European Molecular Biology Laboratory, European Bioinformatics Institute, EMBL-EBI, Hinxton, CB10 1SD, UK.
Nucleic Acids Res. 2014 Jan;42(Database issue):D926-32. doi: 10.1093/nar/gkt1270. Epub 2013 Dec 4.
Expression Atlas (http://www.ebi.ac.uk/gxa) is a value-added database providing information about gene, protein and splice variant expression in different cell types, organism parts, developmental stages, diseases and other biological and experimental conditions. The database consists of selected high-quality microarray and RNA-sequencing experiments from ArrayExpress that have been manually curated, annotated with Experimental Factor Ontology terms and processed using standardized microarray and RNA-sequencing analysis methods. The new version of Expression Atlas introduces the concept of 'baseline' expression, i.e. gene and splice variant abundance levels in healthy or untreated conditions, such as tissues or cell types. Differential gene expression data benefit from an in-depth curation of experimental intent, resulting in biologically meaningful 'contrasts', i.e. instances of differential pairwise comparisons between two sets of biological replicates. Other novel aspects of Expression Atlas are its strict quality control of raw experimental data, up-to-date RNA-sequencing analysis methods, expression data at the level of gene sets, as well as genes and a more powerful search interface designed to maximize the biological value provided to the user.
Expression Atlas（http://www.ebi.ac.uk/gxa）是一个增值数据库，提供不同细胞类型、生物部位、发育阶段、疾病和其他生物及实验条件下基因、蛋白质和剪接变异体表达的信息。该数据库由 ArrayExpress 中精选的高质量微阵列和 RNA-seq 实验组成，经过人工整理、实验因子本体论术语注释，并使用标准化的微阵列和 RNA-seq 分析方法进行处理。Expression Atlas 的新版本引入了“基线”表达的概念，即健康或未处理条件下（如组织或细胞类型）基因和剪接变异体的丰度水平。差异基因表达数据受益于对实验意图的深入整理，从而产生具有生物学意义的“对比”，即两个生物重复集之间的差异成对比较实例。Expression Atlas 的其他新颖之处在于其对原始实验数据的严格质量控制、最新的 RNA-seq 分析方法、基因集水平的表达数据、以及更强大的搜索界面，旨在最大限度地为用户提供生物学价值。
