Project description:B lymphoblastoid cell lines were obtained from Coriell Cell Repositories. Cell lines were grown according to Coriell guidelines and total RNA was extracted, labeled, and hybridized to an Affymetrix Human Genome Focus Array as previously described. We found extensive variation in gene-expression levels and estimate that ~83% of genes are differentially expressed among individuals and that ~17% of genes are differentially expressed among populations. By decomposing total gene-expression variation into within- versus among-population components, we find that most expression variation is due to variation among individuals rather than among populations, which parallels observations of extant patterns of human genetic variation. Experiment Overall Design: We used microarrays to survey patterns of natural gene expression variation in 16 HapMap individuals derived from the CEU and YRI samples.
Project description:Illumina methylation 27 array (Illumina) analysis was performed on 24 HapMap individuals including one CEU trio (family 1463 including NA12878, NA12891, NA12892) and one YRI trio (family Y117 including NA19240, NA19238, NA19239)
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:Paired genomic DNA and cDNA samples obtained from lymphoblastoid cell lines from CEU and YRI HapMap individuals were hybridized to custom Illumina SNP arrays to study allele-specific expression in this tissue.
Project description:We have performed a genome-wide analysis of common genetic variation controlling differential expression of transcript isoforms in the CEU HapMap population using a comprehensive exon tiling microarray covering 17,897 genes. We detected 324 genes with significant associations between flanking SNPs and transcript levels. Of these, 39% reflected changes in whole gene expression and 55% reflected transcript isoform changes such as splicing variants (exon skipping, alternate splice site usage, intron retention), differential 5’ UTR (initiation of transcription) usage, and differential 3’ UTR (alternative polyadenylation) usage. These results demonstrate that the regulatory effects of genetic variation in a normal human population are drastically more complex than previously observed. This additional layer of molecular diversity may account for natural phenotypic variation and disease susceptibility. Keywords: Comparative genomic hybridiation within the CEU HapMap population
Project description:Baseline microRNA (miRNA) expression was evaluated in 107 HapMap lymphoblastoid cell lines (LCLs; 53 CEU and 54 YRI) using Exiqon miRCURY LNA arrays v10.0 (Exiqon array). Total RNA from each of the 107 HapMap sample was labeled and hybridized onto an Exiqon array
Project description:Cisplatin, a platinating agent commonly used in treating several cancers is associated with nephrotoxicity, neurotoxicity and ototoxicity that have hindered its utility. To gain a better understanding of the genetic variants associated with cisplatin induced toxicity, we present a step-wise approach integrating genotypes, gene expression and sensitivity of HapMap cell lines to cisplatin. Cell lines derived from 30 trios of European descent (CEU) and 30 trios of African descent (YRI) were utilized to develop a preclinical model to identify genetic variants and gene expression that contribute to cisplatin induced cytotoxicity in two different populations. Cytotoxicity was determined as cell growth inhibition at increasing concentrations of cisplatin for 48 h. Gene expression on 176 HapMap cell lines (87 CEU and 89 YRI) was determined using the Affymetrix GeneChip® Human Exon 1.0 ST Array. We identified 6, 2 and 9 representative SNPs that contribute to cisplatin-induced cytotoxicity through their effects on 8, 2 and 16 gene expressions in the combined, CEPH and Yoruban populations, respectively. These genetic variants contribute to 27, 29 and 45% of the overall variation in cell sensitivity to cisplatin in the combined, CEPH and Yoruban populations, respectively. Our whole genome approach can be used to elucidate expression quantitative trait loci contributing to a wide range of cellular phenotypes. Keywords: exon array
