Systematic analysis of gene expression in transgenic embryonic stem (ES) cell lines. (a) The proportion of downregulated (blue) and upregulated (red) genes on all chromosomes following doxycyline treatment of transgenic cell lines as indicated. (b) Pie charts illustrating the proportion of downregulated (blue), upregulated (red) and no change (open) genes on the chromosome carrying the transgene, as indicated. (c) Pie chart illustrating the proportion of downregulated genes showing strong (>50%, blue), moderate (30% to 50%, red) and weak (<30%, yellow) downregulation, as indicated. (d) Quantitative PCR analysis of eight chromosome 17 genes showing strong/moderate or weak/no change in Affymetrix microarray data. Two different primer pairs were used for each gene (except Mylc2b). The average percentage reduction determined for probe sets by microarray analysis is shown below the gene symbols.