TY - JOUR
T1 - The genetic legacy of the Indian Ocean slave trade
T2 - Recent admixture and post-admixture selection in the Makranis of Pakistan
AU - Laso-Jadart, Romuald
AU - Harmant, Christine
AU - Quach, Hélène
AU - Zidane, Nora
AU - Tyler-Smith, Chris
AU - Mehdi, Qasim
AU - Ayub, Qasim
AU - Quintana-Murci, Lluis
AU - Patin, Etienne
N1 - Funding Information:
We thank all participants who kindly accepted to provide blood samples. We thank Laure Lémée and the Eukaryote Genotyping platform (Biomics pole) from the Institut Pasteur for generating the SNP genotype raw data. This work was supported by the Institut Pasteur , the Centre National de la Recherche Scientifique , and Agence Nationale de la Recherche grants IEIHSEER ( ANR-14-CE14-0008-02 ), TBPATHGEN ( ANR-14-CE14-0007-02 ), and AGRHUM ( ANR-14-CE02-0003-01 ). C.T.S. and Q.A. were supported by the Wellcome Trust ( 098051 ).
Publisher Copyright:
© 2017 American Society of Human Genetics
Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 2017/12/7
Y1 - 2017/12/7
N2 - From the eighth century onward, the Indian Ocean was the scene of extensive trade of sub-Saharan African slaves via sea routes controlled by Muslim Arab and Swahili traders. Several populations in present-day Pakistan and India are thought to be the descendants of such slaves, yet their history of admixture and natural selection remains largely undefined. Here, we studied the genome-wide diversity of the African-descent Makranis, who reside on the Arabian Sea coast of Pakistan, as well that of four neighboring Pakistani populations, to investigate the genetic legacy, population dynamics, and tempo of the Indian Ocean slave trade. We show that the Makranis are the result of an admixture event between local Baluch tribes and Bantu-speaking populations from eastern or southeastern Africa; we dated this event to ∼300 years ago during the Omani Empire domination. Levels of parental relatedness, measured through runs of homozygosity, were found to be similar across Pakistani populations, suggesting that the Makranis rapidly adopted the traditional practice of endogamous marriages. Finally, we searched for signatures of post-admixture selection at traits evolving under positive selection, including skin color, lactase persistence, and resistance to malaria. We demonstrate that the African-specific Duffy-null blood group—believed to confer resistance against Plasmodium vivax infection—was recently introduced to Pakistan through the slave trade and evolved adaptively in this P. vivax malaria-endemic region. Our study reconstructs the genetic and adaptive history of a neglected episode of the African Diaspora and illustrates the impact of recent admixture on the diffusion of adaptive traits across human populations.
AB - From the eighth century onward, the Indian Ocean was the scene of extensive trade of sub-Saharan African slaves via sea routes controlled by Muslim Arab and Swahili traders. Several populations in present-day Pakistan and India are thought to be the descendants of such slaves, yet their history of admixture and natural selection remains largely undefined. Here, we studied the genome-wide diversity of the African-descent Makranis, who reside on the Arabian Sea coast of Pakistan, as well that of four neighboring Pakistani populations, to investigate the genetic legacy, population dynamics, and tempo of the Indian Ocean slave trade. We show that the Makranis are the result of an admixture event between local Baluch tribes and Bantu-speaking populations from eastern or southeastern Africa; we dated this event to ∼300 years ago during the Omani Empire domination. Levels of parental relatedness, measured through runs of homozygosity, were found to be similar across Pakistani populations, suggesting that the Makranis rapidly adopted the traditional practice of endogamous marriages. Finally, we searched for signatures of post-admixture selection at traits evolving under positive selection, including skin color, lactase persistence, and resistance to malaria. We demonstrate that the African-specific Duffy-null blood group—believed to confer resistance against Plasmodium vivax infection—was recently introduced to Pakistan through the slave trade and evolved adaptively in this P. vivax malaria-endemic region. Our study reconstructs the genetic and adaptive history of a neglected episode of the African Diaspora and illustrates the impact of recent admixture on the diffusion of adaptive traits across human populations.
KW - admixture
KW - African diaspora
KW - DARC
KW - Duffy blood group
KW - FY
KW - Plasmodium vivax malaria
KW - population genetics
KW - post-admixture selection
KW - slave trade
KW - South Asia
UR - http://www.scopus.com/inward/record.url?scp=85033403795&partnerID=8YFLogxK
U2 - 10.1016/j.ajhg.2017.09.025
DO - 10.1016/j.ajhg.2017.09.025
M3 - Article
C2 - 29129317
AN - SCOPUS:85033403795
SN - 0002-9297
VL - 101
SP - 977
EP - 984
JO - American Journal of Human Genetics
JF - American Journal of Human Genetics
IS - 6
ER -