February 17, 2012

Adaptation to high altitude in Ethiopian highlands

There was another paper on adaptation to high altitude of Tibetans.
Another article on Tibetans and Andean high-altitude adaptation, and another one by Bigham et al.


Genome Biology 2012, 13:R1 doi:10.1186/gb-2012-13-1-r1

Genetic adaptation to high altitude in the Ethiopian highlands

Laura B Scheinfeldt et al.

Abstract (provisional)


Background

Genomic analysis of high-altitude populations residing in the Andes and Tibet has revealed several candidate loci for involvement in high-altitude adaptation, a subset of which have also been shown to be associated with hemoglobin levels, including EPAS1, EGLN1, and PPARA, which play a role in the HIF-1 pathway. Here, we have extended this work to high and low altitude populations living in Ethiopia for which we have measured hemoglobin levels. We genotyped the Illumina 1M SNP array and employed several genome-wide scans for selection and targeted association with hemoglobin levels to identify genes that play a role in adaptation to high altitude.

Results

We have identified a set of candidate genes for positive selection in our high-altitude population sample, demonstrated significantly different hemoglobin levels between high and low altitude Ethiopians and have identified a subset of candidate genes for selection, several of which also show suggestive associations with hemoglobin levels.

Conclusions

We highlight several candidate genes for involvement in high-altitude adaptation in Ethiopia, including CBARA1, VAV3, ARNT2 and THRB. Although most of these genes have not been identified in previous studies of high-altitude Tibetan or Andean population samples, two of these genes (THRB and ARNT2) play a role in the HIF-1 pathway, a pathway implicated in previous work reported in Tibetan and Andean studies. These combined results suggest that adaptation to high altitude arose independently due to convergent evolution in high-altitude Amhara populations in Ethiopia.

Link

1 comment:

terryt said...

"These combined results suggest that adaptation to high altitude arose independently due to convergent evolution in high-altitude Amhara populations in Ethiopia".

And probably not particularly early in our development. Quite possibly some time after any meaningful OoA. That would mean that 'Ethiopia' was not a centre of human expansion. humans were confined to the margins for a considerable time. Analysis of the L mt-DNAs suggests strongly that the Ethiopian haplogroups arrived there from elsewhere, presumably very nearby of course.