Functional classification of genes modulated by ATRA during differentiation of NB4 cells.
A total of 169 ATRA-modulated genes (100 up-regulated and 69 down-regulated) are clustered into 10 groups (groups A-J) according to their functions. The expression pattern of each gene is displayed here as a horizontal strip, with the down-regulated genes on the left-hand side of the graph and the up-regulated ones on the right-hand side. For each gene, the ratio of mRNA levels in NB4 cells at the indicated time after ATRA treatment to its level in untreated (time zero) NB4 cells is represented by a color, according to the color scale at the bottom. Genes whose expression was resistant to cycloheximide are highlighted by using the yellow background in the column for gene names. Regarding genes also existing in Golub's system with Affymetrix chips, different colors were used to label the column of their accession numbers. The genes with the same expression pattern in both systems are painted in rose; those modulated in our system but not in Golub's are painted in sky-blue; while those with opposite patterns are painted in purple.
