Cistron


Cistron

A cistron is a gene.[1] The term cistron is used to emphasize that genes exhibit a specific behavior in a cis-trans test; distinct positions (or loci) within a genome are cistronic (i.e., within the same gene) when mutations at the loci exhibit the same simple Mendelian inheritance as would mutations at a single locus.

For example, suppose a mutation at a chromosome position x is responsible for a recessive trait in a diploid organism (where chromosomes come in pairs). We say that the mutation is recessive because the organism will exhibit the wild type phenotype (ordinary trait) unless both chromosomes of a pair have the mutation (homozygous mutation). Similarly, suppose a mutation at another position, y, is responsible for the same recessive trait. The positions x and y are said to be within the same cistron when an organism that has the mutation at x on one chromosome and has the mutation at position y on the paired chromosome exhibits the recessive trait even though the organism is not homozygous for either mutation. When instead the wild type trait is expressed, the positions are said to belong to distinct cistrons / genes.

For example, an operon is a stretch of DNA that is transcribed, to create a contiguous segment of RNA, but contains more than one cistron / gene. The operon is said to be polycistronic, whereas ordinary genes are said to be monocistronic.

References

  1. ^ Lewin, Benjamin (2000). Genes VII. New York: Oxford University Press and Cell Press. p. 955. ISBN 0-19-879276-X. 



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Look at other dictionaries:

  • cistrón — cistron cistron m. genét. Conjunto de varios codones que contienen toda la información necesaria para fabricar una cadena polipeptídica. Medical Dictionary. 2011. cistrón …   Diccionario médico

  • cistron — [ sistrɔ̃ ] n. m. • 1957; de cis et trans selon le modèle des mots sc. en on ♦ Biol. Unité génétique fonctionnelle, définie par le test cis trans, qui correspond à un segment d A. D. N. spécifiant une chaîne polypeptidique. ● cistron nom masculin …   Encyclopédie Universelle

  • cistron — CISTRÓN s. m. (biol.) segment de genă cu funcţie proprie, care poate determina sinteza unui anumit tip de proteină. (< fr., engl. cistron) Trimis de raduborza, 15.09.2007. Sursa: MDN …   Dicționar Român

  • cístron — s. m. [Genética] Fragmento de gene que forma uma unidade funcional. • [Brasil] Plural: cístrones ou cístrons.   ‣ Etimologia: inglês cistron   ♦ Grafia em Portugal: cistrão …   Dicionário da Língua Portuguesa

  • cistron — cistron. См. цистрон. (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.

  • Cistron — Cistron, Gen, definiert als kleinste Funktionseinheit der Proteinsynthese. Durch einen Komplementationstest, den cis trans Test, kann man prüfen, ob Mutationen im selben Gen oder in verschiedenen Genen lokalisiert sind. Dazu werden verschiedene… …   Deutsch wörterbuch der biologie

  • cistron — cìstrōn m <G cistróna> DEFINICIJA fiziol. najmanja funkcionalna jedinica genetske građe, definira se na osnovi cis trans testa; funkcionalni gen ETIMOLOGIJA lat. ≃ cis + trans + on …   Hrvatski jezični portal

  • cistron — [sis′trän΄] n. the smallest sequence of DNA needed to direct the synthesis of a functional polypeptide; a gene …   English World dictionary

  • Cistron — Un cistron est une région du génome correspondant à l unité de codage pour une chaîne polypeptidique. Ce terme est synonyme de région codante d un gène. C est l ensemble des codons qui code une protéine donnée. Ce terme a été inventé par le… …   Wikipédia en Français

  • Cistron — Das Cistron ist ein vom Genetiker Seymour Benzer definierter Begriff, der genetische Einheiten beschreibt, innerhalb derer sich Mutationen nicht mehr komplementieren können.[1] Es ist per Definition aufgrund phänotypischer Kriterien genetisch… …   Deutsch Wikipedia


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