DNA Technology: An Overview
DNA Technology, otherwise known as Recombinant DNA technology, involves joining DNA molecules from different species of organisms that are inserted into a host organism to produce new genetic combinations.
These genetic combinations are important in the fields of healthcare, agriculture, and science. In simple terms, recombinant DNA technology uses genes to create new genetic combinations that have applications in healthcare, agriculture, and science.
Drugs like insulin, somatropin, etc., owe their origin to the existence of DNA technology. These drugs have been used to manage conditions like diabetes mellitus and Turner's syndrome, respectively.
DNA Technology: Origin
Humans have not always been able to combine genes from plant and animal species to form products. In the late 1960s, Werner, Arber, and Hamilton Smith discovered what are known as restriction enzymes. Restriction enzymes are proteins that bind to specific regions of double-stranded DNA, making cuts in the DNA molecule. The process of making cuts is known as cleaving.
In 1970, Howard Temin and David Baltimore independently discovered the enzyme reverse transcriptase from retroviruses. Reverse transcriptase was then used to develop complementary DNA from messenger RNA.
In 1975, Southern blotting was discovered by Edwin Southern. Southern blotting is a laboratory technique that helps identify a specific DNA sequence in the midst of many samples.
In the 1980s, there was a lot of development in DNA technology. The foot and mouth viral antigen was cloned, there was the cloning and development of the human cancer gene, insulin was commercially produced, and the gene gun was developed.
In 1997, the world's first mammalian clone named Dolly was developed from a non-reproductive cell of an animal through cloning by nuclear transplantation.
Today, scientists can switch selected genes on and off with the aid of the CRISPR-Cas9 reversible gene-editing system.
Types of DNA Technology
DNA sequencing: DNA sequencing involves determining the order of nucleotides in deoxyribonucleic acid(DNA). The correct sequence is Adenine, Guanine, Cytosine, and Thymine. DNA sequences can reveal changes that lead to the development of disease. This is why DNA sequencing is used in diagnosis, treatment, and epidemiology studies.
DNA cloning: This involves isolating and producing multiple copies of a particular gene. DNA cloning is used to create recombinant versions of a gene for different purposes: identifying a normal gene and separating it from an abnormal one, identifying genetic mutations, and for gene studies.
Polymerase Chain Reaction: Polymerase Chain Reaction is a fast method of creating multiple copies of small gene segments. It is used for forensic purposes, the determination of genetic disorders, and the diagnosis of viral conditions like Human Immunodeficiency Virus(HIV).
Gel Electrophoresis: This is a laboratory method used to separate DNA, RNA, and protein molecules based on molecular size and electric charge. It is used in the separation of DNA fragments for DNA fingerprinting, the analysis of polymerase chain reaction results, and in gene studies.
DNA Technology and Medicine: How Technology Improves Healthcare
Recombinant DNA technology has changed the practice of medicine; the prevention, diagnosis, and treatment of disease conditions is a much easier process.
Insulin is one of the miracles recombinant DNA technology has given to medicine: the human insulin injection formulation is used in the management of diabetes mellitus as a stabilizer for blood glucose levels.
Another gift that DNA technology has provided is vaccines: recombinant DNA vaccines have been designed to prevent diseases in human beings and animals. Examples include vaccine formulations for the following viruses: influenza virus, rabies virus, and Ebola virus.
Diagnosis of some clinical conditions like measles and tuberculosis is made simpler with the aid of recombinant DNA technology. Genetic disorders can now be easily identified early for prompt management and counseling. DNA technology is the basis of diagnostic tests that are used to detect the presence of HIV, COVID19, and other viruses.
DNA technology has made a great impact in clinical pharmacology. Synthetic monoclonal antibodies are produced with the aid of recombinant DNA technology, eliminating the need for animals in the drug development process. These synthetic monoclonal antibodies are used in research, cancer therapy, and even in the treatment of COVID19.
Somatropin, the human growth hormone, has been produced with the assistance of DNA technology. It is used in the treatment of conditions like dwarfism, chronic kidney disease, Turner's syndrome, Prader Willi syndrome, short bowel syndrome, HIV-associated muscle wasting, etc.
DNA technology has multiple applications in medicine that make disease prevention, diagnosis, and treatment better, thereby improving healthcare all over the world.
DNA Technology in 2021 and Beyond: The Future
In April 2021, researchers at UT San Francisco and the Whitehead Institute described a new CRISPR tool that allows scientists to switch almost all human genes on and off without altering the human genetic code. This has great clinical significance: genes that are linked with certain diseases can simply be turned off, thus improving health and prolonging life in a large percentage of the human population.
There are many speculations about the of DNA technology. No one knows if human genes will be modifiable for a longer than normal lifespan or there will be the development of a higher, more intelligent species. However, one fact is sure: DNA technology will continue to improve disease prevention, detection, and treatment greatly. In addition, there will be the provision of more personalized health care plans for patients, especially those based on gene studies.
