Diversity of HLA Class I and Class II blocks and conserved extended haplotypes in Lacandon Mayans.

Here we studied HLA blocks and haplotypes in a group of 218 Lacandon Maya Native American using a high-resolution next generation sequencing (NGS) method. We assessed the genetic diversity of HLA class I and class II in this population, and determined the most probable ancestry of Lacandon Maya HLA class I and class II haplotypes. Importantly, this Native American group showed a high degree of both HLA homozygosity and linkage disequilibrium across the HLA region and also lower class II HLA allelic diversity than most previously reported populations (including other Native American groups). Distinctive alleles present in the Lacandon population include HLA-A*24:14 and HLA-B*40:08. Furthermore, in Lacandons we observed a high frequency of haplotypes containing the allele HLA-DRB1*04:11, a relatively frequent allele in comparison with other neighboring indigenous groups. The specific demographic history of the Lacandon population including inbreeding, as well as pathogen selection, may have elevated the frequencies of a small number of HLA class II alleles and DNA blocks. To assess the possible role of different selective pressures in determining Native American HLA diversity, we evaluated the relationship between genetic diversity at HLA-A, HLA-B and HLA-DRB1 and pathogen richness for a global dataset and for Native American populations alone. In keeping with previous studies of such relationships we included distance from Africa as a covariate. After correction for multiple comparisons we did not find any significant relationship between pathogen diversity and HLA genetic diversity (as measured by polymorphism information content) in either our global dataset or the Native American subset of the dataset. We found the expected negative relationship between genetic diversity and distance from Africa in the global dataset, but no relationship between HLA genetic diversity and distance from Africa when Native American populations were considered alone

Hitos demográficos del siglo XXI : migración internacional

Al hablar de la migración internacional en el contexto actual, es indispensable reconocer que la migración es parte del engranaje del sistema neoliberal y que su lectura requiere considerar sus múltiples dimensiones y diversas formas, es decir, desde las diferentes perspectivas que den cabida al análisis, la crítica y el consenso de la metodología, para poder identificar las asimetrías del desarrollo y la migración internacional en el contexto de la globalización. Pero también la globalización y la tecnología van remodelando la experiencia personal de un migrante. Estos y otros temas como migración y remesas, políticas migratorias, tratados comerciales y migración, el mercado de trabajo y el capital humano, migración y voto desde el extranjero, migración y género, migración y salud y migración y derechos humanos, son tratados en este libro