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Oocyte, embryo and ovarian tissue cryopreservation are being increasingly proposed for fertility preservation among cancer patients undergoing therapy to enable them to have babies after the cancer is cured. Embryo cryopreservation is not appropriate for single girls without any sperm partner and also because oocyte retrieval is an extended procedure, it is impossible in cases requiring immediate cancer cure. Thus ovarian tissue cryopreservation has been suggested for fertility preservation especial in cancer patients. The main goal of ovarian cryopreservation is re-implanting the tissue into the body to restore fertility and the hormonal cycle. Different cryopreservation protocols have been examined and established for vitrification of biological samples. We have used Cryopin to plunge ovarian tissue into the liquid nitrogen and promising results have been observed. Ovarian tissue re-implantation after cancer cure has one problem- the possibility of recurrence of malignancy in the reimplanted tissue is high. Xenografting-implantation of the preserved tissue in another species- also has its drawbacks such as molecular signaling from the recipient. In vitro follicle culturing is a safer method to obtain mature oocytes for fertilization and the various studies that have been carried out in this area are reviewed in this paper.

Background This study was designed to develop a new co-culture system, assess the effect of luteinizing hormone (LH) using sequential media to promote development and increase the quality of 2-cell murine embryos through the 8-16 cell stage to morula and blastocyst stages. Materials and methods Monolayers for co-culture were prepared from ovine oviduct epithelial cells (OOEC) in DMEM/F12 medium and in-vivo-fertilized 2-cell embryos were collected by flushing from superovulated mice. Co-culture media was treated with 10ng/ml LH. For the control groups, embryos were cultured solely in G1/G2™Ver.5 drops and containing LH; and on OOEC monolayers in G1/G2™Ver.5 drops alone and containing LH as the experimental groups. Development and quality rates were determined for all embryos daily and statistically compared. At the end of the cultivation period, differentially stained trophectoderm (TE) and inner cell mass (ICM) of expanded blastocysts from each group were examined microscopically. Results The embryos cultured on an OOEC monolayer in G1/G2™Ver.5 drops treated with LH had a significantly higher developmental rate than those of the group without LH and the control groups (p≤0.05). The blastocysts from the LH treated co-culture, in comparison with the group without LH and the control groups, also had a significantly higher mean cell number (p≤0.05). Conclusion These findings suggest that elevated periovulatory LH levels may promote preimplantation embryo development. These results have important implications for assisted reproductive technologies in which co-cultures are used to improve pregnancy rates. OOEC cell co-culture system treated by LH could improve in vitro preimplantation embryo development both in terms of quality (increasing blastocyst cellularity) and developmental rate.

Background Ghezel sheep are highly prolific and one of the local sheep breeds in Iran and Turkey. Growth differentiation factor-9 (GDF9) gene has been found to be essential for growth and differentiation of early ovarian follicles. Novel mutations in GDF9 have been associated with increased ovulation rates and high litter sizes in heterozygous carriers. Therefore, fecundity gene for GDF9 (FecGH) mutation in GDF9 is considered as a possible candidate for the increased litter size observed in Ghezel ewes. Materials and methods The aim was to evaluate the frequency of recently reported SNP (FecGH) using polymerase chain reaction (PCR) - single strand conformation polymorphism (SSCP) in 110 Ghezel ewes with a history of high litter size reproductive activity and 75 fertile ewes with normal reproductive activity. Results The GDF9 gene exon II was investigated by this technique to screen whether they are FecGH (S395F) carriers or not. SSCP analysis identified four fragments that contained conformational differences; however the combined results with sequencing analysis data did not reveal the FecGH mutation (C to T) in GDF9 gene in Iranian Ghezel ewes. Conclusion Current results confirmed that FecGH mutation is not present in the selected Iranian Ghezel sheep population and is not associated with Ghezel sheep high prolificacy performance. Therefore, this SNP may not represent a molecular marker for marker assisted selection programs in this population.