Dna Technology
DNA technology is a broad area that covers any use of deoxyribonucleic acid (DNA) modification for purposes that benefit humans. This includes relatively straightforward routines, such as the production of genetic maps using restriction enzymes, all the way through to highly controversial procedures, such as modification of the genome itself to produce desirable effects.
Technology utilizing DNA can be used for purely investigative reasons. This includes such techniques as genetic fingerprinting in all of its guises. This suite of techniques allows researchers to produce genetic maps of chromosomes based on restriction enzyme digests. One of the better-known applications of genetic fingerprinting is in the investigation of parentage of an individual. Another is in the analysis of a crime scene and the consequent detection of the culprits. In both of these cases the same basic idea is utilized. DNA from a sample (either from a child or from a crime scene) is digested to produce characteristic bands that are visualized under UV light after the dyed and digested DNA has been subjected to an electric current. The pattern of bands can then be compared to the presumed parents' DNA banding, and, if matching bands are present, the parentage can be confirmed. With criminal investigations, the DNA sample is compared to that of a suspect, and, if there is a perfect match of bands, the DNA is said to belong to that individual.
DNA technology that deals with actual modifications of the genome is far more controversial than the above cases (which are themselves not free from controversy). Any organism that has DNA can have this DNA modified in one of two ways. The first and simplest involves a modification for that individual. This approach can be used to treat some human diseases. For example, where specific genes are missing and the appropriate proteins are not being manufactured, it is possible in some cases to add the relevant DNA to cells, and this DNA is then expressed to provide the missing protein. Because the corrected DNA cannot be passed from a parent to a child, it is called a non-heritable change. The second and more complex approach involves heritable modifications of the DNA, which can then be passed on to offspring. Heritable changes to human genomes are ethically problematical and, consequently, this approach is more commonly applied to other organisms.
Heritable changes may be carried out on nonhuman organisms for a number reasons, the commonest being to mark populations. For example, many bacteria have genes for antibiotic resistance inserted so the populations can be studied. Genes from other species can also be added; for example, bacteria, mice, and plants have all had luminescent genes from jelly fish added to their genomes for monitoring purposes. Another common reason for adding genes to a foreign organism is for the manufacture of alien products. Some cows have been modified so that they can produce human insulin in their milk. Pigs have been modified to overcome a number of transplantation problems so that some limited transplantation of organs can be carried out from pigs to humans.
DNA technology is a new area of research that still retains enormous controversy. This situation will likely continue for many years as public debate continues and advancing technology constantly out paces the requisite legislation.
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