Genetic engineering. 2


Genetic Engineering: Science



Genetic Engineering, history and future Altering the Face of Science. Science is a creature that continues to evolve at a much higher rate than the beings that gave it birth. The transformation time from tree-shrew, to ape, to human far exceeds the time from analytical engine, to calculator, to computer. But science, in the past, has always remained distant. It has allowed for advances in production, transportation, and even entertainment, but never in history will science be able to so deeply affect our lives as genetic engineering will undoubtedly do. With the birth of this new technology, scientific extremists and anti-technologists have risen in arms to block its budding future. Spreading fear by misinterpretation of facts, they promote their hidden agendas in the halls of the United States congress. Genetic engineering is a safe and powerful tool that will yield unprecedented results, specifically in the field of medicine. It will usher in a world where gene defects, bacterial disease, and even aging are a thing of the past. By understanding genetic engineering and its history, discovering its possibilities, and answering the moral and safety questions it brings forth, the blanket of fear covering this remarkable technical miracle can be lifted.

The first step to understanding genetic engineering, and embracing its possibilities for society, is to obtain a rough knowledge base of its history and method. The basis for altering the evolutionary process is dependent on the understanding of how individuals pass on characteristics to their offspring. Genetics achieved its first foothold on the secrets of nature's evolutionary process when an Austrian monk named Gregor Mendel developed the first "laws of heredity." Using these laws, scientists studied the characteristics of organisms for most of the next one hundred years following Mendel's discovery. These early studies concluded that each 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 genes from his father that were encoded one blue, and the other brown. The same child could also receive two brown genes from his mother. The conclusion for this inheritance 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 are transmitted through chromosomes which reside in the nucleus of every living organism's cells. Each chromosome is made up of fine strands of deoxyribonucleic acids, or DNA. The information carried on the DNA determines the cells function within the organism. Sex cells are the only cells that contain a complete DNA map of the organism, therefore, "the structure of a DNA molecule or combination of DNA molecules determines the shape, form, and function of the [organism's] offspring " (Lewin 1). DNA discovery is attributed to the research of three scientists, Francis Crick, Maurice Wilkins, and James Dewey Watson in 1951. They were all later accredited with the Nobel Price in physiology and medicine in 1962 (Lewin 1).

"The new science of genetic engineering aims to take a dramatic short cut in the slow process of evolution" (Stableford 25). In essence, scientists aim to remove one gene from an organism's DNA, and place it into the DNA of another organism. This would create a new DNA strand, full of new encoded instructions; a strand that would have taken Mother Nature millions of years of natural selection to develop. Isolating and removing a desired gene from a DNA strand involves many different tools. DNA can be broken up by exposing it to ultra-high-frequency sound waves, but this is an extremely inaccurate way of isolating a desirable DNA section (Stableford 26). A more accurate way of DNA splicing is the use of "restriction enzymes, which are produced by various species of bacteria" (Clarke 1). The restriction enzymes cut the DNA strand at a particular location called a nucleotide base, which makes up a DNA molecule. Now that the desired portion of the DNA is cut out, it can be joined to another strand of DNA by using enzymes called ligases. The final important step in the creation of a new DNA strand is giving it the ability to self-replicate. This can be accomplished by using special pieces of DNA, called vectors, that permit the generation of multiple copies of a total DNA strand and fusing it to the newly created DNA structure. Another newly developed method, called polymerase chain reaction, allows for faster replication of DNA strands and does not require the use of vectors (Clarke 1).

The possibilities of genetic engineering are endless. Once the power to control the instructions, given to a single cell, are mastered anything can be accomplished. For example, insulin can be created and grown in large quantities by using an inexpensive gene manipulation method of growing a certain bacteria. This supply of insulin is also not dependent on the supply of pancreatic tissue from animals. Recombinant factor VIII, the blood clotting agent missing in people suffering from hemophilia, can also be created by genetic engineering. Virtually all people who were treated with factor VIII before 1985 acquired HIV, and later AIDS. Being completely pure, the bioengineered version of factor VIII eliminates any possibility of viral infection. Other uses of genetic engineering include creating disease resistant crops, formulating milk from cows already containing pharmaceutical compounds, generating vaccines, and altering livestock traits (Clarke 1). In the not so distant future, genetic engineering will become a principal player in fighting genetic, bacterial, and viral disease, along with controlling aging, and providing replaceable parts for humans.

Medicine has seen many new innovations in its history. The discovery of anesthetics permitted the birth of modern surgery, while the production of antibiotics in the 1920s minimized the threat from diseases such as pneumonia, tuberculosis and cholera. The creation of serums which build up the bodies immune system to specific infections, before being laid low with them, has also enhanced modern medicine greatly (Stableford 59). All of these discoveries, however, will fall under the broad shadow of genetic engineering when it reaches its apex in the medical community.

Many people 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 be treated by genetic engineering, specifically, gene therapy. The basis of gene therapy is to supply a functional gene to cells lacking that particular function, thus correcting the genetic disorder or disease. There are two main categories of gene therapy: germ line therapy, or altering of sperm and egg cells, and somatic cell therapy, which is much like an organ transplant. Germ line therapy results in a permanent change for the entire organism, and its future offspring. Unfortunately, germ line therapy, is not readily in use on humans for ethical reasons. However, this genetic method could, in the future, solve many genetic birth defects such as downs syndrome. Somatic cell therapy deals with the direct treatment of living tissues. Scientists, in a lab, inject the tissues with the correct, functioning gene and then re-administer them to the patient, correcting the problem (Clarke 1).

Along with altering the cells of living tissues, genetic engineering has also proven extremely helpful in the alteration of bacterial genes. "Transforming bacterial cells is easier than transforming the cells of complex organisms" (Stableford 34). Two reasons are evident for this ease of manipulation: DNA enters, and functions easily in bacteria, and the transformed bacteria cells can be easily selected out from the untransformed ones. Bacterial bioengineering has many uses in our society, it can produce synthetic insulins, a growth hormone for the treatment of dwarfism and interferons for treatment of cancers and viral diseases (Stableford 34).

Throughout the centuries disease has plagued the world, forcing everyone to take part in a virtual "lottery with the agents of death" (Stableford 59). Whether viral or bacterial in nature, such disease are currently combated with the application of vaccines and antibiotics. These treatments, however, contain many unsolved problems. The difficulty with applying antibiotics to destroy bacteria is that natural selection allows for the mutation of bacteria cells, sometimes resulting in mutant bacterium which is resistant to a particular antibiotic. This now indestructible bacterial pestilence wages havoc on the human body. Genetic engineering is conquering this medical dilemma by utilizing diseases that target bacterial organisms. these diseases are viruses, named bacteriophages, "which can be produced to attack specific disease-causing bacteria" (Stableford 61). Much success has already been obtained by treating animals with a "phage" designed to attack the E. coli bacteria (Stableford 60).

Diseases caused by viruses are much more difficult to control than those caused by bacteria. Viruses are not whole organisms, as bacteria are, and reproduce by hijacking the mechanisms of other cells. Therefore, any treatment designed to stop the virus itself, will also stop the functioning of its host cell. A virus invades a host cell by piercing it at a site called a "receptor". Upon attachment, the virus injects its DNA into the cell, coding it to reproduce more of the virus. After the virus ...