Imprinting status of chicken IGF2 (A), ASCL2/CASH4 (B), INS (C), and the control genes PHEMX/TSSC6 (D) and TH (E). Biallelic expression was revealed in informative embryos and embryonic membranes including the yolk sac by RT-PCR and sequencing. The SNPs used to distinguish the parental alleles were 1242A/G for IGF2 (Yokomine et al. 2001), 29365A/G for ASCL2/CASH4, 106015G/A for INS, 11747A/G for PHEMX/TSSC6, and 86744G/T for TH. In B and D, the data for the other strand are shown. Three additional SNPs confirmed the biallelic expression of ASCL2/CASH4 (data not shown).