Data from: A genome-wide gene expression signature of environmental geography in leukocytes of Moroccan Amazighs

The different environments that humans experience are likely to impact physiology and disease susceptibility. In order to estimate the magnitude of the impact of environment on transcript abundance, we examined gene expression in peripheral blood leukocyte samples from 46 desert nomadic, mountain agrarian and coastal urban Moroccan Amazigh individuals. Despite great expression heterogeneity in humans, as much as one third of the leukocyte transcriptome was found to be associated with differences among regions. Genome-wide polymorphism analysis indicates that genetic differentiation in the total sample is limited and is unlikely to explain the expression divergence. Methylation profiling of 1,505 CpG sites suggests limited contribution of methylation to the observed differences in gene expression. Genetic network analysis further implies that specific aspects of immune function are strongly affected by regional factors and may influence susceptibility to respiratory and inflammatory disease. Our results show a strong genome-wide gene expression signature of regional population differences that presumably include lifestyle, geography, and biotic factors, implying that these can play at least as great a role as genetic divergence in modulating gene expression variation in humans.

人类所经历的不同环境或可对机体生理状态与疾病易感性产生影响。为评估环境对转录本丰度（transcript abundance）的影响程度，本研究对46名分别来自沙漠游牧、山地农耕与沿海城市的摩洛哥柏柏尔（Amazigh）个体的外周血白细胞（peripheral blood leukocyte）样本开展了基因表达检测。尽管人类个体间存在显著的表达异质性，但仍有多达三分之一的白细胞转录组（transcriptome）被发现与地域差异相关。全基因组多态性分析（genome-wide polymorphism analysis）结果显示，总样本中的遗传分化程度有限，不足以解释上述表达差异。针对1505个CpG位点（CpG site）的甲基化谱分析（methylation profiling）表明，甲基化对本次观测到的基因表达差异的贡献度较低。遗传网络分析（genetic network analysis）进一步揭示，免疫功能的特定维度受地域因素的强烈影响，且可能会影响呼吸道疾病与炎症性疾病的易感性。本研究结果证实，人群地域差异存在显著的全基因组基因表达特征，这类差异推测与生活方式、地理环境及生物因素相关，这意味着上述因素在调控人类基因表达变异方面的作用至少不亚于遗传分化。