Fig. 3

Identification of 20E CRE in BmKr-h1 promoter. a, b Reporter plasmids containing the 5′-flanking and first intron regions of BmKr-h1 were assayed. c Effect of mutation of the putative 20E CRE on the BmKr-h1 promoter activity. The region of the putative 20E CRE is indicated by a red box. d The sequence and the mutated sequences of the region between − 248 ~ − 202 nt of the BmKr-h1 promoter. The underlined nucleotides in blue and red represent the mutated nucleotides. e EMSA analysis of binding of nuclear proteins extracted from BmN cells using a region between − 234 ~ − 202 nt and the mutated probes. f EMSA of the binding of nuclear proteins extracted from BmN cells with the probe of the region between − 248 ~ − 217 nt and the mutated probes. The data shown is mean ± SD (n = 3) and the individual data values are shown in Additional file 2. The significance of the differences between the treatment and control was statistically analyzed at p < 0.05 (*), p < 0.01 (**), and p < 0.001 (***) using t test