A University of Pennsylvania-led team explores gene expression profiles and gene regulation in individuals from East Asian populations. As they report in Genome Biology, the investigators relied on RNA sequencing and array-based genotyping to map expression quantitative trait loci (eQTLs) and splicing QTLs in whole blood samples — together referred to as transcriptomic QTLs (tQTLs) — from 162 individuals from Ethiopia and Tanzania, before digging further into the data for their fine-mapping, causal variant, and natural selection analyses. "We find that variation underlying expression and splicing is broadly shared between African and European cohorts, though there is considerable independent variation at individual loci in Africans, often driven by variation in frequency and effect sizes of tQTLs," the authors note, noting that "[w]hen matched for sample size, Africans show improved fine-mapping of molecular traits, facilitating the identification of causal variants and candidate genes underlying GWAS traits."