BioCoder #10

Chapter 4. How to Build and Use a Gene Gun

Jay Hanson, Arnie Wernick, and Kyle Taylor

What Is a Gene Gun?

The gene gun is a device used to transfect cells with foreign DNA by bombarding the target cells with DNA-coated microparticles. It was originally developed using plant tissue as the target but can also be used with yeast, bacteria, mammalian cell lines, and insects. In plants, it is one of the few ways to get foreign DNA into chloroplasts as well as genomic DNA. It is called a gene gun because it fires small DNA-coated particles (typically gold or tungsten particles because they are dense) into target cells. This method is called biolistic, a combination of the words “biology” and “ballistics” from the Greek ballein, “to throw.” By adjusting the velocity of the particles, any type of cell wall can be penetrated. It is an effective method for inserting foreign DNA into cells and thus transforming the target cells.

Another popular method of doing plant transformations is to use Agrobacterium tumefaciens, a plant pathogen, to introduce a gene of interest into plant cells. Using this method, Agrobacterium injects the foreign DNA into the plant, where it is incorporated into the plant genome at random locations. However, since it involves using a plant pathogen, the USDA regulates it and has disallowed making available any transgenic plants created using this method. However, transgenic plants created using a gene gun are allowed by the USDA. So that is another advantage the ...