FIG. 4.

In utero TCDD exposure significantly decreases ERK activation in UGE cells. Male fetal mice were exposed in utero to corn oil (vehicle) or TCDD (5 μg/kg maternal dose) on E15.5. (A) IHC was used to visualize the pattern of activated phosphorylated ERK protein expression (red) in sagittal UGS sections on E16.5. Results are representative of at least three UGSs per group. Dashed lines were added to demarcate the boundary between UGE and UGM. BL, bladder; E, UGE; M, UGM; and PU, pelvic urethra; S, sinus space. (B) The percentage of ventral UGE (vUGE) cells expressing active phosphorylated ERK (red) was determined in the ventral prostatic budding region (inside black rectangle) by counting separately all the vUGE cells and all the red-stained vUGE cells on three sections per UGS. Results are mean ± SE of n ≥ 3 UGSs per group, each from a different litter. Significant differences among groups (p < 0.05) are indicated by an asterisk.