Biotechnology

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Biotechnology

Biotechnology is the use of any technique involving living organisms to manufacture or change products, to improve the desired characteristics of a plant or animal, or to alter microorganisms for a purpose.

The word biotechnology was coined in 1919 by Karl Ereky to apply to the interaction of biology with human technology. Today, biotechnology refers to a broad range of technologies from genetic engineering (recombinant DNA techniques) to animal breeding and industrial fermentation. More precisely, biotechnology is defined as the integrated use of biochemistry, microbiology, and engineering sciences in order to achieve technological (industrial) application of the capabilities of microorganisms, cultured tissue cells, and their components.

Biotechnology has a long history. For example, yeast microorganisms were harnessed to prepare wine by Egyptians some 4, 000 years before the birth of Christ. In 1865, Gregor Mendel (1822–1884) presented his laws of heredity, which he deduced by the careful observation of the results of breeding different types of pea plants. Although he did not realize it at the time, Mendel was observing the results of the exchange and altered expression of genetic material.

Biotechnology has undergone a dramatic change since the 1970s. Modern biotechnology is largely based on recent developments in molecular biology, especially those in genetic engineering. Organisms from bacteria to cows are being genetically modified to produce products that include pharmaceuticals and foods. New, biotechnology-grounded methods of disease gene isolation, analysis, and detection, as well as gene therapy, are changing medicine.

The modern day conception of biotechnology, with the deliberate experimental manipulation of genetic material, had its roots in the mid years of the twentieth century. In 1940, deoxyribonucleic acid (DNA) was isolated by Oswald Avery (1877–1955). Thirteen years later, James Watson and Francis Crick (1928– and 1916–2004) described the double helix structure of DNA, a feat that earned them a Nobel Prize just a few years later. The modern age of biotechnology began in 1973, when Stanley Cohen (1922–) and Herbert Boyer (1936–) devised recombinant DNA technology; the deliberate introduction of DNA from one species into another. Their work made possible feats such as the production of human insulin by the bacterium Escherichia coli. This genetically engineered human insulin was, in fact, the first genetically engineered product approved for sale in the United States in 1982.

In theory, the steps involved in genetic engineering are relatively simple. First, scientists decide the changes to be made in a specific DNA molecule. It is desirable in some cases to alter a human DNA molecule to correct errors that result in a disease such as diabetes. In other cases, researchers might add instructions to a DNA molecule that it does not normally carry: instructions for the manufacture of a chemical such as insulin, for example, in the DNA of bacteria that normally lack the ability to make insulin. Scientists also modify existing DNA to correct errors or add new information. Such methods are now well developed. Finally, scientists look for a way to put the recombinant DNA molecule into the organisms in which it is to function. Once inside the organism, the new DNA molecule give correct instructions to cells in humans to correct genetic disorders, in bacteria (resulting in the production of new chemicals), or in other types of cells for other purposes.

Molecular geneticists use molecular cloning techniques to replicate various genetic materials such as gene segments and cells. The process of molecular cloning involves isolating a DNA sequence of interest and obtaining multiple copies of it in an organism that is capable of growth over extended periods. Large quantities of the DNA molecule can then be isolated in pure form for detailed molecular analysis. The now-routine ability to generate virtually endless copies (clones) of a particular sequence is the basis of recombinant DNA technology and its application to human and medical genetics.

A technique called positional cloning is used to map the location of a human disease gene. Positional cloning is a relatively new approach to finding genes. A particular DNA marker is linked to the disease if, in general, family members with certain nucleotides at the marker always have the disease, and family members with other nucleotides at the marker do not have the disease. Once a suspected linkage result is confirmed, researchers can then test other markers known to map close to the one found, in an attempt to move closer and closer to the disease gene of interest. The gene can then be cloned if the DNA sequence has the characteristics of a gene and it can be shown that particular mutations in the gene confer disease.

Differences between the organization of the genetic material of organisms like bacteria and “higher” organisms such as humans, and the difference in how the genetic traits coded for by the material are expressed, has complicated the advances in biotechnology. But, increasingly, such species differences are being understood.

Genetic engineering has resulted in a number of impressive accomplishments. Dozens of products that were once available only from natural sources and in limited amounts are now manufactured in abundance by genetically engineered microorganisms at relatively low cost. Insulin, human growth hormone, tissue plasminogen activator, and alpha interferon are examples. In addition, the first trials with the alteration of human DNA to cure a genetic disorder began in 1991.

Commercial applications of biotechnology are numerous. For example, foods are being genetically altered to engineer in more nutritional compounds. The nutraceutical industry is growing to become a potent economic force, generating billions of dollars in sales each year in the United States alone. Genetic manipulation can also help preserve foods longer, allowing a fresher product to reach the supermarket shelves.

An aspect of biotechnology that has garnered much attention since the 1990s is cloning. Until 1997, a fully developed organism could not be cloned. But, in early 1997, the first success at producing live animals by embryo cloning occurred in Edinburgh, Scotland. The procedure that produced Dolly the sheep was reported in the March 6, 1997 edition of Nature.

While embryo cloning is still a hit or miss procedure, the consensus among researchers involved in embryo cloning is that cloning animal embryos will be perfected. The resulting ease of genetic tailoring could produce higher yielding and disease-resistant livestock.

Cloning embryos is similar to what happens naturally when identical twins are created in the womb. All human embryos begin as a single cell. Normally, millions of rounds of division and the formation

KEY TERMS

Hybridization— Development of new breeds of plants or animals achieved by combining the desired traits of two or more species in controlled breeding.

Recombinant DNA research— A process of DNA modification by which two different DNA molecules are combined.

of cells that differ in structure and function from other cells gives rise to a human. With identical twins, as the cell divides it separates into two separate, individual cells. The two separate, individual cells then divide and differentiate independently. The result is two embryos that are identical in the composition of their genetic material.

In embryo cloning, a cell is mechanically encouraged to divide into two separate, individual cells. These grow and develop separately, creating identical twins. There is continuing debate around the moral and ethical limits on cloning human embryos. As of 2006, it is illegal to use federal research funds in the United States to clone human embryos. In November of 2001, the human cloning debate was raised from a theoretical discussion to a concrete discussion. Then, a company in suburban Boston announced that a human cell had been cloned to provide stem cells for research. While the experiment was carried on for only a few cell divisions, the technology required to develop a cloned human being may be almost in place. Indeed, early in 2006 the same company announced its success in establishing cloned human cells that were capable of at least a few cell divisions.

The prospects offered by biotechnology have not been greeted with unanimous enthusiasm by everyone. Many scientists and laypersons assert that the hope of curing or avoiding genetic disorders through biotechnology is a positive advance. Some hold that the genetically derived nutritional enhancement of foods, such as the nutritional supplementation of rice grown in developing countries, is a worthy aim. Others oppose all forms of genetic engineering, or warn of the dangers of having such technology as the commercial property of a few large companies. There are also concerns about genetic privacy, the effects of transgenic organisms on other organisms and the environment, and animal rights.