allele


allele
allelic /euh lee"lik, euh lel"ik/, adj.allelism, n.
/euh leel"/, n. Genetics.
any of several forms of a gene, usually arising through mutation, that are responsible for hereditary variation.
[1930-35; < G Allel, appar. as shortening of G equivalents of ALLELOMORPH or allelomorphic gene; allelo- < Gk allelo-, comb. form of allélon of/to one another, reciprocally]

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Any one of two or more alternative forms of a gene that may occur alternatively at a given site on a chromosome.

Alleles may occur in pairs, or there may be multiple alleles affecting the expression of a particular trait. If paired alleles are the same, the organism is said to be homozygous for that trait; if they are different, the organism is heterozygous. A dominant allele will override the traits of a recessive allele in a heterozygous pairing (see dominance and recessiveness). In some traits, alleles may be codominant (i.e., neither acts as dominant or recessive). An individual cannot possess more than two alleles for a given trait. All genetic traits are the result of the interactions of alleles.

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also called  Allelomorph,  

      any one of two or more genes that may occur alternatively at a given site (locus) on a chromosome. Alleles may occur in pairs, or there may be multiple alleles affecting the expression (phenotype) of a particular trait. If the paired alleles are the same, the organism is said to be homozygous for that trait; if they are different, the organism is heterozygous. A dominant allele will override the traits of a recessive allele in a heterozygous pairing. In some traits, however, alleles may be codominant—i.e., neither acts as dominant or recessive. An example is the human ABO blood system; persons with type AB blood have one allele for A and one for B. (Persons with neither are type O.) See also dominance; recessiveness.

      Most traits are determined by more than two alleles. Multiple forms of the allele may exist, though only two will attach to the designated gene site during meiosis. Also, some traits are controlled by two or more gene sites. Both possibilities multiply the number of alleles involved. All genetic traits are the result of the interactions of alleles. Mutation, crossing over, and environmental conditions selectively change the frequency of phenotypes (and thus their alleles) within a population.

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Universalium. 2010.

Look at other dictionaries:

  • Allele — Allèle On appelle allèles les différentes versions d un même gène. Chaque allèle se différencie par une ou plusieurs différences de la séquence de nucléotides. Ces différences apparaissent par mutation au cours de l histoire de l espèce, ou par… …   Wikipédia en Français

  • Alléle — Allèle On appelle allèles les différentes versions d un même gène. Chaque allèle se différencie par une ou plusieurs différences de la séquence de nucléotides. Ces différences apparaissent par mutation au cours de l histoire de l espèce, ou par… …   Wikipédia en Français

  • allèle — [ alɛl ] n. m. • 1936; abrév. de allélomorphe ♦ L un quelconque des deux gènes différant par leur expression phénotypique bien que leur fonction soit la même, localisés au même site sur chaque membre d une paire de chromosomes homologues (SYN.… …   Encyclopédie Universelle

  • Allele —   [zu griechisch alle̅lōn »gegenseitig«], Singular Allel, das, s, Genetik: durch Mutation veränderbare Zustände eines Gens. Allele sind identische Abschnitte homologer Chromosomen und können eine unterschiedliche Ausprägung des zugehörigen… …   Universal-Lexikon

  • allele — al*lele n. 1. 1 1. one of two or more alternative forms of a gene that can have the same place on homologous chromosomes and are responsible for alternative traits. Syn: allelomorph [WordNet 1.5] 2. either of a pair of Mendelian characters that… …   The Collaborative International Dictionary of English

  • Allele — Allgemeine Informationen Genre(s) Alternative Metal Gründung 2002 Website www.alle …   Deutsch Wikipedia

  • allele — allele. См. аллеломорф. (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.

  • allele — allele. См. доминантный ген. (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.

  • allele — (n.) 1931, from Ger. allel, abbreviation of allelomorph (1902), coined from Gk. allel one another (from allos other; see ALIAS (Cf. alias)) + morphe form (see MORPHEUS (Cf. Morpheus)) …   Etymology dictionary

  • allele — [ə lēl′] n. [Ger allel < Gr allēlōn, of one another] either of a pair of genes located at the same position on both members of a pair of chromosomes and conveying characters that are inherited in accordance with Mendelian law allelic [ə lēl′ik …   English World dictionary

  • Allele — This article is about the forms of a gene. For a non technical introduction to the topic, see Introduction to genetics. For the alternative metal band, see Allele (band). An allele (UK  /ˈæ …   Wikipedia


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