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Bacteriophage

Phages As Valuable Molecular Tools

Much of what has been learned about the mechanisms of viral infection in general has been discerned through the study of bacteriophage. They have proved to be valuable molecular tools for biotechnology, as they can be used as vehicles to move genetic material from one organism into another organism.

It is through this revolutionary use of phages to introduce foreign DNA into new cells that human insulin was first safely and cheaply produced. In a process called lateral gene transfer, genes from one source are transplanted into a different living cell so that they will give the different cell a new characteristic (found in the first cell). For example, specific human genes are implanted in bacterial cells with the aid of phages that allow bacterial cells to produce human insulin and other valuable protein products in great purity and quantity. Lateral gene transfer has given a new, human characteristic to bacterial cells. Bacteriophage act as the deliverers of transferred genes.

Today, bacteriophage used to inject DNA into host cells for research or biotechnology can be "manufactured" in test tubes. Kits containing bacteriophage proteins and structural components are used to create intact phages from pieces that spontaneously self-assemble under the right chemical conditions. In this way, scientists can customize bacteriphage and the DNA they contain for many uses.

Additionally, bacteriophage are only now beginning to fulfill the dream of Felix d'Herelle, in combating infection in humans and animals. The medical potential of many bacteriophage is great as a treatment for blood infection and meningitis for example, along with a host of bacterial infections increasingly resistant to antibiotics.

Resources

Books

Flint, S.J., L.W. Enquist, R.M. Krug, et al. Principles of Virology: Molecular Biology, Pathogenesis, and Control. Washington, DC: American Society for Microbiology Press, 1999.

Stahl, F.W. We Can Sleep Later: Alfred D. Hershey and the Origins of Molecular Biology. Cold Spring Harbor, NY: Cold Spring Harbor Press, 2000.

Summers, W.C. Felix d'Herelle and the Origins of Molecular Biology. New Haven: Yale University Press, 2000.


Brian Hoyle

KEY TERMS

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Bacteriophage

—A virus that infects bacteria.

Icosahedron

—A 20–sided polyhedron.

Additional topics

Science EncyclopediaScience & Philosophy: A-series and B-series to Ballistic Missiles - Categories Of Ballistic MissileBacteriophage - Bacteriophage Structure, Phages As Valuable Molecular Tools