. 2009 Dec 4;5(12):e1000751. doi: 10.1371/journal.pgen.1000751

Table 1. Average fold change in expression of X-linked genes grouped either by sex-matched triploid/diploid comparisons or by X inactivation status.

Group		Number of X-linked genes	Average fold change^a
			XaXaXi/XaXiXi^b	XaXaXi/XaXi	XaXiXi/XYY	XaXiXi/XaXi	XYY/XY	XaXi/XY
Grouped by triploid/diploid expression comparisons	1^c	108	1.2	1.14	1.31	0.95	0.71	0.99
	2^d	88	1.43	1.12	1.09	0.78	1.03	1.43
	3^e	26	1.08	1.08	1.08	1.01	1.04	1.12
Grouped by X inactivation status	4^f	161	1.63	1.22	1.17	0.75	0.73	1.14
	5^g	80	1.55	1.09	0.97	0.70	0.80	1.11
	6^h	37	1.27	1.09	1.46	0.86	0.72	1.12
Totalⁱ		362	1.57	1.17	1.08	0.74	0.79	1.15

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.