Improvement in medical and research technology in the past few years has brought genome mapping to the forefront in several crucial areas.
The basis of this process is a “map” of the genetic structure of an individual organism. Essentially, the system of mapping involves deoxyribonucleic acid (DNA) and another of the basic pieces of identification – chromosomes.
Commonly known as the most basic “stuff” of life for all organisms, DNA is the “instruction sheet” by which living things develop and become individuals. This is where the information about life and living are stored.
The genetic code involving DNA is possible because DNA consists of segments or pieces called genes. These pieces hold the information that provides a unique identity for every individual organism.
Deoxyribonucleic acid or DNA is made of two strands that, if viewed, appear almost as backbones. The tiny structures of life called molecules attach to these strands. Each living thing acquires its appearance and individual characteristics according to how the molecules are arranged along the strands (sequence).
Development of organisms is determined by how DNA “replicates.” In individual cells, DNA is organized in specific ways. The resulting structure is a chromosome. When cells divide the DNA of the original cell is “passed on” to new cells.
In genome mapping, the “fragments” of deoxyribonucleic acid (DNA) are assigned to chromosomes. Researchers find certain “tags” that help in identifying the source of the DNA sample. Fragments can by physically cut by a particular type of enzyme, producing a distinct pattern. This is used for individual identification and no two people are alike (similar to fingerprinting for identification).
Medical research has resulted in this process being used for disease identification. Specific signs or evidence of a particular disease may be evident from genome mapping, a procedure that might determine if there is a link between disease in one generation of a family and possibility of disease in another. This is possible only with the minute pieces of evidence in genes and chromosomes.
In common terms, medical researchers and other scientists use short “sequences” of DNA and places where genes are “on” to tell them where they are in the identification process. This is where the concept of mapping comes in. It’s difficult to describe genome mapping in physical terms because scientists agree that these maps have only one dimension. Human beings are used to maps that have length, width and in some cases, depth. Some research documents have compared the genome map to a straight line that has some identifiable landmarks or markers on it. However, these seldom occur at regular intervals.
Scientific studies and academic texts note that a genome map has less detail than a genome sequence. The sequence indicates the order in which every molecule (base) occurs, while the map identifies only the “landmarks.” Things get a bit more complex sometimes, because mapping and sequencing can be completely separate or they can be somewhat of a “hybrid.” Genome mapping is well underway for humans, but scientists are beginning to employ the process for other large animals as well.