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Gene expression during oocyte maturation and early embryogenesis up to zygotic genome activation requires translational activation of maternally-derived mRNAs. EPAB [embryonic poly(A)-binding protein] is the predominant poly(A)-binding protein during this period in Xenopus, mouse and human. In Xenopus oocytes, ePAB stabilizes maternal mRNAs and promotes their translation. To assess the role of EPAB in mammalian reproduction, we generated Epab-knockout mice. Although Epab(-/-) males and Epab(+/-) of both sexes were fertile, Epab(-/-) female mice were infertile, and could not generate embryos or mature oocytes in vivo or in vitro. Epab(-/-) oocytes failed to achieve translational activation of maternally-stored mRNAs upon stimulation of oocyte maturation, including Ccnb1 (cyclin B1) and Dazl (deleted in azoospermia-like) mRNAs. Microinjection of Epab mRNA into Epab(-/-) germinal vesicle stage oocytes did not rescue maturation, suggesting that EPAB is also required for earlier stages of oogenesis. In addition, late antral follicles in the ovaries of Epab(-/-) mice exhibited impaired cumulus expansion, and a 8-fold decrease in ovulation, associated with a significant down-regulation of mRNAs encoding the EGF (epidermal growth factor)-like growth factors Areg (amphiregulin), Ereg (epiregulin) and Btc (betacellulin), and their downstream regulators, Ptgs2 (prostaglandin synthase 2), Has2 (hyaluronan synthase 2) and Tnfaip6 (tumour necrosis factor α-induced protein 6). The findings from the present study indicate that EPAB is necessary for oogenesis, folliculogenesis and female fertility in mice.

Purpose: To determine if IVM of oocytes from unstimulated cycle is a treatment option for patients who did not deliver after standard IVF-ET., Method: Twenty three women with PCO, thirteen of them with normal cycles and all <35 years old, who failed IVF served as their own control. During the control IVF cycle patients were stimulated with 1730.7 ± 639.5 IU recombinant FSH, a long Buserelin acetate protocol was used and embryo transfer was performed on day 2 or 3 after ICSI. After failed IVF immature oocytes were aspirated transvaginally from antral follicles during spontaneous menstrual cycle. Embryo transfer was performed 2 or 3 days later., Result: 11.4 ± 4.8 mature oocytes and 6.7 ± 3.2 embryos were produced with IVF, which served as the control, compared to 9.7 ± 4.5 mature oocytes and 6.2 ± 3.2 embryos with IVM. There was one clinical pregnancy in the IVF group which did not result in a live birth where as five singleton and one pair of twins with healthy live births and one miscarriage in the IVM group., Conclusion: IVM does not involve ovarian stimulation with possible financial and health consequences. İt may be an useful treatment after unsuccessful IVF.

This report describes the use of in vitro oocyte maturation in two patients with history of repeated oocyte maturation arrest (OMA) from in vitro fertilization. Based on these two cases, in vitro oocyte maturation from unstimulated cycles seems not an alternative treatment option for the patients with history of OMA.