Figure 7.

Bioinformatic prediction and experimental verification of five novel BREs for id1-4 genes. (A, B) Multi-species sequence alignment of the in silico identified novel id enhancers. The SBE and bre7 motifs are highlighted in blue and red, respectively. Putative TF binding sites are indicated. The currently available genomic sequences of Homo (h), Mus (m), Rattus (r), Danio (d), Tetraodon (t) and Fugu (f) are aligned. (C) Luciferase reporter assay of the five novel and the known (id1 −1.0 kb) BREs, cloned upstream of the Xcol minimal promoter (see Supplementary Figure 1C for fragments cloned). Frog embryos were injected with the indicated constructs together with tBR or CABR mRNA and harvested at the gastrula stage for luciferase assay.