Debate Many human genetic engineering pros and cons are there that have stayed the same since its introduction to humanity. When the humans started harnessing the atomic powers, then just few years later they also start recognizing the effects of human genetic engineering on mankind. Many scientists have a belief that gene therapy can be a mainstream for saving lives of many people. A lot of human genetic engineering pros and cons have been involved since the evolution of genetic engineering.
Plasmids are short circular bits of DNA found naturally in bacterial cells. A typical plasmid contains genes and there are usually around 10 copies of a plasmid in a bacterial cell.
Plasmids are copied separately from the main bacterial DNA when the cell divides, so the plasmid genes are passed on to all daughter cells. They are also used naturally for exchange of genes between bacterial cells the nearest they get to sexso bacterial cells will readily take up a plasmid.
Because they are so small, they are easy to handle in a test tube, and foreign genes can quite easily be incorporated into them using restriction enzymes and DNA ligase. One of the most common plasmids used is the R-plasmid or pBR This plasmid contains a replication origin, several recognition sequences for different restriction enzymes with names like PstI and EcoRIand two marker genes, which confer resistance to different antibiotics ampicillin and tetracycline.
The diagram below shows how DNA fragments can be incorporated into a plasmid using restriction and ligase enzymes. The foreign DNA anneals with the plasmid and is joined covalently by DNA ligase to form a hybrid vector in other words a mixture or hybrid of bacterial and foreign DNA.
Several other products are also formed: The cells receiving the vector are called host cells, and once they have successfully incorporated the vector they are said to be transformed.
Vectors are large molecules which do not readily cross cell membranes, so the membranes must be made permeable in some way. There are different ways of doing this depending on the type of host cell.
This heat shock causes some of the cells to take up the vector, though no one knows why. This works well for bacterial and animal cells. Cells are subjected to a high-voltage pulse, which temporarily disrupts the membrane and allows the vector to enter the cell.
This is the most efficient method of delivering genes to bacterial cells. The vector is first incorporated into a virus, which is then used to infect cells, carrying the foreign gene along with its own genetic material. Since viruses rely on getting their DNA into host cells for their survival they have evolved many successful methods, and so are an obvious choice for gene delivery.
Three viruses are commonly used: Bacteriophages or phages are viruses that infect bacteria. They are a very effective way of delivering large genes into bacteria cells in culture. Adenoviruses are human viruses that causes respiratory diseases including the common cold. Their genetic material is double-stranded DNA, and they are ideal for delivering genes to living patients in gene therapy.
The adenovirus is genetically altered so that its coat proteins are not synthesised, so new virus particles cannot be assembled and the host cell is not killed. Retroviruses are a group of human viruses that include HIV. They are enclosed in a lipid membrane and their genetic material is double-stranded RNA.
This means that the foreign genes are replicated into every daughter cell. After a certain time, the dormant DNA is switched on, and the genes are expressed in all the host cells. This method has been used successfully to transform plant cells, which are perhaps the hardest to do. The gene is first inserted into the Ti plasmid of the soil bacterium Agrobacterium tumefaciens, and then plants are infected with the bacterium.
The bacterium inserts the Ti plasmid into the plant cells' chromosomal DNA and causes a "crown gall" tumour. These tumour cells can be cultured in the laboratory and whole new plants grown from them by micropropagation.
Every cell of these plants contains the foreign gene. This extraordinary technique fires microscopic gold particles coated with the foreign DNA at the cells using a compressed air gun. It is designed to overcome the problem of the strong cell wall in plant tissue, since the particles can penetrate the cell wall and the cell and nuclear membranes, and deliver the DNA to the nucleus, where it is sometimes expressed.
A cell is held on a pipette under a microscope and the foreign DNA is injected directly into the nucleus using an incredibly fine micro-pipette.Genetic Engineering [back to top] Genetic engineering, also known as recombinant DNA technology, means altering the genes in a living organism to produce a Genetically Modified Organism (GMO) with a new genotype.
Various kinds of genetic modification are possible: inserting a foreign gene from one species into another, forming a transgenic organism; altering an existing gene so that its. In the medicine field, gene therapy (also called human gene transfer) is the therapeutic delivery of nucleic acid into a patient's cells as a drug to treat disease.
The first attempt at modifying human DNA was performed in by Martin Cline, but the first successful nuclear gene transfer in humans, approved by the National Institutes of Health, was performed in May The CRISPR technology appears to be another, widening intrusion into what we are made of, and how this wonderful living organism can be altered from within, rather than through the introduction of drug therapies, and other external stimuli.
Genetic engineering can be done with plants, animals, or bacteria and other very small organisms. Genetic engineering allows scientists to move desired genes from one plant or animal into another.
Genes can also be moved from an animal to a plant or vice versa. Another name for this is genetically.
Genetic Engineering. Genetic engineering involves the extraction of a gene from one living organism and inserting it into another organism, so that the receiving organism can . The Positive Effects of Genetic Engineering By Lee Morgan; Updated April 24, Manipulating the genetic makeup of living things is called genetic engineering, and scientists are learning more and more about this process each day.