Fig. 2.

G/C content, CpG islands, and exons near the 5′ region of the rat Prop1 gene. CpG site frequency as a ratio of observed to expected (A) is mapped across the 5′ region of Prop1, and the average GC content in this region is shown (B). The structure of rat Prop1 (C) is shown with open and closed boxes indicating the untranslated region and the coding regions, respectively. Enlarged region of the rat Prop1 gene (D), with shaded boxes indicating regions that are evolutionarily conserved among several mammals. Vertical lines in (C) and (D) indicate the positions of CpG sites, and the numbers indicate nucleotide positions, with the putative transcription start site indicated at +1 b. Boxed nucleotide numbers in (D) indicate sites that are hypomethylated in pituitary DNA as compared with liver DNA on E13.5, where the difference in methylation is > 30%.