Colocalization of HLA-G mRNA and HLA-G protein in erythroid cells from first-trimester trophoblast. (A) Detection of either HLA-G mRNA (black) by in situ hybridization with DIG-labeled Pan HLA-G DNA probe or (B) HLA-G5/-G6 proteins (red) by immunohistochemistry by using the 5A6G7 mAb (right panel) on serial sections of first-trimester trophoblast (magnification from the top to the back of the photo: × 100, × 200, × 400). Sections were counterstained with Fast green and hematoxylin to visualize nuclei by in situ hybridization and immunohistochemistry analyses, respectively. EVC indicates extravillous cytotrophoblast; VS, villous syncytiotrophoblast; and M, mesenchymal core.