Fig. 1

a Mutation of Xist on the maternal X-chromosome leads to skewed inactivation of the MeCP2-GFP reporter gene on the paternal X-chromosome. b GFP immunohistochemistry with and without hematoxylin (+H and −H) in the brain of the MeCP2 Xist^mut/MeCP2-GFP female demonstrates no GFP staining. The brain of the MeCP2/MeCP2-EGFP animal exhibits a bimodal nuclear staining for GFP reflective of random MeCP2-EGFP inactivation. c MeCP2-EGFP mRNA level in the brain from MeCP2 Xist^mut/MeCP2-EGFP relative to MeCP2-EGFP/MeCP2 analyzed by RT-qPCR (n = 3 for each group, error bars indicate SD, ***p < 0.001, Student’s t test)