Effects of in-vitro or in-vivo matured ooplasm and spindle-chromosome complex on the development of spindle-transferred oocytes

C-Phycocyanin improves the quality of goat oocytes after in vitro maturation and vitrification

In vitro maturation (IVM) and cryopreservation of goat oocytes are important for establishing a valuable genetic bank for domesticated female animals and improving livestock reproductive efficiency. C-Phycocyanin (PC) is a Spirulina extract with antioxidant, antiinflammatory, and radical scavenging properties. However, whether PC has positive effect on goat oocytes IVM or developmental competence after vitrification is still unknown. In this study, we found that first polar body extrusion (n = 293), cumulus expansion index (n = 269), and parthenogenetic blastocyst formation (n = 281) were facilitated by adding 30 μg/mL PC to the oocyte maturation medium when compared with the control groups and that supplemented with 3, 10, 100 or 300 μg/mL PC (P < 0.05). Although PC supplementation did not affect spindle formation or chromosome alignment (n = 115), it facilitated or improved cortical granules migration (n = 46, P < 0.05), mitochondria distribution (n = 39, P < 0.05), and mitochondrial membrane potential (n = 46, P < 10-4). Meanwhile, supplementation with 30 μg/mL PC in the maturation medium could significantly inhibit the reactive oxygen species accumulation (n = 65, P < 10-4), and cell apoptosis (n = 42, P < 0.05). In addition, PC increased the oocyte mRNA levels of GPX4 (P < 0.01), and decreased the mRNA and protein levels of BAX (P < 0.01). Next, we investigated the effect of PC supplementation in the vitrification solution on oocyte cryopreservation. When compared with the those equilibrate in the vitrification solution without PC, recovered oocytes in the 30 μg/mL PC group showed higher ratios of normal morphology (n = 85, P < 0.05), survival (n = 85, P < 0.05), first polar body extrusion (n = 62, P < 0.05), and parthenogenetic blastocyst formation (n = 107, P < 0.05). Meanwhile, PC supplementation of the vitrification solution increased oocyte mitochondrial membrane potential (n = 53, P < 0.05), decreased the reactive oxygen species accumulation (n = 73, P < 0.05), promoted mitochondria distribution (n = 58, P < 0.05), and inhibited apoptosis (n = 46, P < 10-3). Collectively, our findings suggest that PC improves goat oocyte IVM and vitrification by reducing oxidative stress and early apoptosis, which providing a novel strategy for livestock gamete preservation and utilization.

Genome transfer technique for bovine embryo production using the metaphase plate and polar body

Despite many studies in humans and mice using genome transfer (GT), there are few reports using this technique in oocytes of wild or domestic animals. Therefore, we aimed to establish a GT technique in bovine oocytes using the metaphase plate (MP) and polar body (PB) as the sources of genetic material. In the first experiment, GT was established using MP (GT-MP), and a sperm concentration of 1 × 106 or 0.5 × 106 spermatozoa/ml gave similar fertilization rates. The cleavage rate (50%) and blastocyst rate (13.6%) in the GT-MP group was lower than that of the in vitro production control group (80.2% and 32.6%, respectively). The second experiment evaluated the same parameters using PB instead of MP; the GT-PB group had lower fertilization (82.3% vs. 96.2%) and blastocyst (7.7% vs. 36.8%) rates than the control group. No differences in the amount of mitochondrial DNA (mtDNA) were observed between groups. Finally, GT-MP was performed using vitrified oocytes (GT-MPV) as a source of genetic material. The cleavage rate of the GT-MPV group (68.4%) was similar to that of the vitrified oocytes (VIT) control group (70.0%) and to that of the control IVP group (81.25%, P < 0.05). The blastocyst rate of GT-MPV (15.7) did not differ neither from the VIT control group (5.0%) nor from the IVP control group (35.7%). The results suggested that the structures reconstructed by the GT-MPV and GT-PB technique develop in embryos even if vitrified oocytes are used.

Endometrial thickness as a predictor of pregnancy outcomes in 10787 fresh IVF-ICSI cycles

This retrospective study assessed the predictive value of endometrial thickness (EMT) on HCG administration day for the clinical outcome of fresh IVF and intracytoplasmic sperm injection (ICSI) cycles. A total of 8690 consecutive women undergoing 10,787 cycles over a 5-year period were included. The 5th, 50th and 95th centiles for EMT were determined as 8, 11 and 15 mm, respectively. Group analysis according to these centiles (Group 1: < 8 mm; Group 2: ≥ 8 and ≤11 mm; Group 3: > 11 and ≤15 mm; Group 4: > 15 mm) demonstrated significant differences (P < 0.001) in clinical pregnancy rates (23.0%, 37.2%, 46.2% and 53.3%, respectively), live birth rates per clinical pregnancy (63.3%, 72.0%, 78.1% and 80.3%, respectively), spontaneous abortion rates (26.7%, 23.8%, 19.9% and 17.5%, respectively), and ectopic pregnancy rates (10.0%, 4.3%, 2.1% and 2.2%, respectively). Logistic regression analyses showed EMT as one of the independent variables predictive of clinical pregnancy (OR = 1.097; P < 0.001), live birth (OR = 1.078; P < 0.001), spontaneous abortion (OR = 0.948; P < 0.001), and ectopic pregnancy (OR = 0.851; P < 0.001). Future research should aim to understand the underlying mechanisms relating EMT to conception, ectopic implantation and spontaneous abortion.