Search

MicroRNAs (miRNAs) and mRNAs can serve as indicators of the chromosomal state of an embryo, with different profiles observed in euploid and aneuploid blastocysts. Examining the levels of miRNAs associated with aneuploidy and euploidy, as well as mRNAs related to implantation, can aid in predicting blastocyst chromosomal normality and improving assisted reproductive technology (ART) outcomes. This study analyzed chromosomal abnormality of 25 blastocysts using fluorescence in situ hybridization (FISH) and also the expression of genes ERBB4, SELL, ITGB3, and ITGAV, as well as miRNAs, miR-339, miR-27b, miR-661, miR-30c, miR-191, miR-345, miR-142, miR-141, miR-20a, and miR-372. We found that 17 out of 25 embryos were aneuploid. Moreover, results revealed lower expression levels of miR-30c and miR-372 in aneuploid embryos compared to euploid ones, while ITGAV and ITGB3 showed significantly higher expression in aneuploid embryos. These findings suggest that miR-372, miR-30c, ITGAV, and ITGB3 expression in trophectoderm cells can serve as biomarkers for assessing embryo health. [ABSTRACT FROM AUTHOR]

STUDY QUESTION Are machine learning methods superior to traditional statistics in predicting blastocyst ploidy status using morphokinetic and clinical biodata? SUMMARY ANSWER Mixed effects logistic regression performed better than all machine learning methods for ploidy prediction using our dataset of 8147 embryos. WHAT IS KNOWN ALREADY Morphokinetic timings have been demonstrated to be delayed in aneuploid embryos. Machine learning and statistical models are increasingly being built, however, until now they have been limited by data insufficiency. STUDY DESIGN, SIZE, DURATION This is a multicentre cohort study. Data were obtained from 8147 biopsied blastocysts from 1725 patients, treated from 2012 to 2020. PARTICIPANTS/MATERIALS, SETTING, METHODS All embryos were cultured in a time-lapse system at nine IVF clinics in the UK. A total of 3004 euploid embryos and 5023 aneuploid embryos were included in the final verified dataset. We developed a total of 12 models using four different approaches: mixed effects multivariable logistic regression, random forest classifiers, extreme gradient boosting, and deep learning. For each of the four algorithms, two models were created, the first consisting of 22 covariates using 8027 embryos (Dataset 1) and the second, a dataset of 2373 embryos and 26 covariates (Dataset 2). Four final models were created by switching the target outcome from euploid to aneuploid for each algorithm (Dataset 1). Models were validated using internal–external cross-validation and external validation. MAIN RESULTS AND THE ROLE OF CHANCE All morphokinetic variables were significantly delayed in aneuploid embryos. The likelihood of euploidy was significantly increased the more expanded the blastocyst (P  < 0.001) and the better the trophectoderm grade (P  < 0.01). Univariable analysis showed no association with ploidy status for morula or cleavage stage fragmentation, morula grade, fertilization method, sperm concentration, or progressive motility. Male age did not correlate with the percentage of euploid embryos when stratified for female age. Multinucleation at the two-cell or four-cell stage was not associated with ploidy status. The best-performing model was logistic regression built using the larger dataset with 22 predictors (F1 score 0.59 for predicting euploidy; F1 score 0.77 for predicting aneuploidy; AUC 0.71; 95% CI 0.67–0.73). The best-performing models using the algorithms from random forest, extreme gradient boosting, and deep learning achieved an AUC of 0.68, 0.63, and 0.63, respectively. When using only morphokinetic predictors the AUC was 0.61 for predicting ploidy status, whereas a model incorporating only embryo grading was unable to discriminate aneuploid embryos (AUC = 0.52). The ploidy prediction model's performance improved with increasing age of the egg provider. LIMITATIONS, REASONS FOR CAUTION The models have not been validated in a prospective study design or yet been used to determine whether they improve clinical outcomes WIDER IMPLICATIONS OF THE FINDINGS This model may aid decision-making, particularly where pre-implantation genetic testing for aneuploidy is not permitted or for prioritizing embryos for biopsy. STUDY FUNDING/COMPETING INTEREST(S) No specific funding was sought for this study; university funds supported the first author. A.Ca. is a minor shareholder of participating centres. TRIAL REGISTRATION NUMBER N/A. [ABSTRACT FROM AUTHOR]

Study Question: Can non-invasive imaging with fluorescence lifetime imaging microscopy (FLIM) detect metabolic differences in euploid versus aneuploid human blastocysts?Summary Answer: FLIM has identified significant metabolic differences between euploid and aneuploid blastocysts.What Is Known Already: Prior studies have demonstrated that FLIM can detect metabolic differences in mouse oocytes and embryos and in discarded human blastocysts.Study Design, Size, Duration: This was a prospective observational study from August 2019 to February 2020. Embryo metabolic state was assessed using FLIM to measure the autofluorescence metabolic factors nicotinamide adenine dinucleotide dehydrogenase together with nicotinamide adenine phosphate dinucleotide dehydrogenase (NAD(P)H) and flavin adenine dinucleotide (FAD). Eight metabolic FLIM parameters were obtained from each blastocyst (four for NAD(P)H and four for FAD): short (T1) and long (T2) fluorescence lifetime, fluorescence intensity (I) and fraction of the molecules engaged with enzymes (F). The redox ratio (NAD(P)H-I)/(FAD-I) was also calculated for each image.Participants/materials, Setting, Methods: This study was performed at a single academically affiliated centre where there were 156 discarded frozen blastocysts (n = 17 euploids; 139 aneuploids) included. Ploidy status was determined by pre-implantation genetic testing for aneuploidy (PGT-A). Discarded human blastocysts were compared using single FLIM parameters. Additionally, inner cell mass (ICM) and trophectoderm (TE) were also evaluated. Multilevel models were used for analysis. A post-hoc correction used Benjamini-Hochberg's false discovery rate, at a q-value of 0.05.Main Results and the Role Of Chance: Comparing euploid (n = 17) versus aneuploid (n = 139) embryos, a significant difference was seen in NAD(P)H-F (P < 0.04), FAD-I (P < 0.04) and redox ratio (P < 0.05). Euploid ICM (n = 15) versus aneuploid ICM (n = 119) also demonstrated significantly different signatures in NAD(P)H-F (P < 0.009), FAD-I (P < 0.03) and redox ratio (P < 0.03). Similarly, euploid TE (n = 15) versus aneuploid TE (n = 119) had significant differences in NAD(P)H-F (P < 0.0001) and FAD-I (P < 0.04).Limitations, Reasons For Caution: This study utilized discarded human blastocysts, and these embryos may differ metabolically from non-discarded human embryos. The blastocysts analysed were vitrified after PGT-A biopsy and it is unclear how the vitrification process may affect the metabolic profile of blastocysts. Our study was also limited by the small number of rare donated euploid embryos available for analysis. Euploid embryos are very rarely discarded due to their value to patients trying to conceive, which limits their use for research purposes. However, we controlled for the imbalance with the bootstrap resampling analysis.Wider Implications Of the Findings: These findings provide preliminary evidence that FLIM may be a useful non-invasive clinical tool to assist in identifying the ploidy status of embryos.Study Funding/competing Interest(s): The study was supported by the Blavatnik Biomedical Accelerator Grant at Harvard University. Becker and Hickl GmbH and Boston Electronics sponsored research with the loaning of equipment for FLIM. D.J.N. is an inventor on patent US20170039415A1. There are no other conflicts of interest to declare.Trial Registration Number: N/A. [ABSTRACT FROM AUTHOR]

Can cumulus cells be used as a non-invasive target for the study of determinants of preimplantation embryo quality? Cumulus cells were collected from monosomy 21, trisomy 21 and euploid embryos and subjected to RNA sequencing analysis and real-time polymerase chain reaction assays. The differential gene expression was analysed for different comparisons. A total of 3122 genes in monosomy 21 cumulus cells and 19 genes in trisomy 21 cumulus cells were differentially expressed compared with euploid cumulus cells. Thirteen of these genes were differentially expressed in both monosomy and trisomy 21, compared with euploid, including disheveled segment polarity protein 2 (DVL2) , cellular communication network factor 1 (CCN1/CYR61) and serum response factor (SRF), which have been previously implicated in embryo developmental competence. In addition, ingenuity pathway analysis revealed cell–cell contact function to be affected in both monosomy and trisomy 21 cumulus cells. These findings support the use of cumulus cell gene expression analysis for the development of biomarkers evaluating oocyte quality for patients undergoing fertility preservation of oocytes. [Display omitted] [ABSTRACT FROM AUTHOR]

Tritipyrum is prone to mitotic instability, stiff straw and low fertility. A complete randomized design was used to evaluate morphological diversity, fertility and grain yield of 7 new synthetic Tritipyrum lines and their F1 offspringsin a cross with bread wheat. Fertility, harvest index, biological yield, 1000-grains weight (TGW) and grain yield of Tritipyrum derived genotypes were significantly lower than bread wheat and Triticale. The morphology of Tritipyrum was found to be similar with wheat lines and hybridization between Tritipyrum and bread wheat was efficient for developing early maturelines and reducing stiff straw and plant height. Results showed that mitotic instability in small size grains (TGW< 30 g) were significantly higher than heavy grains (TGW> 30 g) in both parental and F2progenies .Euploidyof Tritipyrum derived genotypes were significantly lower than Triticale and bread wheat. Results suggested that the larger and heavier grains show higher frequency of euploidy and that can be useful for maintenance of the genetic stability of Tritipyrum genotypes. Tritipyrum as a new man made cereal is a good genetic resource for wheat breeding and may complements the role of bread wheat wherever environmental condition is not suitable for wheat cultivation.

Aneuploidy is common and may be a natural occurrence in early human embryos. Selecting against embryos containing aneuploid cells for embryo transfer has been reported to increase clinical pregnancies per transfer in some studies, but not others. Some aneuploidy is due to misallocation of chromosomes during meiosis, in either the egg or sperm, but most aneuploidy is due to misallocation of chromosomes during mitoses after fertilization. Big questions are as follows: Why does this happen? How much aneuploidy in a preimplantation embryo is compatible with normal fetal development? Is aneuploidy increased by in vitro culture, and/or could it be prevented or corrected in the IVF lab? [ABSTRACT FROM AUTHOR]

Tritipyrum is prone to mitotic instability, stiff straw and low fertility. A complete randomized design was used to evaluate morphological diversity, fertility and grain yield of 7 new synthetic Tritipyrum lines and their F1 offspring'sin a cross with bread wheat. Fertility, harvest index, biological yield, 1000-grains weight (TGW) and grain yield of Tritipyrum derived genotypes were significantly lower than bread wheat and Triticale. The morphology of Tritipyrum was found to be similar with wheat lines and hybridization between Tritipyrum and bread wheat was efficient for developing early maturelines and reducing stiff straw and plant height. Results showed that mitotic instability in small size grains (TGW< 30 g) were significantly higher than heavy grains (TGW> 30 g) in both parental and F2progenies .Euploidyof Tritipyrum derived genotypes were significantly lower than Triticale and bread wheat. Results suggested that the larger and heavier grains show higher frequency of euploidy and that can be useful for maintenance of the genetic stability of Tritipyrum genotypes. Tritipyrum as a new man made cereal is a good genetic resource for wheat breeding and may complements the role of bread wheat wherever environmental condition is not suitable for wheat cultivation. [ABSTRACT FROM AUTHOR]

• Allotriploid lilies usually have partial female-fertility regardless of their male-sterility. • Lilium produce Fritillaria-type embyo sacs (tetrasporic embryo sacs), which are different from Polygonum embryo sacs (monsporic embryo sacs). • The hypothesis, " The five same genomes is essential for its endosperm development in interploid hybridizations of Lilium ", could guide breeders how to combine different lily genomes into one cultivar. • The hypothesis would be applied to other Fritillaria-type plant breeding because they have the same type of embryo sacs as Lilium. Based on previous publications, allotriploid (LLO) lily 'Triumphator' is seemingly exceptional to the hypothesis – five same genomes is essential for its endosperm development in interploid hybridizations of Lilium, because it could be hybridized with TTTT, OTOT, or even AA;however, no LLO × LL is used as control in these reports, and its abnormal meiosis is unknown. In order to confirm the speciality, the present research investigated 'Triumphator' (LLO, 2 n = 3 x = 36) for its microsporogenesis, female fertility and its progenies' genome composition. The results of its microsporogenesis showed that the homologous chromosomes of two L-genomes formed bivalents; the chromosomes of O-genome formed univalents, suggesting that intergenomic recombination between L-genome and O-genome hardly occur. This was the reason for that no intergenomic recombinant chromosome was found in its progenies. Interploid hybridizaitons showed that the LLO × LL was much more successful than LLO × TT/OO, strongly suggesting that 'Triumphator' is not exceptional to the lily five same genomes of endosperm hypothesis because the endosperm genomes of LLO × LL, LLO × TT and LLO × OO are 5L + 2O, 4L + 2O + T and 4L + 3O, respectively, i.e. only the endosperm of LLO × LL containing 5 same genomes (5 L). The hypothesis is highly valuable to guide lily breeding. [ABSTRACT FROM AUTHOR]

Despite the high number of recent studies, conflicting data are reported, and there is still considerable disagreement regarding which morphokinetic parameters are useful to predict blastocyst formation, implantation potential and ploidy status of the embryo. The first attempt to develop a model predicting embryo implantation used the time of division to 5 cells, the time between division from 3 to 4 cells and the time between division from 2 to 3 cells (Meseguer et al., 2011). More recently, the aneuploidy status of embryos was related to the start of blastulation and the formation of a full blastocyst. The aneuploidy risk classification built proved beneficial in a correlation with live birth when applied to non-biopsied embryos (Campbell et al., 2013). This retrospective study was based on 1550 blastocysts which were subjected to preimplantation genetic testing for aneuploidy (PGT-A) between August 2011 and December 2018 in Istanbul Memorial Hospital (n=659 euploids; n=831 aneuploids; n=60 mosaics). Incubation was performed in time-lapse incubators (EmbryoScope™). All relevant events (fertilization, cleavages, morula and blastocyst formation) were checked daily, and time of cleavage to two-cell embryo (t2) and subsequent divisions t3, t4, t5, t6, t7, t8, t9+, tM, tSB, tB and tEB were recorded in the EmbryoViewer® workstation. PGT-A was done by NGS ReproSeq on Ion Torrent S5 (Thermo Fisher Scientific) or aCGH (Illumina) following trophectoderm biopsy. Mann-Whitney U and Kruskal Wallis tests were used in this study. When euploid embryos were compared with aneuploids, the time to reach the blastocyst stage was 3 hours earlier in euploids (tB=104.60h vs. 107.64h; p<0.0001). Interestingly, euploids and mosaics were found to have a similar morphokinetic behavior; for example, t2 was 25.6h in euploids and mosaics, and 26.3h in aneuploids (p=0.006). Aneuploids were then subdivided into five groups: 2-chromosome aneuploidies, complex aneuploidies, monosomies, trisomies and partial aneuploidies. The sub-analysis done for the time of the first cleavage t2 was statistically significant (p=0.021) and showed that euploids were different from 2-chromosome aneuploids and from complex aneuploids; complex aneuploids were different from mosaics which were different from partial aneuploids; two-chromosome aneuploids were different from mosaics and from trisomies. A second subgroup analysis was done for the time to achieve the 8-cell stage (t8) and showed that euploids are statistically significantly different from all aneuploid subcategories but not from mosaics (p=0.0017). The mosaic embryos' morphokinetic parameters were similar with the euploid blastocysts. Observed time-lapse differences between euploid and aneuploid blastocysts suggests that the embryos are being affected by the chromosomal constitution throughout the embryo development. Even though the variances at the initial cleavages are as short as half an hour, this increases to a three hour at the blastocyst stage. The study presented above can be used to prioritize the embryos according to the morphokinetic variables to biopsy and diagnose the embryos with highest chance of being euploid thus reducing the costs especially for couples who have more than one blastocyst. [ABSTRACT FROM AUTHOR]

Background: The growing use of preimplantation genetic testing with in vitro fertilization has provided clinicians with more information about the genetics of embryos. Embryos, however, sometimes result with a mixed composition of both aneuploid and euploid cells, called mosaic embryos. The interpretation of these results has varied, leading some clinicians to transfer mosaic embryos and some opt not to. In addition, laboratories providing preimplantation genetic testing for aneuploidy have differing thresholds for determining an embryo aneuploid, mosaic, or euploid. Overall practice patterns for mosaic embryo transfer practices in the United States are unknown.Objective(s): The objectives of the study were to characterize national mosaic embryo transfer practices, including the use of preimplantation genetic testing for aneuploidy, prior history of transferring mosaic embryos, thresholds for determining mosaicism, and willingness to transfer mosaic embryos among assisted reproductive technology clinics in the United States.Study Design: A 14 question online survey assessing current use of preimplantation genetic testing for aneuploidy, thresholds for determining mosaicism, and clinic experience and willingness to transfer mosaic embryos was e-mailed to 405 assisted reproductive technology clinics across the United States. Descriptive statistics and logistic regression were used to analyze survey responses and identify clinical factors associated with reporting having ever transferred a mosaic embryo.Results: Of the 405 US assisted reproductive technology clinics contacted, 252 (62.2%) completed a survey, including 157 private (62.3%), 55 academic (21.8%), and 40 hybrid (15.9%) clinics. Most clinics (168, 66.7%) reported conducting preimplantation genetic testing for aneuploidy on less than 50% of all in vitro fertilization cycles. The most common type of preimplantation genetic testing for aneuploidy technology used was next-generation sequencing at 88.9%. Ninety-one clinics (36.1%) receive mosaicism data on their preimplantation genetic testing for aneuploidy report; the most common thresholds for determining embryo aneuploidy and euploidy by clinics' primary genetics laboratories were <20% normal (36.3%) and >80% normal (46.2%), respectively. Thirty-nine (42.9%) of the 91 have transferred and 57 (62.6%) would transfer a mosaic embryo. Nearly 40% of clinics were unsure about their thresholds for mosaic transfer and one fourth of clinics reported they had no threshold. Private (odds ratio, 1.0, 95% confidence interval, 0.5-1.8) and hybrid (odds ratio, 0.9, 95% confidence interval, 0.4-2.1) clinics were just as likely as academic clinics to report having transferred a mosaic embryo. Clinics in the northeastern United States were more likely to have transferred a mosaic embryo than clinics in other regions (odds ratio, 1.5, 95% confidence interval, 0.9-2.7). Most clinics (72.6%) report they do not have a unique consent for transfer of mosaic embryos.Conclusion: There is uncertainty and variability in the transfer practices of mosaic embryos and classification of mosaicism among US assisted reproductive technology clinics. These findings provide an opportunity to establish mosaicism thresholds and create standardized guidelines for transferring mosaic embryos. [ABSTRACT FROM AUTHOR]