Lineage tracing studies suggest that the placenta is not a de novo source of hematopoietic stem cells
Fig 2
RUNX proteins are not expressed in mouse placental ECs.
(A) Immunofluorescence staining for RUNX (red), CD34 (green) and Endomucin (magenta) in the maternal decidua of E10.5 mouse placenta sections (N = 3 placentas). Lower images indicate boxed regions 1 and 2. White arrows indicate RUNX + hematopoietic cells in maternal vessels. Yellow arrows indicate RUNX + stromal cells within the decidua. (B) Immunofluorescence staining for RUNX (red), CD34 (green) and Endomucin (magenta) in the fetal labyrinth (Lab) and chorioallantoic (CA) plate of the E10.5 mouse placenta (N = 3 placentas). Lower images show boxed regions 3 and 4. Dotted line indicates the border between the CA and labyrinth regions. White arrows indicate RUNX + stromal cells that are adjacent to Endomucin + ECs. The images in panels A and B were obtained using identical imaging settings. (C) Immunofluorescence staining for RUNX (red), CD34 (green) and Endomucin (magenta) in the E10.5 AGM region (N = 3 placentas). Lower images show boxed regions in the upper panel. White arrows indicate RUNX + hemogenic ECs. D and V indicate dorsal and ventral side of the vessel. (D) Immunofluorescence staining for RUNX (red), F4/80 (green) and Coll-I (magenta) in E10.5 mouse placenta sections (N = 3 placentas). Dotted lines outline the CA region between the umbilical cord (UC) and labyrinth (Lab). Lower images show boxed regions 5 and 6. White arrows indicate RUNX+Coll-I + stromal cells; yellow arrows indicate RUNX + F4/80 + fetal macrophages. (E) Immunofluorescence staining for RUNX (red), CD34 (green) and c-Kit (magenta) at the CA plate of the E10.5 wild-type mouse placenta (N = 3 placentas). A, artery. Scale bars: 20 μm.