Arctic introgression and chromatin regulation facilitated rapid Qinghai-Tibet Plateau colonization by an avian predator

The Qinghai-Tibet Plateau (QTP), possesses a climate as cold as that of the Arctic, and also presents uniquely low oxygen concentrations and intense ultraviolet (UV) radiation. QTP animals have adapted to these extreme conditions, but whether they obtained genetic variations from the Arctic during cold adaptation, and how genomic mutations in non-coding regions regulate gene expression under hypoxia and intense UV environment, remain largely unknown. Here, we assemble a high-quality saker falcon genome and resequence populations across Eurasia. We identify female-biased hybridization with Arctic gyrfalcons in the last glacial maximum, that endowed eastern sakers with alleles conveying larger body size and changes in fat metabolism, predisposing their QTP cold adaptation. We discover that QTP hypoxia and UV adaptations mainly involve independent changes in non-coding genomic variants. Our study highlights key roles of gene flow from Arctic relatives during QTP hypothermia adaptation, and cis-regulatory elements during hypoxic response and UV protection. The Qinghai-Tibet Plateau is as cold as the Arctic, but presents unique hypoxia and high ultraviolet conditions. Here the authors find that gene flow from Arctic gyrfalcons aids plateau saker falcons' cold adaptation, and independent non-coding genomic changes underlie hypoxic and ultraviolet responses.

Automated summary

The Qinghai-Tibet Plateau presents extreme temperatures, low oxygen levels, and intense UV radiation. Animals in the plateau have adapted to these conditions, with gene flow from Arctic relatives and non-coding genomic changes playing key roles in their adaptation to hypoxia and UV exposure.