A technique of making changed in the genetic material of an organism using the scientific techniques is called genetic engineering. Due to these changes cells become able to perform different functions.
DNA is the basic unit of our body and it is the blueprint of the hereditary material which passes the information from parents to the offspring. It is the DNA which makes features of an individual and every individual has different features. The segments of the DNA molecule are called genes which enable the DNA to make features. Molecular cloning and transformation are the techniques which are used in genetic engineering. These techniques alter the structure of genes.
Genetic engineering has applied its techniques successfully in every field but the field of medicine and agriculture has taken advantage of genetic engineering most. For example the production of insulin for humans which is used to fight against the diabetes. Modified bacteria were used in making of human insulin. This genetically modified insulin when inserted in the body; it fulfills the need for the insulin. Genetic engineering has succeeded in making the genetically modified mice which are also called as oncomouse or cancer mouse to do research for the disease of cancer. In agriculture, genetic engineering techniques have developed genetically modified crops with more nutrition.
Methods of Genetic Engineering:-
There are three main methods through which genetic engineering techniques work:
The Plasmid Method:-
Plasmid method is the most commonly used method of altering the genes of any microorganism. Bacterial genetic variations take place through this method. Plasmid method occurs in the following way:
1) A plasmid which is a small piece of DNA molecule is used in this method. It is inserted in a container which is already containing the restriction enzymes. These enzymes work together to cut the plasmids into small pieces.
2) Using the restriction enzymes, these cut pieces of plasmids are inserted into the bacteria due to which sticky ends are produced.
3) These sticky ends allow the complementary sequences of DNA molecules to come together and fuse with each other making a ring of DNA molecule. Now some other enzymes are used to make those ringed DNA molecules more stable in the container. After the stability of DNA molecules, they are put in safety to use for further processes.
4) A culture of live bacteria is prepared in which these well formed plasmids or DNA molecules are placed. These plasmids will enter into the bacterial cell and will start expressing themselves as soon as they will enter the cell. In this expression, the plasmids will be able to synthesize new proteins or antibiotic resistance genes. These antibiotic resistance genes distinguish the plasmid bacteria from the non plasmid bacteria.
Scientists use these bacteria for various purposes like drug delivery or other purposes. Some people oppose this method as they say that there are chances that the bacteria might express their own genes and those genes do not have the useful results. Through this method oil spills are also cleaned by using such bacteria.
The vector method:-
Vector method is quiet different from the plasmid method in the sense that in vectors method, vectors of viruses are used which are inserted in the host cell. This method of genetic engineering is better than the plasmid method because it gives good results in the host when the desired features are tested in the host. In this method, when the viral vector is inserted in the host cell, it will start replicating itself by using the genetic information of the host cell.
The Biolistic method:-
This method is also called as gene gun method. This method is totally different from the other two methods because it is related to the engineering of the plants. The required genes are inserted in the gun which is made up of tungsten and are triggered in the host cells. This is how the plants show traits and characteristics for which the DNA was triggered in them.
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