Impaired differentiation of trophoblast giant cells and spongiotrophoblast cells and labyrinthine development in the <i>Mst1/2 </i>DKO placenta.

<p>(A, C and D) Images of hematoxylin/eosin-stained placental sections of the control (Ctr) and <i>Mst1/2</i> DKO embryos at E8.5 (A), E9.5 (C) and E10.5 (D). (B) Statistical analysis of TGC in the ectoplacental cone of E8.5 and E9.5 placental sections. Data are expressed as the means ± SEM (three sections/placenta, three placentas from three pregnant mice per group). ** <i>P</i><0.01. (E) CD31-immunofluoresence staining of cryosections of E9.5 Ctr and <i>Mst1/2</i> DKO placentas. High magnification images of the cropped region in (A), (C), (D) and (E) are shown under each panel, respectively. Dashed lines indicate spongiotrophoblast layers. Arrows and arrowheads indicate fetal nucleated and maternal enucleated red blood cells, respectively. (F) RNA <i>in situ</i> hybridization of E9.5 placental cryosections with a probe for the <i>Prl3d1</i> gene which specifically marks TGC (upper panel) and a probe for the <i>Tpbpa</i> gene which marks spongiotrophoblast cells (lower panel). Inset in lower panel is an enlarged photo to show the existence of a weaker <i>Tpbpa</i> signal in <i>Mst1/2</i> DKO placentas. Images are representative sections from at least three placentas from three pregnant mice per group. Al, allantois; Ctr, control; De, decidua; Gi, trophoblast giant cells; La, labyrinth; Sp, spongiotrophoblast layer.