Natural selection for the Duffy-null allele in the recently admixed people of Madagascar

• Type: Article in International Scientific Journal
• Date: 2014

Authors

Jason A Hodgson (Author) Other; Joseph K Pickrell (Author) Other; Laurel N Pearson (Author) Other; Ellen E Quillen (Author) Other; Antonio Prista (Author) Other; Jorge Rocha (Author) FCUP; Himla Soodyall (Author) Other; Mark D Shriver (Author) Other; George H Perry (Author) Other

Journal

Title: Proceedings of the Royal Society B: Biological Sciences

Vol. 281

Pages: 20140930-20140930

ISSN: 0962-8452

Publisher: The Royal Society

Indexing

ISI Web of Knowledge - 39 Citations

Scopus - 43 Citations

Scientific classification

FOS: Natural sciences > Biological sciences

Other information

Authenticus ID: P-009-MN0

DOI: 10.1098/rspb.2014.0930

Abstract (EN): While gene flow between distantly related populations is increasingly recognized as a potentially important source of adaptive genetic variation for humans, fully characterized examples are rare. In addition, the role that natural selection for resistance to vivax malaria may have played in the extreme distribution of the protective Duffy-null allele, which is nearly completely fixed in mainland sub-Saharan Africa and absent elsewhere, is controversial. We address both these issues by investigating the evolution of the Duffy-null allele in the Malagasy, a recently admixed population with major ancestry components from both East Asia and mainland sub-Saharan Africa. We used genome-wide genetic data and extensive computer simulations to show that the high frequency of the Duffy-null allele in Madagascar can only be explained in the absence of positive natural selection under extreme demographic scenarios involving high genetic drift. However, the observed genomic single nucleotide polymorphism diversity in the Malagasy is incompatible with such extreme demographic scenarios, indicating that positive selection for the Duffy-null allele best explains the high frequency of the allele in Madagascar. We estimate the selection coefficient to be 0.066. Because vivax malaria is endemic to Madagascar, this result supports the hypothesis that malaria resistance drove fixation of the Duffy-null allele in mainland sub-Saharan Africa.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9