Figure 1.Unsupervised hierarchical cluster. A representation of the variation in expression of 1548 genes in different compartments of five kidneys. Each row represents a single gene. Each column represents a single sample. Green squares indicate transcript levels below the mean; black squares, transcript levels equal to the mean; red squares, transcript levels greater than the mean; gray squares, technically inadequate or missing data. Gene filtering criteria were for four-fold variation from the normalized mean and at least 80% well measured spots. Colored bars adjacent to the clustering table indicate the position of the enlarged images. The color of the bar indicates the type of sample in which the cluster of genes is expressed. Red pelvis cluster; Dark blue papillary tip cluster; Brown tubular cluster; Green medullary cluster; Turquoise glomerular cluster; and Orange cortex cluster. Selected gene names are shown.