Natural gene expression variation in the HapMap CEU and YRI samples

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. Keywords: resting expression levels in B lymphoblastoid cell lines We used microarrays to survey patterns of natural gene expression variation in 16 HapMap individuals derived from the CEU and YRI samples.