Linkage Map
A linkage map is a genetic map of a species or experimental population that shows the position of its known genes or genetic markers relative to each other in terms of recombination frequency, rather than a specific physical distance along each chromosome. Linkage mapping is critical for identifying the location of genes that cause genetic diseases.
A genetic map is a map based on the frequencies of recombination between markers during crossover of homologous chromosomes. The greater the frequency of recombination (segregation) between two genetic markers, the farther apart they are assumed to be. Conversely, the lower the frequency of recombination between the markers, the smaller the physical distance between them. Historically, the markers originally used were detectable phenotypes (enzyme production, eye color) derived from coding DNA sequences; eventually, confirmed or assumed noncoding DNA sequences such as microsatellites or those generating restriction fragment length polymorphisms (RFLPs) have been used.
Genetic maps help researchers to locate other markers, such as other genes by testing for genetic linkage of the already known markers.
A genetic map is not a physical map (such as a radiation reduced hybrid map) or gene map.
Read more about this topic: Genetic Linkage
Famous quotes containing the word map:
“If all the ways I have been along were marked on a map and joined up with a line, it might represent a minotaur.”
—Pablo Picasso (1881–1973)