Identification of ovine ovarian putative stem cells

Background: The aim of the present study was to characterize ovine ovarian putative stem cells (PSCs) and their probability of the differentiation potential to oocyte like cells.Methods: In this experiment, the ovaries were collected from two to four years old sheep with the anovulatory phase. Ovarian surface epithelium (OSE) cells were cultured for three weeks, in presence of estrogenic stimuli (phenol red).Result: Two distinct populations of stem cells with variable size were detected in scraped OSE, one smaller and other bigger. The both cells expressed SSEA-1, SSEA3 and VASA pluripotent and germ cells markers. Those stem cell like underwent to oocyte-like cells differentiation after three weeks culture, with diameter up to 135 μm which were similar to natural ovine oocyte. Some of them expressed zona pellucida-like structure. Beside the immunocytochemistry and Real Time PCR results of oocyte-like showed the expression of ZP3 and C-kit protein and gene. Therefore, it looks that, phenol red cause’s size increasing of the stem cells and spontaneous differentiation into oocyte-like structures after three weeks culture. It suggested, estrogenic effects are very important for the development of oocyte-like cells in vitro.Conclusion: As opposed to the existing view of OSE being a bipotent source of oocytes and granulosa cells, mammalian ovaries harbor distinct very small stem cell -like PSCs and tissue committed progenitor stem cells population that have the potential to develop into oocyte-like structures in vitro. This study empirically confirms the presence of putative ovarian stem cells in the OSE layer of sheep.

کلیدواژه ها:

oocyte ، ovarian stem cell ، ovarian surface epithelium ، cell culture