Fig. 3.

TEM observation of luteal steroidogenic cells. A, E: PRG15 (intact); B, C, F, G: PRG21 (intact); D, H: PP3 (intact); I, J: PRG21 (Bafilomycin A1-treated on PRG15 and sampled on PRG21). Irregular shapes of voids (red arrowheads) were observed on PRG15 and increased on PRG21. Another type of luteal cell with few voids and a developed endoplasmic reticulum (green arrowheads) was also observed on PRG21. Luteal cells on PP3 contain increased amounts of lipid droplets (yellow arrowheads). In CL treated with Baf A1 on PRG15, luteal cells with decreased voids, increased lipid droplets (blue arrowheads), and abnormal mitochondrial structures (orange circles and arrowheads) were noted at PRG21. Scale bar, 5 µm (A–D) and 2 µm (E–J).