Figure 4

Immunohistochemical localization of osteopontin in cryostat cross-sections of bovine endometrial tissue during the estrous cycle (A, day 1 cyclic, B, day 14 cyclic, C, day 18 cyclic) and early pregnancy (D, day 18 pregnant, E, day 21 pregnant, F, day 24 pregnant, G, day 30 pregnant). Osteopontin (positive reactivity is red) was detected at the apical surface of glandular (G) and luminal epithelium (LE), associated with blood vessels (V) and on extraembryonic membranes (arrow) luminal to the trophoblast (T), as well as trophoblast itself. A representative control section, treated with rabbit IgG instead of primary antibody, is shown in H. mLE – LE modified by binucleate cell migration. Bar = 50 μm.