This study aimed to investigate the efficacy of cell-free DNA (CF-DNA) in the spent cleavage and blastocyst medium versus blastomere biopsy for sex identification using short tandem repeat (STR) markers for the first time. In total, 39 samples of spent culture medium (SCM) from six couples were collected of which 28 samples were CF-DNA from blastocoel fluid + SCM (day 5) and 11 samples from SCM alone (day 3). The frequencies of allele dropout (ADO), fail rate and informativity markers were considered. The relationship between the morphology of embryos and ADO and the fail number of all markers was investigated. Sex identification rate between CF-DNA isolated from culture medium and fluorescence in situ hybridization (FISH) was then compared with measurement of Agreement Kappa (AK). The highest frequency of informative markers belonged to DXS6801 and HPRT. There was no relationship between the ADO number of all markers and embryo morphology. A significant difference was seen between embryo morphology and fail numbers. AK value between CF-DNA isolated from culture medium and FISH was 0.516, which is moderate. The ability of CF-DNA to detect the correct diagnosis of males and females showed that all values of specificity, sensitivity, positive predictive value, and negative predictive value were 100%. The presence of embryonic CF-DNA in the SCM on day 3 as well as blastocyst medium on day 5 using STR-based multiplex PCR is approximately consistent with FISH for sex identification. Advances in DNA extraction, amplification technique, and testing may allow for preimplantation genetic testing for aneuploidy (PGT-A) and monogenic/single-gene disorders (PGT-M) as a non-invasive approach without biopsy in the future either in sex determination or chromosomal abnormality.

This study aimed to compare the clinical outcomes of using refrigerated versus pre-warmed media for preparing time-lapse dishes in in vitro fertilization (IVF). Patients undergoing their first IVF/ICSI cycle were divided into two groups. The control group used pre-warmed culture media, while the experimental group used refrigerated culture media. The osmotic pressure of the culture droplets in both groups was tested. No statistical differences were found between the two groups’ basic data. The proportion of air microbubbles affecting imaging significantly decreased (4.55% vs. 37.97%, P < 0.001) when using pre-warmed media. However, the blastocyst formation rate (56.62% vs. 49.70%, P = 0.046) and total high-quality embryo rate (22.26% vs. 17.06%, P = 0.047) were significantly higher in the refrigerated media group compared to the pre-warmed media group. The higher rate of high-quality embryos in the refrigerated media group might result in a higher single embryo transfer rate (45.10% vs. 18.52%, P = 0.020) and implantation rate (58.23% vs. 34.69%, P = 0.010). From day –1 to day 1, osmolality increased, with the P-3.5 group showing a significant elevation compared to the other three groups. After 5 days of incubation, the osmotic pressure of group R-4.0 was significantly lower than that of groups P-3.5, P-4.0 and P-3.5. In conclusion, refrigerated culture media dishes helped stabilize the osmotic pressure of the culture microenvironment and reduce water evaporation. The refrigerated group showed a higher rate of high-quality embryos and live births, although pre-warmed culture media effectively reduced the occurrence of air microbubbles that affect embryo imaging in the next day’s dishes.

The objective was to evaluate the use of resveratrol conjugated with silica nanoparticles during the in vitro maturation of bovine oocytes. The oocytes were divided into the following treatment groups during the maturation process: control (n = 159), resveratrol 0.5 μM (n = 158), resveratrol 1 μM (n = 155), nanoparticles conjugated with 0.5 μM resveratrol (n = 159), and nanoparticles conjugated with 1 μM resveratrol (n = 158). Several parameters were assessed, including cumulus oophorus size, reactive oxygen species (ROS) production, oocyte nuclear maturation, cell apoptosis, cleavage rates, and blastocyst production rates. Statistical analysis was conducted using Sigma Plot software (version 11) and SAS Studio, with statistical significance defined as P ≤ 0.05 for the main effects and interactions. The results indicated that the cumulus oophorus size was smaller in the resveratrol 1 μM treatment group, and the oocyte size was reduced in the nanoparticle 1 μM treatment group. No significant differences were detected between the treatment groups in terms of ROS production, oocyte maturation, or cell apoptosis. However, the resveratrol 1 μM treatment group exhibited decreased rates of cleavage and blastocyst formation. In contrast, the nanoparticles 0.5 μM and 1.0 μM treatments showed improved cleavage and blastocyst rates compared with the resveratrol 1.0 μM treatment group. In summary, while resveratrol alone at 1 μM concentration had a negative impact on cleavage and blastocyst rates, the use of silica nanoparticles conjugated with resveratrol (both 0.5 μM and 1 μM) enhanced these outcomes, suggesting a potential advantage in using nanoparticle-conjugated resveratrol for the in vitro maturation of bovine oocytes.

This study aimed to evaluate the effects of acetyl-L-carnitine on follicle survival and growth, stromal cell density and extracellular matrix, as well as on the expression of mRNA for nuclear factor erythroid 2-related factor (NRF2), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and peroxiredoxin 6 (PRDX6) in cultured bovine ovarian cortical tissues. Ovarian fragments (3 × 3 × 1 mm) were cultured for 6 days in α-MEM+ alone or supplemented with 10, 50 or 100 μM acetyl-L-carnitine at 38.5°C with 5% CO2 in humidified air. Before (non-cultured tissues) and after culture, the ovarian fragments were fixed in 4% paraformaldehyde for 12 h for histological analysis or stored at –80ºC for mRNA expression analysis of NRF2, SOD, CAT, PRDX6 and GPX1. The results showed that 100 μM acetyl-L-carnitine increased the percentages of morphologically normal follicles and stromal cell density in cultured ovarian tissues. On the other hand, acetyl-L-carnitine did not influence the percentage of collagen in ovarian tissue nor the expression of mRNAs for NRF2, SOD, CAT, PRDX6 and GPX1. In conclusion, 100 μM acetyl-L-carnitine increased follicle survival and stromal cell density in cultured bovine ovarian tissues but does not influence collagen fibre distribution or the expression of mRNAs for NRF2, SOD, CAT, PRDX6 and GPX1.

With the advancement in the embryo culture media, which supports nutrient requirements of embryos up to 5 to 6 days, there’s a chance to select more viable embryos, which are more likely to result in pregnancy, compared to earlier stages. Also, there is a controversy regarding the frozen embryo transfer compared to the fresh type. To compare the chemical pregnancy rates between fresh embryo transfer (ET), and frozen embryo transfer (FET), on day 3 (cleavage), and day 4 (morula) of development. In this retrospective study, data of 242 fresh and 758 frozen embryo transfer cycles were obtained in one infertility center in Isfahan, Iran. The study’s groups were assigned based on the day of fresh or frozen embryo transfer (day 3, or day 4 embryos) and the embryo grading. Chemical pregnancy was the main outcome measurement (implantation rates). The chemical pregnancy rate was higher in the good quality frozen embryo day 3 and transfer on day 4 group (40.1%). This rate was near the results of transferring the good quality frozen embryo on day 4 (39.2 %). There was no significant difference in the chemical pregnancy rate related to the number of transferred embryos (p = 0.55). The higher PRs, when the embryos were transferred on day 4, provided further support for the morula stage embryo transfer, possibly because of better synchrony with the endometrium. It is concluded that morula/compact embryos are good candidates for embryo transfer, which simultaneously reduces the number of transferred embryos.

Zygote wishes to inform its readers that its Editor-in-Chief has decided to retract the above article after an investigation carried out in compliance with the Committee on Publication Ethics guidelines found that the authors duplicated substantial parts of the following two articles:

1. 1. Kim H, Yamanouchi K, Nishihara M. (2006) Expression of ski in the granulosa cells of atretic follicles in the rat ovary. J. Reprod. Dev. 52, 715–721

2. 2. Kim H, Yamanouchi K, Matsuwaki T, Nishihara M. (2012) Induction of Ski protein expression upon luteinization in rat granulosa cells without a change in its mRNA expression. J. Reprod. Dev. 58, 254–259

Sloan-Kettering virus gene, a product of a cellular proto-oncogene c-Ski is a unique nuclear pro-oncoprotein and belongs to the Ski/Sno proto-oncogene family. The aim of the present study was to locate Ski protein in rat ovaries in order to find insights into the possible involvement of Ski in follicular development. First, expression of c-Ski mRNA in the ovaries of adult female rats was confirmed by RT-PCR. Then, ovaries obtained on the day of estrus were subjected to immunohistochemical analysis for Ski and proliferating cell nuclear antigen (PCNA) in combination with terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). RT-PCR and in situ hybridization revealed that c-Ski mRNA was expressed in the ovaries of the adult rat on the day of estrous and localized mainly in the granulose cells. Ski was expressed in granulosa cells that were positive for TUNEL, but negative for PCNA, regardless of the shape and size of follicles. Expression of Ski in TUNEL-positive granulosa cells, but not in PCNA-positive granulosa cells, was also verified in rats having atretic follicles with double staining. These results indicate that Ski is profoundly expressed in the granulosa cells of atretic follicles, but not in growing follicles. Based on the present findings, Ski may play a role in the apoptosis of granulosa cells during follicular atresia.