Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Genetic variability, molecular evolution, and geographic diversity of HLA-B27
Autore:
Blanco-Gelaz, MA; Lopez-Vazquez, A; Garcia-Fernandez, S; Martinez-Borra, J; Gonzalez, S; Lopez-Larrea, C;
Indirizzi:
Hosp Cent Asturias, Dept Immunol, E-3006 Oviedo, Spain Hosp Cent AsturiasOviedo Spain E-3006 ept Immunol, E-3006 Oviedo, Spain Univ Oviedo, Funct Biol Dept, Oviedo, Spain Univ Oviedo Oviedo SpainUniv Oviedo, Funct Biol Dept, Oviedo, Spain
Titolo Testata:
HUMAN IMMUNOLOGY
fascicolo: 9, volume: 62, anno: 2001,
pagine: 1042 - 1050
SICI:
0198-8859(200109)62:9<1042:GVMEAG>2.0.ZU;2-U
Fonte:
ISI
Lingua:
ENG
Soggetto:
ANKYLOSING-SPONDYLITIS; HLA-B; PEPTIDE-BINDING; Y-CHROMOSOME; POLYMORPHISM; HAPLOTYPES; SUSCEPTIBILITY; POPULATIONS; SELECTION; ALLELES;
Keywords:
HLA-B27 polymorphism; MHC evolution; nucleotide diversity; selection; ankylosing spondylitis;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
33
Recensione:
Indirizzi per estratti:
Indirizzo: Lopez-Larrea, C Hosp Cent Asturias, Dept Immunol, E-3006 Oviedo, Spain Hosp Cent Asturias Oviedo Spain E-3006 006 Oviedo, Spain
Citazione:
M.A. Blanco-Gelaz et al., "Genetic variability, molecular evolution, and geographic diversity of HLA-B27", HUMAN IMMUN, 62(9), 2001, pp. 1042-1050

Abstract

HLA-B27 represents a family of 23 closely related alleles (B*2701-23) thatdiffer at 24 amino acid positions. The pattern of polymorphisms of B27 wasstudied, with special reference to synonymous (Ks) and nonsynonymous (Ka) divergence among alleles. B27 alleles are characterized by the enhanced rate of nonsynonymous nucleotide substitution in the peptide-binding region (PBR). The percentage of substitutions between each of the B27 pairs ranges from 0.2%-3% in exons 2-3 to 1.8%-20.1% in the PBR. A phylogenetic analysis of all B27 alleles is described in order to identify subtypes with a commonevolutionary history. These results, together with the phylogenetic trees obtained from the comparison between exons 2-3 and PBR indicate that polymorphism of B27 is selectively maintained. Most of the differences are clustered in the C/F pocket affecting the specific binding of antigenic peptides. Gene conversion and point mutation are the most important mechanisms responsible for B27 diversification. The interaction of selection, genetic drift, and recombination events is important for generating polymorphism at B27 alleles. We analyzed a large extended B27 positive population from different parts of the world. Our results indicate that B27 subtypes differ in their ethnic distribution, which may be the result of different genetic and geographical origins. Different factors such as genetic drift, bottleneck effect, and admixture among populations could contribute to the genetic constitution of B27. The striking correlation between the structural features of B27 and the ethnic distribution of these subtypes suggests a model of strongdirectional evolution, in which the subtypes could have arisen from B*2705. Human Immunology 62. 1042-1050 (2001). (C) American Society for Histocompatibility and Immunogenetics, 2001. Published by Elsevier Science Inc.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 30/09/20 alle ore 09:18:57