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BMC Genomics

, 15:332

Human and rodent genomics

Abstract

BackgroundThe HUGO Pan-Asian SNP Consortium PASNP has generated a genetic resource of almost 55,000 autosomal single nucleotide polymorphisms SNPs across more than 1,800 individuals from 73 urban and indigenous populations in Asia. This has offered valuable insights into the correlation between the genetic ancestry of these populations with major linguistic systems and geography. Here, we attempt to understand whether adaptation to local climate, diet and environment partly explains the genetic variation present in these populations by investigating the genomic signatures of positive selection.

ResultsTo evaluate the impact to the selection analyses due to the considerably lower SNP density as compared to other population genetics resources such as the International HapMap Project HapMap or the Singapore Genome Variation Project, we evaluated the extent of haplotype phasing switch errors and the consistency of selection signals from three haplotype-based approaches iHS, XP-EHH, haploPS when the HapMap data is thinned to a similar density as PASNP. We subsequently applied haploPS to detect and characterize positive selection in the PASNP populations, identifying 59 genomics regions that were selected in at least one PASNP populations. A cluster analysis on the basis of these 59 signals showed that indigenous populations such as the Negrito from Malaysia and Philippines, the China Hmong, and the Taiwan Ami and Atayal shared more of these signals. We also reported evidence of a positive selection signal encompassing the beta globin gene in the Taiwan Ami and Atayal that was distinct from the signal in the HapMap Africans, suggesting the possibility of convergent evolution at this locus due to malarial selection.

ConclusionsWe established that the lower SNP content of the PASNP data conferred weaker ability to detect signatures of positive selection, but the availability of the new approach haploPS retained modest power. Out of all the populations in PASNP, we identified only 59 signals, suggesting a strong need for high-density population-level genotyping data or sequencing data in order to achieve a comprehensive survey of positive selection in Asian populations.

KeywordsHaplotype phasing Positive selection Population structure Genetic diversity Electronic supplementary materialThe online version of this article doi:10.1186-1471-2164-15-332 contains supplementary material, which is available to authorized users.

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Author: Xuanyao Liu - Woei-Yuh Saw - Mohammad Ali - Rick Twee-Hee Ong - Yik-Ying Teo

Source: https://link.springer.com/







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