Figure 6.

Interaction of Enhancers and Igf2 Promoter in Newborn Liver

A, 3C analysis was performed using a reverse primer (Eco 14R) and one of each of 32 forward primers across the Igf2/H19 region. Note that the 32 sites include the 24 sites of the Igf2/H19 region in Figs. 1–4 and as well as four upstream and four downstream sites. Cross-linked liver DNA (50 ng) was amplified for 36 cycles. Major 3C products of correct size were observed in the 140-kb region (columns a through 30). A correct PCR product from Eco 14 forward/reverse primers was observed at column 14. B, Digestion with KpnI was used to identify the two parental alleles. Paternal allele (M. spretus) has the KpnI restriction site. All 3C products derived from the paternal chromosome contain a common KpnI fragment of 105 and 101 bases (two strands of DNA, seen as a doublet). M at the top indicates size marker. M, Maternal; P, paternal.