Fig. 7.

The Tissue × Gene Matrix tab on GXD search summaries enables the comparison of expression patterns of different genes. The matrix columns show genes whose expression was examined, and the rows display the tissues that were examined. By using the gray check boxes to filter the search results, the matrix also allows for refinement of search results by gene, as well as tissue. Most of the cell coloring conventions are the same as those for the Tissue × Stage Matrix, as described in Fig. 6, with the exception that in this matrix the white cells indicate there are no annotations in the database. The Tissue × Gene Matrix is especially useful when interpreting the return for Differential Expression searches (Fig. 4). This figure shows the matrix generated by a search for genes expressed in the renal medulla but not detected or assayed in renal cortex. The matrix makes it immediately clear which genes have been examined and shown not to be expressed in the renal cortex (red cells) and those for which there is no expression information about the renal cortex in GXD (white cells), either because these results have not been reported in the literature or because they have not yet been recorded in GXD