Genetic Engineering: 2012

Outline:

Is feasible to use genetic engineering?

ABSTRACT

Human genetic engineering could be very beneficial to humanity by disallowing children to be born with genetic diseases. Future generations of humans could be designed to improve upon the species. However, there are many potentially irreversible consequences that could occur as a result of genetically engineering an unborn child. The consequences revolve around the potential destruction or alteration of the American social structure and the government. In order to preserve the status of the human race, this technology should be heavily regulated and approached with extreme caution. The usual process of racing to patent an exciting medical innovation should avoided so this idea does not get out of hand. This article provides a background of human genetic engineering and gene therapy as well as the ethics and future involved in making this medical advancement a viable option.

INTRODUCTION

Genetic engineering is by no means a brand new technology. The first genetically modified food was a tomato created in the early 1990’s, and the first mammal was cloned in1996. Like all technology though, genetic engineering continues to rapidly expand.

Genetic engineering of plants and animals is now a widespread process implemented in cultures all over the world; over 100 million hectares of genetically modified crops are cultivated every year. The success of genetically engineered plants and animals has led to the discussions of the risks.

What Is Genetic Engineering?

Genetic engineering refers to a set of technologies that are being used to change the genetic makeup of cells and move genes across species boundaries to produce novel organisms. The techniques involve highly sophisticated manipulations of genetic material and other biologically important chemicals.

Genes are the chemical blueprints that determine an organism's traits. Moving genes from one organism to another transfers those traits. Through genetic engineering, organisms are given new combinations of genes—and therefore new combinations of traits—that do not occur in nature and, indeed, cannot be developed by natural means. Such an artificial technology is radically different from traditional plant and animal breeding.

Novel organisms

Nature can produce organisms with new gene combinations through sexual reproduction. A brown cow bred to a yellow cow may produce a calf of a completely new color. But reproductive mechanisms limit the number of new combinations. Cows must breed with other cows (or very near relatives). A breeder who wants a purple cow would be able to breed toward one only if the necessary purple genes were available somewhere in a cow or a near relative to cows. A genetic engineer has no such restriction. If purple genes are available anywhere in nature—in a sea urchin or an iris—those genes could be used in attempts to produce purple cows. This unprecedented ability to shuffle genes means that genetic engineers can concoct gene combinations that would never be found in nature.

Techniques of Genetic Engineering

Genetic engineering is a very young discipline, and is only possible due to the development of techniques from the 1960s onwards. Watson and Crick have made these techniques possible from our greater understanding of DNA and how it functions following the discovery of its structure in 1953. Although the final goal of genetic engineering is usually the expression of a gene in a host, in fact most of the techniques and time in genetic engineering are spent isolating a gene and then cloning it. This table lists the techniques that we shall look at in detail.

Technique		Purpose
1	cDNA	To make a DNA copy of mRNA
2	Restriction Enzymes	To cut DNA at specific points, making small fragments
3	DNA Ligase	To join DNA fragments together
4	Vectors	To carry DNA into cells and ensure replication
5	Plasmids	Common kind of vector
6	Gene Transfer	To deliver a gene to a living cells
7	Genetic Markers	To identify cells that have been transformed
8	Replica Plating *	To make exact copies of bacterial colonies on an agar plate
9	PCR	To amplify very small samples of DNA
10	DNA probes	To identify and label a piece of DNA containing a certain sequence
11	Shotgun *	To find a particular gene in a whole genome
12	Antisense genes *	To stop the expression of a gene in a cell
13	Gene Synthesis	To make a gene from scratch
14	Electrophoresis	To separate fragments of DNA

Medical Discoveries and Applications

Genetic engineering is the human altering of the genetic material of living cells to make them capable of producing new substances or performing new functions. The technique became possible during the 1950s when Francis Crick (1916-) and James Watson (1928-) discovered the structure of DNA molecules. Crick, Watson and later researchers learned how these molecules store and transmit genetic information.

DNA (deoxyribonucleic acid) is found in the nucleus of all living cells. It is structured as a double helix, with two twisted strands parallel to each other with rungs like a ladder between the strands. Each strand consists of four chemical bases: guanine (G), adenine (A), thymine (T) and cytosine (C). These bases are repeated in particular arrays of sequences throughout the DNA molecule. The patterns they create provide the instructions on how cells will develop and what their tasks will be. DNA is packed into structures called chromosomes within the cell.

Gene Splicing

Genetic engineering allows scientists to identify specific genes, remove them, and clone (duplicate) them and use them in another part of the same organism, or in an entirely different one. For instance, cells of bacteria colonies can be changed by genetic engineering to produce proteins, hormones or other substances that may be useful in treating illnesses in humans or other animals.

This process is called gene splicing or recombinant (as in recombining) DNA technique. Genetic engineers can also increase the amount of certain antibodies for treatment by using hybridomas (altered rapidly growing cancer cells and cells that make antibodies) to form monoclonal anti-bodies. They can also use the polymerase chain reaction technique to make perfect copies of DNA fragments from very small samples so that the origin of the substance (hair, blood) can be identified. This procedure is used in DNA fingerprinting in criminal cases.

Cloning and Engineering

Although the structure of DNA was discovered in the 1950s, it was not until the early 1970s that scientists figured out how to clone and engineer genes. The first experiments were done with simple organisms such as bacteria, viruses and plasmids (rings of free DNA in bacteria). Hamilton 0. Smith, Daniel Nathans and Werner Arber were the first researchers to realize that the bacteria made enzymes, called restriction enzymes, that would "cut" DNA chains in specific places. The scientists could then use these enzymes to cut the DNA into segments, cut out a segment that gave disease-causing instructions, and replace it with a segment that gave correct instructions for healthy functioning.

One could also use this technique to alter a bacterium to perform a certain function (such as making insulin for sugar metabolism) and then reproduce itself many times to provide this hormones for treating diseases such as diabetes. There are limits to this ability, however. Scientists must start with a complete organism, and cannot change everything in it. They can only make a limited number of changes, so the organism can remain essentially the same. Our knowledge of the total genetic code for humans, which contains millions of patterns is limited, so we cannot transfer complicated traits like intelligence, which are a mixture of genetic and environmental influences.

Human Applications

One of the most exciting potential applications of genetic engineering involves the treatment of genetic disorders. Medical scientists now know of about 3,000 disorders that arise because of errors in an individual's DNA. Conditions such as sickle-cell anemia, Tay-Sachs disease, Duchenne muscular dystrophy, Huntington's chorea, cystic fibrosis, and Lesch-Nyhan syndrome are the result of the loss, mistaken insertion, or change of a single nitrogen base in a DNA molecule.

Genetic engineering makes it possible for scientists to provide individuals who lack a certain gene with correct copies of that gene. For instance, in 1990 a girl with a disease caused by a defect in a single gene was treated in the following fashion. Some of her blood was taken, and the missing gene was copied and inserted into her own white blood cells, then the blood was returned to her body. If—and when—that correct gene begins to function, the genetic disorder may be cured. This type of procedure is known as human gene therapy (HGT).

Agricultural Applications

Genetic engineering also promises a revolution in agriculture. It is now possible to produce plants that will survive freezing temperatures, take longer to ripen, convert atmospheric nitrogen to a form they can use, manufacture their own resistance to pests, and so on. By 1988 scientists had tested more than two dozen kinds of plants engineered to have special properties such as these. Domestic animals have been genetically "engineered" in an inexact way through breeding programs to create more meaty animals, etc., but with genetic engineering, these desirable traits could be guaranteed for each new generation of animal.

Potential Consequences of Genetic

Engineering Human genetic engineering undoubtedly has mystical allures. It doesn’t take much of a search to encounter a variety of convincing arguments for the development of human genetic engineering with a purpose of bettering the human species. Adams (2004) argues that the human race is running on outdated software, and in order to continue to positively progress, we need to up date our genetic code with human genetic engineering. The most promising notion of human genetic engineering is the possibility of phasing out genetic diseases completely with germline genetic engineering; if no genetic diseases are passed on to offspring, they will cease to exist(Baird, 2007; Shanks, 2005). As a result, the number of aborted fetuses would decrease dramatically since parents would no longer face the tough decision of aborting their child because it will have a genetic disease. Also, money currently spent by the government to ensure financial stability for genetically disabled humans could be spent elsewhere, leading to certain improvements in other government-funded programs. A more radical possibility of human genetic engineering includes the ability for parents to choose the genes of their children to code for a certain appearance, intellect, and even personality. This ideology might seem closer to science fiction than reality, but if scientists can link a gene to a trait, it can be genetically engineered. For instance, if scientists discovered a particular set of genes that controlled the ability to recognize patterns, those genes could be optimized and placed into embryos. This theory could even extend to the possibility implanting animal traits into humans. Children could be born with the eyesight of an eagle or the scentre cognition of a dog. With all these potential benefits, one could find it hard to imagine why anyone would argue against it. However, the potential downfall of humankind could be just the case to go against human genetic engineering. Is the allure of controlling our own evolution and natural selection overshadowing the imminent threat to our species posed by genetically engineering ourselves? This paper aims to point out the possible pitfalls and negative effects that may be over looked when discussing the future of human genetic engineering. Some may be blind to the many possible outcomes from a lack of knowledge, but others could have their judgment clouded by the excitement of creating genetic super humans. Obvious ethical arguments focus on the notion of “playing God,” but ethical arguments are purely opinion-based. Evans (2002) explains that ethical debates about human genetic engineering naturally turn into political and social debates, and ultimately into debates about who should have jurisdiction over the research. Therefore, ethical views cannot be cited as evidence for or against human genetic engineering. When debating the topic of human genetic engineering, certain fields need to be taken into serious consideration: the effects on the future of the government and on American society and social structure.

Social Outcomes

The social structure of the United States faces drastic changes if genetic engineering reaches the point where it is possible for parents to design the genetic makeup of their children. Classism has existed in the past to a certain degree, but the basis for that classism is unfounded. There is no argument that can disprove the fact that every human is inherently equal in the sense that every human is the same species. If parents have the ability to improve the genetic code of their children, the human species will cease to be just one species. To make that conclusion, several things must be assumed to be true. The first is that the opportunity for parents to design their children would come at a cost. The second is that the majority of the population would not be able to afford such a procedure for their future children. Last is the assumption that such procedures would be performed by privatized companies, not government-owned facilities. By following the first two assumptions, only families with enough money will be able to design their children to be more attractive and intelligent than the average human. These genetically designed children will be more likely to grow up to be financially successful and have enough money to design their own children. This trend would continue, and the lineage of those families would continue to get richer with future generations. By the last assumption, the procedure for genetically engineering one’s child would be performed by a privatized company. With the consumers of the child designing service getting

g richer with each generation, the privatized companies would be able to charge more and more for their services. This seems like a natural trend of economics, but the importance lies in the distance that has been created between the families that can afford to design their children and the families that cannot. Such a system would not allow for that gap to ever be bridged; genetically designed families would begin occupying more positions of power and wealth, driving all other families to lower class positions, closing the door on the dream of designing their own children. Looking far enough down the road, genetically designed humans would occupy a certain percentage of the uppermost echelon of society, while all others would subside to being labor workers and holding positions with minimal power. By this time, one might wonder what the effects have been on the actual genetic code of “humans.” It would not be surprising to find that such extended periods of germline genetic engineering have changed the actual genome of the human species. Very little research exists that aims to prove that possible outcome, but some writers have discussed the thought. Silver (1997) argues that the result of this process would be the separation of humans into two non-mating species – the genetically engineered population and the non-genetically engineered population. The most difficult question will be to decide which species will be considered human. Speculating as to the long-term results of such an occurrence is unimaginable because an event has never transpired among a species with enough self-awareness to understand what has happened. That is not to say that such an occurrence has not taken place among less intelligent species. In fact that occurrence is the reason for the diversity of species on this plant; all species are derived from a common ancestor, separated by genetic changes over long periods of time. African cichlids are a prime example of speciation over a relatively short period of time. Cichlids in Lake Victoria and Lake Malawi exhibit very high rates of speciation resulting from sexual selection (Ritchie, 2007). This example can be applied to the situation of genetically engineered children because the speciation would result from the lack of mating between the genetically engineered population and the non-genetically engineered population.

Conclusions: Bad and Good Aspects

Good Aspects

Gene Therapy:

Gene therapy is used to treat genetic disease at the molecular level by correcting what is wrong with defective genes.

Creation of Disease Resisters:

With genetic engineering, it will be possible to change the genes to make a disease not as serious. The amount of diseases will dwindle and the most relevant diseases will not be as prominent anymore.

Possibilities of Genetic Engineering:

Overtime, new technology will be created. These new types will lead to the creation of a better suited environment.

Bad Aspects

Genetically Modified Organisms (GMOs):

The new technique of genetic engineering presents problems on many levels. Scientists can now create plants, animals, and even microorganism by manipulating their genes in an unnatural way. Genetically modified organisms (GMO) can spread throughout nature and interbreed with natural organisms, which can lead to unpredictable futures. The release of GMOs into the environment is known as "genetic pollution" and causes future threats to our environment since GMOs cannot be recalled once they are in the environment. This causes a moral issue as some people believe that since GMOs are a new invention, they should not be released into the environment, especially because there is not sufficient scientific understanding on how these modified organisms will affect the health of humans and our environment (Green Peace).

Widespread Crop Failure:

Genetic engineers hope to profit by patenting genetically engineered seeds.Most genetically modified crops today have been designed to improve farming, but when a farmer plants these seeds, all the seeds have identical genetic structure. This can lead to widespread crop failure if a fungus, virus or pest develops and attacks the particular crop.

Health Hazards:

Genetically engineered foods have caused the deaths of thirty seven people and caused 1,500 to be partially paralyzed. 5,000 more people were temporarily disabled by a syndrome that was finally linked to Tryptophan made by genetically engineered bacteria.

Ethical Problems:

Genetic engineering raises many ethical problems. Some of these problems include cloning. The first type of cloning was exhibited by Dolly in 1996. The death of Dolly in 2003 posed many questions about the safety of genetic engineering and cloning.

Many critics also worry about where genetic engineering might lead. If we can cure genetic disorders, can we also design individuals who are taller, more intelligent, or better looking? Is that a good application of the technology? Will the altered agricultural products be safe for humans, or will they change us in some unknown way? Will the altered bacteria used to create synthetic versions of substances such as insulin create new bacteria that are harmful to humans? Will humans know when to say "enough" to the changes that can be made? These are some of the ethical questions that surround genetic engineering.

Many other applications of genetic engineering have already been developed or are likely to be realized in the future. In every case, however, the glowing promises of each new technique are balanced by the new social, economic, and ethical questions that are being raised.

Key Words

Gene

A unit of heredity which is transferred from a parent to offspring and is held to determine some characteristic of the offspring; in particular, a distinct sequence of DNA forming part of a chromosome.

Engineering

The branch of science and technology concerned with the design, building, and use of engines, machines, and structures.

Genetic

Relating to genes or heredity.

Organism

An individual animal, plant, or single-celled life form.

Molecule

Group of atoms bonded together, representing the smallest fundamental unit of a compound that can take part in a chemical reaction.

DNA

Biochemistry deoxyribonucleic acid, a substance present in nearly all living organisms as the carrier of genetic information, and consisting of a very long double-stranded helical chain of sugars joined by phosphate bonds and cross-linked by pairs of organic bases.

cell

The smallest structural and functional unit of an organism, consisting of cytoplasm and a nucleus enclosed in a membrane.

human

Relating to or characteristic of humankind

technique

A way of carrying out a particular task, especially the execution of an artistic work or a scientific procedure

disease

A disorder of structure or function in a human, animal, or plant, especially one that produces specific symptoms or that affects a specific part.

species

A group of living organisms consisting of similar individuals capable of exchanging genes or of interbreeding, considered as the basic unit of taxonomy and denoted by a Latin binomial, e.g. Homo sapiens.

References