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:Studies in Aotearoa New Zealand found higher bone mineral density and lower rate of hip fracture in people of Polynesian ancestry compared to Europeans. We hypothesised that differences in osteoblast gene expression contribute to the differences in bone properties between the two groups, and aimed to identify mechanisms that underlie the bone phenotype.
Project description:The genetic structure of some native Bolivians has been substantially influenced by admixture from Europeans, which we estimate to have occurred approximately 360 – 384 years ago. Consistent with historical accounts of male admixture, Y-chromosome haplogroups typical of Europeans were found in 39% of our Bolivian samples. No evidence of African admixture was found in native Bolivians. The Mesoamerican Totonacs have little evidence of European or African admixture. Our analysis indicates that some admixed Bolivians have Native American mtDNA and Y-chromosomes but harbor up to 30% European autosomal ancestry, demonstrating the need for autosomal markers to assess ancestry in admixed populations. From a dense genome-wide panel of 815,377 markers, we developed a set of 324 AIMs, specific for Native American ancestry. As few a 40-50 of these markers successfully predict New World ancestry in the ascertainment panel of Bolivians and Totonacs. The markers easily distinguish New World from Old World ancestry, even for populations more closely related to the Americas such as central and eastern Asians, and were effective for New World vs. Old World comparisons in five other geographically and culturally distinct populations of the Americas. SNPs demonstrating very high divergence between the two Native American populations and major Old World populations are found on haplotypes that are shared and occur at similar frequencies in other indigenous low-admixture American populations examined here (i.e. Pima, Maya, Colombian, Karitiana, and Surui). After excluding the possibility of recent relatedness, our results indicate that native Bolivians and Totonacs share ancestry with other American populations through a substantial contribution from a common founding population, population bottlenecks, and possible natural selection on functional variation.
Project description:Medieval era encounters of nomadic groups of the Eurasian Steppe and largely sedentary East Europeans had a variety of demographic and cultural consequences. Amongst these outcomes was the emergence of the Lipka Tatars - a Slavic-speaking Sunni-Muslim ethno-religious minority residing in modern Belarus, Lithuania and Poland, whose ancestors arrived in these territories via several migration waves, mainly from the Golden Horde. Our results show that Belarusian Lipka Tatars share a substantial part of their gene pool with Europeans as indicated by their Y-chromosomal, mitochondrial DNA and autosomal variation. Nevertheless, Belarusian Lipkas still retain a strong genetic signal of their nomadic ancestry, witnessed by the presence of common Y-chromosomal and mitochondrial DNA variants as well as autosomal segments identical by descent between Lipkas and East Eurasians from temperate and northern regions. Hence, we document Lipka Tatars as a unique example of former Medieval migrants into Central Europe, who became sedentary, changed language to Slavic, yet preserved their faith and retained, both uni- and bi-parentally, a clear genetic echo of a complex population interplay throughout the Eurasian Steppe Belt, extending from Central Europe to northern China.
Project description:The focus of this submission is to genetically identify the population fingerprint of the contemporary population and sub-populations of Northern Lebanon. To this end, the HumanOmniExpress 12 array has been used to comprehensively genotype 344 selected samples from different communities. The samples were collected with careful scrutiny to their heritage, documenting at least two generations of ancestry for each sample.
Project description:Here, we identified a long-chain acyl-CoA-responsive transcriptional repressor, FdmR, as the key regulator of mycobacterial fatty acid catabolism. We employed ChIP-Seq to identify the genomic binding regions for FdmR. FdmR was found to bind upstream of fadA2, fabG4, fadE24, fixA, MMAR_1683, fadE5, icl, desA3, desA3_1, and MMAR_2730.We then demonstrated that FdmR acts as a valve to direct the fatty acid flux from β-oxidation towards lipid biosynthesis, thereby avoiding the overactive catabolism and accumulation of biologically toxic intermediates. This regulatory mechanism enables a high rate of cell growth with modest consumption of fatty acid substrates.
Project description:Pyrimidine catabolism is implicated in hepatic steatosis. Dihydropyrimidine Dehydrogenase (DPYD) is an enzyme responsible for uracil and thymine catabolism, and DPYD human genetic variability affects clinically observed toxicity following 5-Fluorouracil (5-FU) administration. In an in vitro model of diet-inducedfatty acid-induced steatosis, the pharmacologic inhibition of DPYD resulted in protection from lipid accumulation. Additionally, a gain-of-function mutation of DPYD, created through clustered regularly interspaced short palindromic repeats associated protein 9 (CRISPR-Cas9) engineering, led to an increased lipid burden, which was associated with altered mitochondrial functionality in a hepatocarcionma cell line. The studies presented herein describe a novel role for DPYD in hepatocyte metabolic regulation as a modulator of hepatic steatosis.
Project description:Medieval era encounters of nomadic groups of the Eurasian Steppe and largely sedentary East Europeans had a variety of demographic and cultural consequences. Amongst these outcomes was the emergence of the Lipka Tatars - a Slavic-speaking Sunni-Muslim ethno-religious minority residing in modern Belarus, Lithuania and Poland, whose ancestors arrived in these territories via several migration waves, mainly from the Golden Horde. Our results show that Belarusian Lipka Tatars share a substantial part of their gene pool with Europeans as indicated by their Y-chromosomal, mitochondrial DNA and autosomal variation. Nevertheless, Belarusian Lipkas still retain a strong genetic signal of their nomadic ancestry, witnessed by the presence of common Y-chromosomal and mitochondrial DNA variants as well as autosomal segments identical by descent between Lipkas and East Eurasians from temperate and northern regions. Hence, we document Lipka Tatars as a unique example of former Medieval migrants into Central Europe, who became sedentary, changed language to Slavic, yet preserved their faith and retained, both uni- and bi-parentally, a clear genetic echo of a complex population interplay throughout the Eurasian Steppe Belt, extending from Central Europe to northern China. 6 samples were analysed with the Illumina platform HumanOmniExpress-24 v1.0 BeadChip and are described herein. Please note that the submitted information does not compromise participant privacy and is in accord with the original consent in addition to all applicable laws, regulations, and institutional policies. The submitter verified that there are no privacy concerns and that our human data can be open access.