tailieunhanh - Báo cáo y học: " Large scale comparison of global gene expression patterns in human and mous"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Wertheim cung cấp cho các bạn kiến thức về ngành y đề tài: Large scale comparison of global gene expression patterns in human and mouse. | Zheng-Bradley et al. Genome Biology 2010 11 R124 http content 11 12 R124 Genome Biology RESEARCH Open Access Large scale comparison of global gene expression patterns in human and mouse Xiangqun Zheng-Bradley Johan Rung Helen Parkinson Alvis Brazma Abstract Background It is widely accepted that orthologous genes between species are conserved at the sequence level and perform similar functions in different organisms. However the level of conservation of gene expression patterns of the orthologous genes in different species has been unclear. To address the issue we compared gene expression of orthologous genes based on 2 557 human and 1 267 mouse samples with high quality gene expression data selected from experiments stored in the public microarray repository ArrayExpress. Results In a principal component analysis PCA of combined data from human and mouse samples merged on orthologous probesets samples largely form distinctive clusters based on their tissue sources when projected onto the top principal components. The most prominent groups are the nervous system muscle heart tissues liver and cell lines. Despite the great differences in sample characteristics and experiment conditions the overall patterns of these prominent clusters are strikingly similar for human and mouse. We further analyzed data for each tissue separately and found that the most variable genes in each tissue are highly enriched with human-mouse tissuespecific orthologs and the least variable genes in each tissue are enriched with human-mouse housekeeping orthologs. Conclusions The results indicate that the global patterns of tissue-specific expression of orthologous genes are conserved in human and mouse. The expression of groups of orthologous genes co-varies in the two species both for the most variable genes and the most ubiquitously expressed genes. Background Over the past two decades both tissue specificity and the conservation of expression between orthologous genes .