Average fold change in expression of X-linked genes grouped either by sex-matched triploid/diploid comparisons or by X inactivation status.

a Average expression fold change between cultures after normalization to autosomal gene expression b Xa: active X chromosome, Xi: inactive X chromosome c Group 1: genes with similar expression in XaXiXi versus XaXi d Group 2: genes with similar expression in XYY versus XY e Group 3: genes that overlap between groups 1 and 2, i.e. have similar expression in both XaXiXi versus XaXi and XYY versus XY comparisons. f Group 4: genes subject to X inactivation (not expressed in rodent x human hybrid cell lines that retain an inactive human X [14]. g Group 5: genes that variably escape from X inactivation (expressed in 1-6/9 hybrid lines) [14]. h Group 6: genes that consistently escape from X inactivation (expressed in 7-9/9 hybrid lines) [14]. PAR1 genes were not included. i All 362 X-linked genes detected by microarray expression analysis in all diploid and triploid cell cultures.