Chickens laying pharmaceutical eggs?
The domestic fowl can be very good biofactories!
Chicken eggs are of special interest to pharmaceutical companies as eggs can be manipulated to produce therapeutic proteins in their whites. These manufactured proteins can be extracted and used to make pharmaceutical products. Avian eggs naturally produce large amounts of protein, mainly ovalbumin, in their albumen or egg white. (Lillico, S. G.., et. al)
The Roslin Institute, where Dolly the first mammal clone was born, have again achieved yet another milestone; this time involving transgenic chickens. Chickens have been engineered to produce proteins needed for anti-cancer drugs in their egg whites. (BBC News, 2007)
Other animals including sheep and cattle can also be genetically modified to make useful human proteins in their milk. But chickens with their shorter life cycles and egg laying ability allow them to be valuable pharmaceutical sources. The production of life-saving proteins in the egg whites of chickens may open up a pathway for faster and less costly drugs. Further advantages include the large supply of drugs that can be generated due to the considerable egg productivity, and viability to produce proteins toxic to mammalian cells. (Lillico, S. G.., et. al)
However, unlike the mammals, the egg is harder to genetically modify because it is not so transparent. This feature of the chicken egg makes viewing for injection difficult. Transgenic chickens are the result of injecting substances (e.g. DNA to make a certain protein) into the embryos. The difficult hurdle is to create a suitable environment for the extracted embryo to develop normally after the injection. (Union of Concerned Scientists, 1998)
Chicken eggs are of special interest to pharmaceutical companies as eggs can be manipulated to produce therapeutic proteins in their whites. These manufactured proteins can be extracted and used to make pharmaceutical products. Avian eggs naturally produce large amounts of protein, mainly ovalbumin, in their albumen or egg white. (Lillico, S. G.., et. al)
The Roslin Institute, where Dolly the first mammal clone was born, have again achieved yet another milestone; this time involving transgenic chickens. Chickens have been engineered to produce proteins needed for anti-cancer drugs in their egg whites. (BBC News, 2007)
Other animals including sheep and cattle can also be genetically modified to make useful human proteins in their milk. But chickens with their shorter life cycles and egg laying ability allow them to be valuable pharmaceutical sources. The production of life-saving proteins in the egg whites of chickens may open up a pathway for faster and less costly drugs. Further advantages include the large supply of drugs that can be generated due to the considerable egg productivity, and viability to produce proteins toxic to mammalian cells. (Lillico, S. G.., et. al)
However, unlike the mammals, the egg is harder to genetically modify because it is not so transparent. This feature of the chicken egg makes viewing for injection difficult. Transgenic chickens are the result of injecting substances (e.g. DNA to make a certain protein) into the embryos. The difficult hurdle is to create a suitable environment for the extracted embryo to develop normally after the injection. (Union of Concerned Scientists, 1998)
By Michelle Wong
41194993
Primary Resources:Lillico, S. G.., Sherman, A., McGrew, M.J., Robertson, C.D., Smith, J., Haslam, C., Barnard, P., Radcliffe, P.A., Mitrophanous, K.A., Elliot, E.A., Sang, H.M. 2007. Oviduct-specific expression of two therapeutic proteins in transgenic hens. Proceedings of the National Academy of Sciences of the United States of America, 104, pp1771-1776.
Petitte, James N., Mozdziak, Paul E. 2007. The incredible, edible, and therapeutic egg. Proceedings of the National Academy of Sciences of the United States of America, 104, pp1739-1740.
Secondary Resources:
BBC News (2007) ‘Anti-cancer chicken eggs produced.’ Accessed May, 2007.
http://news.bbc.co.uk/2/hi/science/nature/6261427.stm
Union of concerned scientists (1998). The Gene Exchange. Accessed May, 2007.
http://go.ucsusa.org/publications/gene_exchange.cfm?publicationID=271
For interest you can read about the ethical issues on transgenic chickens here:
http://www.upc-online.org/genetic/102803ge.htm
