Fig. 4.

Abnormal syncytiotrophoblasts in the Atp11a-deficient placenta. (A) A schematic representation of syncytiotrophoblasts in the mouse placental labyrinthine layer. Two layers of syncytiotrophoblasts, SynT-I (green) and SynT-II (pink), separate fetal and maternal blood. SynT-I and SynT-II express MCT1 and MCT4, respectively. Nuclei are shown in the blue circle. Red blood cells are in red. (B) Cryosections of the E13.5 Atp11a^+/+ and Atp11a^k/k placenta were stained with anti-MCT1 (green), anti-MCT4 (red), and DAPI (blue). Scale bar, 100 μm. (C and D) Electron microscopy of the labyrinthine layer of the placenta. Sections of the placenta in E13.5 Atp11a^+/+ and Atp11a^k/k mice were analyzed by transmission electron microscopy (C) or scanning electron microscopy (D). The boxed area (Upper) was enlarged in the Bottom in (C). The arrowheads indicate degenerated nuclei. The cell boundary was surrounded by an orange line in D. Scale bar, 100 μm (C, Upper), 20 μm (C, Lower), 10 μm (D). End, endothelial cell; mono-TP, mononuclear trophoblasts. (E) Cryosections from the E13.5 Atp11a^+/+ and Atp11a^k/k placenta were stained with TUNEL. Red, TUNEL; blue, DAPI. Scale bar, 250 μm. Right: Total TUNEL-positive area was quantified with three sections per placenta, and the ratio against the DAPI-positive area in the labyrinthine layer was plotted (n = 3 for Atp11a^+/+ or Atp11a^+/k and n = 6 for Atp11a^k/k). P values calculated by Student’s t test are shown. (F) RNA from the E13.5 Atp11a^+/+ (+/+) and Atp11a^k/k (k/k) placenta (n = 3 for each) was subjected to real-time RT-PCR to assess the mRNA levels of the indicated genes . The average values were plotted with SD (bars).