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Complementation (genetics)

The complementary action of different genetic factors. The term usually implies two homologous chromosomes or chromosome sets, each defective because of mutation and unable by itself to promote the normal development or metabolism of the organism, but able to do so jointly when brought together in the same cell. See Chromosome, Mutation

S. Benzer proposed the term cistron for the unit within which mutants do not complement each other. The word gene is often used in the same sense. The usual biochemical function of a cistron, or gene, is to determine the structure of a specific polypeptide component of a protein. Full complementation between different genes is the rule except when, as sometimes in bacteria, the genes form part of a functionally coordinated complex (operon). Allelic mutants (mutants within one gene) show limited complementation in some cases, for example, when certain pairs of mutant polypeptides correct each other's defects through coaggregation in a complex protein. See Genetics, Operon

McGraw-Hill Concise Encyclopedia of Bioscience. © 2002 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



in genetics, the complementary action of two alleles of a single gene or two different genes of the same chromosomal set.

Interallelic complementation is associated with the synthesis in heterozygotes of two different but functionally similar protein molecules instead of the one protein molecule of homozygotes. Moreover, heterozygotes often have hybrid protein molecules made of polypeptide chains that are synthesized under the control of two different alleles. In heterozygotes with defective mutant alleles, complementation may be expressed in a restoration of the ability to synthesize a normally functioning protein—an ability that would be partly or wholly lost to each mutant separately.

Interallelic complementation seems to be the main cause of monogenic heterosis—the superiority of heterozygotes over homozygotes in viability and rate of growth. Detailed complementation charts have been constructed for the genes of certain viruses, bacteria, and fungi.

Intergenic complementation is a manifestation of the interaction of nonallelic genes (epistasis), whereby a defect expressed in the impairment of a given metabolic process is compensated by other genes. The term “complementarity” is sometimes used in biological literature in a sense similar or identical to complementation.


Fincham, J. Geneticheskaia komplementatsiia. Moscow, 1968. (Translated from English.)


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.


The act of replacing a set by its complement.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
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Although XP can be suspected by clinical features such as extreme UV sensibility in exposed areas and the appearance of numerous lentigines or skin cancer at early ages, molecular genetic testing is recommended for confirmation of the patient's mutation and complementation group characterization.
(2000) PEX3 is the causal gene responsible for peroxisome membrane assembly-defective Zellweger syndrome of complementation group G.
The characterisation of the simple past form dared selecting BI complementation, which is categorised either as a blend (Denison 1998; Schluter 2010) or as a modal verb in the relevant literature (Beths 1999; Taeymans 2004), is the main point of disagreement among the scholars.
[4] Nonstandard abbreviations: TSH, thyroid-stimulating hormone; TSI, thyroid-stimulating immunoglobulin; EFC-cAMP, cAMP XS enzyme fragment complementation.
On the one hand, it has been claimed that the various complement clause types have no meaning of their own, and the meaning of the sentence is defined by the complement-taking predicate alone (see e.g., Givon 1990: 516, as well as early generative treatments of complementation).
I probably don't know you any more, Complementation is just an implication That we are choosing to ignore.
GE Healthcare Life Sciences also signed an exclusive agreement with DiscoveRX to distribute its HitHunter cAMP EFC (enzyme fragment complementation)-based assays for high-throughput GPCR screening, and also expanded its agreement for DiscoveRX's kinase assays to include exclusive distribution in Asia Pacific.
Results indicated that the insurance group with free ambulatory care had a nonsignificantly higher number of inpatient admissions than enrollees facing a $1.50 deductible for ambulatory care, suggesting a trend toward a complementation effect between ambulatory and inpatient care (Phelps 1992).
Although there is no obvious complementation by her sire Sadler's Wells, her closer family boasts Rule Of Law and stamina should not be an issue.

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