Distribution of local ancestry and evidence of adaptation in admixed populations

Admixed American populations have different global proportions of European, Sub-Saharan African, and Native-American ancestry. However, individuals who display the same global ancestry could exhibit remarkable differences in the distribution of local ancestry blocks. We studied for the first time the distribution of local ancestry across the genome of 264 Brazilian admixed individuals, ascertained within the scope of the Brazilian Initiative on Precision Medicine. We found a decreased proportion of European ancestry together with an excess of Native-American ancestry on chromosome 8p23.1 and showed that this is due to haplotypes created by chromosomal inversion events. Furthermore, Brazilian non-inverted haplotypes were more similar to Native-American haplotypes than to European haplotypes, in contrast to what was found in other American admixed populations. We also identified signals of recent positive selection on chromosome 8p23.1, and one gene within this locus, PPP1R3B, is related to glycogenesis and has been associated with an increased risk of type 2 diabetes and obesity. These findings point to a selection event after admixture, which is still not entirely understood in recent admixture events.

Bibliographic Details

Main Authors:	Secolin, Rodrigo, Mas-Sandoval, Alex, Arauna, Laura R., Torres, Fábio R., de Araujo, Tânia K., Santos, Marilza L., Rocha, Cristiane S., Carvalho, Benilton S., Cendes, Fernando, Lopes-Cendes, Iscia, Comas, David
Other Authors:	Fundação de Amparo à Pesquisa do Estado de São Paulo
Format:	artículo biblioteca
Published:	Springer Nature 2019-09-25
Subjects:	Evolutionary biology, Genetics,
Online Access:	http://hdl.handle.net/10261/207864 http://dx.doi.org/10.13039/501100001807 http://dx.doi.org/10.13039/501100002809 http://dx.doi.org/10.13039/501100003329
Tags:	Add Tag No Tags, Be the first to tag this record!