OBJECTIVETo evaluate the safety and risk of cryopreservation in female fertility preservation.

DATA SOURCESThe data analyzed in this review were the English articles from 1980 to 2013 from journal databases, primarily PubMed and Google scholar. The criteria used in the literature search show as following: (1) human; embryo; cryopreservation/freezing/vitrification, (2) human; oocyte/immature oocyte; cryopreservation/ freezing/vitrification, (3) human; ovarian tissue transplantation; cryopreservation/freezing/vitrification, (4) human; aneuploidy/DNA damage/epigenetic; cryopreservation/freezing/vitrification, and (5) human; fertility preservation; maternal age.

STUDY SELECTIONThe risk ratios based on survival rate, maturation rate, fertilization rate, cleavage rate, implantation rate, pregnancy rate, and clinical risk rate were acquired from relevant meta-analysis studies. These studies included randomized controlled trials or studies with one of the primary outcome measures covering cryopreservation of human mature oocytes, embryos, and ovarian tissues within the last 7 years (from 2006 to 2013, since the pregnancy rates of oocyte vitrification were significantly increased due to the improved techniques). The data involving immature oocyte cryopreservation obtained from individual studies was also reviewed by the authors.

RESULTSVitrifications of mature oocytes and embryos obtained better clinical outcomes and did not increase the risks of DNA damage, spindle configuration, embryonic aneuploidy, and genomic imprinting as compared with fresh and slow-freezing procedures, respectively.

CONCLUSIONSBoth embryo and oocyte vitrifications are safe applications in female fertility preservation.

Cryopreservation ; methods ; Female ; Humans ; Oocytes ; cytology ; Ovary ; cytology ; Pregnancy

To study the effects of mouse cytomegalovirus (MCMV) on the in vitro maturation, fertilization, cleavage and blastula formation of mouse oocytes, the immature oocytes were infected in vitro by MCMVs of different dosages (100 TCID(50), 10 TCID(50) and 1 TCID(50)). The oocytes were then observed for in vitro maturation, fertilization, cleavage and blastula formation and the ultrastructural changes after the culture with the viruses. Our results showed that no significant differences were found in IVM, IVF, cleavage and blastula formation among the groups treated with of virus of various dosages. And ultrastructural abnormality was observed in the oocytes treated by 100 TCID(50) of viruses. It is concluded that MCMV did not have any conspicuous effects on IVM, IVF, cleavage and blastula formation of murine immature oocytes.
Blastocyst ; Cells, Cultured ; Cleavage Stage, Ovum ; Cytomegalovirus Infections ; Fertilization ; Muromegalovirus/*pathogenicity ; Oocytes/cytology ; Oocytes/growth & development ; Oocytes/*virology

Mouse follicular oocytes, denuded and intact, were cultured in pyruvate salt sol and glutamine salt sol supplemented bovine serum albumin to compare the maturation rate. Glutamine has no effect on maturation of the denuded mouse oocyte but has an effect on maturation of the intact oocyte by increasing the maturation rate, depending on the increased concentration of glutamine (0.4 mM to 2 mM). Changes in osmolarity of the operation medium from 280 mOsm to 310 mOsm has no discernible effect on the oocyte maturation. A high frequency of abnormal 1st polar bodies was observed in pyruvate salt sol. and this may be due to the increased energy source in the cytoplasm of the 1st polar body when the po1ar body was extruded into the perivitelline space after the 1st meiosis.
Animal ; Cell Division ; Female ; Glutamine/metabolism ; In Vitro ; Mice ; Oocytes/cytology ; Oocytes/metabolism* ; Ovum/metabolism* ; Pyruvates/metabolism

Mouse follicular oocytes, denuded and intact, were cultured in pyruvate salt sol and glutamine salt sol supplemented bovine serum albumin to compare the maturation rate. Glutamine has no effect on maturation of the denuded mouse oocyte but has an effect on maturation of the intact oocyte by increasing the maturation rate, depending on the increased concentration of glutamine (0.4 mM to 2 mM). Changes in osmolarity of the operation medium from 280 mOsm to 310 mOsm has no discernible effect on the oocyte maturation. A high frequency of abnormal 1st polar bodies was observed in pyruvate salt sol. and this may be due to the increased energy source in the cytoplasm of the 1st polar body when the po1ar body was extruded into the perivitelline space after the 1st meiosis.
Animal ; Cell Division ; Female ; Glutamine/metabolism ; In Vitro ; Mice ; Oocytes/cytology ; Oocytes/metabolism* ; Ovum/metabolism* ; Pyruvates/metabolism

The successful cryopreservation of reproductive cells has important practical significance in many fields. In order to improve the recovery rate and viability of cryopreserved cells, it is necessary to study the permeability characteristics of cell membrane to both water and cryoprotectant. In this paper we review the studies on membrane permeability of animal reproductive cell for the recent years. We firstly list the typical permeability data of spermatozoa and oocyte membrane for water and cryoprotectant. We then analyze the effects of these characteristics on the design of cryopreservation protocol. We also introduce the latest experimental methods to measure the cell membrane permeability.
Animals ; Cell Membrane Permeability ; physiology ; Cryopreservation ; methods ; Female ; Humans ; Male ; Oocytes ; cytology ; Spermatozoa ; cytology

This experiment was undertaken in order to know the effect of leucocytes on the maturation of mouse oocytes in vitro. Leucocytes obtained from heart puncture of mouse (3 X 10(4) cells/mm3) inhibited the maturation of mouse oocytes. The egg toxic activity declined with decreasing leucocyte concentration. It was found that egg toxic effect of leucocytes is not species specific. The activity of intact leucocytes or equal numbers of leucocytes that were destroyed was similar and which seems not to be influenced by the physiological stats of leucocytes.
Animal ; Culture Media ; Female ; Leukocytes* ; Metaphase ; Mice ; Oocytes/cytology* ; Ovum/cytology*

This experiment was undertaken in order to find out if there is any morphological change in oocytes and two-cell embryos whose development have been suppressed by progesterone for six hours in vitro. It can be observed that some part of the outer side of nuclear membrane of the suppressed oocytes was damaged. The number of nuclear pores has decreased in suppressed oocytes and this suggests that progesterone might suppress the transport of intermediary metabolites between cytoplasm and nucleus. Sometimes, closely packed aggregates of parallel or irregular endoplasmic reticula were observed in suppressed oocytes. Microvilli of suppresed oocytes showed signs of degradation and the perivitelline space became apparent. Thus it is presumed that the egg membrane has constricted during cultivation under progesterone in vitro. The other cell organelles such as mitochondria, multivesicular bodies, cortical granules and fibrillar lattices showed no difference in morphology between treated and control (intact) oocytes. In two-cell embryos, there was also no evident morphological change except for the fact that many vacuoles appeared clearly in suppressed embryonal cells. In brief, there was no fundamental morphological change in the oocytes and the embryonal cells exposed to progesterone for six hours even though it inhibits their development. The action of progesterone should be investigated thoroughly.
Animal ; Embryo/cytology* ; Embryo/drug effects ; Female ; In Vitro ; Mice ; Oocytes/drug effects ; Oocytes/ultrastructure* ; Ovum/ultrastructure* ; Progesterone/pharmacology*

Oocyte-like cells (OLC) can be generated by stem cells after the induction and differentiation in vitro, and maturated when transplanted in vivo to improve the development potential. Human amniotic fluid stem cells (hAFSC) were cultured for 10 days in porcine follicle fluid (pFF) that was extracted from the medium follicle with high levels of hormones and Bmp 15 protein. After the induction, the cell aggregates showed the germ cell-like cells and produced the germ cell marker oct4, and triggered epigenetic changes with high expression of methylation transferase gene dnmt3b. The cell aggregates were packaged into porcine theca folliculi to form grafts, which were then transplanted into mouse renal capsule. After one month of transplantation, the morphology of OLC from a graft was not only similar to oocytes, but also expressed the germ cells markers (oct4, nanog, stella, ifitm3, dazl, nanos3, bmp15, and gd9). The results demonstrate that the in vivo differentiation model was useful for OLC development.
Amniotic Fluid ; cytology ; Animals ; Biomarkers ; Cell Differentiation ; Female ; Humans ; Mice ; Oocytes ; cytology ; Ovarian Follicle ; Stem Cells ; cytology ; Swine

Apoptosis of abnormal oocytes is essential for defective oocyte elimination during prepubertal ovary development, and the ubiquitin system regulates the cell apoptosis via the degradation of specific proteins. Ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1) is a component of the ubiquitin system, and the UCH-L1-dependent apoptosis is important for spermatogenesis. In the present study, the change in the number of follicles and the expression of UCH-L1 in oocytes were determined in prepubertal mouse ovaries by immunohistochemical techniques. A significant decrease in the follicular pool was found in prepubertal mouse ovaries during the period of day 21 to day 28 after birth, and accordingly, the UCH-L1 protein expression was increased, to some degree in association with Jun activation domain-binding protein 1 (Jab1) and cyclin-dependent kinase inhibitor p27(Kipl). The increased UCH-L1 protein, together with the corresponding changes of Jab1 was detected in morphologically abnormal oocytes of prepubertal ovaries. Through the immunofluorescent colocalization, UCH-L1 was shown concentrating in abnormal oocytes, and a parallel change in Jab1 was also seen. The affinity analysis confirmed the interaction between UCH-L1 and Jab1 in ovaries. These results suggest that UCH-L1 plays an important role, possibly in association with Jab1 and p27(Kipl), in selective elimination of abnormal oocytes during mouse prepubertal development.
Animals ; Apoptosis ; Female ; Mice ; Oocytes ; cytology ; Ovary ; enzymology ; Ubiquitin Thiolesterase ; metabolism

OBJECTIVETo investigate the influence of two different vitrification cryopreservation methods on the spindles of mouse M II oocytes.

METHODSThree groups were included in the experiment, Group A, Group B and the control ( fresh oocytes). Mouse oocytes were vitrified by using cryoloop, with ethylene glycol( EG) in Group A and with EG + dimethyl sulphoxide ( DMSO) in Group B as cryoprotectants, and then the oocytes were placed directly into liquid nitrogen. Three hours after the frozen oocytes were thawed they were fixed, and the microtubule and chromosome were stained by indirect immunofluorescent method.

RESULTSThe survival rates of the oocytes after treated by the two vitrification cryopreservation methods had no difference ( 80. 3% vs 87. 5% , P > 0. 05) . The rate of the intact spindles in Group A was much lower than that of the control and Group B ( 15. 2% vs 78.7% , 15. 2% vs 77. 5% , P < 0. 05). But there was no difference between the latter two groups (78. 7% vs 77. 5% , P >0. 05). The oocytes with normal chromosome in Group A were much less than in the control and Group B (17.4% vs 76. 6% , 17. 4% vs 72. 5% , P <0. 05) , with no difference between the latter two groups(76. 6% vs 72. 5% , P >0. 05) ; The oocytes with abnormal chromosome were more in Group A than in the control and Group B (82. 6% vs 19. 1% , 82. 6% vs 27. 5% , P <0. 05) , with no difference between the latter two groups (19.1% vs 27.5% , P >0.05).

CONCLUSIONThe changed vitrification cryopreservation method helps conserve the intact spindle configuration of mouse oocytes.

Animals ; Cryopreservation ; methods ; Cryoprotective Agents ; Female ; Fertilization in Vitro ; Mice ; Mice, Inbred ICR ; Oocytes ; cytology ; Spindle Apparatus