null allele

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null allele

A segment of DNA which is not known to encode a protein product.

null allele

a form of a gene whose product is either absent at the molecular level, or is present but has no measurable phenotypic function. For example, in a heterozygote with INCOMPLETE DOMINANCE one gene form is a ‘null allele’ and is inactive, while the other allele is unable to compensate for the null allele and so produces an intermediate phenotype.

allele

one of two or more alternative forms of a gene at the same site or locus in each of a pair of chromosomes, which determine alternative characters in inheritance. Called also allelomorph.

blank allele
an allele which produces an antigen which cannot be detected.
null allele
see silent allele (below).
silent allele
one that produces no detectable effect.
References in periodicals archive ?
Null alleles were detected in both wild and hatchery Mercenaria mercenaria.
The null allele frequency was calculated using Micro-Checker (Van Oosterhout et al.
Molecular comparison of waxy null alleles in common wheat and identification of a unique null allele.
We also calculated F-statistics and AMOVA excluding loci that showed null alleles with MICROCHECKER.
The results were scanned for inconsistencies of the type encountered when null alleles are segregating.
We found no evidence of null alleles on the first two loci (Esc[mu]1 and Esc[mu]4) with combined probability for all cases of P > 0.
Half of the VNTR loci (VNTR-3, VNTR-9, VNTR-36, and VNTR-37) showed null alleles with different frequencies ranging from 2.
For the CYP2C19 gene (cytochrome P450, family 2, subfamily C, polypeptide 19), the known null alleles (CYP2C19[sup.
This paper goes on to confirm the strong link between mutations in filaggrin as a genetic factor in AD and investigates the observation that individuals carrying one or more filaggrin null alleles can show early-onset AD that persists well into adulthood.
Lambda KOS incorporates a yeast shuttle vector system used to rapidly create several manipulations of the mouse genome including point mutations, conditional knockouts, null alleles and humanized alleles.