Sepw1 basal expression depends on MTF-1. (a) Semiquantitative RT–PCRs for Sepw1 mRNA using total liver RNA from pI–pC-induced male Mtf1Mx-cre or Mtf1loxP mice. The animals had obtained either mock s.c. injections (−Cd) or s.c. injections with 20 µmol/kg body weight CdSO4 (+Cd) 6 h before sacrificing them. RT–PCRs for Hprt mRNA were used as internal control to adjust the amount of total RNA used. (b) S1 analysis for Sepw1 mRNA with RNA described in (a), using a 32P-labeled Sepw1 S1 probe. A 32P-labeled S1 probe for Hprt mRNA was used to adjust the amount of RNA used. (c) MRE core consensus sequences TGCRCNC (bold letters) and flanking sequences found in a region of 1000 bp upstream from Sepw1 transcription start; the position of each core sequence is indicated. (d) EMSA with liver protein extracts of a male Mtf1loxP or a pI–pC-induced, male Mtf1Mx-cre mouse, both mock-treated. MTF-1 protein–DNA complex formation was tested with 32P-labeled Sepw1 MRE1 or MRE2 oligonucleotide, respectively. Specificity of binding was verified with excess of unlabeled competitor MREd or unrelated Gal4 oligonucleotide. 32P-labeled MRE-s was included to indicate the position of an MTF-1-DNA complex; bandshifts for the common transcription factor Sp1 with 32P-labeled Sp1 consensus oligonucleotide were obtained as protein loading control.