Figure 3.

Differential methylation in the XLαs region of GNAS1. The probe used was a 1.9-kb SacI–AscI genomic fragment containing both the XLαs and A20 exons (shaded boxes). Genomic DNA from parthenogenetic (left) or normal (right) lymphoblastoid cell DNA was digested with SacI, alone or in combination with AscI, NotI, or BssHII. SacI generates a fragment of ≈6 kb; the expected fragment sizes derived from additional cleavage at the methylation sensitive sites are indicated on the diagram. λ, λHindIII marker; 23, 9.4, 6.6, 4.4, 2.3, 2.0, 0.56 kb. kb, 1-kb ladder (GIBCO/BRL); upwards from arrow 1.0, 1.6, 2.0, 3.1, 4.1, 5.1, 6.1, 7.1 kb.