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HLA-A10
HLA-A10 is a broad antigen HLA- A serotype. The ancestral A10 type is believed to be A*2601, which via gene conversion with other HLA-A allele An allele (, ; ; modern formation from Greek ἄλλος ''állos'', "other") is a variation of the same sequence of nucleotides at the same place on a long DNA molecule, as described in leading textbooks on genetics and evolution. ::"The chro ...s produced A*2501, A*3401, A*4301 and A*6601. A10 serotypes in general show a pattern of more recent expansion. A34 is an excellent example, appearing to have expanded from the middle east, with linkage disequilibrium with B alleles into Austronesia, South Pacific, Philippines and as far north as Taiwan (where it is found in the Taiwan Ami and Yami tribal groups but rare in ethnic Chinese nor in Hong Kong Chinese). A*66 appears to have expanded from North Africa into the Middle East or Europe and A26 appears to have expanded Black Sea and, after the initial settlement from the southern West ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HLA-A25
A25 frequencies A*2501 distribution is primarily located in Western Eurasia. Frequency tends to be highest in the populations that underwent later neolithization suggesting A*2501 spread in Europe. The high frequency in Saudi Arabia is suggestive of a source. References {{HLA-A serotypes 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Leukocyte Antigen
The human leukocyte antigen (HLA) system or complex is a complex of genes on chromosome 6 in humans which encode cell-surface proteins responsible for the regulation of the immune system. The HLA system is also known as the human version of the major histocompatibility complex (MHC) found in many animals. Mutations in HLA genes may be linked to autoimmune disease such as type I diabetes, and celiac disease. The HLA gene complex resides on a 3 Mbp stretch within chromosome 6, p-arm at 21.3. HLA genes are highly polymorphic, which means that they have many different alleles, allowing them to fine-tune the adaptive immune system. The proteins encoded by certain genes are also known as ''antigens'', as a result of their historic discovery as factors in organ transplants. HLAs corresponding to MHC class I ( A, B, and C), all of which are the HLA Class1 group, present peptides from inside the cell. For example, if the cell is infected by a virus, the HLA system brings fragme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HLA-A
HLA-A is a group of human leukocyte antigens (HLA) that are encoded by the HLA-A locus, which is located at human chromosome 6p21.3. HLA is a major histocompatibility complex (MHC) antigen specific to humans. HLA-A is one of three major types of human MHC class I transmembrane proteins. The others are HLA-B and HLA-C. The protein is a heterodimer, and is composed of a heavy α chain and smaller β chain. The α chain is encoded by a variant HLA-A gene, and the β chain (β2-microglobulin) is an invariant β2 microglobulin molecule. The β2 microglobulin protein is encoded by the B2M gene, which is located at chromosome 15q21.1 in humans. MHC Class I molecules such as HLA-A are part of a process that presents short polypeptides to the immune system. These polypeptides are typically 7-11 amino acids in length and originate from proteins being expressed by the cell. There are two classes of polypeptide that can be presented by an HLA protein: those that are supposed to be expressed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Conversion
Gene conversion is the process by which one DNA sequence replaces a homologous sequence such that the sequences become identical after the conversion event. Gene conversion can be either allelic, meaning that one allele of the same gene replaces another allele, or ectopic, meaning that one paralogous DNA sequence converts another. Allelic gene conversion Allelic gene conversion occurs during meiosis when homologous recombination between heterozygotic sites results in a mismatch in base pairing. This mismatch is then recognized and corrected by the cellular machinery causing one of the alleles to be converted to the other. This can cause non-Mendelian segregation of alleles in germ cells. Nonallelic/ectopic gene conversion Recombination occurs not only during meiosis, but also as a mechanism for repair of double-strand breaks (DSBs) caused by DNA damage. These DSBs are usually repaired using the sister chromatid of the broken duplex and not the homologous chromosome, so they wou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allele
An allele (, ; ; modern formation from Greek ἄλλος ''állos'', "other") is a variation of the same sequence of nucleotides at the same place on a long DNA molecule, as described in leading textbooks on genetics and evolution. ::"The chromosomal or genomic location of a gene or any other genetic element is called a locus (plural: loci) and alternative DNA sequences at a locus are called alleles." The simplest alleles are single nucleotide polymorphisms (SNP). but they can also be insertions and deletions of up to several thousand base pairs. Popular definitions of 'allele' typically refer only to different alleles within genes. For example, the ABO blood grouping is controlled by the ABO gene, which has six common alleles (variants). In population genetics, nearly every living human's phenotype for the ABO gene is some combination of just these six alleles. Most alleles observed result in little or no change in the function of the gene product it codes for. However, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HLA-A34
A34 allele frequencies A*3401 A*3401 when found outside of Africa is primarily found in the South Asia, Austronesia and the South/Central part of the West Pacific Rim (WPR). It appears to have made it to Eastern Taiwan's indigenous tribes (Ami, Yami) but not more north of this region. It has not been detected in any sampling of Japan. Over most of the East Pacific Rim region where it is found it is limited to 1 or 2 common haplotypes in strong linkage disequilibrium. This indicates its presence in the WPR region is the result of recent migrations. The A*3401 migration from Africa is supported by its presence in East Africa and South Africa and by current models of human migration, this allele was likely represented in the first wave of immigrants. However, in areas were mixtures of these alleles are commonly found, Persian Gulf region and India, A*3401 is relatively uncommon, scarce, or absent. The exception is Saudi Arabia, in which A34 is at 2.8% and among Israeli Jews at 8.8% ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
