Plant & Soil Sciences eLibraryPRO
Loading
control panel control panel
 

Transformation 2 - Transformation Methods

Rate Me

Gene Gun

 
Troy Weeks uses the gene gun to transform sorghum cells.
Many methods of delivering extra DNA into the nucleus of plant cells have been tried, and several have been successfully used to produce transgenic plants. The first to be discussed is the gene gun, also called particle acceleration or microprojectile bombardment. While this method was used to create several commercial events such as RoundupReady soybean, it has several limitations that make it less appealling than the use of Agrobacterium as a transformation method. We will describe the Agrobacterium method in the next section. The gene gun is a good example of a creative idea being developed into a practical technology.

Microscopic gold particles are used as ’bullets’ to deliver DNA into callus cells.
The gold particles are coated with hundreds of copies of the gene of interest.
The gene gun can be used on either tissue culture cells or seedlings (to make chimeric plants) of any species. As the name implies, this method works by shooting DNA into the plant cells. As seen in these figures from the animation, microscopic gold or tungsten particles are coated with hundreds of copies of the gene(s) to be introduced.

In earlier versions of the gene gun, DNA coated metal was loaded into a 22-caliber cartridge and then shot into plant tissue culture cells. Current versions place the tissue culture cells in a vacuum chamber and then propel the metal particles with a high pressure gas that is released in a sudden burst much like a popped balloon.







Gene gun transformation begins by growing cells in tissue culture, bombarding the cells with gene coated gold particles in the gene gun, selecting out transgenic cells on selection media, and regenerating the transgenic cells into plants. Once inside the nucleus of a cell, the genes dissolve off of the gold particle and can potentially insert into a chromosome. A major limitation of this method is that several copies of the transgene will often insert into a chromosomal position. These high copy insertion events can be detected as DNA that should not be expressed by the plant cell and the transgene copies are silenced.

Comments

Be the first to write a comment...

Control Panel cancel

Create activities for your moodle courses. Moodle Go to moodle
Select and group e-Library Lessons to create your own package... My Communities
Community Blogs Community Media

My Joined Communities

 
My Blogs - a journal of my thoughts... My Blogs
 
My Comments - my thoughts expressed as a feedback... My Comments
 
Classes that I am taking Registered Classes
Class Blogs Class Media
 
Check the scores of assesments that you have taken Taken Assessments
 
clear
Please confirm your selection.