If both alleles at a gene (or locus ) on the homologous chromosomes are the same, they and the organism are homozygous with respect to that gene (or locus). (wikipedia.org)
Allelic variation at a locus is measurable as the number of alleles ( polymorphism ) present, or the proportion of heterozygotes in the population. (wikipedia.org)
For example, at the gene locus for the ABO blood type carbohydrate antigens in humans, classical genetics recognizes three alleles, I A , I B , and i, that determine compatibility of blood transfusions . (wikipedia.org)
Studies in mammals, including humans (9), birds (10), and medaka (11), support the existence of a single locus of the gene, although the presence of multiple alleles has been reported in pigs (12) and goldfish (13). (thefreedictionary.com)
The word "allele" is a short form of allelomorph ("other form", a word coined by British geneticists William Bateson and Edith Rebecca Saunders ), which was used in the early days of genetics to describe variant forms of a gene detected as different phenotypes . (wikipedia.org)
Homozygous1
It was formerly thought that most individuals were homozygous for the "wild type" allele at most gene loci, and that any alternative "mutant" allele was found in homozygous form in a small minority of "affected" individuals, often as genetic diseases , and more frequently in heterozygous form in " carriers " for the mutant allele. (wikipedia.org)
Genes2
The interaction of multiple genes-and the variation in these genes ("alleles") between individuals-help to determine a person's eye color phenotype . (wikipedia.org)
AIRR sequencing (AIRR-seq) studies rely on databases of known BCR germline variable (V), diversity (D), and joining (J) genes to detect somatic mutations in AIRR-seq data via comparison to the best-aligning database alleles. (frontiersin.org)
Loci3
Haplotypes: the joint distribution of alleles at linked loci. (lancs.ac.uk)
We prove a result concerning the joint distribution of alleles at linked loci on a chromosome drawn from the population at stationarity. (lancs.ac.uk)
Furthermore, this allele is independent of the alleles at different loci on any chromosomes in the population. (lancs.ac.uk)
Genotypes2
We previously presented TIgGER, a computational method to identify subject-specific V gene genotypes, including the presence of novel V gene alleles, directly from AIRR-seq data. (frontiersin.org)
Here we present and apply an improved version of the TIgGER algorithm which can detect alleles that differ by any number of SNPs from the nearest database allele, and can construct subject-specific genotypes with minimal prior information. (frontiersin.org)
Such a "wild type" allele was historically regarded as leading to a dominant (overpowering - always expressed), common, and normal phenotype, in contrast to " mutant " alleles that lead to recessive, rare, and frequently deleterious phenotypes. (wikipedia.org)
To assess the evolutionary stability of these lineages and the extent of ancestral polymorphisms of Ab within Mus species, we extended our restriction site polymorphism analysis to include 86 alleles from 120 independently derived H2 haplotypes from 12 separate species and subspecies of Mus. (ncku.edu.tw)
Population2
Here, we investigated the association between the presence of rare HRAS1 minisatellite alleles and lung cancer in the population studied. (aacrjournals.org)
Population stratification of 8500 alleles from 23 independent studies showed that aggregation of rare HRAS1 alleles appears twice as frequently in the genomes of cancer patients as in normal unaffected controls. (aacrjournals.org)
Genetic2
Furthermore, interracial variations in allele frequencies and variations between Caucasian subpopulations suggest that genetic variations may be involved in susceptibility to lung oncogenesis, especially in certain ethnic populations. (aacrjournals.org)
Alleles of the apolipoprotein E (ApoE) gene are known to modulate the genetic risk for developing late-onset Alzheimer's disease (AD) and have been associated with hippocampal volume differences in AD. (iospress.com)
Rare alleles3
Rare alleles were differentiated from common alleles ( a1 , a2 , a3 , and a4 ) by shifts in electrophoretic mobility. (aacrjournals.org)
Furthermore, a meta-analysis showed a higher distribution of rare alleles in our study of Caucasian Spaniards than was found in other studies of American and Northern European Caucasian populations. (aacrjournals.org)
However, the original algorithm was unable to detect alleles that differed by more than 5 single nucleotide polymorphisms (SNPs) from a database allele. (frontiersin.org)
Using a large cohort of more than 1,400 adolescents, this study found no hippocampal volume or hippocampal asymmetry differences between carriers and non-carriers of the ApoE ε4 or ε2 alleles, nor dose-dependent effects of either allele, suggesting that regionally specific effects of these polymorphisms may only become apparent in later life. (iospress.com)
A phylogenetic tree revealing the relationships of these Ab alleles with respect to restriction site polymorphisms, but excluding the retroposon insertions, demonstrated that these lineages have distinctive genomic structures beyond the retroposon polymorphisms. (ncku.edu.tw)
Populations1
The term " wild type " allele is sometimes used to describe an allele that is thought to contribute to the typical phenotypic character as seen in "wild" populations of organisms, such as fruit flies ( Drosophila melanogaster ). (wikipedia.org)
Risk alleles10
Are minor alleles more likely to be risk alleles? (biomedcentral.com)
Natural selection has led to a high tendency of risk alleles to be enriched in minor alleles in Mendelian diseases. (biomedcentral.com)
Using data in the NHGRI-EBI Catalog and the VARIMED database, we investigated whether (1) GWASs more easily detect risk alleles and (2) facilitate evolutionary insights by comparing risk allele frequencies of different diseases. (biomedcentral.com)
We conducted computer simulations of P -values for association tests when major and minor alleles were risk alleles. (biomedcentral.com)
We compared the expected proportion of SNVs whose risk alleles were minor alleles with the observed proportion. (biomedcentral.com)
50% risk alleles were minor alleles because of the larger difference in the power of GWASs to differentiate between minor and major alleles, especially with low MAFs or when the number of controls exceeds the number of cases. (biomedcentral.com)
Minor alleles are more likely to be risk alleles in the published GWASs on complex diseases. (biomedcentral.com)
One reason is that minor alleles are more easily detected as risk alleles in GWASs. (biomedcentral.com)
Even when correcting for the GWAS's power imbalance, minor alleles are more likely to be risk alleles, especially in some diseases whose average risk allele frequencies are low. (biomedcentral.com)
They hypothesized that previously selectively neutral variants become risk alleles when the environment changes. (biomedcentral.com)
Gene alleles1
TIgGER predictions are validated both computationally (using a leave-one-out strategy) and experimentally (using genomic sequencing), resulting in the addition of three new immunoglobulin heavy chain V (IGHV) gene alleles to the IMGT repertoire. (frontiersin.org)
During thermal cycling, the relevant allele-specific primer binds to the template and elongates, thus attaching its tail sequence to the newly synthesized strand. (idtdna.com)
The complement of the allele-specific tail sequence is generated during subsequent rounds of PCR, enabling the FRET cassette to bind to the DNA. (idtdna.com)
Genomic1
In this report, we demonstrate by nucleotide sequencing that the genomic sequences of prototypic alleles from all three lineages diverge significantly and that lineage 3 is derived from lineage 2 by two insertional events in intron 2. (ncku.edu.tw)
Methods1
All together, these methods allow for much higher accuracy in germline allele assignment, an essential step in AIRR-seq studies. (frontiersin.org)
Found2
All these six substitutions at the same positions have been found only in HLA-B*44 alleles, suggesting that Cw*0503 is a result of recombination between Cw*0501 and one of B*44 alleles. (elsevier.com)
Lineage 3 alleles were found only in the Mus musculus subspecies, suggesting that it diverged from lineage 2 more recently. (ncku.edu.tw)
VNTR3
Four hundred sixty-six HRAS1 VNTR alleles from 233 lung cancer patients and 892 alleles from 446 unaffected controls were typed using PCR-long agarose gel electrophoresis assay of peripheral blood lymphocyte DNA. (aacrjournals.org)
A higher percentage of rare HRAS1 VNTR alleles in lung cancer patients than in unaffected controls (32.7 versus 21.9%) was confirmed. (aacrjournals.org)
We conclude that the presence of rare HRAS1 VNTR alleles may be an inherited predisposing factor in lung cancer. (aacrjournals.org)
Presence1
Odds ratio was calculated to evaluate increased risk of lung cancer associated to the presence of rare HRAS1 alleles. (aacrjournals.org)