Reporter analysis of the mouse Scgb3a1 gene. (A) Transient transfection of serial deletion luciferase reporter constructs into mtCC cells. Relative luciferase activity is shown as the mean ± SD based on the activity of pGL4 (shown as construct 0) as 1 from three independent experiments, each carried out in duplicate. (B) Mouse Scgb3a1 promoter sequence of -600 bp to the transcription start site. Start points of the deletion constructs, -59, -91, -184, -273, and -598 are shown. NF-Y binding 'CCAAT" sites are boxed. PU-boxes are shown in shaded boxes. A STAT binding site previously described for IL-4/13-induced increase of Scgb3a1 gene expression is shown in black box with white letters. GATA, HNF3β, and C/EBP binding sites identified by low stringency TF search analysis are indicated by over-bracket, overlined and underlined, respectively. CpG methylation sites are indicated in a gray box for complete methylation, and circled for unmethylated sites (see also Fig. 7 and Table 1).