Gene mapping

Genome mapping is the creation of a genetic map assigning DNA fragments to chromosomes.

When a genome is first investigated, this map is nonexistent. The map improves with the scientific progress and is perfect when the genomic DNA sequencing of the species has been completed. During this process, and for the investigation of differences in strain, the fragments are identified by small tags. These may be genetic markers (PCR products) or the unique sequence-dependent pattern of DNA-cutting enzymes. The ordering is derived from genetic observations (recombinant frequency) for these markers or in the second case from a computational integration of the fingerprinting data. The term "mapping" is used in two different but related contexts.

Two different ways of mapping are distinguished. Genetic mapping uses classical genetic techniques (e.g. pedigree analysis or breeding experiments) to determine sequence features within a genome. Using modern molecular biology techniques for the same purpose is usually referred to as physical mapping.

Physical Mapping

Physical Mapping is the process of determining how DNA contained in a group of clones overlap without having to sequence all the DNA in the clones. Once the map is determined, we can use the clones as a resource to efficiently contain stretches of genome in large quantity. This type of mapping is more accurate than genetic maps.

In maps based on a genetic fingerprinting of the clones, the stretches of DNA are identified according to how they are cut by a restriction enzyme. Once cut, the DNA fragments are separated by electrophoresis. The resulting pattern of DNA migration (ie. its fingerprint) is used to identify what stretch of DNA is in the clone. By analysing the fingerprints, contigs are assembled by automated (FPC) or manual means (Pathfinders) into overlapping DNA stretches. Now a good choice of clones can be made to efficiently sequence the clones to determine the DNA sequence of the organism under study (seed picking).

Macrorestriction is a type of physical mapping wherein the high molecular weight DNA is digested with a restriction enzyme having a low number of restriction sites.

Outlined above are alternative ways to investigate to create genetic maps (radiation hybrids, STS,...).

Genes can be mapped prior to the complete sequencing of a by independent approaches like in situ hybridization. Once the genome has been sequenced, in-silico approaches perform the gene finding. The such suggested genes are compared with the experimental evidence for the respective gene.

Disease-association

The process to identify a genetic element that signs responsible for a disease is also referred to as "mapping". If the locus in which the search is performed is already considerably constrained, the search is called the "fine-mapping" of a gene. This information is derived from the investigation of disease-manifestations in large families (Genetic linkage) or from populations-based genetic association studies.

ee also

* Human Genome Project
* Quantitative trait locus
* Genetic fingerprinting
* Genetic linkage
* Sulston score

References

*cite book
author = Terry A. Brown
year = 2006
title = Genomes 3
publisher = Garland Science Publishing
location = New York

External links

* [http://www.bcgsc.bc.ca Genome Sciences Centre] of British Columbia


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • gene mapping — gene mapping. См. картирование генов. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • gene mapping — Genetics. 1. any of a number of methods used to construct a model of the linear sequence of genes of a particular chromosome. 2. the act of constructing such a model. [1975 80] * * * gene mapping see under ↑map • • • Main Entry: ↑gene gene… …   Useful english dictionary

  • gene mapping — gene′ map ping n. gen the act or process of determining the precise location of a gene or genes on a particular chromosome • Etymology: 1975–80 …   From formal English to slang

  • gene mapping — See: mapping …   Glossary of Biotechnology

  • gene mapping — /ˈdʒin mæpɪŋ/ (say jeen maping) noun the identification of the place on one of the twenty three pairs of human chromosomes where a particular gene lies …   Australian English dictionary

  • gene mapping — Genetics. 1. any of a number of methods used to construct a model of the linear sequence of genes of a particular chromosome. 2. the act of constructing such a model. [1975 80] * * * …   Universalium

  • Gene mapping — The process of determining the relative positions of genes on a chromosome (or another piece of DNA) and the distances between the genes in linkage units or in physical units. * * * determining information about genetic loci on chromosomes, such… …   Medical dictionary

  • mapping — mapping. = gene mapping (см.). (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Mapping — In geomatics or geospatial science and technology: Mapping usually refers to map making and often used instead of cartography. Mapping term is also sometimes used for geospatial data collection (e.g. LIDAR mapping) but in fact it is not mapping… …   Wikipedia

  • gène — [ ʒɛn ] n. m. • 1911; d ab. all., puis angl. gene, du gr.→ gène ♦ Biol. Unité définie localisée sur un chromosome (⇒ locus), responsable de la production des caractères héréditaires et des protéines. ⇒ génotype, phénotype. Gène dominant, récessif …   Encyclopédie Universelle


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.