Biogenetic Engineering

I’m going to turn to a slightly different technique. It’s called genetic engineering. It involves cutting a gene from one organism and paste it into the DNA of another. So as to transfer a trait or characteristics. For example, if the insulin gene is cut from a human chromosome and then pasted into a bacterium, then the bacteria can produce human insulin. Likewise, if the weevil resistance gene from the kidney bean is transferred to the pea then the peas are protected from the insect damage. Gene therapy. With the genetic engineering technique, then gene therapy becomes possible.

It involves inserting a new gene into the body to help fight the disease, or to delete a mutated gene that causes a disease, or to replace a mutated gene that causes disease with a healthy copy of the gene, or to silence or inactivate a mutated gene that is ill functional, or to exchange a mutated gene. We cannot talk about gene therapy without mentioning the vectors. So what is a vector? A vector is a vehicle to insert foreign genetic material into another target cell. For example, we can use virus as a vector to carry the normal human DNA and uploaded or unloaded into the target cell.

There are four major types of vectors: plasmids, viruses, cosmids, and artificial chromosomes. The first two, the plasmids and the viruses are most frequently used. With the viral sector or vector, pardon the target cells such as the patient’s liver or lung cells are literally infected with the virus.

There are four viruses: Retroviruses, Adenoviruses, and the other two viruses. All these viruses do have still have their problems. This is a plasmid vector. It’s a circular DNA. And we use a restriction enzyme to cut open the structure. Now here we have a piece of gene of our interest in the DNA or in the nucleotide, and we cut it open with the same restriction enzyme. And then we glue and paste it into the circular DNA. Now we have a recombinant vector which is ready to upload or unload the gene of interest to the target cell. So as you can tell, the plasmid vector still utilize the traditional cut-and-paste technology, the recombinant DNA technology, with a slight twist. Viral vector.

Let’s look at this example. This cell has the original gene. Now we have a viral vector carrying a new gene to be inserted into the original gene. So this target cell becomes infected by the virus. Now the new gene coexists with the original gene. And typically, we have a so-called marker gene to tell which cells are successfully infected. and which cells are not successfully infected.