By: Hannah Lee
What is Genome Mapping?
Genome mapping is a method by which researchers can identify the location of a specific gene on a particular region of a chromosome as well as its relative location to other genes on the same chromosome. The two common types of genome maps are linkage maps and physical maps. Linkage maps show how far apart genes are relative to each other on the chromosome using the frequency by which they are inherited together. Physical maps are used to represent chromosomes and use nucleotide bases to measure the approximate physical distance between specific genes.
Applications:
There are several applications that can be made through genetic mapping. Medical applications can be made when researchers try to identify the gene(s) responsible for causing rare disorders caused by monogenic (single-gene) mutations, such as cystic fibrosis. The genes that may cause more common disorders – like asthma – can also be identified. Genome mapping can also provide evidence that “a disease transmitted from parent to child is linked to one or more genes”[2]. Genes linked to desirable traits in crops or livestock can also be located and used to enhance agricultural efficiency; for example, genes that make plants more nutritious or pesticide-resistant can be identified.
Method:
In order to create a genome map, DNA samples, such as blood or hair, must be collected from individuals who have the specific trait or disease being studied. The DNA will be isolated in the laboratory which can be done through several different methods and researchers will look for special patterns in the DNA that only appear in those who have the trait or disease. Once the patterns are identified, genetic markers are tagged; genetic markers are “characteristic patterns in the chemical bases”[3] of the individual’s DNA. Scientists will keep track of those genetic markers and genes that appear particularly close to it on the chromosome, the closer the genes are, the more likely they are to be linked or inherited together. Using this information, researchers are able to construct a genome map.
The Human Genome Project:
The Human Genome Project, or HGP, was a collaborative project from 1990 - 2003 to complete the mapping and decoding of the entire human genome. The project has revealed the human genome holds about 20,500 genes. The HGP was a huge breakthrough in genome mapping and made it possible for people to better understand genomics and the mechanisms to decode genomes for other organisms.
All in all, genome mapping is a process with numerous benefits, for both humans and other living organisms, that has been greatly advanced through modern-day technology.
Sources:
“Genetic Mapping Fact Sheet.” Genome.gov, https://www.genome.gov/about
genomics/fact-sheets/Genetic-Mapping-Fact-Sheet.
“Genome Mapping.” National Center for Biotechnology Information, U.S. National Library of
Medicine, https://www.ncbi.nlm.nih.gov/probe/docs/applmapping/.
“Human Genome Project Information archive1990–2003.” ARCHIVE: Potential Benefits of
the Human Genome Project, https://web.ornl.gov/sci/techresources/Human_Genome/project/benefits.shtml#:~:text=Increasingly%20detailed%20genome%20maps%20have,disease%2C%20and%20familial%20breast%20cancer.
“The Human Genome Project.” Genome.gov, https://www.genome.gov/human-genome
project.
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