Figure 2

Chromatin signature of CNS1 region in Homo sapiens, Mus musculus and Xenopus tropicalis. (a) Snapshots of representative DNase-seq tracks from ENCODE database in human (https://www.encodeproject.org)^25,26. The overall profiles spanning a larger region including CNS2 and the description of the biological materials are shown in Fig. S1a. Open chromatin state is clearly detected at CNS1 level in embryonic kidney tissue and renal cells. In contrast, CNS1 is not accessible to DNase in non-renal cells expressing HNF1B (Caco-2 and A549 cells) as well as in spinal cord or neural progenitors where HNF1B is not expressed. (b) Characteristics of enrichment patterns for histone modifications and p300. (c) Snapshots of representative ATAC-seq and histone modifications tracks as indicated from ENCODE database (https://www.encodeproject.org)^25,26 in kidney, lung and liver of E15.5 mouse embryo. The overall profiles spanning a larger region including CNS2 is shown in Fig. S2b. Although Hnf1b is expressed in developing kidney, liver and lung, CNS1 shows characteristics of an active enhancer only in the developing kidney. (d) Snapshots of representative p300 and histone modifications tracks as indicated from the epigenome reference maps in Ref.²⁷ in Xenopus tropicalis embryos at stages 10.5, 16 and 30. The overall profiles spanning a larger region including CNS2 is shown in Fig. S1c. CNS1 is associated with active enhancer marks (p300, H3K4me1) in embryos at neurula and tailbud stages (stage 16 and 30, respectively) when hnf1b is expressed in the developing pronephros but not at early gastrula (stage 10.5). In (a,c,d), the blue box indicates the 306-bp CNS1 location.