Fig. 2

Comparison between superdomains on the Xi in human and mouse. a Topological domains on the Xi compared between human and mouse. An allelic contact map of the human Xi generated based on published Hi-C data obtained in human lymphoblastoid cell line GM12878 [6] is shown on top (red) and aligned to a contact map of the mouse Xi based on our data obtained in mouse F1 brain by DNase Hi-C and in situ DNase Hi-C at bottom (blue). The Xi maps are compared based on the position of homologous genes between human (hg19) and mouse (mm9) (see “Materials and methods”). The human and mouse X chromosomes were oriented such that the position of DXZ4/Dxz4 and the adjacent PLS3/Pls3 genes are in the same orientation at the right extremity of the hinge region. Each pair of homologous genes is connected by a colored line between the contact maps and genes within blocks of conserved regions are indicated in a similar color. Several inversions and transpositions are apparent and the content of the superdomains is only partially conserved. b Gene content of the hinge region in mouse (~72.8–72.9 Mb). Dxz4 is located at one extremity of the hinge region, which also contains the minisatellite Ds-TR. The size and location of the hinge region were estimated as described in the text (see also Additional file 5)