Genomic structure and transcriptional regulation of the mouse Oct4 gene. The diagram represents ~24 kb of the genomic region surrounding the Oct4 gene
. The gene has five exons, depicted as blue boxes. The identified upstream regulatory regions include the promoter, proximal enhancer, and distal enhancer. The sizes of the regulatory elements are stretched to enhance clarity. The transcription factors bind to these regions, and are shown above within colored boxes; they either activate (green box) or repress (red box) transcription. HRE = hormone responsive element; Sp1 = GC-rich site recognized by the Sp1/Sp3 family of transcription factors. CR1, CR2, CR3, and CR4 are conserved regions (CRs) at the 5’ upstream region of the Oct4 gene.