Silencing propagates along the length of iXist transgene expressing autosomes. The figure illustrates at 1 Mb resolution the distribution of downregulated (dark blue bars) and upregulated (red bars) genes on the transgene-bearing chromosomes for cell lines 8A, 12B and 3E, respectively. The height of the bar indicates the frequency of genes per Mb (maximum height in the different cell lines corresponds to 12-14 genes/Mb). Tracks showing the frequency of genes (green), and, full-length L1 elements (light blue), are also shown. The approximate position of the transgene integration site is indicated with a red arrow.