Ethics, Public Opinion and Genetically Modified Organisms.: Breif Overview of Current GM Techniques

Bacterial Carriers

Bacteria are effective carriers of DNA via the use of a plasmid vector. Bacteria used are specifically chosen based on how they interact with the plant. They are then prepared in a solution which induces their cell wall to become porous. A plasmid which has had a gene of interest inserted will then be able to merge with the bacterial DNA. The bacteria will then display the gene of interest. The bacteria is then cultured and each new cell will express the gene. Upon infecting the target plant, the gene can then be transferred to the plant to allow the desired trait.

Viral Carrier

A virus can make an effective carrier for modifying an organism. The virus chosen will be one that does not cause any kind of disease or death. Through the addition of the chosen DNA to the virus genome, the virus can infect the target. Once the virus invades the cell and makes copies of itself, the chosen DNA can be added to the targeted cell.

Calcium Phosphate Precipitation

The target DNA sequence would be exposed to calcium phosphate, which results in the creation of miniscule granules. The targeted cells react to the granules by essentially 'swarming' them and ingesting them, thereby allowing the granule to release the DNA, delivering it to the host’s nuclei and chromosomes.

Using Electroporation To Create GM Organisms

In electroporation, the prepped target cells are saturated in a solution with the chosen DNA. A brief but strong electric shock is transmitted through the solution, causing little tears in the walls of the cells. This allows for the new genetic material to penetrate the nuclei. Afterwards, the cells are put in a different solution that coaxes the repair of their walls, which works to 'trap' the DNA of the donor in the cell. The chosen DNA becomes joined with the host chromosomes to give the host this new gene.

Gene Silencing Technique

When gene silencing is used, the gene that is responsible for the undesired trait that needs to be silenced will first be identified in the organism. Then, another copy of the gene is attached but in the other direction, which prevents the expression of that trait. For instance, an allergen that triggers an allergic reaction in humans could be 'silenced' in this manner.

Gene Splicing

Gene splicing includes the modification of DNA, and then insertion into a target host cell to allow for genes and resulting traits to be modified. An enzyme is then used to fuse the newly added gene into the chromosome.