Basics Conceding A Genetically Engineered Organelle

By Paul Jackson


The advent of genetically modified organisms, GMOs, continues to generate a heated debate in many quarters all over the world. This has particularly been fuelled by the adoption of genetic engineering techniques in food production. Transgenic organisms, which are created through exchange of genetic materials between different species of organisms are likely to cause even greater divisions. The use of a genetically engineered organelle is also possible.

The nucleus has been the main area targeted by researchers when it comes to genetic modification. Following a number of problems that have been experienced, alternative organelles which can be worked on to bring out similar effects have been sought. Both chloroplasts and mitochondria have their own genome which has made them the most obvious option. The former are only present in green plants while the latter exist in a variety of cells.

Mitochondria are arguably the second most important organelles in cells only second to the nucleus. Their absence within the cell means that the cell will be unable to produce energy essential for most of its processes. While alternative methods of respiration may exist, these are only effective for a limited period of time beyond which the entire cell is likely to die. Mitochondria have their own genome though it is a lot smaller than what is found in the nucleus.

One of the theories that attempts to explain the presence of the genetic material within this organelle claims that mitochondria were initially independent, unicellular organisms. Proponents of this theory believe that mitochondria were initially parasitic organisms but would eventually evolve over thousands of years to be incorporated into cells to become symbiotic. The ovulation led to loss of part of their genome that made it difficult for them to exist independently. The same theory can be used for chloroplasts.

Chloroplasts are organelles found in green plants. They are mostly involved in a process known as photosynthesis which entails food production in the presence of energy derived from sunlight. Other important functions include synthesis of amino and fatty acids and mediation of cellular immune responses. Chloroplasts have a DNA that is often arranged in circular pattern. This DNA is usually inherited by daughter cells after cell division and thus modifications made on it are similarly inherited.

There are a number of processes involved in modifying the genome of an organism. The first step is to isolate the gene that his to be inserted into the organism. Options at this point include synthesis of the desired gene in a laboratory or obtaining it from a living cell. A number of genes which have been identified in the past have been stored in the genetic library and can be obtained from there. To make the gene of interest active, it is combined by other elements such as the promoter and terminator regions.

Once the gene has been isolated, the next step is to have it inserted into the organelle. This may either be the mitochondria or the chloroplast depending on the organism. For bacterial organisms, this process may be aided by either electric shocking or thermal stimulation. Animal cells are modified through microinjection while plant cells may be subjected to agrobacteria mediated recombination, biolistics or electroporation.

It is worth noting that inserting a genetic material into a cell only affects that cell at the time. The cell has to be propagated so as to have a whole organism. Plant cells are regenerated through tissue culture while animal cells are allowed to just undergo cell division since the cells involved are stem cells capable of dividing.




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