Allele-specific expression of imprinted genes within the proximal mouse chromosome 6 domain in wild types and mice carrying chromatin remodeling targeted gene deletions. Sequence traces obtained from RT-PCR products are shown for the following: (A) wild-type embryo and placenta from C57BL/6J × M. mus castaneus; (B) the reactivation of the repressed allele for Peg10 and Sgce in Dnmt3l−/+ (C57BL/6J × M. mus castaneus) embryo and trophoblast giant cells from placenta; (C) allele-specific expression of genes in Ehmt2−/− (C57BL/6J × JF1) embryo and placenta, only Tfpi2 imprinting is affected; and (D) maintained imprinting in Eed−/− (JF1 × CD1) TS cells for all genes except Tfpi2. Ppp1r9a and Pon2 display biallelic expression in wild-type TS cells, so their imprinting status could not be assessed in the Eed−/− TS cell line.
