Figure 2.

Organization of the XLαs region of GNAS1. The map is not to scale, and not all restriction sites are shown, with the exception of AscI and NotI. Grey lines above the exons represent the splicing patterns observed in the majority of XLαs-containing RT-PCR products and below the line the splicing pattern seen in the 359933 cDNA clone. Italic letters indicate restriction sites: S, SacI; B, BamHI; N, NotI; As, AscI; Ng, NgoMI; Bs, BssHII; (F), FokI (polymorphic site). Asterisks indicate those sites whose methylation status was assessed by Southern blotting (see text). The distance between the two AscI sites is ≈30 kb. The 2.5-kb genomic region that was sequenced is indicated. The A20 exon is black; other exons are gray or white for untranslated regions. The exon labeled A has been described (26). Small black arrows indicate approximate positions of primers used for RT-PCR.