Fig. 1: In silico analysis and in vivo validation using zebrafish to identify cis-regulatory elements of Myb.

a, b Analysis of published ChIP-seq data demonstrates that multiple transcription factors bind around the mouse Myb locus in HPC-7 cells (a, upper) and MEL cells (a, lower) and the human MYB locus in Jurkat cells (b). A total of 11 candidate enhancer elements are shown in red or grey rectangles (#1 to #11). Elements #4 and #5 are common between HPC-7 cells and MEL cells, and the element #10 is common among 3 cell lines. Two clusters of retroviral integration sites (RIS) are indicated in blue rectangles. RTCGD Retrovirus Tagged Cancer Gene Database. c, d In vivo functional confirmation of selected regions using zebrafish. The candidate cis-regulatory elements were cloned into the upstream of an EGFP reporter construct, and injected into zebrafish embryos. c The EGFP activity driven by the candidate element #3 (Myb −74 kb) is specific to zebrafish hematopoietic organs: kidneys (pronephros, white thick arrow) and pronephric tubules (white thin arrows). Scale bar: 0.2 mm. d The EGFP activity by the candidate element #4 (Myb −68 kb) is specific to circulating cells (white arrows). Three snapshots from one video are shown. Scale bar: 0.2 mm. e Analysis of publicly available ChIP-seq data demonstrates that H3K4me1 signal intensity is relatively high in the candidate element #3 (Myb −74 kb) of hematopoietic stem/progenitor cells and lymphoid cells, and in the candidate element #4 (Myb −68 kb) of hematopoietic stem/progenitor cells and myeloid cells.