Systematic allelic analysis defines the interplay of key pathways in X chromosome inactivation by Nesterova, TB, Wei, G, Coker, H, Pintacuda, G, Bowness, JS, Zhang, T, Almeida, M, Bloechl, B, Moindrot, B, Carter, EJ, Rodrigo, I, Pan, Q, Bi, Y, Song, C-X, Brockdorff, N