Biotechnology and DNA Structure, Replication, and Technology
Better Living through Biotechnology
Over the last 30 years, biotechnology has completely reshaped the way we live our lives. A discussion over whether this has been a good or a bad thing is in the Ethics section. Nevertheless, there have been many major advances since the advent of PCR and recombinant DNA techniques.
One of the most significant advances is the sequencing revolution. We now can easily sequence whole genomes upward of 3 billion bases, which gives us almost more information than we know what to do with. Most genome sequencing is done by "shotgun" sequencing chunks of DNA in BACs, which is a sequencing technique that is random and scattered over large parts of the genome, much like how a shotgun shoots. The National Science Foundation (NSF) has begun a project looking at sequencing multiple different species to recreate the "Tree of Life." This tree should not be confused with Shmoop's horror movie Tree of Death that opens next summer.
Over 180 different species have had their genomes sequenced. While this research has proven to be interesting, the final usefulness of this sequencing effort has yet to be realized. One practical vision is that, in the near future, personal genomics will be a reality, where each person will have their genome sequenced, and we can easily tailor what types of medicines would be appropriate for an individual based on their genomic information.
The use of biotechnology has completely revolutionized medicine. Now it is much easier to generate vaccines than it was previously, and more effective vaccines can be made through biotechnology. DNA technology and sequencing allows us to perform DNA tests to determine paternity, to calculate the probability of developing a genetic disorder, and even to identify a missing person or murderer. However, being a psychic detective has nothing to do with biotechnology. If an individual has a genetic disorder, we can repair it through gene therapy (see the "Spiderman and Other Examples of Recombinant DNA" section).
Plant biotechnology is one of the most discussed uses of biotechnology, with much work focused on improving crop yield by making plants resistant to pesticides, pests, droughts, and other environmental stresses. Other work includes actually improving the amount of useable crop a plant will yield, or even improving the taste, texture, or appearance of food. One example is modifying plants so that they do not spoil so quickly, or can make enzymes for food production. With all this biotechnology improving the quality of food, we at Shmoop like to use the good old-fashioned way of making vegetables more palatable: adding a lot of cheese.
One example of genetically modifying plants to produce enzymes is the production of a "vegetarian" variant of rennet. Rennet is an enzyme used to coagulate cheese, and many vegetarians do not eat cheese because animal rennet is used, which is derived from sheep intestines. Production of "vegetarian" rennet from E. coli is an active industry, as is production of maltogenic amylase, an enzyme that keeps bread fresher and longer. These examples show how biotechnology improves or allows us more opportunities to consume food.
Another intriguing use of biotechnology is the concept of "pharming," where plants and animals produce chemicals that can be used medicinally simply through their consumption. Examples of pharming are plants that make insulin or proteins for certain vaccines, as well as added nutrients. "Golden rice" is an example of genetically modified rice that has more vitamins, and was intended for consumption in developing countries.
Biotechnology applications that have yet to be fully realized, but hold potentially amazing results, include the following: bioremediation, or the process of using bacteria to remove environmental pollutants; biocomputers, or computers that use biological molecules like DNA and proteins to perform computational tasks; and nanobiotechnology, or the nexus of nanotechnology and biotechnology. The much-discussed field of "cloning" whole organisms has had few successes, but the ethical ramifications of such work have drawn such ire that cloning research has progressed slowly. Or, maybe the dislike of clones is due to everyone hating Star Wars Episode II: Attack of the Clones.