Fig1D. Copyright: Reprinted with permission from Elsevier from [PMID:10495277] Mech Dev 1999 87(1-2): 129-142,Tanaka M; Puchyr M; Gertsenstein M; Harpal K; Jaenisch R; Rossant J; Nagy A, Parental origin-specific expression of Mash2 is established at the time of implantation with its imprinting mechanism highly resistant to genome-wide demethylation. Copyright 1999.