TY - JOUR T1 - Adaptively introgressed Neandertal haplotype at the OAS locus functionally impacts innate immune responses in humans JF - bioRxiv DO - 10.1101/051466 SP - 051466 AU - Aaron J. Sams AU - Anne Dumaine AU - Yohann Nédélec AU - Vania Yotova AU - Caroline Alfieri AU - Jerome E. Tanner AU - Philipp W. Messer AU - Luis B. Barreiro Y1 - 2016/01/01 UR - http://biorxiv.org/content/early/2016/05/04/051466.abstract N2 - The 2’-5’ oligoadenylate synthetase (OAS) locus encodes for three OAS enzymes (OAS1-3) involved in innate immune response. This region harbors high amounts of Neandertal ancestry in non-African populations; yet, strong evidence of positive selection in the OAS region is still lacking. Here we used a combination of neutral coalescent simulations and neutrality tests to firmly demonstrate a signal of adaptive introgression at the OAS locus. Furthermore, we characterized the functional consequences of the Neandertal haplotype in the transcriptional regulation of OAS genes at baseline and infected conditions. We found that cells from people with the Neandertal-like haplotype express lower levels of OAS3 upon infection, as well as distinct isoforms of OAS1 and OAS2. Notably, the Neandertal-introgressed haplotype reintroduced an ancestral splice variant of OAS1 encoding a more active protein, suggesting that adaptive introgression occurred as a means to resurrect adaptive variation that had been lost outside Africa. ER -