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 ?
Fgfr1 null mutant embryos die during gastrulation and segmentation, while homozygous embryos of Fgfr2 knockout die before gonad formation (18, 19).
Although Fgfr3/Fgfr4 double null mutant mice were viable, only a few animals sired and the growth of these animals was severely retarded (21), which were not observed in individual Fgfr3 or Fgfr4 null mutant animals (20, 21).
For example, the KOMP already has generated over 400 null mutant mouse lines and, at the current production rates, is set to produce a total of over 800.
Residual guanosine 3', 5'-bispyrophosphate synthetic activity of relA null mutants can be eliminated by spoT null mutations.
To make null mutant mice, it takes at least about one year from the construction of the targeting vector if there is no delay during the whole procedure from steps such as colony selection of ES cells, chimera production and confirmation of germ line transmission for the mice.
Decreased ethanol sensitivity and tolerance development in gamma-PKC null mutant mice is dependent on genetic background.
Ethanol levels were significantly higher in the null mutant administered the combined treatments.
Saccharomyces Rab4 and Rab5 null mutants were no longer able to support the intemalization of the Leishmania adenosine permease by TOR.
A mitogen-activated protein kinase encoding gene, tvkl, from Trichoderma vixens was cloned, and its role during the mycoparasitism, conidiation, and biocontrol was examined in tvkl null mutants.
albicans Als family of adherence molecules is defined by the adherence profile of null mutants.
Once successfully cloned, this recombinant gene will be used to rescue collagen IV null mutants, and we will be able to select for a functional tagged protein.
Table 2 Community-Wide Resources for Genetically Engineered Mouse Models Resource Description Knockout Mouse Project NIH initiative with the aim of generating (KoMP) mouse knock-outs in ES cells for every gene International Knockout Consortium that coordinates international Mouse Consortium (IKMC) effort to produce mouse null mutants in ES cells for every gene Knockout Mouse Project Project aimed at producing knockout mice Phase 2 ([KoMP.