Fig. 2.
Perchlorate disrupts thyroid morphology. Horizontal paraffin section H&E stained thyroid follicles of 18 dpf (A and B) and adult (C–F) stickleback at 20× magnification (A–C), and 60× magnification (E and F) showing thyrocyte morphology in untreated (A, C and E) and treated (B, D and F) stickleback. TF = thyroid follicle; Ad = adipocyte; SM = smooth muscle; VA = ventral aorta; CA = cartilage. Perchlorate causes hyperplasia of small thyroid follicles. Perchlorate causes an increase in the number of thyroid follicles and a dramatic decrease in thyroid follicle width.