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.

人类所处的不同环境，可能会对其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名分别隶属于沙漠游牧、山地农耕与沿海城市群体的摩洛哥柏柏尔（Moroccan Amazigh）个体的外周血白细胞（peripheral blood leukocyte）样本开展了基因表达检测。尽管人类基因表达存在显著异质性，但仍有近三分之一的白细胞转录组（leukocyte transcriptome）被证实与地域差异存在关联。全基因组多态性（genome-wide polymorphism）分析结果显示，总样本的遗传分化程度有限，无法解释上述表达差异。针对1505个CpG位点（CpG site）的甲基化谱（methylation profiling）分析表明，甲基化对本次观测到的基因表达差异的贡献较为有限。遗传网络分析（genetic network analysis）进一步提示，免疫功能的特定维度受地域因素显著调控，并可能影响呼吸道与炎症性疾病的易感性。本研究结果证实，全基因组范围内存在显著的人群地域差异基因表达特征，这类特征大概率涵盖生活方式、地理环境与生物因素，提示上述因素在调控人类基因表达变异方面的作用，至少与遗传分化的影响不相上下。