Fig. 1.

Thyrotroph-specific activity of Tshb-cre transgene. A, Transgene expression was analyzed in frozen sections from e14.5 and e15.5 fetuses carrying a Rosa26 cre reporter gene with a Tshb-cre transgene (transgenic) or without it (controls). X-gal staining (blue) was detected in the caudomedial aspect of the anterior lobe (A) and in the rostral tip (R) in Tg(Tshb-cre) mice but not in controls (×200). B, X-gal staining of intact adult pituitary glands (×50) was followed by fixation, paraffin embedding, sectioning, and hormone-specific antibody staining (×630). Black arrows indicate selected cells with X-gal stain and hormone. C, Frozen sections from adult nonpituitary tissues were stained with X-gal to detect ectopic transgene activity. The magnification bar in the e14.5 transgenic and the brain sections is equivalent to 50 μm and applies to the embryonic pituitary, brain, heart, testis, kidney, liver, and lung sections. The magnification bar for the thyroid sections is equivalent to 30 μm. The magnification bar in the TSHB immunostaining is equivalent to 10 μm and applies to all the pituitary hormone antibody staining. POMC, Proopiomelanocortin; PRL, prolactin.