1. Implication of MEK1 and MEK2 in the establishment of the blood–placenta barrier during placentogenesis in mouse 
Jean Charron, Vickram Bissonauth, Valérie Nadeau 
Reproductive BioMedicine Online 
Volume 25, Issue 1, Pages (July 2012)
DOI: /j.rbmo
Copyright © 2012 Reproductive Healthcare Ltd. Terms and Conditions

2. Figure 1
Structure of the mouse placenta and organization of the different cell layers in the labyrinth. (A) Schematic representation of the mouse placenta (left panel) and histological section of an embryonic-day-12.5 placenta (right panel). The dotted line delineates the maternal and embryonic portions. Bar=250μm. (B) Schematic illustration of the triple layer of trophoblast cells and the fetal endothelium in the labyrinthine region involved in the formation of the blood–placenta barrier (left panel) and visualization of the double layer of syncytiotrophoblast cells (right panel) by immunofluorescence with antibodies against monocarboxylate transporters (MCT1, red; MCT4, green) as specific markers of the apical membrane of the SynT-I and the basal membrane of the SynT-II, respectively (Nagai et al., 2010). Nuclei are blue (4(,6-diamidino-2-phenylindole)), maternal red blood cells are orange due to autofluorescence and fetal erythrocytes have blue nuclei and green cytoplasm. Maternal erythrocytes and sinuses are delineated by the layer of SynT-I (red), while fetal erythrocytes and endothelial cells of fetal blood vessels are included within a layer of SynT-II (green). In the fetal blood vessels, an endothelial cell juxtaposed to the SynT-II layer is indicated. Fetal and maternal blood circulations are isolated by three tight layers of cells including the fetal vascular endothelial cells, the SynT-I and the SynT-II. SynT-I, type-I syncytiotrophoblast; SynT-II, type-II syncytiotrophoblast. Bar=25μm. (For interpretation of the references to colours in this figure legend, the reader is referred to the web version of this paper.)
Reproductive BioMedicine Online  , 58-67DOI: ( /j.rbmo )
Copyright © 2012 Reproductive Healthcare Ltd. Terms and Conditions

3. Figure 2
Differential activation of ERK/MAPK and p38/MAPK pathways in the cells of the labyrinth. The embryonic vascular network is revealed with an antibody against CD31 (left panel) while activation of the ERK/MAPK and p38/MAPK signalling pathways is highlighted with antibodies against the phospho-active forms of ERK and p38, respectively (middle and right panels). The images were taken using differential interference contrast microscopy. Embryonic and maternal erythrocytes are detectable in the fetal vessels (FBV) and maternal sinuses (MS), respectively. Embryonic red blood cells are large and nucleated. Activation of the p38/MAPK pathway is limited to FBV, whereas ERK activation is restricted to cells lining MS. Black arrows indicate fetal vascular endothelial cells. White arrows show the trophoblast cells bordering MS. Bar=50μm.
Reproductive BioMedicine Online  , 58-67DOI: ( /j.rbmo )
Copyright © 2012 Reproductive Healthcare Ltd. Terms and Conditions