Table 1.

Z-scores for co-citation analysis of genes whose expression changes with age.

Co-citation analysis to identify patterns of gene expression using the Genomatix BiblioSphere™ Program. The gene lists used for co-citation analysis were from Supplemental Tables 1A and 1B. Not all genes were identified by the Genomatix Bioliosphere™ as co-cited. Therefore, the total genes evaluated in Table 1 are less than the totals shown in Supplemental Tables 1A and 1B. Analysis was done separately for genes in the ad libitum fed gene list (left columns), the calorie-restricted gene list (middle columns), and for genes in the ad libitum fed minus the calorie-restricted lists (right columns). In each case the analysis was done for all genes (all), or only those genes that increased (positive) or only those genes that decreased (negative). The Genomatix Bibliosphere™ filters are the designated filters that sort PubMed abstracts according to established criteria. The Z scores determine the extent to which a gene is expressed in excess of (+ value) or less than (− value) expected from a random distribution calculated by the Genomatix Bibliosphere™ program from the PubMed database. A Z score of 3 is statisically significant. A color code is used to visualize the patterns of alterations in Z score between the different groups. A Z score of <3 is designated uncolored, Z scores of 3-19 are designated yellow, 20-49 designated orange, and >50 designated pink, as illustrated at the bottom of the table.