Cargando…

Strong Selection at MHC in Mexicans since Admixture

Mexicans are a recent admixture of Amerindians, Europeans, and Africans. We performed local ancestry analysis of Mexican samples from two genome-wide association studies obtained from dbGaP, and discovered that at the MHC region Mexicans have excessive African ancestral alleles compared to the rest...

Descripción completa

Detalles Bibliográficos
Autores principales: Zhou, Quan, Zhao, Liang, Guan, Yongtao
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4749250/
https://www.ncbi.nlm.nih.gov/pubmed/26863142
http://dx.doi.org/10.1371/journal.pgen.1005847
_version_ 1782415251135791104
author Zhou, Quan
Zhao, Liang
Guan, Yongtao
author_facet Zhou, Quan
Zhao, Liang
Guan, Yongtao
author_sort Zhou, Quan
collection PubMed
description Mexicans are a recent admixture of Amerindians, Europeans, and Africans. We performed local ancestry analysis of Mexican samples from two genome-wide association studies obtained from dbGaP, and discovered that at the MHC region Mexicans have excessive African ancestral alleles compared to the rest of the genome, which is the hallmark of recent selection for admixed samples. The estimated selection coefficients are 0.05 and 0.07 for two datasets, which put our finding among the strongest known selections observed in humans, namely, lactase selection in northern Europeans and sickle-cell trait in Africans. Using inaccurate Amerindian training samples was a major concern for the credibility of previously reported selection signals in Latinos. Taking advantage of the flexibility of our statistical model, we devised a model fitting technique that can learn Amerindian ancestral haplotype from the admixed samples, which allows us to infer local ancestries for Mexicans using only European and African training samples. The strong selection signal at the MHC remains without Amerindian training samples. Finally, we note that medical history studies suggest such a strong selection at MHC is plausible in Mexicans.
format Online
Article
Text
id pubmed-4749250
institution National Center for Biotechnology Information
language English
publishDate 2016
publisher Public Library of Science
record_format MEDLINE/PubMed
spelling pubmed-47492502016-02-26 Strong Selection at MHC in Mexicans since Admixture Zhou, Quan Zhao, Liang Guan, Yongtao PLoS Genet Research Article Mexicans are a recent admixture of Amerindians, Europeans, and Africans. We performed local ancestry analysis of Mexican samples from two genome-wide association studies obtained from dbGaP, and discovered that at the MHC region Mexicans have excessive African ancestral alleles compared to the rest of the genome, which is the hallmark of recent selection for admixed samples. The estimated selection coefficients are 0.05 and 0.07 for two datasets, which put our finding among the strongest known selections observed in humans, namely, lactase selection in northern Europeans and sickle-cell trait in Africans. Using inaccurate Amerindian training samples was a major concern for the credibility of previously reported selection signals in Latinos. Taking advantage of the flexibility of our statistical model, we devised a model fitting technique that can learn Amerindian ancestral haplotype from the admixed samples, which allows us to infer local ancestries for Mexicans using only European and African training samples. The strong selection signal at the MHC remains without Amerindian training samples. Finally, we note that medical history studies suggest such a strong selection at MHC is plausible in Mexicans. Public Library of Science 2016-02-10 /pmc/articles/PMC4749250/ /pubmed/26863142 http://dx.doi.org/10.1371/journal.pgen.1005847 Text en © 2016 Zhou et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
spellingShingle Research Article
Zhou, Quan
Zhao, Liang
Guan, Yongtao
Strong Selection at MHC in Mexicans since Admixture
title Strong Selection at MHC in Mexicans since Admixture
title_full Strong Selection at MHC in Mexicans since Admixture
title_fullStr Strong Selection at MHC in Mexicans since Admixture
title_full_unstemmed Strong Selection at MHC in Mexicans since Admixture
title_short Strong Selection at MHC in Mexicans since Admixture
title_sort strong selection at mhc in mexicans since admixture
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4749250/
https://www.ncbi.nlm.nih.gov/pubmed/26863142
http://dx.doi.org/10.1371/journal.pgen.1005847
work_keys_str_mv AT zhouquan strongselectionatmhcinmexicanssinceadmixture
AT zhaoliang strongselectionatmhcinmexicanssinceadmixture
AT guanyongtao strongselectionatmhcinmexicanssinceadmixture