Figure 2.

Ki67-Labelling Index (Ki67-LI) correlated with endometrial epithelial cell proliferation only in the epithelial compartment of the stratum functionalis. Epithelial LGR5 expression scores also correlated with the expression of the previously known progenitor markers SOX9 and SSEA-1 in sequential tissue sections across the cycle. (A) Representative images of Ki67, SOX9 and SSEA-1 IHC in luminal, stratum functionalis, stratum basalis epithelial compartments of the eutopic endometrium and Fallopian tubes in the proliferative and secretory stages of the menstrual cycle (all images ×400, scale bar 10 μm). (B) Quantification of percentage Ki67-positive cells (Ki-67 LI) throughout the cycle. A minimum of 25 fields of cells were counted at ×400 magnification (n = 7 per group). The stratum functionalis in the proliferative phase has the highest Ki67-LI and is statistically higher than the stratum functionalis epithelium in the secretory phase (P < 0.05). Ki67-LI decreased dramatically in the secretory phase of the cycle in all epithelial compartments (Prol = Proliferative, Sec = Secretory Funct = stratum Functionalis, Bas = stratum Basalis).