A genome map is a visual diagram that represents an organism’s complete genetic structure. Many people confuse genome with genes, but the difference is that the genes are just one part of the genome, which is the entire structure consisting of other components such as the deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). In a sense, a gene map is an outline of just one room in the house, but a genome map is the blueprint of not just the house, but also the backyard, the porch, and the entire lot the house is sitting on. Genome mapping can be applied to any organisms and animals, but probably the most common application is the international project called the “Human Genome Project” that helps decode the entire genome of the human body.
One should always remember that a genome map is just a representation, and not the actual thing itself. It only uses numbers, letters, and colors to symbolize the components in a language humans can understand. Some scientists draw the map in a linear way, like rows and rows of colored bar codes sitting side by side, or on top of each other. These bar codes have a numbered code beside them, such as “D14S72,” that can refer to a certain chromosome. Other scientists prefer illustrating the map in a circle, with little colored lines lined up beside each other and numbers just below them.
The purpose of the genome map is to locate other undiscovered genes by looking at the already-discovered genes that can serve as “landmarks,” very much like a landmark on a city map that tells a driver where he is going. Sequenced DNA, in which scientists have determined how the DNA components are arranged, can also be other landmarks. By analyzing these genes and DNA, scientists can also calculate and predict which genes are connected to them, thereby making the map larger and more comprehensive.
A genome map is very useful when it comes to researching about certain diseases, especially genetic ones such as Huntington’s disease and certain types of cancers. What scientists usually do is trace the genes that have been inherited by a family from generation to generation. It has been found that some gene “landmarks” that have been passed down have a tendency to position themselves closely to the specific gene responsible for the disease. In this way, a genome map helps scientists narrow down and find certain genes and, as a result, help a person or a family take preventative measures to prepare for or guard against the disease.