Enhanced FGFR signaling in the epithelium of <i>Msx1^d/dMsx2^d/d</i> uteri.

<p>A. The level of p-FRS2 was examined in the uterine sections of <i>Msx1^f/fMsx2^f/f</i> (upper panel) and <i>Msx1^d/dMsx2^d/d</i> (lower panel) mice on day 4 of pregnancy by immunohistochemistry. Magnification: a and d: 10×, b and e: 20×, c and f: 40×. B. The level of p-ERK was examined in the uterine sections of <i>Msx1^f/fMsx2^f/f</i> (upper panel) and <i>Msx1^d/dMsx2^d/d</i> (lower panel) mice on day 4 of pregnancy by immunohistochemistry. Magnification: a and d: 10×, b and e: 20×, c and f: 40×. L, G and S indicate luminal epithelium, glandular epithelium, and stroma respectively. C. FGFR-specific inhibitor PD173074 was applied to one uterine horn of <i>Msx1^d/dMsx2^d/d</i> (n = 3) mice on day 3 of pregnancy. The other horn served as vehicle-treated control. Uterine horns were collected on day 4 morning and sections were subjected to immunohistochemistry to detect p-FRS2, Ki67, and Muc-1.