DNA Fingerprinting in Molecular Biology - Assignment Example

DNA FINGERPRINTING IN MOLECULAR BIOLOGY Although a novice in the scientific fields, DNA fingerprinting became one of the fastest known and adapted genetic technologies in the world. The applications of this field are very large, and its legal and ethical percepts too. This is the technology of the future and will improve constantly with time. The complexity of the technology makes it hard to fathom how Sir Alec Jeffreys was able to discover it in the early 1970s. This was the time when scientific technologies were still in their beginner stages, and it was until 20 or so years later that any real inventions and revolutions were to take place in DNA technologies. Jeffreys began at the simplest, by detecting single copies of the genes and the phenomena of introns. It was this research that introduced the genuine concepts of restricted fragment length polymorphism or RFLP.(Newton, 2004, np) By this technique it was possible to divide the DNA in to smaller pieces, which in turn led to discovery of SNP or single nucleotide polymorphism. The SNP became a designation for points in DNA that show variation in the nucleotide arrangement, which prevents their cutting. These two discoveries were going to affect the entire future of the genetic technologies. (Newton, 2004, np) The discovery of the DNA printing made it an exclusive fact that humans differ substantially from other life forms, a notion he had pride on for many millennia. Now DNA finger printing is a common house hold concept, as people know that in order to identify someone, a small trace of him or her is required in the form of hair, fingerprint, semen, saliva etc. Jeffreys studied the variations in the human DNA, and focused on those variations that would come up in repeat DNA sequences. This research led him to conclude that no two DNA strands can be the same, and act as genetic "fingerprints" to the person.(Sir Alex Jeffreys, 2007, np) The finding again was augmented by data derived from experiments on seal myoglobin genes, where the phenomena of mini-satellites in human genome was discovered. This was a major breakthrough in the start of the research of genetic fingerprinting. (Sir Alex Jeffreys, 2007, np) Mini or micro satellites are located on the non-coding DNA, and it is this DNA that accumulates random variations at faster pace than the coding DNA. Many of these non-coding DNA genes are gene regulators, but a significant amount does not contain any information at all. These "junk DNA" are essentially the phenomenon which is known as the micro-satellites. The micro-satellites contain short and repetitive DNA sequences within the sequence. Usually their location is easily predicted, however, this sequence repetition is variable in every individual.(Olson, 2006, np) It is the micro-satellites that are cut when DNA fragmentation results, which lead to various lengths of band formation or RFLPs. The main concept behind this individuality of specie within itself is the arrangement of base pairs in the DNA. This arrangement difference is what differentiates species and animals and plants, as well as persons from each other. Therefore, every DNA sequence is unique. The DNA sequence in one organism will be the same in all of its cells, whether unicellular or multi-cellular. The number of base pairs is different in every species, along with its configuration, which differentiates the various species from each other. (Antler, 2003, para 1) DNA fingerprinting is now being used in many fields of common life and advanced genetic researches. One of the most interesting areas is the diagnosis of inherited disease within an individual. It is now a known fact that humans inherit many illness genes, which are contributory in progression of the disease. Ethical issues aside, in prenatal and newborn infants, this technology can be used to identify any inherited disorders that they may be carrying, and institute treatment should the need arise. Due to the increased involvement of genetic engineering in every day medical practice, new researchers and specialists such as genetic counselors and researchers are coming to light. While in syndromic families and patients, the DNA fingerprinting may be a good way to screen and treat individuals, there lies a true ethical dilemma about the knowledge and the impact of it on the family and the person himself. The question arises about who has the right to know about the patient's genes. And if a gene is a lethal gene with chances that the disease will not take place in a person's life, should the information be passed on at all. (Betsch, 1994, np) One positive aspect of this fingerprinting at early stages is that it is helping researchers identify more of the defect and ill genes and thereby is increasing their knowledge about the genetic components of the disease. In turn, gene fingerprinting can be a crucial helper in creating treatments and drugs that cure the disease. While the homozygous or heterozygous patterns of most of the diseases are now well known, the individual genetic contribution is many steps ahead in reaching treatments of genetic conditions. (Betsch, 1994, np) DNA fingerprinting is fast becoming a source of identification akin to fingerprinting methods used in the past. With the advent of modern methods of identity theft, the law agencies are looking for fool proof methods to identify people. Now any physical evidence of a person is enough to know the identity of the person, and therefore can help in clearing innocent victims of various crimes. (Betsch, 1994, np) Now DNA fingerprinting is known by a variety of names. These include DNA profile analysis and DNA typing.(Olson, 2006, np) When an RFLP is formed, the solution must be arranged in the sequence of the length of the RFLPs to give it readability. For this purpose, the solution of the DNA fragments are loaded on to a slab comprising of agarose gel and salt solution.(Olson, 2006, np) By application of current, the RFLPs migrate through the gel, with DNA being negatively charged. The speed of migration for each RFLP will vary according to the size of the RFLP. The shorter fragments are able to travel faster than the heavier ones. This pattern can then be seen as bands, which are individual for every person. The image that appears on the x-ray is what gives the technique its name. The more the similarity between the two DNAs, the more similar will be the patterns of the DNA fingerprints. This is how the paternity of a child can be estimated with greatest accuracy, as many of the sequences will match. This technology is therefore one of the best in identifying individuals and their biological relations. (Olson, 2006, np) New approaches and breakthroughs in this field have continued to take place, and have revolutionized the field. Among these was emphasis placed on using stringent hybridization conditions. The procedure has become more sensitive, and the amount of DNA now required to get a complete analysis has been markedly reduced. Profile banding helps clearer image acquisition. Other such introductions and modifications have greatly improved the accuracy of this technique. (Day, 2002, pp. 95) DNA fingerprinting received its first attention from media in 1987, in Bristol, UK. The case was about a burgulary and rape, where the semen sample taken from the victim was used to DNA fingerprint the accused. The perfect match led to the arrest of the burglar. (Day, 2002, pp. 91) The next big application came in immigration areas, where identification of people to their biological families was carried out. The accuracy of the procedure made it one of favorite procedures of the immigration and customs till today. It is essential that in the case of father, seven to eight paternal bands must be the same in the child being tested. Failure to do so excludes the person from paternity.(Day, 2002, pp. 91) One of the most popular trials in DNA fingerprinting was the OJ Simpson trial. While the evidence strongly suggested OJ Simpson as the guilty party, he was acquitted on the grounds about the authenticity of the blood sample on his shoe, and the quality of it. (Smith, 2005, pp 69) This finding points to one of the greatest ethical dilemmas in DNA profiling. The genetic data becomes of questionable value should it become contaminated by physical or chemical means. Older genetic material has a greater chance of getting contaminated, which can jeopardize the authenticity of the sample. Again, not every DNA sample that was acquired from the site of investigation points to the killer, and therefore, thorough investigation is required before a person is called guilty. DNA can be falsely planted and again used for fraudulent schemes, raising the question as to who should have the information about a person's DNA. In the initial DNA fingerprinting, the use of multilocus was widely used. However, in 1986 and 1987, the identification of the single locus took place. The single locus was unique as it provided a certain characteristic that could be matched in 1 in 50 people. These probes were named as the SLPs and the VNTR probes. These probes helped formed two band patterns, and it was this method which later came to be known as the DNA profile. This method however, only gives an outline and not the full picture of the individual. The introduction of the SLPs was beneficial for the jurors who were facing difficulties in understanding these genetic paraphernalia. This method became one of the most used methods for determining paternity. (Day, 2002, pp. 95) Another technology that has made it possible to utilize a small sample of DNA for multiple purposes is through polymerase chain reaction or PCR. This method allows formation of multiple copies of the DNA, which helps in preserving the sample. The PCR machine is capable of reading and reproducing the sequence of the genetic evidence and thereby making several copies of the sample. (Smith, 2005, pp 72) The polymerase enzyme first acts to split the two strands of chromosomes into individual strands. These bases are then paired with their respective new ones. In this manner the DNA strands are split and made again until sufficient copies are attained. THE FUTURE: DNA fingerprinting has revived the forensic identification of the past. While forensic identification is a methodology used from the late 19th century, it was one of the pioneers in identifying various characterizing traits of humans. For example, identification of the blood group types has been done by forensics along with the finger print analysis. It was the forensic departments that first publicized the use of individual marks such as fingerprints in the identification of people. (ASLME, 2004, np) Now with the advent of the DNA fingerprinting, the forensics is again given a new leash in life. Fingerprinting methods were fast becoming an obsolete method as now criminals ensure they leave behind none of their fingerprints. With the help of other genetic samples, the forensics are better able to identify the criminals and bring them to justice. Initially, this technology was not accepted in the courts as being too complicated. However, with simpler methods and more awareness, the juries now agree on the validity of the findings attained from DNA profiles and analysis. The forensics are now working on creating DNA fingerprint data bases. This is primarily done so by storing DNA samples of new born babies via a blood drop obtained. Mostly, this procedure is done for screening out any genetic diseases, or syndromes. However, their use is not limited there. As the time progresses, DNA fingerprints can be used as identity tools, as are being done so right now. (ASLME, 2004, np) THE ETHICAL DILEMMA: While DNA fingerprinting may be a blessing for many medical, legal and law agencies, it still poses many ethical questions by the community. The genetic information is the most personal account of any human being in another person's hands. How this material is used or manipulated can be very tricky. (ASLME, 2004, np) Many people do not feel comfortable about sharing this much information about themselves with the others. While genetic tendencies and lethal genes can be identified, chances are there may be nothing a person can do to rid himself of the condition. The question here becomes should the patient be given an unnecessary burden to carry when it may never take place, or if it does, may not be reversible or curable at all. Misuse of these samples can be carried out advance criminals, thus convicting innocents. Also, disseminating the genetic information of a person to another may lead to serious consequences, such as abortion. This places immense responsibilities on the one who carries the information. He or she is essentially carrying a very vital piece of information that can work both ways. The ethical decisions in this area are very complex. (ASLME, 2004, np) CONCLUSION: DNA fingerprinting is one of the most advanced procedures to date which has increased knowledge about the human functioning many times. This technology is working to identify and cure diseases in people at early stages, and helps them in preventing themselves of developing inherent tendencies for certain diseases. DNA profiling is also increasing effectiveness in locating criminals, in identifying them, and in putting them in jail. It is helping prevent innocent people from getting victimized. It is now one of the biggest areas of research, which is helping the pharmaceutical industries create better drugs. With more information on the way, the human genome as well as all living genome creates a new science and a new biologic reality. WORKS CITED Christine Antler, 2003. A Brief Tour of DNA Fingerprinting. The Science Creative Quarterly, Issue 3, September 07 to April 08. site last accessed on December 13th, 2007 from http://www.scq.ubc.ca/a-brief-tour-of-dna-fingerprinting/ ASLME, 2004. DNA Fingerprinting and Civil Liberties Project, 2004. American Society of Law, Medicine and Ethics. Site last accessed on December 13th, 2004 from http://www.aslme.org/dna_04/description.php David F. Betsch, 1994. DNA Fingerprinting in Human Health and Society. Site last accessed on December 13th, 2007 from http://www.accessexcellence.org/RC/AB/BA/DNA_Fingerprinting_Basics.html Ian N M Day, 2002. Molecular Genetic Epidemiology: A Laboratory Perspective. Published 2002 by Springer publishers. Sir Alec Jeffreys, 2007. An Unmistakable Sign of Identity. Site last accessed on December 13th, 2007 from http://www.epo.org/topics/innovation-and-economy/inventors/archive/2007/jeffreys.html Giles Newton, 2004. Discovering DNA Fingerprinting. Site last accessed on December 13th, 2007 from http://genome.wellcome.ac.uk/node30032.html Andrew Olsen, 2006. Who Done It Fingerprinting and Forensic. Site last accessed on December 13th, 2007 from http://www.sciencebuddies.org/mentoring/project_ideas/BioChem_p009.shtml Gina Smith, 2005.The Genomics Age: How DNA Technology is Transforming the Way We Live and Who. Published by Amacom Div American Mgmt Assn. Read More