5′SAGE: 5′-end Serial Analysis of Gene Expression database

To comprehensively identify transcription start sites and the frequencies of individual mRNAs in human cell libraries, a method of 5′ end Serial Analysis of Gene Expression (SAGE) was developed recently, which makes it possible to collect a large amount of start site information, and subsequently, we have established a related database server called 5′SAGE. This database displays the observed frequencies of individual 5′ end SAGE tags and previously unknown transcription start sites in the promoter regions, introns and intergenic regions of known genes. 5′SAGE will be useful for analyzing promoter regions and start site variation in different tissues, and is freely available at http://5sage.gi.k.u-tokyo.ac.jp/.