A vector is a recombinant DNA carrier, all types have three generic properties; introduction to the host cell can be accomplished easily, each vector contains a replication origin enabling it to reproduce inside the cell and in order to determine which cells contain the vector a simple assay can be carried out, such as, growing the cells on agar plates. At present, there are many different types of vectors available for use the best expression system depends on the gene involved (Hartl, 2011). Examples of vectors include; Plasmids, Bacteriophages, Artificial chromosomes, bacteria, cell free systems and viruses (Klug et al., 2003). The fundamentals of molecular genetics is centred around the “Central Dogma”, this governs protein expression and demonstrates how genetic information in DNA is expressed in a polypeptide chain as show in Figure 1 below.
DNA does not code directly for proteins it does so through Ribose Nucleic Acid (RNA), a similar molecule to DNA but, the sugar it contains is called ribose, the molecule itself is single stranded and within the nucleotide base Thymine (T) is replaced with Uracil (U) which still binds to Adenine (A) in the same manner. There are three types of RNA, messenger RNA (mRNA), ribosomal RNA (rRNA) and transfer RNA (tRNA) as well as this, each gene includes a particular nucleotide sequence that initiates and stops transcription. Each of which are involved in the intermediary process of transcribing and translating DNA into a protein (Hartl, 2011).
With the use of recombinant DNA essential products can be produced on a large scale in a short period of time i.e. human insulin for type two diabetics. As well as this there are various agricultural advantages, such as, the growth rate of some animals...
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...ely monitored. Taking all these points into consideration, the future of gene therapy has great potential (Cummings, 2003).
References:
Balazs, D. A. G. W., 2011. Liposomes for use in Gene Delivery. Journal of Drug Delivery, 2011(326497), p. 12.
Cummings, M. R. K. W. S., 2003. Concepts of Genetics. 7th ed. Chicago: Prentice Works.
Gan, C., 1989. Gene gun accelerates DNA coated paritcles to transform intact cells. The Scientist, 3(18), p. 25.
Hartl, D. L., 2011. Essential Genetics: A Genomics Perspective. Fifth edition ed. s.l.:Jones and Bartlett.
McCluskey, D. J., 2013. Genetic approaches to treating disease. Coleraine: Univeristy of Ulster.
Robbins, P. D. G. S. C., 1998. Viral vectors for gene therapy. Pharmacology and Therapeutics, 80(1), pp. 35-47.
Sara Cormier, D. D. T. D. J. Z., 2009. Hamilton-Wentworth District School Board, California: McMaster University.
Brooker R J. Genetics: Analysis and Principles. Twin Cities (MN): McGraw Hill; 2005. 842 p.
There have been four somewhat recent successful gene therapy treatments. The four deal with correcting hemophilia, bone marrow transplants, skin cancer, and vessel growth. In the success with the bone marrow transplants, French researchers collected bone marrow cells from patients, used gene therapy to correct the bone marrow, and then returned the bone marrow to the patient. This was 80% successful as reports 16 months after the transplants showed. Squamous cell carcinoma, skin cancer of the head and neck, was treated using gene therapy as well. The fourth trial was where DNA was used to carry a substance that stimulates blood vessel growth to damaged heart tissue and in this trial there was much success noted.
[7] Klug, W., Cummings, M., Spencer, C., Palladino M. (2012) Concepts of Genetics: Tenth Edition. Pearson's Education, Inc.
It was in the 1980’s that scientist began looking at alternative ways of treatments, one is gene therapy. Scientist would insert human genes into a bacteria cell. Then the bacteria cell would transcribe and translate the information into a protein. Once that is done the scientist would then introduce the protein into human cells. Gene therapy can be simply viewed as inserting bits of foreign DNA into a patient’s tissue in hope...
Gene therapy works by introducing new and functioning genetic material to damaged genes to help it function and to produce beneficial proteins. If a gene is inserted directly into a cell, it usually will not function. So to complete this task, a vector, a modified virus is used to carry and deliver the new gene. There are two different categories of vectors than can be utilized in this process; recomb...
Another hurdle is that the expression of the desired genetic product is often localized to the tissues in which the vectors are introduced. Thus muscle-targeting vectors need to be developed to allow systemic treatment of DMD. Finally, the use of viral vectors to introduce genetic material may carry a risk of insertional mutagenesis as fraction of the viral vector may be integrated into the host genome.
...y into a cell it usually will not function the desired way. Instead, a carrier called a vector is genetically engineered to deliver the gene. Certain viruses are often used as vectors because they can deliver the new gene by infecting the cell. The viruses are modified so they can’t cause disease and will not be fought off by the patient’s immune system. The vector can be injected or given by IV directly into a specific place in the patient’s body. The vector can also be introduced after , a sample of the patient’s cells are removed and exposed to the vector in a lab. The cells with the vector are then returned to the patient.
Li, Julang. "Mechanisms Involved in Targeted Gene Replacement in Mammalian Cells." Genetics. Vol. 156, 809-821. Oct. 2000.
Cummings, Michael R. & William S. Klug. Concepts of Genetics 4th Ed. New York: Macmillan College Publishing Company, 1994
...logy. In L. R. Castilho, A. M. Moraes, E. F. P. Augusto & M. Butler (Eds.), Animal cell technology: From biopharmaceuticals to gene therapy (pp. 1-12). Abingdon, OX: Taylor & Francis Group.
Gene therapy is a method used by doctors that ‘uses genes as medicine’. It repairs faulty or damaged gene copies by transferring a therapeutic or working gene into specific parts of faulty gene copy. This means that gene therapy can be used to replace a faulty gene or to introduce a new gene whose function is to modify the clinical course of a condition or to cure a problem in the gene (Refer to image 2). Image 1 shows how gene therapy is completed using an adenovirus vector while image 2 explains the method of gene therapy and shows how cells are removed, altered and injected back into the patient. Gene therapy has potential to treat and cure many medical conditions such as various types of cancer, degenerative diseases and viral infections such as AIDS. Research into gene therapy still needs to be done before this approach to the treatment of certain conditions will realise its full potential. Trials are being conducted in the United States and Europe and a modest number initiated in other countries, including Australia. The majority of these trials are focussing on treating acquired conditions such as cancer (European Society of Gene & Cell therapy, 2011).
5. Leiden, Dr. Jeffrey M. "Gene therapy -- Promises, Pitfalls, and Prognosis." The New England Journal of Medicine 28 September 1995: 871-873.
Current research methods of transfection, delivering foreign DNA into cells, have capitalized on using non-viral vectors because of the recent advantages researchers have been able to exploit. The process of transfecting cells runs into a number of problems by way of the cell’s own defense mechanisms. Vectors must be able to not only enter the cell past the cell’s membrane but also must be able to make its way into the cell’s nucleus to access the targeted genetic material. The problem with traditional transfection methods is that they are not able to enter the cell in high efficiency without triggering an immune response. This, coupled with the inability for prolonged gene expression in vivo even once transfected, results in a very expensive and ineffective method for introducing a foreign plasmid into the cell. In the past viral vectors had been used with a degree of success in vitro, but because they lack a high degree transfection efficiency and duration of gene expression using them for transfection could not produce substantial practical applications. Another problem is that these laboratory-engineered viruses had low success rates in vivo due to activating an immune response. New techniques are being discovered by modifying non-viral vectors in novel ways, producing increasingly effective methods for transporting DNA into cells with the hope of clinical application and advancing gene therapy.
Gene therapies necessity, stems from the fact that it can cure, life threatening gene based diseases, with minimal after effects. Although there are some ethical and physical issues that can occur through this technology, when comparing it to the other genetic technologies, it’s quite reliable. Although it is in its infancy, the technology has still been present for several years, with the first case of gene therapy being done in 1990. Sure, there have been some complications, but its still a growing technology with a strong future in front of
Gene therapy is an experimental technique that uses genes to treat or prevent disease. Currently, there are a lot of studies and experiments that allow doctors to treat a disorder by inserting a gene into a patient’s cells instead of using drugs or direct surgery. Researchers are testing several approaches to gene therapy, such as replacing a mutated gene that causes disease with a healthy copy of the gene, inactivating, or “knocking out,” a mutated gene that is functioning improperly, introducing a new gene into the body to help fight a disease, and helping to regenerate precious cells. Although gene therapy has a very active and promising approach for a number of disease, there are still several risks and side effects. Hence, the therapy