Linkage
The tendency for genes and other genetic markers to be inherited together because of their location near one another on the same chromosome. A gene is a functional physical unit of heredity that can be passed from parent to child. All genes in humans are pieces of DNA. Most genes contain information for making a specific protein. The term "genetic marker" is broader. A genetic marker is simply a segment of DNA with an identifiable physical location on a chromosome whose inheritance can be followed. A genetic marker can have a function and thus be a gene. Or a marker can be a section of DNA with no known function. Because DNA segments that lie near each other on a chromosome tend to be inherited together, markers are often used as tools for tracking the inheritance pattern of a gene that has not yet been identified but whose approximate location is known. The statistical estimate of whether two loci are likely to lie near each other on a chromosome and are therefore likely to be inherited together is called a LOD score. A LOD score of 3 or more is generally taken to indicate that the two loci are linked and are close to one another.
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1. A chemical covalent bond. 2. The relationship between syntenic loci sufficiently close that the respective alleles are not inherited independently by the offspring; a characteristic of loci, not genes.
- genetic l. l. (2).
- medical record l. the assemblage of lifetime or long-term individual medical histories from vital and medical data derived from multiple sources.
- record l. a method of assembling the information contained in two or more sets of medical records, or a set of medical records and vital records such as birth or death certificates, and a procedure to ensure that each individual's records are counted only once; facilitated by a unique numbering system such as the Hogben number or soundex code to identify individuals with precision.
- sex l. inheritance of a trait or a sex chromosome or gonosome. A man receives all his sex-linked genes from his mother and transmits them all to his daughters but not to his sons; a recessive sex-linked character is much more likely to be expressed in the male. SEE ALSO: sex chromosomes, under chromosome.

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link·age 'liŋ-kij n
1) the manner in which atoms or radicals are connected by chemical bonds in a molecule
2) the relationship between genes on the same chromosome that causes them to be inherited together compare MENDEL'S LAW (2)

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n.
(in genetics) the situation in which two or more genes lie close to each other on a chromosome and are therefore very likely to be inherited together. The further two genes are apart the more likely they are to be separated by crossing over during meiosis.

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link·age (lingkґəj) 1. the connection between different atoms in a chemical compound, or the symbol representing it in structural formulas; see also bond. 2. in genetics, the association of genes having loci on the same chromosome, which results in the tendency of a group of such nonallelic genes to be associated in inheritance.

Medical dictionary. 2011.

Look at other dictionaries:

  • linkage — [ liŋkaʒ ] n. m. • 1921; mot angl. (depuis 1874 en chim., géom.) « liaison », de to link « lier » ♦ Anglic. Génét. Liaison existant entre les gènes d un chromosome; association de facteurs héréditaires qu elle entraîne. Équiv. fr. liaison… …   Encyclopédie Universelle

  • Linkage — generally means the manner or style of being united , and can refer to:*Genetic linkage *Linkage (mechanical) *Linkage (policy) *Linkage (linguistics) *Linkage (software) *Linkage (BitTorrent client)*Linkage is also a commonly used phrase in most …   Wikipedia

  • Linkage — Album par Mami Kawada Sortie 24 mars 2010 Durée 58:07 Genre …   Wikipédia en Français

  • Linkage — occurs when an investor is able to purchase a security on one financial exchange and sell it on another. Certain depositary receipts, such as American Depositary Receipts (ADRs), allow for linkage, which means that an investor can purchase shares …   Investment dictionary

  • Linkage — Link age (l[i^][ng]k [asl]j; 48), n. 1. The act of linking; the state of being linked; also, a system of links. [1913 Webster] 2. (Chem.) Manner of linking or of being linked; said of the union of atoms or radicals in the molecule. [1913 Webster] …   The Collaborative International Dictionary of English

  • linkage — LINKÁGE CAJ/ s. n. (biol.) înlănţuire (strânsă) a genelor care se găsesc în acelaşi cromozom. (< engl. linkage) Trimis de raduborza, 15.09.2007. Sursa: MDN …   Dicționar Român

  • linkage — 1874, from LINK (Cf. link) (v.) + AGE (Cf. age). To understand the principle of Peaucellier s link work, it is convenient to consider previously certain properties of a linkage, (to coin a new and useful word of general application), consisting… …   Etymology dictionary

  • linkage — [liŋk′ij] n. 1. a linking or being linked 2. a series or system of links, slides, cranks, wheels, or gears for transmitting power or motion 3. Biol. the tendency of some genes to remain together and act as a unit (linkage group) in inheritance,… …   English World dictionary

  • linkage — linkage. См. сцепление. (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.

  • linkage — I noun affiliation, affinity, alliance, association, bond, coalescence, combination, concatenation, confluence, conjugation, conjunction, connection, coupling, hookup, interconnection, intersection, joinder, joining, junction, juncture, linking,… …   Law dictionary

  • linkage — /ˈlinkadʒ, ingl. ˈlɪŋkɪdʒ/ [vc. ingl., propriamente «concatenazione», da link «anello d una catena»] s. m. inv. (biol.) associazione …   Sinonimi e Contrari. Terza edizione

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