Enhanced proliferation in the uterine epithelium and lack of receptivity in <i>Msx1^d/dMsx2^d/d</i> mice.

<p>A. Immunohsitochemical localization of Ki67 in the uterine sections of <i>Msx</i>1<i>^f/fMsx</i>2<i>^f/f</i> (left panel, a and c) and <i>Msx</i>1<i>^d/dMsx</i>2<i>^d/d</i> (right panel, b and d) mice on day 4 of pregnancy. Panels a and b indicate lower magnification (20×) and c and d indicate higher magnification (40×). L and G indicate luminal epithelium and glandular epithelium respectively. B. Real-time PCR was performed to analyze the expression of glandular factors, <i>Lif</i>, <i>Foxa2</i> and <i>Spink3</i> in uteri of <i>Msx</i>1<i>^f/fMsx</i>2<i>^f/f</i> and <i>Msx</i>1<i>^d/dMsx</i>2<i>^d/d</i> mice on day 4 of pregnancy. The level of <i>Ck18</i> was used as internal control to normalize gene expression. The data are represented as the mean fold induction ± SEM, ***p<0.0001. C. Transmission electron microscopy of uterine sections obtained from <i>Msx1^f/f Msx2^f/f</i> (left panel, a and b) and <i>Msx1^d/dMsx2^d/d</i> (right panel, c and d) mice on day 4 of pregnancy. Panels a and c indicate lower magnification (5Kx) and b and d indicate higher magnification (30Kx). D. Immunohistochemical analysis of Muc-1 expression in the uterine sections of <i>Msx</i>1<i>^f/fMsx</i>2<i>^f/f</i> (upper panel) and <i>Msx</i>1<i>^d/dMsx</i>2<i>^d/d</i> (lower panel) mice on day 1 (a and d), day 4 (b and e) and day 5 (c and f) of pregnancy. L indicates luminal epithelium.