Creating Bt Cotton is one of many biotechnology methods allowing a specific or desired trait/gene to be transferred from a subject to a plant.
In the case of Bt cotton, the subject is an agrobacterium called Bacillus Thuringienesis. (Science Behind Bt Cotton. (n.d.))This bacterium has two genes of interest, the Cry1Ac gene, and the Cry2Ab gene. One product of Bt cotton, called Bollgard, is made using only the Cry1Ac gene, while another product, called Bollgard 2, is made using both the Cry1Ac and Cry2Ab genes. In general, the process of creating both of these products is the same, and there are two methods that can be used.
To begin with, the gene must be extracted from the bacterium. Once the gene is extracted, it is transferred to a gallforming bacteria (agrobacterium) which transfers the gene to the cotton plant. To do this, the agrobacterium is allowed to naturally invade cotton plant tissue in a tissue culture environment, inserting the transferred gene into the DNA of the cotton tissue. The resultant tissue is the cultured and screened to produe a normal cotton plant, only with the new gene in the plant's DNA. This method is most commonly used when transferring the Cry1Ac gene, but can also be used to transfer the Cry2Ab gene.
However, there is another method that was attempted with the transfer of the Cry2Ab gene. This is called the 'gene gun' method. It was developed to remove the requirement for the agrobacterium and to speed up the development and selection process. The gene gun method involves the coating of small gold particles with DNA material required for the insertion (including the Cry2Ab gene) and projecting it into the cell nucleus of the cotton nucleus. Only a small percentage of this method of transfer have been successful, which is why it is not as commonly used as the first method.
The final product of both of these methods of insertion is a normal cotton plant, but containing either one or two new genes which make it Bt cotton.
(How Was Bt Cotton Produced?. (n.d.))
In the case of Bt cotton, the subject is an agrobacterium called Bacillus Thuringienesis. (Science Behind Bt Cotton. (n.d.))This bacterium has two genes of interest, the Cry1Ac gene, and the Cry2Ab gene. One product of Bt cotton, called Bollgard, is made using only the Cry1Ac gene, while another product, called Bollgard 2, is made using both the Cry1Ac and Cry2Ab genes. In general, the process of creating both of these products is the same, and there are two methods that can be used.
To begin with, the gene must be extracted from the bacterium. Once the gene is extracted, it is transferred to a gallforming bacteria (agrobacterium) which transfers the gene to the cotton plant. To do this, the agrobacterium is allowed to naturally invade cotton plant tissue in a tissue culture environment, inserting the transferred gene into the DNA of the cotton tissue. The resultant tissue is the cultured and screened to produe a normal cotton plant, only with the new gene in the plant's DNA. This method is most commonly used when transferring the Cry1Ac gene, but can also be used to transfer the Cry2Ab gene.
However, there is another method that was attempted with the transfer of the Cry2Ab gene. This is called the 'gene gun' method. It was developed to remove the requirement for the agrobacterium and to speed up the development and selection process. The gene gun method involves the coating of small gold particles with DNA material required for the insertion (including the Cry2Ab gene) and projecting it into the cell nucleus of the cotton nucleus. Only a small percentage of this method of transfer have been successful, which is why it is not as commonly used as the first method.
The final product of both of these methods of insertion is a normal cotton plant, but containing either one or two new genes which make it Bt cotton.
(How Was Bt Cotton Produced?. (n.d.))