Project description:Characterization of ancestry-linked peptide variants in disease-relevant patient tissues represents a foundational step to connect patient ancestry with molecular disease pathogenesis. Nonsynonymous single nucleotide polymorphisms (SNPs) encoding missense substitutions within tryptic peptides exhibiting high allele frequencies in European, African, and East Asian populations, termed peptide ancestry informative markers (pAIMs), were prioritized from 1000 genomes. In silico analysis shows that as few as 20 pAIMs can determine ancestry proportions similarly to >260K SNPs (R2=0.9905). Multiplexed proteomic analysis of >100 human endometrial cancer cell lines and uterine leiomyoma (ULM) tissues combined resulted in the quantitation of 62 pAIMs that correlate with self-described race and genotype-confirmed patient ancestry. Candidates include a D451E substitution in GC vitamin D-binding protein previously associated with altered vitamin D levels in African and European populations. These efforts describe a generalized set of markers for proteoancestry assessment that will further support studies investigating the impact of ancestry on the human proteome and how this relates to the pathogenesis of uterine neoplasms.
Project description:Low-pass sequencing (sequencing a genome to an average depth less than 1× coverage) combined with genotype imputation has been proposed as an alternative to genotyping arrays for trait mapping and calculation of polygenic scores. To empirically assess the relative performance of these technologies for different applications, we performed low-pass sequencing (targeting coverage levels of 0.5× and 1×) and array genotyping (using the Illumina Global Screening Array (GSA)) on 120 DNA samples derived from African and European-ancestry individuals that are part of the 1000 Genomes Project. We then imputed both the sequencing data and the genotyping array data to the 1000 Genomes Phase 3 haplotype reference panel using a leave- one-out design. We evaluated overall imputation accuracy from these different assays as well as overall power for GWAS from imputed data, and computed polygenic risk scores for coronary artery disease and breast cancer using previously derived weights. We conclude that low-pass sequencing plus imputation, in addition to providing a substantial increase in statistical power for genome wide association studies, provides increased accuracy for polygenic risk prediction at effective coverages of ∼ 0.5× and higher compared to the Illumina GSA.
Project description:Variation in gene expression is a fundamental aspect of human phenotypic variation. Several studies have analyzed gene expression levels in populations of different continental ancestry, and concluded that there is variation across populations at a fraction of expressed genes. Here we analyze gene expression levels in African American cell lines, which differ from previously analyzed cell lines in that samples from this population have variable proportions of continental ancestry. We show that for most genes examined, gene expression varies with genetic ancestry. Experiment Overall Design: Lymphoblastoid cell lines (LCL) for 60 HapMap CEU, 60 HapMap YRI, and 82 AFA from the Human Variation Panel were obtained from Coriell Cell Repositories. LCLs were grown in culture, total RNA was extracted and hybridized to Affymetrix HG-FOCUS arrays.
Project description:This data set comprises population (46 samples) measurements of RNA expression levels for a subset of the 1000 Genomes Project CEPH samples. This data was generated as part of the following study: - Population Variation and Genetic Control of Modular Chromatin Architecture in Humans. Cell. 2015 Aug 27;162(5):1039-50. doi: 10.1016/j.cell.2015.08.001. Epub 2015 Aug 20. An additional set of 111 samples from the 1000 Genomes Project (GBR and TSI populations) were also assayed using RNA-seq. This data was generated as part of the following study: - Chromatin 3D interactions mediate genetic effects on regulatory networks.
Project description:We use androgen receptor chromatin immunoprecipitation (AR ChIP) on frozen prostate adenocarcinoma samples and normal prostate counterparts in men of European ancestry as well as men of African (AA) ancestry and derive a model whereby increased androgen signaling drives higher levels of lipogenesis in AA prostate tumors.
Project description:We use androgen receptor chromatin immunoprecipitation (AR ChIP) on frozen prostate adenocarcinoma samples and normal prostate counterparts in men of European ancestry as well as men of African (AA) ancestry and derive a model whereby increased androgen signaling drives higher levels of lipogenesis in AA prostate tumors.
