Project description:While Neanderthals are extinct, fragments of their genome still persist in the genomes of contemporary humans. Here, we show that such Neanderthal-like sequences are not distributed randomly in contemporary human genomes. Specifically, while genome-wide frequency of Neanderthal-like sites is close to 6% in all out-of-Africa populations, genes involved in lipid catabolism contain large excess Neanderthal-like sequences in Europeans (24.3%), but not in Asians (12.4%). While lipid catabolism cannot be assayed in Neanderthals, we took advantage of genetic divergence between human populations, chimpanzees and Neanderthals to predict metabolic divergence expected from the observed excess of Neanderthal gene flow into Europeans. We confirmed predicted changes in lipid catabolism using hydrophobic metabolome measurements in the brain tissue and further linked these metabolic changes to gene expression divergence. 14 human and 6 chimpanzee samples were sequenced.
Project description:While Neanderthals are extinct, fragments of their genome still persist in the genomes of contemporary humans. Here, we show that such Neanderthal-like sequences are not distributed randomly in contemporary human genomes. Specifically, while genome-wide frequency of Neanderthal-like sites is close to 6% in all out-of-Africa populations, genes involved in lipid catabolism contain large excess Neanderthal-like sequences in Europeans (24.3%), but not in Asians (12.4%). While lipid catabolism cannot be assayed in Neanderthals, we took advantage of genetic divergence between human populations, chimpanzees and Neanderthals to predict metabolic divergence expected from the observed excess of Neanderthal gene flow into Europeans. We confirmed predicted changes in lipid catabolism using hydrophobic metabolome measurements in the brain tissue and further linked these metabolic changes to gene expression divergence.
Project description:Some Neanderthal introgressed variation underwent selective sweeps, but little is known about their functional significance. We used a Massively Parallel Reporter Assay (MPRA) to test 5,353 high-frequency introgressed variants for evidence of being in active cis-regulatory elements (CREs) and modulating gene expression in immune cell lines. We identified 2,546 variants in CREs and 292 expression-modulating variants (emVars). These emVars are predicted to regulate genes that are enriched for function in innate immune pathways including interferon signaling, toll like receptor pathways, and anti-viral response; one such emVar is significantly associated with protection against severe COVID-19 response. Using CRISPR-Cas9, we deleted two CREs containing expression-modulation variants linked to immune function, rs11624425 and rs80317430, identifying their primary genic targets as ELMSAN1, and PAN2 and STAT2 respectively, three genes differentially expressed during influenza infection. Overall, we present the first database of directly identified expression-modulating Neanderthal-introgressed alleles contributing to potential immune response in modern humans.
Project description:Using a minimally destructive acid-etch procedure, this study successfully identified sex from a Neanderthal tooth fragment (c. 90,100-92,000 years old).
