Genetic Engineering Essay
Genetic Engineering, history and future Altering the Face of Science Science isa creature that continues to evolve at a much higher rate than the beings thatgave it birth. The transformation time from tree-shrew, to ape, to human farexceeds the time from analytical engine, to calculator, to computer. Butscience, in the past, has always remained distant. It has allowed for advancesin production, transportation, and even entertainment, but never in history willscience be able to so deeply affect our lives as genetic engineering willundoubtedly do. With the birth of this new technology, scientific extremists andanti-technologists have risen in arms to block its budding future. Spreadingfear by misinterpretation of facts, they promote their hidden agendas in thehalls of the United States congress. Genetic engineering is a safe and powerfultool that will yield unprecedented results, specifically in the field ofmedicine. It will usher in a world where gene defects, bacterial disease, andeven aging are a thing of the past. By understanding genetic engineering and itshistory, discovering its possibilities, and answering the moral and safetyquestions it brings forth, the blanket of fear covering this remarkabletechnical miracle can be lifted. The first step to understanding geneticengineering, and embracing its possibilities for society, is to obtain a roughknowledge base of its history and method. The basis for altering theevolutionary process is dependant on the understanding of how individuals passon characteristics to their offspring. Genetics achieved its first foothold onthe secrets of nature’s evolutionary process when an Austrian monk named GregorMendel developed the first “laws of heredity.” Using these laws,scientists studied the characteristics of organisms for most of the next onehundred years following Mendel’s discovery. These early studies concluded thateach organism has two sets of character determinants, or genes (Stableford 16).
For instance, in regards to eye color, a child could receive one set of genesfrom his father that were encoded one blue, and the other brown. The same childcould also receive two brown genes from his mother. The conclusion for thisinheritance would be the child has a three in four chance of having brown eyes,and a one in three chance of having blue eyes (Stableford 16). Genes aretransmitted through chromosomes which reside in the nucleus of every livingorganism’s cells. Each chromosome is made up of fine strands of deoxyribonucleicacids, or DNA. The information carried on the DNA determines the cells functionwithin the organism. Sex cells are the only cells that contain a complete DNAmap of the organism, therefore, “the structure of a DNA molecule orcombination of DNA molecules determines the shape, form, and function of theorganism’s offspring ” (Lewin 1). DNA discovery is attributed to theresearch of three scientists, Francis Crick, Maurice Wilkins, and James DeweyWatson in 1951. They were all later accredited with the Nobel Price inphysiology and medicine in 1962 (Lewin 1). “The new science of geneticengineering aims to take a dramatic short cut in the slow process ofevolution” (Stableford 25). In essence, scientists aim to remove one genefrom an organism’s DNA, and place it into the DNA of another organism. Thiswould create a new DNA strand, full of new encoded instructions; a strand thatwould have taken Mother Nature millions of years of natural selection todevelop. Isolating and removing a desired gene from a DNA strand involves manydifferent tools. DNA can be broken up by exposing it to ultra-high-frequencysound waves, but this is an extremely inaccurate way of isolating a desirableDNA section (Stableford 26). A more accurate way of DNA splicing is the use of”restriction enzymes, which are produced by various species ofbacteria” (Clarke 1). The restriction enzymes cut the DNA strand at aparticular location called a nucleotide base, which makes up a DNA molecule. Nowthat the desired portion of the DNA is cut out, it can be joined to anotherstrand of DNA by using enzymes called ligases. The final important step in thecreation of a new DNA strand is giving it the ability to self-replicate. Thiscan be accomplished by using special pieces of DNA, called vectors, that permitthe generation of multiple copies of a total DNA strand and fusing it to thenewly created DNA structure. Another newly developed method, called polymerasechain reaction, allows for faster replication of DNA strands and does notrequire the use of vectors (Clarke 1). The possibilities of genetic engineeringare endless. Once the power to control the instructions, given to a single cell,are mastered anything can be accomplished. For example, insulin can be createdand grown in large quantities by using an inexpensive gene manipulation methodof growing a certain bacteria. This supply of insulin is also not dependant onthe supply of pancreatic tissue from animals. Recombinant factor VIII, the bloodclotting agent missing in people suffering from hemophilia, can also be createdby genetic engineering. Virtually all people who were treated with factor VIIIbefore 1985 acquired HIV, and later AIDS. Being completely pure, thebioengineered version of factor VIII eliminates any possibility of viralinfection. Other uses of genetic engineering include creating disease resistantcrops, formulating milk from cows already containing pharmaceutical compounds,generating vaccines, and altering livestock traits (Clarke 1). In the not sodistant future, genetic engineering will become a principal player in fightinggenetic, bacterial, and viral disease, along with controlling aging, andproviding replaceable parts for humans. Medicine has seen many new innovationsin its history. The discovery of anesthetics permitted the birth of modernsurgery, while the production of antibiotics in the 1920s minimized the threatfrom diseases such as pneumonia, tuberculosis and cholera. The creation ofserums which build up the bodies immune system to specific infections, beforebeing laid low with them, has also enhanced modern medicine greatly (Stableford59). All of these discoveries, however, will fall under the broad shadow ofgenetic engineering when it reaches its apex in the medical community. Manypeople suffer from genetic diseases ranging from thousands of types of cancers,to blood, liver, and lung disorders. Amazingly, all of these will be able to betreated by genetic engineering, specifically, gene therapy. The basis of genetherapy is to supply a functional gene to cells lacking that particularfunction, thus correcting the genetic disorder or disease. There are two maincategories of gene therapy: germ line therapy, or altering of sperm and eggcells, and somatic cell therapy, which is much like an organ transplant. Germline therapy results in a permanent change for the entire organism, and itsfuture offspring. Unfortunately, germ line therapy, is not readily in use onhumans for ethical reasons. However, this genetic method could, in the future,solve many genetic birth defects such as downs syndrome. Somatic cell therapydeals with the direct treatment of living tissues. Scientists, in a lab, injectthe tissues with the correct, functioning gene and then re-administer them tothe patient, correcting the problem (Clarke 1). Along with altering the cells ofliving tissues, genetic engineering has also proven extremely helpful in thealteration of bacterial genes. “Transforming bacterial cells is easier thantransforming the cells of complex organisms” (Stableford 34). Two reasonsare evident for this ease of manipulation: DNA enters, and functions easily inbacteria, and the transformed bacteria cells can be easily selected out from theuntransformed ones. Bacterial bioengineering has many uses in our society, itcan produce synthetic insulins, a growth hormone for the treatment of dwarfismand interferons for treatment of cancers and viral diseases (Stableford 34).
Throughout the centuries disease has plagued the world, forcing everyone to takepart in a virtual “lottery with the agents of death” (Stableford 59).
Whether viral or bacterial in nature, such disease are currently combated withthe application of vaccines and antibiotics. These treatments, however, containmany unsolved problems. The difficulty with applying antibiotics to destroybacteria is that natural selection allows for the mutation of bacteria cells,sometimes resulting in mutant bacterium which is resistant to a particularantibiotic. This now indestructible bacterial pestilence wages havoc on thehuman body. Genetic engineering is conquering this medical dilemma by utilizingdiseases that target bacterial organisms. these diseases are viruses, namedbacteriophages, “which can be produced to attack specific disease-causingbacteria” (Stableford 61). Much success has already been obtained bytreating animals with a “phage” designed to attack the E. colibacteria (Stableford 60). Diseases caused by viruses are much more difficult tocontrol than those caused by bacteria. Viruses are not whole organisms, asbacteria are, and reproduce by hijacking the mechanisms of other cells.
Therefore, any treatment designed to stop the virus itself, will also stop thefunctioning of its host cell. A virus invades a host cell by piercing it at asite called a “receptor”. Upon attachment, the virus injects its DNAinto the cell, coding it to reproduce more of the virus. After the virus isreplicated millions of times over, the cell bursts and the new viruses arereleased to continue the cycle. The body’s natural defense against such cellinvasion is to release certain proteins, called antigens, which “plugup” the receptor sites on healthy cells. This causes the foreign virus tonot have a docking point on the cell. This process, however, is slow and noteffective against a new viral attack. Genetic engineering is improving thebody’s defenses by creating pure antigens, or antibodies, in the lab forinjection upon infection with a viral disease. This pure, concentrated antibodyhalts the symptoms of such a disease until the bodies natural defenses catch up.
Future procedures may alter the very DNA of human cells, causing them to produceinterferons. These interferons would allow the cell to be able determine if aforeign body bonding with it is healthy or a virus. In effect, every cell wouldbe able to recognize every type of virus and be immune to them all (Stableford61). Current medical capabilities allow for the transplant of human organs, andeven mechanical portions of some, such as the battery powered pacemaker. Currentscience can even re-apply fingers after they have been cut off in accidents, orattach synthetic arms and legs to allow patients to function normally insociety. But would not it be incredibly convenient if the human body couldsimply regrow what it needed, such as a new kidney or arm? Genetic engineeringcan make this a reality. Currently in the world, a single plant cell candifferentiate into all the components of an original, complex organism. Certaintypes of salamanders can re-grow lost limbs, and some lizards can shed theirtails when attacked and later grow them again. Evidence of regeneration is allaround and the science of genetic engineering is slowly mastering itstechniques. Regeneration in mammals is essentially a kind of “controlledcancer”, called a blastema. The cancer is deliberately formed at theregeneration site and then converted into a structure of functional tissues. Butbefore controlling the blastema is possible, “a detailed knowledge of theswitching process by means of which the genes in the cell nucleus areselectively activated and deactivated” is needed (Stableford 90). To obtainproof that such a procedure is possible one only needs to examine an earlyembryo and realize that it knows whether to turn itself into an ostrich or ahuman. After learning the procedure to control and activate such regeneration,genetic engineering will be able to conquer such ailments as Parkinson’s,Alzheimer’s, and other crippling diseases without grafting in new tissues. Thebroader scope of this technique would allow the re-growth of lost limbs,repairing any damaged organs internally, and the production of spare organs bygrowing them externally (Stableford 90). Ever since biblical times the lifespanof a human being has been pegged at roughly 70 years. But is this number trulyfinite? In order to uncover the answer, knowledge of the process of aging isneeded. A common conception is that the human body contains an internalbiological clock which continues to tick for about 70 years, then stops. Analternate “watch” analogy could be that the human body contains acertain type of alarm clock, and after so many years, the alarm sounds anddeterioration beings. With that frame of thinking, the human body does not beginto age until a particular switch is tripped. In essence, stopping this processwould simply involve a means of never allowing the switch to be tripped. W.
Donner Denckla, of the Roche Institute of Molecular Biology, proposes the alarmclock theory is true. He provides evidence for this statement by examining thesimilarities between normal aging and the symptoms of a hormonal deficiencydisease associated with the thyroid gland. Denckla proposes that as we get olderthe pituitary gland begins to produce a hormone which blocks the actions of thethyroid hormone, thus causing the body to age and eventually die. If Denckla’stheory is correct, conquering aging would simply be a process of altering thepituitary’s DNA so it would never be allowed to release the aging hormone. Inthe years to come, genetic engineering may finally defeat the most unbeatableenemy in the world, time (Stableford 94). The morale and safety questionssurrounding genetic engineering currently cause this new science to be cast in afalse light. Anti-technologists and political extremists spread falseinterpretation of facts coupled with statements that genetic engineering is notnatural and defies the natural order of things. The morale question ofbiotechnology can be answered by studying where the evolution of man is, andwhere it is leading our society. The safety question can be answered byexamining current safety precautions in industry, and past safety records ofmany bioengineering projects already in place. The evolution of man can bebroken up into three basic stages. The first, lasting millions of years, slowlyshaped human nature from Homo erectus to Home sapiens. Natural selectionprovided the means for countless random mutations resulting in the appearance ofsuch human characteristics as hands and feet. The second stage, after the fulldevelopment of the human body and mind, saw humans moving from wild foragers toan agriculture based society. Natural selection received a helping hand as mantook advantage of random mutations in nature and bred more productive species ofplants and animals. The most bountiful wheats were collected and re-planted, andthe fastest horses were bred with equally faster horses. Even in our recenthistory the strongest black male slaves were mated with the hardest workingfemale slaves. The third stage, still developing today, will not require thechance acquisition of super-mutations in nature. Man will be able to create suchsuper-species without the strict limitations imposed by natural selection. Byexamining the natural slope of this evolution, the third stage is a natural andinevitable plateau that man will achieve (Stableford 8). This omniscient controlof our world may seem completely foreign, but the thought of the Egyptianserecting vast pyramids would have seem strange to Homo erectus as well. Manyclaim genetic engineering will cause unseen disasters spiraling our world intochaotic darkness. However, few realize that many safety nets regardingbioengineering are already in effect. The Recombinant DNA Advisory Committee (RAC)was formed under the National Institute of Health to provide guidelines forresearch on engineered bacteria for industrial use. The RAC has also set veryrestrictive guidelines requiring Federal approval if research involvespathogenicity (the rare ability of a microbe to cause disease) (Davis, Roche69). “It is well established that most natural bacteria do not causedisease. After many years of experimentation, microbiologists have demonstratedthat they can engineer bacteria that are just as safe as their naturalcounterparts” (Davis, Rouche 70). In fact the RAC reports that “therehas not been a single case of illness or harm caused by recombinant engineeredbacteria, and they now are used safely in high school experiments” (Davis,Rouche 69). Scientists have also devised other methods of preventing bacteriafrom escaping their labs, such as modifying the bacteria so that it will die ifit is removed from the laboratory environment. This creates a shield of completesafety for the outside world. It is also thought that if such bacteria were toescape it would act like smallpox or anthrax and ravage the land. However,laboratory-created organisms are not as competitive as pathogens. Davis andRoche sum it up in extremely laymen’s terms, “no matter how much Frostbanyou dump on a field, it’s not going to spread” (70). In fact Frostbran,developed by Steven Lindow at the University of California, Berkeley, wassprayed on a test field in 1987 and was proven by a RAC committee to becompletely harmless (Thompson 104). Fear of the unknown has slowed the progressof many scientific discoveries in the past. The thought of man flying orstepping on the moon did not come easy to the average citizens of the world. Butthe fact remains, they were accepted and are now an everyday occurrence in ourlives. Genetic engineering too is in its period of fear and misunderstanding,but like every great discovery in history, it will enjoy its time of realizationand come into full use in society. The world is on the brink of the mostexciting step into human evolution ever, and through knowledge and exploration,should welcome it and its possibilities with open armsBibliographyClarke, Bryan C. Genetic Engineering. Microsoft (R) Encarta. MicrosoftCorporation, Funk ; Wagnalls Corporation, 1994. Davis, Bernard, and LissaRoche. “Sorcerer’s Apprentice or Handmaiden to Humanity.” USA TODAY:The Magazine of the American Scene GUSA 118 Nov 1989: 68-70. Lewin, Seymour Z.
Nucleic Acids. Microsoft (R) Encarta. Microsoft Corporation, Funk ; WagnallsCorporation, 1994. Stableford, Brian. Future Man. New York: Crown Publishers,Inc., 1984. Thompson, Dick. “The Most Hated Man in Science.” Time 23Dec 4 1989: 102-104