Figure 7

Disruption of intact ovarian structure by re-aggregation resulted in oocyte loss due to an oocyte-specific deficiency. To distinguish between oocyte-specific or somatic cell-specific mechanisms of re-aggregation-induced oocyte loss, germ cells from e12.5 female genital ridges of Oct4-GFP transgenic mice were purified from somatic cells by FACS, and GFP+ and alkaline phosphatase (AP+) germ cells were cultured in vitro for three days to induce meiosis (SYCP3+) and to synchronize germ cells with later ovarian stages. Subsequently, cultured GFP+ germ cells were co-aggregated with permissive e16.5 or P2 stage ovarian tissue and transplanted for three weeks. In contrast to Oct4-GFP transgenic ovary controls with robust oocyte-specific GFP expression, e12.5-derived GFP+ oocytes were not detected after transplantation and indicated a re-aggregation induced oocyte-specific impairment following pre-ovarian genital ridge disruption.