Genetic Engineering, 97
In 1953, Francis Crick and James Watson discovered the structure of DNA and opened up a new world of genetic experimentation. Today, 44 years later, biologists are working on projects that might provide possible cures for many genetic diseases. This field, called Genetic Engineering, is becoming a household word even with those segments of our population that are not scientifically oriented. Genetic engineering refers to a number of different techniques that have been developed to create or alter genetic material in various microorganisms, plants, animals, and humans. These changes are made to create new or improved biological products that can be used as foods, medicines, and other purposes. Genetic engineering is used in a large number of fields with research appearing in a number of areas. It involves either altering genes or taking genes from their normal location in one organism and either transferring them elsewhere or putting them back into the original organism in!
different combinations. The simple definition is “a form of applied genetics in which scientists directly manipulate genes” (Towle, 851). Genetic Engineering has many more aspects to it than the definition includes. Some of these aspects are ethics, techniques and regulations. As we move into the next millennium, Genetic Engineering will become more important to society.
The processes and procedures of Genetic Engineering are numerous and can be quite complicated. Before any scientist could begin to utilize the benefits of Genetic Engineering, they had to understand the building blocks of life, or DNA. DNA, or deoxyribonucleic acid, is a double stranded molecule called a double helix. DNA acts like a blueprint of our bodies, containing all of the genetic information. A short segment of DNA makes up a gene that codes for a particular protein. These genes are found on chromosomes and control certain hereditary traits. After scientists understood DNA, they were ready to begin to use it to genetically alter cells.
Gene splicing is one process that scientists use. It involves taking a gene from one organism and placing it in another organism’s DNA. One of the first successful gene splicing experiments involved the DNA of the E. coli bacteria and a human interferon gene. First the plasmid, or small ring of DNA, was removed from the E. coli bacteria. Next a restriction enzyme was used to open the plasmid and create a sticky end. The bacterial plasmid and the human interferon gene were then combined. Because both had sticky ends, they bonded readily. By creating this new plasmid comprised of the human and bacterial DNA, the E. coli bacteria was able to produce insulin in mass quantities.
Another popular technique of Genetic Engineering is cloning. By cloning something, an exact duplicate is made. An example of cloning that appears in nature is identical twins. Scientists use cloning on a daily basis to replicate genetic material. Cloning involves manipulating a cell from an organism so that it grows into an exact duplicate of that organism. Most recently a sheep was cloned. This was a major scientific breakthrough because the sheep was the first mammal ever to be cloned. To clone the sheep, scientists first removed udder cells from a six year old pregnant sheep. The udder cell ( mammary cell ) was chosen because it contains copies of every gene needed to make a sheep. The only problem with this was that only the genes for proteins needed by the mammary cells were active. Scientists overcame this barrier by employing a totally new technique. First they grew the cells in a nutrient rich environment. Then they cut the nutrients back to one twentieth o!
f what the cells needed to grow. Five days later the cells were quiescent, or frozen at the stage of development where their genes are able to be reprogrammed. Next an egg was provided by another sheep with the nucleus removed to eliminate all genetic information coming from the egg donor. A quiescent cell was then fused with the egg by means of an electric spark and clusters of embryonic cells began to grow. Finally the embryos were implanted into a surrogate mother and the lamb that resulted was a genetic duplicate of the donor ewe.
Yet a third form of Genetic