Comparative analysis of the primate X-inactivation center region and reconstruction of the ancestral primate XIST locus

Reconstruction of the ancestral primate XIST locus and comparison of multispecies conserved regions. Horizontal lines represent the XIST locus in human and the reconstructed primate ancestor. Human exons (dark blue); ancestral primate DNA corresponding to those exons (gray). Each XIST-specific repeat (A, B, Bh, C, D, E, F) is color-coded and shown with approximate size and location. (Dark gray boxes) Approximate locations of conserved noncoding sequences (CNS). See Figure 6 for more details about each CNS. (Open triangles) Human and ancestrally reconstructed primate-specific insertions. (Triangles without a label) Insertion of nonrepetitive sequence.