null allele


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Related to null allele: Null mutation

null allele

[′nəl ə‚lēl]
(genetics)
An allele that does not produce a functional product and behaves as a recessive.
References in periodicals archive ?
All mismatches, however, were found at homozygous loci where occurrence of null allele cannot be excluded.
The departures in segregation pattern from the expected ratio, which was observed for the Ccmic3 locus in Families A1 and A7, were initially thought to be caused by the presence of a null allele.
Molecular comparison of waxy null alleles in common wheat and identification of a unique null allele.
The results of the combined genotype analysis show that 80% of the patients have a null allele, that is, combinations -/-, -/+, +/-, with the double null genotype being the most frequent, representing 40% (Table 4).
Similarly, 33% of varieties that had the null allele of Pinb-D1b had PSI value greater than 40, suggesting medium hard to soft grain texture.
This pattern suggests that a null allele is segregating; particularly as a mutation that could have altered a 16 repeat allele to a 14 repeat allele (a two repeat change) is a rare event.
A recessive alleles model was used with missing genotypes entered as null allele homozygotes.
The GSTM1 gene on chromosome 1p13, according to the three alleles, can be grouped into two classes: GSTM1-null homozygote for the null allele (GSTM1-0), nonfunctional class and GSTM1-1 with at least one of the GSTM1a or GSTM1b alleles, functional class [8].
The proposal of the existence of a null allele in the heterozygous individual is based on the intensity of the bands in the gels (Kephart, 1990).