reasons. The most well known reason is for the use of medical research. For example, cats that have been modified with genes from jellyfish and rhesus monkeys, have shown increased resistance again feline HIV (see section "A Case Study on GMOs") . Because feline HIV and human HIV and AIDS are closely related, many believe that a better treatments for these viruses can be created from this research (6).
Animals that have been modified for food are also growing in popularity. For example, researchers in China added human fat and chicken enhancers, that contained the code for creating omega-3 fatty acids, to pig embryos. The pigs born from this combination contained omega-3 fatty acids which are not found normally in pig meat. Omega-3 fatty acids are incredibly good for the human body, thus having new sources for these acids could be beneficial (8). Another, perhaps unexpected, example can be seen by looking at the modification of some dairy cows. In Argentina researchers added human milk proteins to the genes of a dairy cow. The cow was then cloned to create Rosita, the first cow that produces milk that is similar in structure to human breast milk. It is believed that this milk could be used to provide newborn babies the nutrients they may not get if their mother is unable to nurse them (7).
Other uses for genetically modified animals also include exotic pets (for example glowing fish) and disease resistance for other animals.
References
1.) U.S. Department of Energy Genome Program. (n.d.). Genetically Modified Foods and Organisms.
Retrieved from: http://www.ornl.gov/sci/techresources/Human_Genome/elsi/gmfood.shtml
2.) Center for Genetics and Soceity. (14 April 2005). Background: Cloned and Genetically Modified
Animals. Retrieved from http://www.geneticsandsociety.org/article.php?id=386
3.) G.B. Sunil. Kumar, T.R. Ganapathi, D.J. Revathi, L. Srinivas, V.A. Bapat. (21 February 2005). Expression of Hepatits B Surface Antigen in Transgenic Banana Plants. Planta. 222. Retrieved from http://www.springerlink.com/content/j28573pu42212114/
4.) G., Bruening, J.M., Lyons. (July-August 2000). The Case of the FLAVR SAVR Tomato. California Agriculture. 54. Retrieved from http://ucanr.org/repository/CAO/landingpage.cfm?article=ca.v054n04p6&fulltext=yes
5.) Pamela, Ronald. (11 August 2011). Genetically Engineered Crops-What, How and Why. [Web log comment]. Retrieved from http://blogs.scientificamerican.com/guest-blog/2011/08/11/genetically-engineered-crops/
6.) Coghlan, Andy. (11 September 2011). Glowing Transgenic Cats Could Boost AIDS Research.
NewScientist. Retrieved from:
http://www.newscientist.com/article/dn20896-glowing-transgenic-cats-could-boost-aids-research.html
7.) Yapp, Robin. (2011 June 11). Scientist Create Cow that Produces 'Human' Milk. The Telegraph. Retrieved from http://www.telegraph.co.uk/news/worldnews/southamerica/argentina/8569687/Scientists-create-cow-that-produces-human-milk.html
8.) Liangxue, Lai. (2006). Generation of Cloned Transgenic Pigs Rich in Omega-3 Fatty Acids. Nature Biotechnology.
Retrieved from: http://www.ornl.gov/sci/techresources/Human_Genome/elsi/gmfood.shtml
2.) Center for Genetics and Soceity. (14 April 2005). Background: Cloned and Genetically Modified
Animals. Retrieved from http://www.geneticsandsociety.org/article.php?id=386
3.) G.B. Sunil. Kumar, T.R. Ganapathi, D.J. Revathi, L. Srinivas, V.A. Bapat. (21 February 2005). Expression of Hepatits B Surface Antigen in Transgenic Banana Plants. Planta. 222. Retrieved from http://www.springerlink.com/content/j28573pu42212114/
4.) G., Bruening, J.M., Lyons. (July-August 2000). The Case of the FLAVR SAVR Tomato. California Agriculture. 54. Retrieved from http://ucanr.org/repository/CAO/landingpage.cfm?article=ca.v054n04p6&fulltext=yes
5.) Pamela, Ronald. (11 August 2011). Genetically Engineered Crops-What, How and Why. [Web log comment]. Retrieved from http://blogs.scientificamerican.com/guest-blog/2011/08/11/genetically-engineered-crops/
6.) Coghlan, Andy. (11 September 2011). Glowing Transgenic Cats Could Boost AIDS Research.
NewScientist. Retrieved from:
http://www.newscientist.com/article/dn20896-glowing-transgenic-cats-could-boost-aids-research.html
7.) Yapp, Robin. (2011 June 11). Scientist Create Cow that Produces 'Human' Milk. The Telegraph. Retrieved from http://www.telegraph.co.uk/news/worldnews/southamerica/argentina/8569687/Scientists-create-cow-that-produces-human-milk.html
8.) Liangxue, Lai. (2006). Generation of Cloned Transgenic Pigs Rich in Omega-3 Fatty Acids. Nature Biotechnology.