Figure 8.

Comparison of Igf1 promoter elements. (A) Schematic of human IGF1 gene promoter 1 and exon 1. Bent arrows indicate transcription start sites in exon 1, and the location of the ATG codon is labeled. Coding DNA is in black and noncoding DNA in white. The locations of binding segments for transcription factors HNF-1, C/EBPα/β, HNF-3, and C/EBPδ are shown. The presence of sites identical to the human sequences in different species is indicated by + for each transcription factor site, and absence is depicted by −. Altered nucleotides within similar sites are shaded in gray.