RESUMO
The peopling of the Canary Islands has been widely debated. The mitochondrial DNA and Y-chromosome data support the idea of a Berber genetic origin coming from the North of Africa (maternal) and a later contribution of the Spanish invaders (paternal). The frequencies of the HLA class II alleles from the Tenerife Island (another Canary Island) have previously been published, postulating a Berber and Atlantic/Iberian contributions to the current population. The HLA class I and class II allele frequencies, haplotype frequencies and phylogenetic comparisons were performed in 215 unrelated individuals from Gran Canaria Island (belonging to the kidney transplant waiting list), with at least three generations of ancestors from Canary Islands, in order to study the different ethnical HLA contributions to the genetic background of the Canary Islanders. Results showed the presence of a compound HLA haplotype of putative Phoenician-Berber origin, A*33:01-C*08:02-B*14:02-DRB1*03:01-DQB1*02:01, likely coming from the combination of haplotypes A*30:02-C*05:01-B*18:01-DRB1*03:01-DQB1*02:01 and A*33:01-C*08:02-B*14:02-DRB1*01:02-DQB1*05:01 of North African (probably Berber) and West Asian Mediterranean (probably Phoenician) origins, respectively. The latter haplotypes and others from the same origin (Berber/Phoenician) are also present in the population studied. Besides, other contributions from the North of Europe, North England-Iberian (Atlantic contribution), and Western Europe/Mediterraneans (Spanish colonization) are also discussed. These data conclude that the current genetic background of the Canary Islands inhabitants has been generated over the years by different ways with an original Phoenician-Berber substrate and several genetic contributions generated in different invasions.
RESUMO
HLA-DQB1*02:02:01:02 has an intron sequences coming from a combination of DQB1*02:01:01 and DQB1*02:02:01:01.
Assuntos
Alelos , Cadeias beta de HLA-DQ/genética , Humanos , EspanhaRESUMO
HLA-DQB1*02:02:01:02 has an intron sequences coming from a combination of DQB1*02:01:01 and DQB1*02:02:01:01.
RESUMO
HLA-DQB1*03:03:02:04 and DQB1*03:03:02:02 alleles differ by a single point mutation in intron 2.
Assuntos
Alelos , Cadeias beta de HLA-DQ/genética , Mutação Puntual , Sequência de Bases , Códon , Sangue Fetal/química , Expressão Gênica , Loci Gênicos , Teste de Histocompatibilidade , Humanos , Íntrons , Dados de Sequência Molecular , EspanhaRESUMO
Generation of the HLA-A*80:01:01:01 allele has been analysed using its complete sequence. Direct comparison of the sequences and phylogenetic trees using the human leukocyte antigen (HLA)-A representative alleles and the major histocompatibility complex (MHC)-A sequences of non-human primates has been made. Results based on exon sequences confirm previously published, but considering only the sequences of the introns, two distinct regions can be differentiated. The first one comprises from the 5' untranslated region region to the first part of intron 3 sequence (shared with A2 family), and the second one includes the sequence from the end of intron 3 to intron 7 (shared with A1/A3/A11/A36/A30 family). Each of them clusters with Gorilla and Chimpanzee MHC-A sequences, respectively, suggesting an origin coming from a common ancestor to Gorilla and Chimpanzee.
Assuntos
Alelos , Éxons , Antígenos HLA-A/genética , Íntrons , Filogenia , Regiões 5' não Traduzidas , Animais , Sequência de Bases , Evolução Biológica , Gorilla gorilla , Antígenos HLA-A/classificação , Antígenos HLA-A/imunologia , Humanos , Dados de Sequência Molecular , Pan troglodytes , Polimorfismo Genético , Isoformas de Proteínas/classificação , Isoformas de Proteínas/genética , Isoformas de Proteínas/imunologiaRESUMO
HLA-G alleles follow a different pattern of polymorphism generation that those of the HLA classical I alleles. However, this polymorphism maintenance could have an evolutionary specific pathways based on non coding regions as introns, 14 bp deletion/insertion (exon 8) or promoter regions. For this reason, a systematic sequencing study of HLA-G promoter region was done in 36 individuals with a total of 15 different alleles. From the 12 sequences obtained, 7 were new sequences and not previously described. Results show that the sequences have three different patterns of evolution confirming the results obtained in the rest of the sequence regions (exons, introns and 3'UTR) where three different lineages were established. Only one of these lineages includes the non-human primate promoter sequences suggesting the possibility of this lineage could come directly from non-human primates while the other two could be generated after the speciation. More non-human primates MHC-G promoter sequences must be obtained to confirm this hypothesis. Expression and functional assays could be done considering the differences obtained in the promoter regions involving the HLA-G function (mRNA expression, isoforms).
Assuntos
Evolução Molecular , Antígenos HLA-G/genética , Polimorfismo Genético , Regiões Promotoras Genéticas/genética , Regiões 3' não Traduzidas/genética , Alelos , Animais , Éxons/genética , Antígenos HLA-G/classificação , Humanos , Íntrons/genética , Dados de Sequência Molecular , Filogenia , Primatas/genética , Análise de Sequência de DNARESUMO
HLA-G*01:03:01:02 and G*01:03:01:01 differ by a two nucleotide changes in intron 3.
Assuntos
Sangue Fetal/metabolismo , Antígenos HLA-G/genética , Íntrons , Polimorfismo Genético , Alelos , Sequência de Bases , Transplante de Células-Tronco de Sangue do Cordão Umbilical/métodos , Humanos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase/métodos , Análise de Sequência de DNA , Homologia de Sequência do Ácido NucleicoRESUMO
Several studies have indicated the gene conversion as the most important mechanism about the MHC polymorphism generation when intron sequences are studied. The data obtained confirm that the B*83:01 allele is generated by gene conversion event including exon 2 and partial intron 1 and 2 between B*44 and B*56 alleles.
Assuntos
Conversão Gênica , Antígenos HLA-B/genética , Polimorfismo Genético , Sequência de Bases , Éxons , Humanos , Íntrons , Dados de Sequência Molecular , Alinhamento de SequênciaRESUMO
America first inhabitants and peopling are still debated. In order to increase knowledge about these questions, we have aimed to detect HLA genes of an Amerindian secluded community: Jaidukama, who lives in North Colombia Equatorial forest. HLA genotyping and extended haplotype calculations were carried out in 39 healthy individuals belonging to 13 families. HLA frequencies were compared to other Amerindians and worldwide populations by calculating genetic distances, relatedness dendrograms and correspondence analyses. Only four DRB1 alleles were found (*0404, *0407, *1402 and *1602); however a total of 17 Amerindian different extended class I-class II HLA haplotypes were directly counted from the family studies, nine of them were specific of Jaidukamas. Some of the alleles or group of alleles within an extended haplotype (i.e. DQB1-DRB1) were also found in Asians and Pacific Islanders, further supporting existence of Asian and Pacific gene flow with Amerindians or a common founder effect. It is further supported that HLA extended haplotypes vary faster than alleles in populations. It is concluded that this unique model of Amerindian secluded families study suggests that rapid HLA haplotype variation may be more important than allele variation for survival (starting immune responses). This work may also be useful for future transplant programs in the area.
Assuntos
Alelos , Povo Asiático/genética , Antígenos HLA/genética , Haplótipos/genética , Indígenas Sul-Americanos/genética , Havaiano Nativo ou Outro Ilhéu do Pacífico/genética , Cromossomos Humanos/genética , Colômbia , Frequência do Gene/genética , Geografia , Humanos , FilogeniaRESUMO
Recombination between HLA-G*01010101/02 and HLA-G*01010201 generates HLA-G*010120.
Assuntos
Antígenos HLA/genética , Antígenos de Histocompatibilidade Classe I/genética , Recombinação Genética , Sequência de Bases , Antígenos HLA-G , Humanos , Dados de Sequência MolecularRESUMO
HLA-G*01010301 and G*01010302 differ by a single point mutation in intron 5.
Assuntos
Antígenos HLA/genética , Antígenos de Histocompatibilidade Classe I/genética , Polimorfismo de Nucleotídeo Único , Alelos , Sequência de Bases , Antígenos HLA-G , Teste de Histocompatibilidade , Humanos , Íntrons/genética , Dados de Sequência Molecular , Isoformas de Proteínas/genética , Análise de Sequência de DNA , Homologia de Sequência do Ácido NucleicoRESUMO
Three nucleotide changes and one insertion in intron 2 upon human leucocyte antigen (HLA)-G*01010105 generate HLA-G*01010106.
Assuntos
Alelos , Antígenos HLA/genética , Antígenos de Histocompatibilidade Classe I/genética , Íntrons/genética , Sequência de Bases , DNA/genética , DNA/isolamento & purificação , Primers do DNA/genética , Feminino , Sangue Fetal/química , Conversão Gênica , Antígenos HLA-G , Teste de Histocompatibilidade/métodos , Humanos , Dados de Sequência Molecular , Mutagênese Insercional , Reação em Cadeia da Polimerase , Polimorfismo Genético , Gravidez , Análise de Sequência de DNA/instrumentação , Análise de Sequência de DNA/métodos , Terminologia como AssuntoRESUMO
Human leukocyte antigen (HLA)-E is a nonclassical class I (Ib) gene with a restricted polymorphism. Only eight DNA alleles and three proteins of this gene have been described and their frequencies analyzed in Caucasian, Oriental, Asian Indian, and Negroid populations. In the present study, HLA-E polymorphism has been analyzed in six Amerindian and Mestizo populations from North and South America and compared with previously described populations. HLA-E*0101 is the most frequent allele found in all populations except in Afrocolombian and Wayu Amerindians, in which blood group analyses show a high admixture with Caucasian and African populations. Mazatecan and Mapuche (two Amerindian groups from North and South America, respectively) presented similar HLA-E frequencies, whereas Wayu Indians are more similar to the Afrocolombian population. The Mexican and Colombian Mestizo show similar allele frequencies to Amerindians with high frequencies of HLA-E*0101 and HLA-E*010302 alleles. Also, frequencies in Negroids and Asian Indians present a similar distribution of HLA-E alleles. These data are in agreement with worldwide restricted polymorphism of HLA-E because no new allele was detected in the six populations studied. The allelic frequencies show differences among Caucasian, Oriental, Mestizo and Indian populations. Ape major histocompatibility complex-E allelism is also very restricted: common chimpanzee (one allele); bonobo (two alleles); gorilla (two alleles); orangutan (one allele); rhesus monkey (eight alleles); cynomolgus monkey (two alleles); and green monkey (two alleles).
Assuntos
Povo Asiático/genética , Etnicidade/genética , Antígenos HLA/genética , Antígenos de Histocompatibilidade Classe I/genética , Polimorfismo Genético , População Branca/genética , Alelos , Animais , Chile/etnologia , Colômbia/etnologia , Frequência do Gene , Hominidae/genética , Humanos , México , Pan paniscus/genética , Pongo pygmaeus/genética , Conformação Proteica , Antígenos HLA-ERESUMO
Six proteins, one null allele and 22 human leukocyte antigen (HLA)-G alleles were found in humans. Bonobo, chimpanzee and gorilla only show one allele and orangutan shows five alleles. All Cercopithecus alleles show stop codons at position 164 (Macaca mulatta with seven DNA alleles, Macaca fascicularis with seven DNA alleles and Cercopithecus aethiops with three DNA alleles). Cotton-top tamarin New World monkeys showed 20 DNA and protein alleles; the major histocompatibility complex (MHC)-G New World sequences seem to be closer to MHC-E and lack typical MHC-G primates intron 2-specific deletion. This seems to suggest that MHC-G genes in New World primates are not orthologous and that their function may be similar to that of classical presenting MHC genes.
Assuntos
Evolução Biológica , Antígenos HLA/genética , Antígenos de Histocompatibilidade Classe I/genética , Complexo Principal de Histocompatibilidade/genética , Polimorfismo Genético , Animais , Sequência de Bases , Família , Feminino , Antígenos HLA-G , Homozigoto , Humanos , Complexo Principal de Histocompatibilidade/imunologia , Masculino , Dados de Sequência Molecular , Linhagem , Primatas/genética , Homologia de Sequência do Ácido NucleicoRESUMO
The generation of the B*41 alleles has been analysed using exon 1, intron 1, exon 2, intron 2 and exon 3 sequences. Results showed that B*4102 may have been generated as the first B*41 allele by a recombination mechanism between B*400102 and B*0801 or B*4201 involving intron 2. B*4101, B*4104 and B*4107 alleles could have been generated from B*4102 by a gene conversion event taking three different fragments from sequences belonging to intron 2/exon 3 of B*45, B*50 or B*49 alleles. B*4105 and B*4106 could be generated from B*4101 allele by point mutations, and B*4103 generation is unclear due to the lack of intron 2. The importance of introns in HLA-B allele polymorphism generation is stressed.
Assuntos
Alelos , Antígenos HLA-B/genética , Íntrons/genética , Recombinação Genética , Sequência de Bases , Humanos , Dados de Sequência Molecular , Polimorfismo Genético , Alinhamento de Sequência , Homologia de Sequência do Ácido NucleicoAssuntos
Alelos , Complexo Principal de Histocompatibilidade/genética , Primatas/genética , Animais , Sequência de Bases , Linhagem Celular , Evolução Molecular , Éxons , Gorilla gorilla/genética , Gorilla gorilla/imunologia , Humanos , Íntrons , Complexo Principal de Histocompatibilidade/imunologia , Dados de Sequência Molecular , Pan paniscus/genética , Pan paniscus/imunologia , Pan troglodytes/genética , Pan troglodytes/imunologia , Polimorfismo Genético , Pongo pygmaeus/genética , Pongo pygmaeus/imunologia , Primatas/imunologia , Alinhamento de SequênciaRESUMO
The major histocompatibility complex (MHC)-F class Ib locus shows a limited polymorphism, and the function of its mainly intracellular protein is not clear. We have identified human leucocyte antigen (HLA)-F orthologous DNA sequences in Pongidae in order to study the MHC-F gene evolution and its products' function. HLA-F orthologous cDNA transcripts are found in chimpanzee and in the new primate species studied (bonobo, gorilla and orangutan). Analyses of the predicted amino acid sequences and their comparison with other primate MHC-F proteins show that MHC-F may be a protein with a typical class I structure and that the key residues of the peptide-binding region (PBR) are highly conserved in MHC-F in all studied primates species. Thus, MHC-F conservation along the primate evolution suggests an important role in cellular physiology. It is possible that the MHC-F protein could be involved, together with MHC-G and MHC-E, in the natural killer (NK) cell activity regulation, although rhesus macaque does not express MHC-G and MHC-E orthologues. The evolutionary pathway of the six-base-pair deletion at exon 2 existing in some primates is put forward.
Assuntos
Evolução Molecular , Éxons/genética , Genes MHC Classe I/genética , Locos de Características Quantitativas/genética , Deleção de Sequência/genética , Sequência de Aminoácidos , Animais , Linhagem Celular , Éxons/imunologia , Genes MHC Classe I/imunologia , Hominidae , Humanos , Dados de Sequência Molecular , Locos de Características Quantitativas/imunologia , Análise de Sequência de Proteína/métodos , Deleção de Sequência/imunologiaRESUMO
Aymara Amerindians from the Titicaca Lake Andean highlands are studied for HLA-A, HLA-B, HLA-DRB1 and HLA-DQB1 gene frequencies. Genetic distances, neighbour-joining and correspondence analyses are performed by using other Amerindian and worldwide populations (15384 chromosomes are studied). The HLA genetic profile of Aymaras is different from neighbouring and language-related Quechuas (Incas). Both Quechuas and Aymaras seem to present an HLA-DRB1*0901 high frequency, which is present in a very low frequency or absent in Mesoamericans (Mazatecans, Mayans) and most studied Amerindians. Moreover, it is observed a closer relatedness of Aymaras with Amerindians from the Amazon Basin and Chaco lowlands, compared to Quechuans.
Assuntos
Indígena Americano ou Nativo do Alasca/genética , Antígenos HLA/genética , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe I/genética , Bolívia , Frequência do Gene , Haplótipos , HumanosRESUMO
The HLA allele frequency distribution of the Mayans from Guatemala was studied and compared with those of other First American Natives and worldwide populations (a total of 12,364 chromosomes and 6182 individuals from 60 different populations). The main conclusions were (1): the closest Amerindian group to Mayans is the Arhuacs, who were the first recorded Caribbean Islands' inhabitants (2). Mayans are not so close to Mesoamerican Zapotec, Mixe and Mixtec Amerindians, who genetically cluster together. Mixe had been related to Mayans only on linguistic bases (3). DRB1*0407 and DRB1*0802 alleles are found in 50% of Mayans; these alleles are also found in other Amerindians, but the Mayans' high frequencies may be showing a founder effect for this Mesoamerican-Caribbean population (4). Extended Mayan specific HLA haplotypes are described for the first time (5). Language and genes do not completely correlate in microgeographical studies (6). Significant genetic input from outside is not noticed in Meso and South American Amerindians according to the genetic analyses; while all world populations (including Africans, Europeans, Asians, Australians, Polynesians, North American Na-Dene Indians and Eskimos) are genetically related. Meso and South American Amerindians tend to remain isolated in the neighbour joining analyses.
Assuntos
Etnicidade/genética , Antígenos HLA/genética , Indígenas Centro-Americanos/genética , Alelos , Efeito Fundador , Frequência do Gene , Genética Populacional , Guatemala , Antígenos HLA-B/genética , Antígenos HLA-DR/genética , Haplótipos , Humanos , Desequilíbrio de Ligação , Análise de Sequência de DNARESUMO
HLA-A, -B, -DRB1, -DQA1 and -DQB1 alleles have been studied in three relatively isolated populations of northern Spain from Cantabria ( Pas Valleys inhabitants or Pasiegos and Cabuernigos) and from the Basque Country (Arratia Valley inhabitants). These populations have been compared with neighbouring ones and other Mediterraneans by using neighbour-joining dendrograms and plane genetic distances.