Fig. 1

Alignment of a region on chromosome 8 in X. tropicalis and the X. laevis L and S subgenomes annotated with experimental ChIP-seq data (gastrula-stage embryos; NF stage 10.5). Shown are the gene annotation (black), repeats (gray), ChIP-seq profiles for H3K4me3 (green), p300 (yellow), RNA Polymerase II (RNAPII; brown), and H3K36me3 (dark green). The sequence conservation is indicated by gray lines. Conserved H3K4me3 and p300 peaks are denoted by green and yellow lines, respectively. The anp32e gene is expressed in X. tropicalis and both the L and S subgenome of X. laevis. The plekho1 gene, on the other hand, has lost promoter and enhancer activity on the X. laevis S locus and shows no experimental evidence of being expressed