Figure 3.

The relative expression of known T₃-inducible genes was reduced in the intestine of animals exposed to BPA. The cDNA was generated from total RNA of tadpoles treated as in Fig. 2 and subjected to qRT-PCR. A, Direct T₃-response genes ST3, TH/bZIP, and TRβ were examined. B, Late T₃-response genes MMP-2, TIMP2, and BMP4 were examined. The results are expressed as fold induction of the transcript with respect to the control gene, rpl8. The expected increase in relative levels of transcript with respect to rpl8 was observed in the presence of T₃. For graphical presentation, results were expressed as fold induction as compared with the DMSO vehicle control. Data are shown as means ± se (n = 3; pooled samples of 10 intestines for each treatment). In the animals treated with T₃+BPA, the expression levels of ST3, TH/bZIP, MMP-2, and TIMP2 genes were significantly reduced in the intestine. An asterisk indicates significant differences in mRNA expression levels between T₃ and T₃+BPA treatment groups (P ≤ 0.05).