tailieunhanh - Báo cáo y học: "Promoter features related to tissue specificity as measured by Shannon entropy"

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: Promoter features related to tissue specificity as measured by Shannon entropy. | Research Open Access Promoter features related to tissue specificity as measured by Shannon entropy Jonathan Schug Winfried-Paul Schuller Claudia Kappen J Michael Salbaum Maja Bucan and Christian J Stoeckert Jr Addresses Center for Bioinformatics University of Pennsylvania Philadelphia PA 19104 USA. ỶDepartment of Genetics Cell Biology and Anatomy University of Nebraska Medical Center Omaha NE 68198 USA. Department of Genetics University of Pennsylvania Philadelphia PA 19104 USA. Correspondence Jonathan Schug. E-mail jschug@ Published 29 March 2005 Genome Biology 2005 6 R33 doi 186 gb-2005-6-4-r33 The electronic version of this article is the complete one and can be found online at http 2005 6 4 R33 Received 16 November 2004 Revised 27 January 2005 Accepted 16 February 2005 2005 Schug et al. licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License http licenses by which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Abstract Background The regulatory mechanisms underlying tissue specificity are a crucial part of the development and maintenance of multicellular organisms. A genome-wide analysis of promoters in the context of gene-expression patterns in tissue surveys provides a means of identifying the general principles for these mechanisms. Results We introduce a definition of tissue specificity based on Shannon entropy to rank human genes according to their overall tissue specificity and by their specificity to particular tissues. We apply our definition to microarray-based and expressed sequence tag EST -based expression data for human genes and use similar data for mouse genes to validate our results. We show that most genes show statistically significant tissue-dependent variations in expression level. We find that the most tissue-specific genes typically have