Platelet-rich plasma promotes the development of isolated human primordial and primary follicles to the preantral stage.

This study aimed to assess the effects of platelet-rich plasma (PRP) on growth and survival of isolated early human follicles in a three-dimensional culture system. After fresh and vitrified-warmed ovarian tissue was digested, isolated early preantral follicles and ovarian cells were separately encapsulated in 1% alginate (w/v). The encapsulated follicles and ovarian cells were cultured together in a medium supplemented with foetal bovine serum (FBS), PRP, PRP + FBS, or human serum albumin (HSA) for 10 days. Growth and survival of the follicles were assessed by measurement of diameter and staining with trypan blue. Follicular integrity was assessed by histological analysis. After culturing, all follicles increased in size, but growth rate was greater in follicles isolated from fresh samples than those from vitrified-warmed ones (P < 0.001). Similarly, follicular viability of fresh samples after culturing was higher than that of vitrified-warmed ones. The growth and survival rates of follicles from both fresh and vitrified groups cultured in PRP supplemented media were significantly higher than those of other groups (growth P < 0.001 and survival P < 0.05, in both groups). In conclusion, media supplementation with PRP can better support viability and growth of isolated human early preantral follicles in vitro.

Development of sheep primordial follicles encapsulated in alginate or in ovarian tissue in fresh and vitrified samples.

In vitro follicle growth is a promising strategy for female fertility preservation. This study was conducted to compare the development of ovine follicles either isolated or in the context of ovarian cortical pieces after short term (8 days) three-dimensional culture in fresh and vitrified samples. Four different experiments were conducted; I) culture of ovarian cortical pieces encapsulated in 0.5% and 1% alginate and without alginate encapsulation (CP-0.5%, CP-1% and CP, respectively), II) culture of isolated primordial and primary follicles encapsulated in 1% and 2% alginate (IF-1% and IF-2%, respectively), III) culture of fresh and vitrified-warmed cortical pieces (F-CP and Vit-CP, respectively), and IV) culture of fresh and vitrified-warmed encapsulated isolated follicles (F-IF and Vit-IF, respectively). The number of secondary follicles after culture was negatively influenced by encapsulation of ovarian cortical pieces (6.3 ± 3.3 and 10.6 ± 0.9 vs 21.5 ± 2.3 in CP-0.5% and CP-1% vs CP, respectively). The diameter of follicles in IF-2% was higher than IF-1% (54.06 ± 2 vs 41.9 ± 1.5) and no significant difference in follicular viability was observed between the two groups. The proportions of different follicular types and their viability after culture in vitrified-warmed cortical pieces were comparable with fresh ones. The viability of vitrified-warmed isolated follicles was lower than fresh counterparts. The growth rate of fresh follicles was higher than vitrified-warmed follicles after culture (47.9 ± 1 vs 44.6 ± 1). In conclusion, while encapsulation of ovarian cortical pieces decreased the follicles' development, it could better support the growth of isolated follicles. Moreover, the viability and growth rate of isolated-encapsulated follicles was decreased by vitrification.

Developmental Competence and Pluripotency Gene Expression of Cattle Cloned Embryos Derived from Donor Cells Treated with 5-aza-2'-deoxycytidine.

BACKGROUND: Reconstructed embryos from terminally differentiated somatic cells have revealed high levels of genomic methylation which results in inappropriate expression patterns of imprinted and non-imprinted genes. These aberrant expressions are probably responsible for different abnormalities during the development of clones. Improvement in cloning competency may be achieved through modification of epigenetic markers in donor cells. MATERIALS AND METHODS: Our objective was to determine if treatment of donor cells for 72 hours with 5-aza-2'-deoxycytidine (5-aza-dc; 0-0.3 µM), a DNA methyl transferase inhibitor, improved development and expression of Oct-4. RESULTS: In comparison with untreated cells, 0.01 and 0.08 µM 5-aza-dc treated cells insignificantly decreased the blastocyst rate (32.1% vs. 28.6% and 27.2%, respectively) while it was significant for 0.3 µM treated cells (6.5%). Embryo quality as measured by the total cell number (TCN) decreased in a dose-related fashion, which was significant at 0.08 and 0.3 µM 5-aza-dc treated cells when compared with 0 and 0.01 µM 5-aza-dc treated cells. Although reconstructed embryos from 0.08 and 0.3 µM 5-aza-dc treated cells showed lower levels of DNA methylation and histone H3 acetylation, development to blastocyst stage was decreased. The epigenetic markers of embryos cloned from 0.01 µM 5-aza-dc remained unchanged. CONCLUSION: These results show that 5-aza-dc is not a suitable choice for modifying nuclear reprogramming. Finally, it was concluded that the wide genomic hypomethylation induced by 5-aza-dc deleteriously impacts the developmental competency of cloned embryos.

Sperm status and DNA dose play key roles in sperm/ICSI-mediated gene transfer in caprine.

In relation to the growing recent interest in the establishment of sperm-mediated gene transfer (SMGT) technology as a convenient and effective method for the simple production of transgenic animals, in this study the possibility of using SMGT to produce transgenic caprine embryos was investigated for the first time. Buck sperm were directly incubated with different concentrations (0-500 ng) of pcDNA/his/Lac-Z plasmid and used for IVF or ICSI. Sperm used for ICSI were categorized into motile or live-immotile group before being injected into oocytes. In a separate experiment, dead sperm prepared by repeated freezing/thawing were used for DNA-incubation before ICSI. Sham injection was carried out by intracytoplasmic injection of approximately the same volume of media containing different doses of DNA using an ICSI needle. Transgene expression and transmission were detected by X-Gal staining and PCR analysis of developed embryos, respectively. A reasonable blastocyst rate was observed in all the groups. Only embryos in the sham group were negative for transgene transmission. Transgene expression was completely dependent on the delivery technique and status of sperm, and was only observed in the live-immotile and dead ICSI groups. The results of this study showed that the technique (IVF vs. ICSI vs. sham injection), sperm status (motile vs. live-immotile vs. dead) and to some extent DNA concentration affect embryo development, transgene transmission and expression.