FIG. 3.

Representative examples of laminin immunohistochemistry to assess labyrinth vasculature. Genotype is indicated at top and age at left. Columns represent groups of placentas by genotype: PO/BW, female PO × male BW and female bw × male po, respectively. A–C = E10 placentas, D–F = E13 placentas and G–I = E16 placentas (all ages are Mus equivalent). Double arrowheads represent embryonic blood vessels; single arrowheads indicate compromised maternal blood sinuses. Such tears were never observed in PO/BW or female bw × male po sections. All pictures were taken of the labyrinth at ×40 magnification.