These 4 disequilibrium loci (BP017, BP301, and AF039660, AF039661) also had the highest estimated null allele
frequency among all loci examined ([p.
To determine whether amplification failure caused by mutations in primer-binding regions or by complete deletions of the VNTR region were the reason for these null alleles
or the insertion of fragments such as mobile genetic elements resulted in larger (and therefore by capillary electrophoresis) undetectable fragments, the respective fragments were analyzed by using standard gel electrophoresis.
Development of a codominant PCR-based marker for the wheat Wx-B1 null allele
Although more expensive, sequencing can detect null alleles
, is not subject to inference by replacement therapy, and does not require a sample bank of unusual phenotypes.
Tests of Hardy-Weinberg equilibrium for each locus were conducted within each population with GENALEX, and the frequency of null alleles
was estimated using the expectation maximization method in FREENA (Chapuis & Estoup 2007) and the maximum likelihood method in ML-NULLFREQ (Kalinowski & Taper 2006).
Besides the SZ and ZZ allele combinations, a combination of other deficient, dysfunctional, or null alleles
at the [[alpha].
were detected at loci D11 and K37 in the Tasik Bera and Endau River populations.
An additional shortcoming is that phenotyping alone cannot distinguish between an individual who is homozygous for a single allele and an individual who is heterozygous for that allele in trans to a null allele
Hardy-Weinberg equilibrium and treatment of the null allele
Markers were selected based on high polymorphism, low frequency of null alleles
, and similar annealing temperatures, as reported by the original designers of each marker (Magoulas et al.
This mutation causes the arginine at position 506 to change to a stop codon, producing a null allele
and probably causing a 50% decrease in the measured factor V activity in a heterozygote.
For null allele
frequency, our study showed some microsatellite loci frequencies near to 20%.