Fig. 2

Morphological analysis of electronic microscopy. The passage 1 (P1) endometrial epithelial cells were cultured in an air–liquid interface (ALI) state for 2 weeks, and the ALI epithelial cultures and the P2 submerged monolayer cultures were employed for morphological analysis by scanning electronic microscopy (SEM) (A, B) and transmission electron microscopy (TEM) (C–E). (A, B) Representative images of SEM for endometrial epithelial cells cultured in an ALI state (A) and the logarithmic phase of submerged P2 cell culture (B). A′ and B′ were the higher magnifications of corresponding enlarged fields in A and B, respectively. Cells in submerged monolayer cultures showed a morphology of inerratic shapes with smooth surfaces, while ALI cultured cells exhibited anomalous shapes and rough cell surfaces with abundant secretions and microvilli on the surface of culture. (C–E) Representative TEM images of endometrial epithelial cells grown in ALI culture at magnification of 5,000× (C), 10,000× (D), and 15,000× (E) showed nucleus (n), microvilli (v), cilia (c), mitochondria (m), bridge (b), and secretory protein particles (p). Scale bars: 10 μm (A and B), 5 μm (A′, B′, and C), and 2 μm (D and E)