Resveratrol treatment during goat oocytes maturation enhances developmental competence of parthenogenetic and hand-made cloned blastocysts by modulating intracellular glutathione level and embryonic gene expression.

PURPOSE: The aim of the present study was to determine whether supplementation of resveratrol, a stilbenoid antioxidant with therapeutic significance, influences goat (Capra hircus) oocyte maturation and subsequent embryonic development and expression of apoptosis and early embryonic development-related genes. METHODS: Five different concentrations of resveratrol (0.1, 0.25, 0.5, 2.0 and 5.0 µM) were used in in vitro maturation (IVM) medium. Cell tracker blue and 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA) fluorescent stains were used to assay intracellular glutathione and reactive oxygen species levels in mature oocytes. Parthenogenetic activation and hand-made cloning were performed to check the developmental potential following resveratrol treatment. We used quantitative real-time PCR to analyze embryonic gene expression. RESULT: Compared to control, no significant improvement was observed in nuclear maturation in resveratrol-treated groups and at 5.0 µM concentration maturation rate decreased significantly (P < 0.05). But resveratrol treatment at the concentrations of 0.25, 0.5 µM significantly reduced intracellular ROS, and increased GSH concentrations. Oocytes treated with 0.25, 0.5 µM resveratrol when subsequently used for PA and HMC, higher extent of blastocyst yields were observed. Expression analysis of proapoptotic (Bax) gene in mature oocytes, cumulus cells, and HMC-derived blastocysts revealed lesser transcript abundances in various resveratrol-treated groups., however no change in the same was observed for antiapoptotic gene (Bcl2). Differential expression of genes associated with developmental competence and nuclear reprogramming was also observed in HMC-derived blastocysts. CONCLUSION: Our results show that resveratrol treatment at optimum concentrations (0.25 and 0.5 µM) during IVM produced beneficial microenvironment within oocytes by increasing the intracellular GSH, decreasing ROS level and this in turn, stimulated embryonic development and regulated gene expression.

Roscovitine treatment improves synchronization of donor cell cycle in G0/G1 stage and in vitro development of handmade cloned buffalo (Bubalus bubalis) embryos.

This study investigated the effects of serum-starvation, total confluence, and roscovitine treatment on cell-cycle synchronization of buffalo ear skin fibroblasts to the G0/G1 stage and on the developmental competence of cloned embryos. Serum starvation of total confluence cultures for 24 h had a higher (p<0.05) proportion of cells at G0/G1 stage (94.4%) compared with serum starved cyclic and nonstarved confluent cultures (76.8 and 86.0%, respectively), whereas differences between cyclic cells with or without serum starvation were not significant. The proportion of cells at G0/G1 was higher (p<0.05) with 20 and 30 µM roscovitine treatment than that with 10 µM (94.4, 96.4, and 86.6%, respectively), which was similar to that for total confluence (86.0%). MTT assay showed that cell viability decreased as dose of roscovitine increased. The blastocyst rate was significantly higher (p<0.05) when nuclear transfer embryos were reconstructed using donors cells from total confluence, confluence serum starved, and roscovitine-treated (20 and 30 µM) groups (48.8, 48.9, 57.9, and 62.9%, respectively) compared to nontreated cyclic cells (20.2%). However, the cleavage rate and total cell number of cloned embryos were similar for all the groups. The number of ICM cells was improved by 30 µM roscovitine treatment (45.25 ± 2.34). The cryosurvival rate of blastocysts derived from cells synchronized with 20 or 30 µM roscovitine was higher compared to that for total confluence group (33.6, 37.8 vs. 23.8%). In conclusion, treatment with 30 µM roscovitine is optimal for harvesting G0/G1 stage cells for producing high quality cloned buffalo embryos, and that it is better than serum-starvation or total confluence for cell synchronization.

Effect of cytoplasmic volume on developmental competence of buffalo (Bubalus bubalis) embryos produced through hand-made cloning.

This study examined the effects of cytoplasmic volume on the developmental competence of hand-made cloned buffalo embryos. Two different cell types, that is, buffalo fetal fibroblast (BFF) and buffalo embryonic stem (ES) cell-like cells were taken as donor cell and fused with one, two, or three demicytoplasts to generate embryos with decreased, normal (control), and increased cytoplasmic volume. Using BFF as a nuclear donor, the cleavage rate was similar in all the groups (p > 0.05), but the blastocysts rate was significantly lower (p < 0.05) for embryos generated with decreased cytoplasmic volume. Using ES cell-like cells, the cleavage and blastocyst rate with increased cytoplasmic volume was significantly higher (p < 0.05) compared that with reduced cytoplasmic volume. Blastocysts produced from embryos having increased cytoplasmic volume had significantly higher (p < 0.05) cell number than normal (control) embryos in both BFF and ES cell-like cells groups. Pregnancies were established in all the groups except for the embryos reconstructed with decreased cytoplasmic volume. The pregnancy rate was almost double for embryos reconstructed using increased cytoplasmic volume compared to that with the controls. Most of the pregnancies aborted in the first trimester and one live calf was delivered through Caesarean, which died 4 h after birth.