Figure 2

Microarray and QRT-PCR results. (A) Identification of differentially regulated genes. (B) Number of differentially expressed genes following o, p'-DDT treatment in the mouse liver. Differentially expressed genes were selected based on a p1(t) ≥ 0.999 at two or more time points and an absolute fold change ≥ 1.5 at one or more time points relative to time-matched vehicle controls. All differentially expressed genes are listed in Additional file 3. (C) Verification of microarray results by QRT-PCR. QRT-PCR results relative to time-matched vehicle controls are shown as bar and presented as mean ± SE. Microarray results are represented as lines. The dashed line indicates the expression level of the time-matched vehicle control. The asterisk (*) indicates a significant (p < 0.05) difference from the time-matched vehicle controls for QRT-PCR, n = 5. (D) Hepatic expression of PXR/CAR-target genes in o, p'-DDT-treated mouse. A heat map of o, p'-DDT elicited microarray expression profiles for selected PXR-, CAR-specific and PXR/CAR-shared target genes identified in the literature [20–23]. While some CAR-regulated genes such as Cyp1a1, Fmo5, Sult1d1 or Abcc2 were moderately induced, several PXR-target genes, including ApoA4, Ces2, Gstm2 or Insig2, exhibited strong induction. However, other PXR-target genes such as Hmgcs1 and Hmgcs2 were down-regulated.