Figure 1. Inducible BRAF^V600E expression in thyroid cells reversibly activates MAPK signaling and thyroid growth.

Eight-week-old Tg-rtTA/tetO-BRAF^V600E mice were fed dox-chow (on) for 1 week and then regular chow (off) for the indicated times. (A–C) qRT-PCR was performed to measure gene expression levels of mutant BRAF (A), DUSP5 (B), or PLAT (C) after normalization to β-actin. Bars represent mean ± SEM (n ≥ 8 animals/group). (D) Western blots of protein lysates from thyroid tissue probed with antibodies to BRAF, p-MEK, p-ERK1/2, total ERK1/2, or tubulin. (E) Representative gross appearance of thyroid glands of Tg-rtTA/tetO-BRAF^V600E at the indicated times. The boundaries of the thyroid are demarcated by dashed lines. Scale bar: 1 mm.