As part of MGD’s efforts to represent experimentally supported regulatory regions in the mouse genome, over 164 000 Transcriptional Start Sites (TSS) identified by investigators at the RIKEN Institute using Cap Analysis Gene Expression (CAGE) sequencing (9) were loaded into MGD. TSS sites are particularly informative for delineating the structure of promoter regions of genes; many genes have more than one promoter region that controls the expression of alternative transcript forms. Over 22 000 of the TSS sites identified by the RIKEN data are associated with annotated mouse genes. From a gene detail page, users can see the annotated TSS sorted by distance from the gene's 5′ end.
