Fig. 3. Loss of imprinted expression in embryonic day (E) 9.5 B6(CAST7)XB6 placentas following preimplantation culture in Whitten's medium. Embryos at the 2-cell stage were cultured to the blastocyst stage then transferred to recipient females. Postimplantation embryo-placental sets were recovered at E9.5. B6(CAST7)XB6 in vivo-derived controls (Vivo), B6XB6(CAST7) Whitten's cultured controls (BCW), the remaining samples are B6(CAST7)XB6 KSOMaa (K) or Whitten's (W) cultured conceptuses. Red bar height indicates the level of maternal expression, while blue bar height represents the level of paternal-specific expression.