Long-Term Oocyte-Like Cell Development in Cultures Derived from Neonatal Marmoset Monkey Ovary

Figure 5

Oocyte-like cells derived from OCCs highly express germ cell markers. (a) Oocyte-like cells that spontaneously developed even in high cell culture passages. The cells were freely floating in the cell culture medium and had a diameter of approximately 40 μm. The passage number is indicated in the upper right corner of each picture. Sometimes small spherical structures attached to the OLCs could be seen slightly resembling polar bodies (arrow). (b) Left: a group of natural marmoset monkey oocytes. Some oocytes are still associated with granulosa cells. Right: higher magnification of a marmoset monkey oocyte with a robust Zona pellucida. (c–l) Oocyte-like cells express pluripotency and germ cell markers. Relative mRNA levels of selected pluripotency and germ cell markers in oocyte-like cells as revealed by real-time quantitative RT-PCR. For OCT4A, SALL4, and LIN28, ES cells were used as positive control. Neonatal ovary was used as positive control for the germ cell markers. Fibroblasts served as biological negative control. (m) DAPI staining of a natural oocyte (left) and of an OLC. While the oocyte shows strongly compacted chromatin, the DAPI staining of the OLC is homogenous indicating a different chromatin state in OLCs and natural oocytes.

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