GermSAGE: a comprehensive SAGE database for transcript discovery on male germ cell development

GermSAGE is a comprehensive web-based database generated by Serial Analysis of Gene Expression (SAGE) representing major stages in mouse male germ cell development, with 150 000 sequence tags in each SAGE library. A total of 452 095 tags derived from type A spermatogonia (Spga), pachytene spermatocytes (Spcy) and round spermatids (Sptd) were included. GermSAGE provides web-based tools for browsing, comparing and searching male germ cell transcriptome data at different stages with customizable searching parameters. The data can be visualized in a tabulated format or further analyzed by aligning with various annotations available in the UCSC genome browser. This flexible platform will be useful for gaining better understanding of the genetic networks that regulate spermatogonial cell renewal and differentiation, and will allow novel gene discovery. GermSAGE is freely available at http://germsage.nichd.nih.gov/