Effects of different stocking densities on the development of reproductive and immune functions in young breeder pigeons during the rearing period

1. Stocking density (SD) is closely related to animal performance. This experiment was designed to evaluate the development of reproductive and immune functions of young pigeons under different SDs.2. A total of 288 (half male and half female) 40-day-old pigeons (body weight 400 ± 15 g) were allocated into four groups: High stocking density (HSD; 0.308 m3/bird), standard stocking density (SD; 0.616 m3/bird), and low stocking density (LSD; 1.232 m3/bird) and a caged (control; 0.04125 m3/bird). Every group had six replicates of the same sex.3. The results showed that caged male pigeons had the highest testis index, testosterone content, and gene expression of the androgen receptor gene. LSD treatment induced the highest concentrations of oestradiol, progesterone and mRNA levels of reproductive hormone receptor genes in female pigeons. In male pigeons, the spleen index (organ weight calculated as a percentage of total body weight) showed a peak level (0.09 ± 0.020) in the LSD group, and the thymus index peaked (0.23 ± 0.039) in SD group. However, the index for ovary, spleen, thymus and bursa of Fabricius in female pigeons showed no significant changes among different groups.4. The IL-1β, IL-8, IFN-γ, TGF-β and toll-like receptor 2 (TLR-2) mRNA levels reached their maximum values in both male and female pigeon spleens in the LSD group.5. Young male pigeons housed in cages showed increased testicular development while low stocking density increased the development of reproductive function in young female pigeons. A larger activity space could help enhance the immune function of both male and female pigeons.

Prenyllongnols A-D, New Prenylated Acylphloroglucinols that Fight Concanavalin A-Induced Autoimmune Hepatitis

Autoimmune hepatitis is a serious hepatic disorder with unknown nosogenesis, and natural products have been deemed to be one of the most significant sources of new drugs against this disease. Prenyllongnols A-D (1-4), four undescribed prenylated acylphloroglucinols, were isolated from Hypericum longistylum. Compounds 1-4 exhibited remarkable immunosuppressive activities in murine splenocyte proliferation under the induction of concanavalin A (Con A), and IC50 values ranged from 2.98 ± 0.21 to 6.34 ± 0.72 μM. Furthermore, in a Con A-challenged autoimmune hepatitis mouse model, the mice in the group that were pretreated with isolate 2 significantly ameliorated liver injury and decreased proinflammatory cytokine production. Notably, natural product 2 was the first prenylated acylphloroglucinol to protect against concanavalin A-induced autoimmune hepatitis. This finding underscores the potential of prenylated acylphloroglucinol-type metabolites as promising candidates for designing novel immunosuppressors in the quest for new antiautoimmune hepatitis drugs.

Expression of ICAM-1 and E-selectin in different metabolic obesity phenotypes: discrepancy for endothelial dysfunction

OBJECTIVES

Endothelial dysfunction, the earliest vascular alteration, is a consequence of metabolic disorders associated with obesity. However, it is still unclear whether a proportion of obese individuals without metabolic alterations associated with obesity, defined as "metabolically healthy obesity (MHO)", exhibit better endothelial function. We therefore aimed to investigate the association of different metabolic obesity phenotypes with endothelial dysfunction.

METHODS

The obese participants without clinical cardiovascular disease from the MESA (Multi-Ethnic Study of Atherosclerosis) were allocated to the different metabolic obesity phenotypes based on their metabolic status, including MHO and metabolically unhealthy obesity (MUO). Associations of metabolic obesity phenotypes with the biomarkers of endothelial dysfunction, including soluble intercellular adhesion molecule-1 (sICAM-1) and soluble E-selectin (sE-selectin), were evaluated using multiple linear regression models.

RESULTS

Plasma levels of sICAM-1 and sE-selectin were respectively measured in 2371 and 968 participants. Compared to the non-obese participants, those with MUO were associated with higher concentrations of sICAM-1 (β 22.04, 95% CI 14.33-29.75, P < 0.001) and sE-selectin (β 9.87, 95% CI 6.00-13.75, P < 0.001) after adjusting for confounders. However, no differences were found for the concentrations of sICAM-1 (β 0.70, 95% CI - 8.91 to 10.32, P = 0.886) and sE-selectin (β 3.69, 95% CI - 1.13 to 8.51, P = 0.133) in the participants with MHO compared to the non-obese participants.

CONCLUSIONS

Individuals with MUO were associated with elevated biomarkers of endothelial dysfunction, but the association with endothelial dysfunction was not found in those with MHO, indicating that the individuals with MHO might exhibit better endothelial function.

The Predictive Value of Circulating Exosomal PD-L1 in Cervical Cancer Immunotherapy

PURPOSE/OBJECTIVE(S)

Programmed death ligand 1 (PD-L1) expression was wildly used as a predictor of immune Check-Point Inhibitors (ICIs) efficiency. However, emerging results showed that PD-L1 was of great heterogeneity in sampling time and site. Recently, some studies found that exosomal PD-L1(ExoPD-L1) was related to ICIs response. In this study, we aimed to explore the predictive value of ExoPD-L1 in ICIs treatment of cervical cancer (CC) for the first time.

MATERIALS/METHODS

A total of 40 primarily diagnosed CC patients who accepted radical radiotherapy (RT) from March 2021 to October 2022 were included. The consecutive tumor sample were collected before and during RT. Another 37 advanced CC patients who accepted ICIs combination therapy from June 2020 to October 2022 were enrolled in this study. Blood samples were collected from each participant before and during treatment. Exosomes were derived by differential centrifugation, which was further identified by Western blot (WB) (CD9/TSG101/Calnexin), transmission electron microscope analysis and nanoparticle tracking analysis. ExoPD-L1 detection was conducted by enzyme-linked immuno-sorbent assay (ELISA). The knockout of PD-L1 was conducted via CRISPR/Cas9 assay and the overexpress of PD-L1 was conducted by lentiviral transfection. CD8+ T cells were extracted from murine spleen by CD8+ T Cell Isolation Kit. Immune cells and cytokines markers were detected by multicolor flow cytometry.

RESULTS

The consecutive detection of PD-L1 showed a dynamic change during RT. Compared with the level before RT, PD-L1 expression elevated in most patients (87.5%, 35/40) after RT. And the responders (n = 18) had elevated ExoPD-L1 level at the first two circles in the ICIs combination therapy (P<0.001). Whereas the level of pre-treatment ExoPD-L1 couldn't stratified clinical responders and non-responders (P = 0.181). The median follow-up time was 14.13 months. The mPFS in increased group vs. decreased group: not reach vs.11.02 months (P = 0.025, HR: 0.218, 0.052-0.913). Continuous blood sampling of mice models also found that effective therapeutic intervention could increase ExoPD-L1 in the early stage. The combination of exosome inhibitor GW4869 and anti-PD-1 further inhibited tumor growth. Mice were injected with external ExoPD-L1OE and ExoPD-L1KO. The results showed that ExoPD-L1OE suppressed body immunity and promoted tumor growth. The results of flow cytometry showed that ExoPD-L1OE inhibited CD8+ T cells from releasing interferon-and granzyme B. And ExoPD-L1OE also suppressed the CD8+ T cells proliferation in murine spleen. The coculture of CD8+ T cells and exosomes in vitro also confirmed the above conclusion.

CONCLUSION

Compared with unstable and impressionable tumoral PD-L1, ExoPD-L1 seems to be better predictor for the efficacy of immunotherapy in CC, which was with easy accessibility and continuation. Exosome PD-L1 played an immunosuppressive role by inhibiting the proliferation and functional factor release of CD8+ T cell.

Maintenance Therapy for Recurrent or Metastatic Cervical Cancer: A Multicenter, Cohort Study

PURPOSE/OBJECTIVE(S)

Maintenance therapy with alternative agents after chemotherapy was shown to improve the overall survival in some advanced cancers such as breast cancer, lung cancer, ovarian cancer and so on. However, maintenance therapy is not accepted as the standard treatment for recurrent/metastatic cervical cancer. Aim of this study is to elucidate the efficacy of maintenance therapy in cervical cancer and to explore the factors associated with the prognosis of recurrent or metastatic cervical cancer.

MATERIALS/METHODS

In this multicenter cohort study, we retrospectively collected patients with a diagnosis of either recurrent or stage IVB cervical cancer to receive first-line chemotherapy with or without maintenance therapy. Patients did not have disease progression with first-line chemotherapy and were divided into maintenance therapy group (Arm A) and conventional chemotherapy group (Arm B). Information on clinical characteristics, metastasis information, treatment outcome and survival of patients was collected using an electronic medical record system. The endpoints of the study were OS and PFS. Data were analyzed for general characteristics and survival using statistical software, and the results were considered statistically significant at P < 0.05.

RESULTS

Between January 2019 and July 2021, a total of 270 patients were enrolled from 6 institutions in China. 26 patients were excluded because of short treatment cycles (less than 3 cycles). Finally, a total of 66 patients in Arm A and 178 patients in Arm B were analyzed for survival. The addition of maintenance significantly prolonged overall survival. Overall survival at 3 year was 50.1% in Arm A and 27.8% in Arm B (median overall survival, ≥36 months vs. 22 months; P<0. 001). The median progression-free survival was 21 months in Arm A and 14 months in Arm B (P = 0.025). Univariate survival analysis showed that age, maintenance therapy, combined radiotherapy, and number of extra-pelvic metastases were associated with PFS. Further multifactorial analysis showed that maintenance therapy, combined radiotherapy, and number of extra-pelvic metastases were independent prognostic factors for patients with recurrent or metastatic cervical cancer.

CONCLUSION

The addition of maintenance therapy significantly prolonged overall survival as well as progression-free survival in patients with recurrent or metastatic cervical cancer and did not increase the incidence of serious adverse events. It is time to consider maintenance therapy as the standard treatment after conventional chemotherapy for recurrent or metastatic cervical cancer, rather than waiting for disease progression.

Effects of different stocking densities on organ development, blood biochemical indices, and antioxidative status of breeder pigeons during the rearing period

The present experiment was conducted to investigate the effect of different stocking densities on the organ development, blood biochemical indices, and antioxidative status of breeder pigeons during the rearing period. A total of 280 (half male and half female) 40-day-old young pigeons were allocated into 4 groups, including 3 experimental groups (in compartments of the flying room): the high stocking density (HSD) (0.308 m3/bird), standard stocking density (SD) (0.616 m3/bird), and low stocking density (LSD) (1.232 m3/bird) and a caged control (0.04125 m3/bird). The results showed that the contents of corticosterone and heat shock protein 70 in males and the corticosterone content in females were higher in the control than in the other groups. The relative weight of liver, lung, and gizzard in males of the HSD group was the highest among the 4 treatments, whereas the abdominal fat index in the control group was higher than those in the other 3 treatments. Body weight and the relative weight of liver and abdominal fat in female pigeons in HSD group increased significantly. The levels of serum urea nitrogen and uric acid in pigeons of LSD group increased significantly, while the concentration of total cholesterol and the activity of alanine aminotransferase were higher in the control group. Ion (K+, Ca2+, and Na+) concentrations in female pigeon serum were also elevated in the control. The activity of antioxidant enzymes, including the total antioxidant capacity, superoxide dismutase, and glutathione peroxidase in pigeon breast muscle and liver had different degrees of inhibition when the space room was crowded. Moreover, the level of malondialdehyde in the liver of male caged pigeons was higher than that in the other treatments. In summary, rearing in cages or at a high density caused stress responses in the breeder pigeons. The stocking density of breeder pigeons during the rearing period should be ranged from 0.616 m3/bird to 1.232 m3/bird.

[Therapeutic mechanism of Shenbing Decoction Ⅲ for renal fibrosis in chronic kidney disease: a study with network pharmacology, molecular docking and validation in rats]

OBJECTIVE

To observe the effect of Shenbing Decoction Ⅲ for improving renal function and pathology in rats with 5/6 nephrectomy and analyze its therapeutic mechanism for renal fibrosis in chronic kidney disease using network pharmacology combined with molecular docking.

METHODS

Forty male SD rats were randomized into two groups to receive two-staged 5/6 nephrectomy (n=30) or sham operation (n=10), and 2 weeks after the final operation, serum creatinine level of the rats was measured. The rats with nephrectomy were further randomized into Shenbing Decoction Ⅲ group, losartan group and model group for daily treatment with the corresponding drugs via gavage starting at 1 week after 5/6 nephrectomy. After 16 weeks of treatment, serum creatinine and urea nitrogen levels of the rats were measured, and HE staining and Western blotting were used to examine the changes in renal pathology and fibrosis-related factors. Network pharmacology combined with molecular docking study was performed to explore the therapeutic mechanism Shenbing Decoction Ⅲ against renal fibrosis in chronic kidney disease, and Western blotting was used to verify the expressions of the core targets.

RESULTS

Compared with those in the model group, the rats receiving 5/6 nephrectomy and Shenbing Decoction Ⅲ treatment showed significantly reduced serum creatinine and urea nitrogen levels, lessened renal pathologies, and improvement of the changes in epithelial mesenchymal transition-related proteins. Network pharmacological analysis showed that the main active ingredients of Shenbing Decoction Ⅲ were acacetin, apigenin, eupatilin, quercetin, kaempferol and luteolin, and the key targets included STAT3, SRC, CTNNB1, PIK3R1 and AKT1. Molecular docking study revealed that the active ingredients of Shenbing Decoction Ⅲ had good binding activity to the key targets. Western blotting showed that in rats with 5/6 nephrectomy, treatment with Shenbing Decoction Ⅲ obviously restored the protein expression of STAT3, PI3K, and AKT in renal tissue.

CONCLUSION

Shenbing Decoction Ⅲ can reduce renal injury induced by 5/6 nephrectomy in rats, and its therapeutic effects are mediated possibly by its main pharmacologically active ingredients that alleviate renal fibrosis via modulating multiple targets including STAT3, PIK3R1, and AKT1.

Evaluation of CT angiography obstruction score and pulmonary perfusion defect score using the third-generation dual-source CT for pulmonary embolism

AIM

To investigate the application value of computed tomography (CT) angiography (CTA) obstruction score and pulmonary perfusion defect score on the third-generation dual-source CT for pulmonary embolism and the changes of the right ventricular function.

MATERIALS AND METHODS

The clinical data of 52 patients with pulmonary embolism (PE) confirmed using the third-generation dual-source dual-energy CTPA were analysed retrospectively. These patients were divided into the severe group and non-severe group according to their clinical manifestations. The results of CTPA and dual-energy pulmonary perfusion imaging (DEPI) were recorded by two radiologists for index computation. The ratio of the maximum short-axis diameter of the right ventricle (RV) to that of the left ventricle (LV) was also recorded. The correlation analysis between RV/LV and the mean values of CTA obstruction score and perfusion defect score was performed. Correlation analysis and agreement analysis were performed on the data measured by two radiologists, CTA obstruction score, and pulmonary perfusion defect score.

RESULTS

CTA obstruction score and perfusion defect score measured by the two radiologists had good correlation and agreement. CTA obstruction score, perfusion defect score, and RV/LV were significantly lower in the non-severe group than in the severe PE group. RV/LV had a significant positive correlation with CTA obstruction score and perfusion defect score (p<0.05).

CONCLUSION

The third-generation dual-source dual-energy CT plays a positive role in assessing PE severity and RV function and can provide additional information for the clinical management and treatment of PE patients.

ERK Inhibition Promotes Engraftment of Allografts by Reprogramming T-Cell Metabolism

Extracellular regulated protein kinases (ERK) signaling is a master regulator of cell behavior, life, and fate. Although ERK pathway is shown to be involved in T-cell activation, little is known about its role in the development of allograft rejection. Here, it is reported that ERK signaling pathway is activated in allograft-infiltrating T cells. On the basis of surface plasmon resonance technology, lycorine is identified as an ERK-specific inhibitor. ERK inhibition by lycorine significantly prolongs allograft survival in a stringent mouse cardiac allotransplant model. As compared to untreated mice, lycorine-treated mice show a decrease in the number and activation of allograft-infiltrated T cells. It is further confirmed that lycorine-treated mouse and human T cells are less responsive to stimulation in vitro, as indicated by their low proliferative rates and decreased cytokine production. Mechanistic studies reveal that T cells treated with lycorine exhibit mitochondrial dysfunction, resulting in metabolic reprogramming upon stimulation. Transcriptome analysis of lycorine-treated T cells reveals an enrichment in a series of downregulated terms related to immune response, the mitogen-activated protein kinase cascade, and metabolic processes. These findings offer new insights into the development of immunosuppressive agents by targeting the ERK pathway involved in T-cell activation and allograft rejection.

Nomogram for predicting axillary upstaging in clinical node-negative breast cancer patients receiving neoadjuvant chemotherapy

PURPOSE

The prediction of axillary lymph node status after neoadjuvant chemotherapy (NAC) becoming critical because of the advocation of the de-escalation of axillary management. We investigate associated factors of axillary upstaging in clinical node-negative (cN0) breast cancer patients receiving NAC to develop and validate an accurate prediction nomogram.

METHODS

We retrospectively analyzed 1892 breast cancer patients with stage of cT1-3N0 treated by NAC and subsequent surgery between 2010 and 2020 in twenty hospitals across China. Patients randomly divided into a training set and validation set (3:1). Univariate and multivariate logistic regression analysis were performed, after which a nomogram was constructed and validated.

RESULTS

In total, pathologic node negativity (ypN0) achieved in 1406 (74.3%) patients and another 486 (25.7%) patients upstaged to pathologic node positive (ypN+). Breast pathologic complete response (bpCR) was achieved in 445 (23.5%) patients and non-bpCR in 1447 (76.5%) patients. A nomogram was established by ER, tumor histology, HER2 status, cycle of NAC treatment, and the bpCR, which were confirmed by multivariate logistic analysis as independent predictors of nodal upstaging in the training cohort (n = 1419). The area under the receiver operating characteristic curve (AUC) of the training cohort and validation cohort (n = 473) were 0.73 (95% CI 0.693-0.751) and 0.77 (95% CI 0.723-0.812) respectively.

CONCLUSION

We present a nomogram with a nationwide large sample data which can effectively predict axillary upstaging after neoadjuvant chemotherapy to give better advice for individualized axillary lymph node management of breast cancer.

The nodal positivity rate in breast pCR patients with initially, clinically node-negative breast cancer after neoadjuvant systemic therapy: A systematic review and meta-analysis

Background

The axillary lymph node positive (ypN+) rate in patients with clinically node-negative (cN0) breast cancer who have achieved breast pathologic complete response (bpCR) after neoadjuvant systemic therapy (NST) is extremely low, and this population has the potential to be exempt from sentinel lymph node biopsy (SLNB). However, an overview of the ypN+ rate in this population for different breast cancer subtypes is lacking.

Objective

To provide the pooled ypN+ rate in cN0 patients who achieved bpCR after NST in different breast cancer subtypes defined by hormone receptor (HR) status and human epidermal growth factor receptor 2 (HER2) status.

Methods

A systematic literature search was conducted in Embase and PubMed on July 20, 2022. Two authors independently selected studies that met the inclusion criteria and extracted all data. The pooled ypN+ rates for each subtype were calculated by a random-effects model using the Stata 16.0 metaprop command.

Results

The pooled analysis of 9609 cN0 patients who achieved bpCR showed that the ypN+ rate was lowest for the HR+/HER2+ (0%) subtype, followed by HR+/HER2- (5.1%), HR-/HER2+ (0.6%), and HR-/HER2- (0.3%). Additionally, 6571 cT1-T2N0 patients who achieved bpCR had a pooled ypN+ rate of 0.6%, and the ypN+ rates for different subtypes were as follows: HR+/HER2+ (1.7%), HR+/HER2- (2.7%), HR-/HER2+ (0.1%), and HR-/HER2- (0.8%).

Conclusion

Our results suggested that cN0 patients who achieve bpCR may be exempt from axillary surgery in the HR+/HER2-, HR+/HER2+, and HR-/HER2- subtypes because of the extremely low probability of residual axillary lymph node disease. However, the safety of omitting axillary surgery needs to be further confirmed by prospective studies.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/#recordDetails, identifier CRD42022351739.

Evaluation of outcome of chemotherapy for breast cancer patients older than 70 years: A SEER-based study

Background

With the aging of the population, the number of elderly breast cancer cases has increased. However, there is a lack of effective randomized clinical trial data to support whether elderly patients should receive chemotherapy. Our goal was to observe the relationship between chemotherapy and breast cancer-specific survival (BCSS) in elderly breast cancer patients and to identify those who could benefit from chemotherapy.

Methods

We collected the data of patients who were diagnosed with invasive ductal carcinoma and older than 70 years in the SEER database from 1995 to 2016. The independent predictors of BCSS were identified by Cox regression analysis. Propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) were performed to eliminate confounding factors.

Results

A total of 142,537 patients were collected, including 21,782 patients in the chemotherapy group and 120,755 patients in the non-chemotherapy group. We identified the same potential predictors of BCSS after PSM and IPTW, such as age, race, grade, stage, therapy, subtype. A nomogram for predicting 3-year, 5-year and 10-year BCSS was constructed. The 3-year, 5-year and 10-year AUCs of the nomogram were 0.842, 0.819, and 0.788. According to the risk stratification of model predictive scores, patients in the high-risk group achieved the greatest improvement in BCSS after receiving chemotherapy.

Conclusions

Our study suggests that women older than 70 years with larger tumors, higher grade, positive nodes, negative hormone receptor and inactive local therapy gain prognostic benefits from chemotherapy, but for those with low- and median-risk, conventional chemotherapy should be administered cautiously.

Highly Efficient and Chemoselective Tandem Hydroformylation‐Hydrogenation of Alkenes to Alcohols over g‐CN Supported Bimetallic Rh and Co Nanoparticles Catalysts

The objective of the tandem hydroformylation-hydrogenation of alkenes to corresponding alcohols was to design an efficient and stable heterogeneous catalyst. To this end, a series of novel heterogeneous graphitic carbon nitride (g-CN) supported bimetallic Rh-Co nanoparticle catalysts (Rh-Co/g-CN) were prepared and subsequently studied for this one-pot two-step reaction. The lamellar structure makes Rh and Co nanoparticles with diameters of <1 nm and 20 nm, respectively, homogeneously deposited on the surface of g-CN layers, exhibit remarkable conversion of styrene (99.9 %) and chemoselectivity for alcohol (87.8 %). More importantly, Co nanoparticles are found to play an important role in the improvement of the chemoselectivity for alcohol due to the formation of catalytic active species [HCo(CO)_y ]. Besides the detailed investigation of the catalytic properties of Rh-Co/g-CN under different reaction conditions, the reuse of Rh-Co/g-CN was conducted for five times and no evident decrease in the activity and chemoselectivity was observed. Therefore, we expect that this work could offer an initial insight into g-CN-based heterogeneous catalyst on the tandem hydroformylation-hydrogenation reaction.

Inhibition of posterior capsule opacification by adenovirus-mediated delivery of short hairpin RNAs targeting TERT in a rabbit model

PURPOSE

Posterior capsule opacification (PCO) is the most common postoperative complication after cataract surgery and cannot yet be eliminated. Here, we investigated the inhibitory effects of telomerase reverse transcriptase (TERT) gene silencing on PCO in a rabbit model.

METHODS

After rabbit lens epithelial cells (LECs) were treated with adenovirus containing short hairpin RNAs (shRNA) targeting TERT (shTERT group), adenovirus containing scramble nonsense control shRNA (shNC group) or PBS (control group), quantitative real-time polymerase chain reaction and Western blotting were used to measure the expression levels of TERT, and a scratch assay was performed to assess the LEC migration. New Zealand white rabbits underwent sham cataract surgery followed by an injection of adenovirus carrying shTERT into their capsule bag. The intraocular pressure and anterior segment inflammation were evaluated on certain days, and EMT markers (α-SMA and E-cadherin) were evaluated by Western blotting and immunofluorescence. The telomerase activity of the capsule bag was detected by ELISA. At 28 days postoperatively, haematoxylin and eosin staining of the cornea and iris and electron microscopy of the posterior capsule were performed.

RESULTS

Application of shTERT to LECs downregulated the expression levels of TERT mRNA and protein. The scratch assay results showed a decrease in the migration of LECs in the shTERT group. In vivo, shTERT decreased PCO formation after cataract surgery in rabbits and downregulated the expression of EMT markers, as determined by Western blotting and immunofluorescence. In addition, telomerase activity was suppressed in the capsule bag. Despite slight inflammation in the iris, histologic results revealed no toxic effects in the cornea and iris.

CONCLUSION

TERT silencing effectively reduces the migration and proliferation of LECs and the formation of PCO. Our findings suggest that TERT silencing may be a potential preventive strategy for PCO.

[Analysis of morphometric changes in the anterior alveolar bone in bimaxillary protrusion adult patients after retraction with cone-beam CT]

Objective: To measure and analyze the morphometric changes in the anterior alveolar bone during treatment and retention stage after retraction in bimaxillary adults using cone-beam CT(CBCT). Methods: Fifteen adult patients, four males and 11 females, aged 19 to 28 years[(22.2±3.1) years], who have completed orthodontic treatment and extracted four first premolar teeth for retraction in the Department of Orthodontics, The Affiliated Stomatological Hospital of Nanchang University from January 2016 to December 2018 were selected. CBCT was taken to assess the labial and palatal vertical bone level, total bone thickness at crest area, middle root area and apical area in pre-treatment (T1), post-treatment (T2) and at follow-up (maintained for more than two years) (T3). The differences in alveolar bone morphology at different stages were compared by single factor repeated measure ANOVA, and Pearson correlation analysis was performed on the amount of alveolar bone change in treatment stage and retention stage. Results: There were statistically significant differences in the alveolar bone height of the palatal side of maxillary anterior teeth, the labial side of maxillary lateral incisors and canine among three time points (P<0.05). The height difference of palatal alveolar bone of anterior teeth in T1-T2 stage was statistically significant (P<0.05). Palatal alveolar bone of upper and lower central incisors decreased by (1.52±0.32) and (4.96±0.46) mm, respectively. The height difference of anterior palatal alveolar bone was statistically significant in T2-T3 stage(P<0.05), the palatal alveolar bone height of central incisors increased by (1.20±0.27) and (3.14±0.35) mm respectively. The height difference of palatal alveolar bone in the anterior teeth of T1-T3 stage was statistically significant (P<0.05), and the height of palatal alveolar bone of central incisors was decreased (0.33±0.11) and (1.82±0.39) mm, respectively. There were statistically significant differences in the thickness of the cervical and middle root alveolar bone of anterior teeth among three time points (P<0.05). The difference of alveolar bone thickness of the cervical and middle root of anterior teeth at T1-T2 was statistically significant (P<0.05). decreased by (0.63±0.10) and (0.67±0.09) mm in lateral incisors, respectively. In the T2-T3 stage, the alveolar bone thickness of the crest area of the lower anterior teeth was significantly different (P<0.05), the alveolar bone thickness of mandibular central incisor crest area increased (0.09±0.03) mm. There were statistically significant differences in alveolar bone thickness in crest area and middle root of the incisors during T1-T3 stage (P<0.05), among which the middle root decreased by (0.38±0.16) mm and (0.63±0.13) mm, respectively. There was no statistically significant difference in other areas (P>0.05). The change of alveolar bone height in palatal side of upper anterior teeth at T2-T3 was very strongly negatively correlated with the change in T1-T2. The change of alveolar bone height in labial side of upper anterior teeth and lingual side of lower anterior teeth and the thickness of incisor root and neck were moderately strongly negatively correlated (r≤-0.8, P<0.001), the change of alveolar bone height in labial side of upper anterior teeth and lingual side of lower anterior teeth and the thickness of incisor crest area were moderately strongly negatively correlated (-0.8<r≤-0.4, P<0.05). Conclusions: For adult patients after retraction, anterior alveolar bone decreased significantly. In the retention stage, the same degree of bone apposition will occur, but still have alveolar bone loss compared with pre-treatment. The amount of alveolar bone change in the retention stage correlated with the amount of alveolar bone change in the treatment stage.

Dynamic changes in protein concentrations of keratins in crop milk and related gene expression in pigeon crops during different incubation and chick rearing stages

1. The objective of this study was to examine the keratin composition of crop milk, the variation of epithelial thickness and keratin (K) gene expression in samples from young pigeon during incubation and chick rearing.2. Crop milk was collected from 1-, 3- and 5-day-old squab crops for keratin content analysis. Results showed that K4 accounted for the highest proportion of all detected keratins.3. In total, 42 pairs of adult pigeons were allocated to seven groups according to different stages to collect crop samples. Gene expression studies showed that the K3 gene expression was maximised at rearing Day 15 (15) and R1 in males and females, respectively. K6a gene level was the greatest at R15 in females, whereas it peaked at incubation Day 4 (I4) in males. The K12, K13, K23 and K80 gene levels were inhibited at the peak period of crop milk formation in comparison with I4. In females, K cochleal expression peaked at I10, whereas it was the greatest at R25 in males. K4 and K14 gene expression was the highest at I10 in females, while K4 and K14 were minimised at I17 and R7 in males, respectively. Gene expressions of K5, K8, K19 and K20 in males and K19 in females were maximised at R1. The K5, K20 and K75 gene levels in females peaked at R7. K75 and K8 expressions in males and females reached a maximum value at R25 and I17, respectively.4. The epithelial thickness of male and female crops reached their greatest levels at R1 and had the highest correlation with K19.5. These results emphasised the importance of keratinisation in crop milk formation, and different keratins probably play various roles during this period. The K19 was probably a marker for pigeon crop epithelium development. The sex of the parent pigeon affected keratin gene expression profiles.

New Insight into the Concanavalin A-Induced Apoptosis in Hepatocyte of an Animal Model: Possible Involvement of Caspase-Independent Pathway

Concanavalin A (Con A) is known to be a T-cell mitogen and has been shown to induce hepatitis in mice through the triggering of conventional T cells and NKT cells. However, it remains unknown whether Con A itself can directly induce rapid hepatocyte death in the absence of a functional immune system. Here, by using an immunodeficient mouse model, we found Con A rapidly induced liver injury in vivo despite a lack of immunocyte involvement. We further observed in vitro that hepatocytes underwent a dose-dependent but caspase-independent apoptosis in response to Con A stimulation in vitro. Moreover, transcriptome RNA-sequencing analysis revealed that apoptosis pathways were activated in both our in vivo and in vitro models. We conclude that Con A can directly induce rapid but non-classical apoptosis in hepatocytes without the participation of immunocytes. These findings provide new insights into the mechanism of Con A-induced hepatitis.

[Effect of CKIP-1 on hepatocyte apoptosis in nonalcoholic fatty liver disease]

Objective: To explore the effect and underlying mechanism of casein kinase 2 interacting protein-1 (CKIP-1) on hepatocyte apoptosis in nonalcoholic fatty liver disease (NAFLD). Methods: Experimental study. An NAFLD cell model was established by inducing human hepatoma cell line, HepG₂ cells, with oleic acid (OA). Flag-CKIP-1 expression vector and shRNA-CKIP-1 were transfected into HepG₂ cells. Flow cytometry was used to detect the effect of CKIP-1 on the activity and apoptosis of NAFLD hepatocytes. The levels of apoptosis-related proteins were detected by Western blot. CKIP-1 knockout mice in C57BL/6 back-ground were fed with either standard or high-fat diet for 8 weeks. Apoptosis-related signal proteins in NAFLD hepatocytes were detected by immunohistochemistry. Results: After CKIP-1 was transfected into HepG₂ cells, the degree of OA induced cell liposis was significantly reduced (P<0.05). Annexin V-FITC/PI flow cytometry showed that CKIP-1 reduced the apoptosis of steatotic hepatocytes. Overexpression of CKIP-1 could significantly inhibit the expression of caspase-3 and caspase-9 and increase the expression of Bcl-2/Bax (P<0.05). Knockdown of CKIP-1 could increase the expression of caspase-3 and caspase-9 (P<0.05). CKIP-1 knockout could further increase the expression of caspase-3 and caspase-9 in NAFLD mice (P<0.01,P<0.05), and further decrease the expression of Bcl-2/Bax (P<0.05). Conclusion: CKIP-1 inhibited the apoptosis of steatotic hepatocytes by up-regulating the expression of apoptosis inhibitor gene, Bcl-2/Bax, and affecting the proteases, caspase-3 and caspase-9.

Lipid accumulation and oxidative stress in the crop tissues of male and female pigeons during incubation and chick-rearing periods

The current study aimed to evaluate the changes in lipid accumulation and oxidative status in pigeon crops during different breeding stages. Forty-two pairs of adult pigeons were randomly assigned to 7 groups. Lipid droplet accumulation in pigeon crops was visualized by using oil red O staining from d 17 of incubation (I17) to d 7 of chick rearing (R7). Transmission electron microscopy analysis showed swollen mitochondria with disintegration of cristae and typical characteristics of endoplasmic reticulum stress in crop tissues at R1 compared with those at I4. During the peak of pigeon milk formation, the concentrations of reactive oxygen species, and oxidative damage markers (advanced oxidation protein products, 8-hydroxy-2 deoxyguanosine, and malondialdehyde) and the enzyme activities of total superoxide dismutase and glutathione peroxidase were all elevated significantly (P < 0.05). The protein concentration of B-cell lymphoma-2 associated X in crop tissues was significantly higher at R1, while the level of B-cell lymphoma-2 protein in males was the highest at I4 (P < 0.05). The ratio of B-cell lymphoma-2 associated X protein (Bax)/B-cell lymphoma-2 (Bcl-2) in both male and female crops peaked at R1 (P < 0.05). Gene expression of the key enzymes involved in mitochondrial and peroxisomal fatty acid β-oxidation was investigated in crops. In males, the gene expression of carnitine palmitoyltransferase 1a peaked at R15, and that of carnitine palmitoyltransferase 2 increased significantly from R1 to R15 (P < 0.05). The mRNA abundance of long chain 3-hydroxyacyl-CoA dehydrogenase increased to the maximum value at R1 and I17 in males and females, respectively. From I17 to R7, the mRNA levels of acyl-CoA oxidase 1 and acyl-CoA oxidase 2 were decreased in pigeon crops (P < 0.05). Conclusively, lipid droplet accumulation was found in male and female pigeon crops from the end of incubation to the early stage of chick rearing. Although antioxidant defence and mitochondrial fatty acid β-oxidation were both mobilized, oxidative stress in crop tissues still occurred during the peak of milk formation.

Comprehensive analysis of cuproptosis-related genes and tumor microenvironment infiltration characterization in breast cancer

Background

Cuproptosis is a newly discovered programmed cell death dependent on overload copper-induced mitochondrial respiration dysregulation. The positive response to immunotherapy, one of the most important treatments for invasive breast cancer, depends on the dynamic balance between tumor cells and infiltrating lymphocytes in the tumor microenvironment (TME). However, cuproptosis-related genes (CRGs) in clinical prognosis, immune cell infiltration, and immunotherapy response remain unclear in breast cancer progression.

Methods

The expression and mutation patterns of 12 cuproptosis-related genes were systematically evaluated in the BRCA training group. Through unsupervised clustering analysis and developing a cuproptosis-related scoring system, we further explored the relationship between cuproptosis and breast cancer progression, prognosis, immune cell infiltration, and immunotherapy.

Results

We identified two distinct CuproptosisClusters, which were correlated with the different patterns between clinicopathological features, prognosis, and immune cell infiltration. Moreover, the differences of the three cuproptosis-related gene subtypes were evaluated based on the CuproptosisCluster-related DEGs. Then, a cuproptosis-related gene signature (PGK1, SLC52A2, SEC14L2, RAD23B, SLC16A6, CCL5, and MAL2) and the scoring system were constructed to quantify the cuproptosis pattern of BRCA patients in the training cohort, and the testing cohorts validated them. Specifically, patients from the low-CRG_score group were characterized by higher immune cell infiltration, immune checkpoint expression, immune checkpoint inhibitor (ICI) scores, and greater sensitivity to immunotherapy. Finally, we screened out RAD23B as a favorable target and indicated its expression was associated with breast cancer progression, drug resistance, and poor prognosis in BRCA patients by performing real-time RT-PCR, cell viability, and IC50 assay.

Conclusions

Our results confirmed the essential function of cuproptosis in regulating the progression, prognosis, immune cell infiltration, and response to breast cancer immunotherapy. Quantifying cuproptosis patterns and constructing a CRG_score could help explore the potential molecular mechanisms of cuproptosis regulating BRCA advancement and provide more effective immunotherapy and chemotherapy targets.

Blood loss during liver transplantation is a predictor of postoperative thrombosis

Liver transplantation (LT) is an effective way to cure end-stage liver diseases (ESLDs), which have generally been regarded as examples of acquired bleeding disorders. However, postoperative thrombosis after LT is recognised and remains a life-threatening complication. This study aimed to show that blood loss during LT is a predictor of postoperative thrombosis and to establish a predictive model. We analysed the medical records of all patients who underwent LT at the First Affiliated Hospital of Xi'an Jiaotong University from January 2017 to April 2019 to identify the risk factors for post-transplant thrombosis. The predictive nomogram was established based on independent predictors identified by logistic regression analysis. Blood loss during LT of ≥31.25 mL/kg can predict postoperative thrombosis, and the nomogram achieved an accurate prediction.

Identification of necroptosis-related subtypes and prognosis model in triple negative breast cancer

Background

Necroptosis is considered to be a new form of programmed necrotic cell death, which is associated with metastasis, progression and prognosis of various types of tumors. However, the potential role of necroptosis-related genes (NRGs) in the triple negative breast cancer (TNBC) is unclear.

Methods

We extracted the gene expression and relevant clinicopathological data of TNBC from The Cancer Genome Atlas (TCGA) databases and the Gene Expression Omnibus (GEO) databases. We analyzed the expression, somatic mutation, and copy number variation (CNV) of 67 NRGs in TNBC, and then observed their interaction, biological functions, and prognosis value. By performing Lasso and COX regression analysis, a NRGs-related risk model for predicting overall survival (OS) was constructed and its predictive capabilities were verified. Finally, the relationship between risk_score and immune cell infiltration, tumor microenvironment (TME), immune checkpoint, and tumor mutation burden (TMB), cancer stem cell (CSC) index, and drug sensitivity were analyzed.

Results

A total 67 NRGs were identified in our analysis. A small number of genes (23.81%) detected somatic mutation, most genes appeared to have a high frequency of CNV, and there was a close interaction between them. These genes were remarkably enriched in immune-related process. A seven-gene risk_score was generated, containing TPSG1, KRT6A, GPR19, EIF4EBP1, TLE1, SLC4A7, ESPN. The low-risk group has a better OS, higher immune score, TMB and CSC index, and lower IC50 value of common therapeutic agents in TNBC. To improve clinical practicability, we added age, stage_T and stage_N to the risk_score and construct a more comprehensive nomogram for predicting OS. It was verified that nomogram had good predictive capability, the AUC values for 1-, 3-, and 5-year OS were 0.847, 0.908, and 0.942.

Conclusion

Our research identified the significant impact of NRGs on immunity and prognosis in TNBC. These findings were expected to provide a new strategy for personalize the treatment of TNBC and improve its clinical benefit.

P-798 Utilization of Haploid Androgenetic Blastomeres to Characterize Male Genomic Inheritance and as a Male Gamete Substitute

Study question

Can sperm genomes be replicated by generating androgenetic embryos, and can resulting haploid blastomeres be used as a substitute for male gametes with known genotype?

Summary answer

Once utilized as male gametes, haploid androgenetic blastomeres can be used for gamete genotyping and can sustain embryo development to live offspring.

What is known already

Heterozygosity in human spermatozoa may represent a risk to offspring health. This has led to attempts to replicate the gamete genome by generating haploid embryonic stem cells (haESCs) that can be used to typify heterozygosity or as gamete substitutes. Although haESC lines are unstable with a tendency to self-diploidize, utilizing haploid androgenetic cells in the early embryonic stages, such as the blastomere stage, can provide multiple copies of genetically functional pseudo-gametes.

Study design, size, duration

Haploid androgenetic embryos were generated using spermatozoa from B6 heterozygous mice (B6-EGFP x B6D2F1) and cultured until the 8-cell stage. Individual haploid blastomeres with green fluorescent protein (GFP) expression were fused with activated recipient oocytes. Resulting conceptuses were cultured in a time-lapse system to monitor each stage of preimplantation development. Blastocysts with GFP expression were transferred to pseudo-pregnant surrogates. Pregnancy and offspring reproductive health were evaluated. Piezo-actuated ICSI was performed on unmanipulated oocytes as control.

Participants/materials, setting, methods

To generate haploid androgenetic embryos, metaphase II oocytes of B6D2F1 mice were treated with cytochalasin B, enucleated under Oosight®, and inseminated by piezo-actuated ICSI. Haploid androgenetic embryos were cultured to the 8-cell stage. Androgenetic blastomeres with GFP expression were coated with inactivated Sendai-virus and grafted to an activated recipient oocyte from another cohort. Cleavage parameters of reconstructed zygotes were compared to controls. Blastocysts were transferred into the uterine cavity of a 2.5-day post-coitus CD-1 surrogate.

Main results and the role of chance

A total of 421 oocytes were enucleated with a survival rate of 98.6%. The ooplasts underwent ICSI; 351 (84.6%) constructs developed a single male pronucleus 4-6h post-ICSI, and 208 (59.3%) constructs cleaved to the 8-cell stage. Parthenogenic activation by calcium ionophore was successful in 96.4% of the recipient oocytes, confirmed by the appearance of a single female pronucleus. A total of 148 haploid androgenotes with GFP expression were grafted onto corresponding activated oocytes; 145 successfully fused. Up to 2 unused sibling haploid blastomeres per embryo were genotyped using whole exome sequencing by a reference laboratory. A total of 481 untreated oocytes were inseminated, yielding 437 control zygotes. The cleavage of reconstructed embryos into the 2-cell (96.4%), 4-cell (94.3%), and 8-cell stage (91.4%) was comparable to that of control conceptuses (97.5%, 93.8%, and 92.7% respectively). Although morula compaction (80.0%) and blastulation (60.7%) were lower than control (89.2% and 80.8%, P &lt;0.001, respectively), morphokinetic parameters were comparable. A total of 45 blastocysts were transferred into 5 recipient mice; 8 blastocysts implanted (17.8%) in 2 surrogates, yielding 5 live offspring (11.1%) weighing 1.51±0.22g. All live offspring expressed GFP and were confirmed fertile once reaching adulthood.

Limitations, reasons for caution

Although copies of gamete substitutes were generated that could be genotyped and used to produce live offspring with the desired phenotype in a mouse model, the system needs to be optimized and proven reproducible in humans, specifically in regard to the role of the sperm centrosome.

Wider implications of the findings

Once our proposed technique is implemented in humans, it may benefit patients to control germline heterozygosity by allowing genotyping of identical copies of the gametes. This technique, when used in conjunction with heritable genomic editing, can obviate the inherently highly condensed sperm genome to provide genome-edited gamete substitutes.

Trial registration number

N/A

P-117 A novel method to select spermatozoa with the best morphokinetic characteristics and superior genomic integrity

Study question

Can an automated device based on membrane electrophoresis be used to select spermatozoa with superior morphokinetic characteristics and lower sperm chromatin fragmentation (SCF)?

Summary answer

Albeit at an expense of concentration, a membrane-electrophoretic device was able to isolate a proportion of spermatozoa with the highest motility, morphology, and genomic integrity.

What is known already

Conventional sperm selection based on density gradient centrifugation (DGC) can enhance the proportion of progressively motile spermatozoa; however, DGC methods are limited in their ability to select spermatozoa with higher genomic integrity. Membrane-based microfluidic technologies (MFSS) have already been used clinically to select for spermatozoa with a superior chromatin status; however, these methods are based on the intrinsic characteristics of motile spermatozoa capable of selecting themselves. By incorporating an extrinsic electrophoretic drive, membrane electrophoresis would overcome a limitation of progressive motility in the semen sample and be able to isolate viable gametes with better morphology and reduced SCF.

Study design, size, duration

From August 2020 to December 2021, semen samples from 68 men were evaluated by standard semen analysis and simultaneously processed by DGC or a novel membrane-electrophoretic sperm sorter (EPSS) to select for progressively motile spermatozoa. Concentration, motility, progressive motility, morphology, and SCF were measured and compared between raw, DGC-, and EPSS-processed specimens.

Participants/materials, setting, methods

Fresh ejaculates were evaluated by standard semen analysis according to WHO 2021 criteria. Following complete liquefaction, specimens were divided into two equal aliquots for DGC and EPSS sorting. SCF was assessed by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay under fluorescent microscopy; at least 500 spermatozoa were evaluated for each specimen with a normal threshold of ≤ 15%.

Main results and the role of chance

A total of 68 men with an average age of 38.1±6 years had the following average semen parameters: volume of 3.1±1 mL, concentration of 58.2±33 x106/mL, 43.3±9% motility, 40.5±9% forward progression motility, and a normal morphology of 2.9±0.8%. When comparing the final parameters between the EPSS and DGC methods, despite a reduced sperm concentration (7.3±9 x106/mL vs 45.0±36 x106/mL, P&lt;0.0001, respectively), EPSS was highly selective for motile spermatozoa, yielding significantly higher motility (93.1±16% vs. 86.8±15% P&lt;0.0001) and forward progressive motility (92.3±17% vs 85.2±15%, P&lt;0.0001). Despite an overall lower sperm recovery rate (21.4±25% vs 75.4±17%, P&lt;0.0001), normal morphology improved to 3.4±0.8% (P&lt;0.0001) after EPSS but remained unchanged in the DGC-processed sample. Although both EPSS and DGC improved SCF from 12.2±9% in the raw specimen to 4.8±6% and 6.6±7% (P &lt; 0.0001), respectively, EPSS outperformed DGC (P &lt; 0.05). Moreover, the DGC method took up to 60 min to process, whereas the EPSS technique took a total of 6 min.

Limitations, reasons for caution

The selection of spermatozoa by EPSS is a promising technique to isolate progressively motile spermatozoa with enhanced morphology and superior chromatin integrity, albeit at a lower concentration. This is a preliminary study; the benefit and safety of this method must be further demonstrated by insemination or IVF treatment.

Wider implications of the findings

A membrane electrophoresis device may be a viable alternative method to MFSS to identify spermatozoa with superior morphokinetic characteristics and intact chromatin. Moreover, incorporating an automated device can reduce gamete processing time while minimizing labor costs and inter-operator errors.

Trial registration number

N/A

P-107 A Novel Sperm Selection Technique for Embryos of the Desired Sex

Study question

Can a novel sperm selection technique (GST) yield higher rates of embryos and offspring of the desired sex in couples undergoing ICSI with PGT-A?

Summary answer

GST consistently enriched spermatozoa, resulting in a higher proportion of embryos and offspring of the desired sex without impairing clinical outcomes or offspring health.

What is known already

Although various methods to select sex-specific spermatozoa have been proposed over the years, many of these techniques have been shown to have varying degrees of success in addition to being time-consuming and costly. Moreover, the use of fluorescence and electrical charges in some of these methods has raised concerns about their potential contribution to congenital malformations. Here, we tested a novel sperm selection method aimed at achieving a higher proportion of embryos of the desired sex, without compromising clinical outcome or offspring health.

Study design, size, duration

Over a 6-year period, ejaculates from male partners of couples (n = 109) undergoing ICSI with PGT-A were processed using GST to enrich spermatozoa for the couples’ preferred sex. Standard sperm processing was carried out for couples undergoing ICSI exclusively to assess conceptus aneuploidy, comprising the control group (n = 1,261). The proportion of male and female spermatozoa in the initial and selected specimens, PGT-A results, and ICSI outcomes were compared between the two groups.

Participants/materials, setting, methods

A total of 1,370 couples were treated in 2,483 ICSI cycles. Standard sperm processing was performed for 1,261 couples who did not have an offspring sex preference. For 109 consenting couples, GST was used to enrich spermatozoa for their desired sex (IRB 1306014043). To confirm sex enrichment, ≥1,000 sperm cells were screened by fluorescent in-situ hybridization (FISH) for 9 chromosomes. The couples’ PGT-A results and ICSI outcomes were compared between the control and GST cohorts.

Main results and the role of chance

For the control cohort (n = 1,261), ejaculates were processed in the standard fashion. Spermatozoa sex ratio was unaffected. These couples (maternal age, 37.1±4yrs; paternal age, 39.1±6yrs) underwent 2,356 ICSI cycles (1.2±1), yielding an 80.9% fertilization rate (14,830/18,321). PGT-A results confirmed that 46.6% (n = 760) of their embryos were female and 53.4% (n = 872) were male. They achieved a 76.3% (725/950) implantation rate and a 64.9% (617/950) clinical pregnancy rate resulting in 569 healthy deliveries (48% female, 52% male).

From the study cohort (n = 109), 60 couples desired a female and 49 desired a male child. Those who desired female offspring (maternal age, 37.9±4yrs; paternal age, 40.8±6yrs) obtained an 81.6% sperm sex enrichment, per FISH. They underwent 74 ICSI cycles and achieved a 77.6% (592/763) fertilization rate resulting in 78.1% (235/301) female embryos that generated a 79.3% (23/29) implantation rate, yielding 16 singleton deliveries of healthy female offspring that are developing normally.

The 49 couples (maternal age, 37.6±3yrs; paternal age, 40.8±5yrs) preferring male offspring obtained an 80.8% sperm sex enrichment. They underwent 53 ICSI cycles and achieved a 74.7% (481/644) fertilization rate with an equivalent proportion of male embryos (231/292, 79.1%). Their implantation rate was 90.9% (20/22), yielding 14 healthy male singletons, all developing normally.

Limitations, reasons for caution

Although our sperm sex selection method does not guarantee offspring of a specific sex, it allowed couples participating in the study to obtain a greater proportion of conceptuses of their desired genotype. This method does not aim to replace PGT-A, but rather reduce embryo wastage.

Wider implications of the findings

Semen specimens processed by GST yielded satisfactory fertilization and embryo development, comparable to those from the control cohort. Moreover, offspring health was not negatively affected. These encouraging findings indicate that our method is safe and can consistently enrich for the desired embryo sex in a reliable and ethically palatable manner.

Trial registration number

n/a

O-215 Embryo developmental competence of de novo male gametes in a novel three-dimensional culture

Study question

Are de novo gametes generated from mouse embryonic stem cells (mESCs) in a novel three-dimensional (3D) culture system capable of supporting full preimplantation development?

Summary answer

A novel 3D culture system yielded de novo male gametes capable of fertilizing an oocyte and supporting full preimplantation development.

What is known already

In regenerative medicine, several 3D culture systems have been shown to be capable of producing functional tissue implants. In reproductive biology, recent studies have reported preliminary success in generating functional de novo gametes through soft-agar culture and testicular organoids, in the mouse model. However, a heterologous transplantation technique is required to obtain functional gametes.

Study design, size, duration

mESCs were first cultured on a gelatin-coated 6-well plate with fibroblasts in monolayer and later spherified using sodium alginate. Spheres were submerged in specifically designed conditioned media to encourage differentiation of the mESCs into germ-like cells. Over the course of differentiation, cells were assessed for germ cell differentiation biomarkers. Considering that normal spermatogenesis occurs in 30 days, utilization of the de novo gametes was planned for days 15, 22, 29, and 36.

Participants/materials, setting, methods

mESCs were differentiated by submerging the spheres in EpiLC medium containing Activin A, bFGF, and KSR for 3 days followed by PGCLC medium containing BMP4, LIF, SCF, and EGF for up to 36 days. Differentiation was assessed for markers DAZL (spermatogonium), VASA (spermatocyte), BOULE (post-meiotic stage), and acrosin (spermatid). Differentiated cells were then injected into oocytes and activated by calcium ionophore. Embryo development was monitored in a time-lapse incubator.

Main results and the role of chance

Expression of DAZL in 20% and VASA in 15% of the cells at day 3 demonstrated progression into spermatogenesis. On day 10, DAZL and VASA were assessed again, revealing increases to 45% and 18%. A small proportion of cells expressed post-meiotic biomarkers, BOULE (1%) and acrosin (2%). On day 15, VASA expression plateaued at 17%, BOULE expression peaked at 10%, and acrosin reached 5%. On day 22, expression of VASA increased slightly to 19%, BOULE decreased to 8%, and acrosin peaked at 7%. On day 29, VASA expression peaked at 20%, acrosin expression remained stable at 7%, and BOULE expression dropped to 2%. On day 36, VASA was still expressed at 13%, and few cells expressed acrosin (1%); there was complete loss of BOULE expression. 

Our mouse ICSI control achieved 89.2% fertilization and 77.8% blastocyst rates. De novo gametes were injected into oocytes on days 15, 22, 29, and 36, achieving fertilization rates of 35.0%, 61.1%, 81.8%, and 75.0%, respectively. Correspondently, hatching blastocysts were obtained at rates of 5.0%, 16.7%, 36.4%, and 8.3%, respectively.

Limitations, reasons for caution

Despite the ability to fertilize normally, the blastulation rate remained suboptimal. Most importantly, the ability to generate live offspring still needs to be documented.

Wider implications of the findings

Our novel 3D differentiation model can generate functional gametes and is aimed at obviating the need for allo-/xeno-geneic transplantation. If reproducibility and the ability to obtain healthy offspring are confirmed, this method may represent a tool for achieving neogametogensis in mammals.

Trial registration number

N/A

P-797 Benefit of Replicating Mammalian Gametes

Study question

Can haploid parthenogenetic and androgenetic embryos generate haploid embryonic stem cells (haESCs) and function as respective oocytes and spermatozoa?

Summary answer

Haploid embryos generated blastocysts capable of yielding haESCs. Haploid blastomeres of both sexes served as multiple copies of gamete substitutes.

What is known already

Although creating diploid digyneic or dispermic embryos through nuclear transfer is possible, the conceptuses rarely achieve normal preimplantation development due to unbalanced epigenomes, demonstrating the requirement of both parental epigenomes in the course of embryogenesis. Haploid parthenogenetic embryos can be achieved by inducing calcium oscillations of a metaphase II oocyte, while the paternal counterpart can be generated through the insemination of enucleated oocytes. These embryos may serve to generate haESCs for heterozygosity identification and can be used for reproductive purposes in animal models.

Study design, size, duration

To generate parthenogenetic embryos, metaphase II oocytes from B6D2F1 mice were artificially activated. Androgenetic embryos were generated from the insemination of enucleated oocytes. Haploid embryos were cultured to blastocysts and seeded on feeder cells (MEF) to derive haESCs. Haploid blastomeres from 8-cell embryos of either sex were isolated and used as artificial gametes; artificial oocytes were generated by grafting a parthenogenetic blastomere to an enucleated recipient oocyte. Androgenetic blastomeres were used as male gametes.

Participants/materials, setting, methods

Parthenogenetic embryos were generated by exposing metaphase II oocytes to calcium ionophore. Another cohort of B6D2F1 oocytes were enucleated and underwent piezo-ICSI to generate androgenetic embryos. Sendai-virus–mediated nuclear transfer was performed using parthenogenetic blastomeres as donor nucleuses to generate artificial oocytes and subsequently fertilized. Androgenetic blastomeres were used as sperm substitutes by fusion with an intact oocyte to generate zygotes. Control embryos were generated by piezo-actuated ICSI. Developmental characteristics were recorded by time-lapse microscopy.

Main results and the role of chance

A total of 129 oocytes were parthenogenetically activated by calcium ionophore, and 119 developed a female pronucleus. Androgenetic embryos were generated from the insemination of 375 ooplasts; 317 developed a male pronucleus. The monopronuclear appearance of haploid embryos of both sexes was comparable to the fertilization of control at 90.7%.

Haploid embryo development for both sexes up to the 4-cell stage matched the control. However, from the 8-cell stage onward, parthenogenetic and androgenetic embryos cleaved at a lower rate compared to the control at 76.4%, 59.3% and 92.7% (P &lt; 0.0001), respectively. The haploid genome affected the rate of compaction at 73.6%, 55.3%, and 89.2% (P&lt;0.0001), respectively, and the rate of blastulation at 27.8%, 11.2%, and 80.8% (P&lt;0.00001) respectively. Androgenetic embryos showed delayed cleavage from the 4-cell stage onward, while the parthenogenetic counterparts had similar morphokinetics to the control.

A total of 20 parthenogenetic and 18 androgenetic blastocysts were plated on MEF, yielding 5 parthenogenetic and 3 androgenetic haESC lines. Both haESCs yielded beating cardiomyocytes on day 10 of differentiation while maintaining haploidy.

The utilization of haploid pseudo blastomeres as gametes yielded 93 reconstructed biparental embryos that resulted in 71 blastocysts (76.3%). Time-lapse morphokinetics were comparable to the control.

Limitations, reasons for caution

Haploid embryos developed to blastocysts at a remarkably lower rate than the control, particularly the androgenotes; however, they can yield pluripotent haESCs capable of differentiation in the mesoderm and subsequent cardiogenesis prone to self-diploidization. Once this system is replicated in humans, the role of the centrosome needs to be investigated.

Wider implications of the findings

Our study has demonstrated the feasibility of propagating both male and female genomes from single gametes for reproductive applications. Indeed, once a stable culture of haESCs is achieved, genotyped pluripotent haESCs can be used to help identify heterozygosity for inherited disorders.

Trial registration number

N/A

O-251 Defining the exclusive role of male genome integrity on conceptus development

Study question

To determine the effect of sperm DNA fragmentation on embryo development by ruling out a female factor component.

Summary answer

By utilizing healthy donor oocytes, it is possible to quantify the sole deleterious effect of sperm DNA fragmentation and explore the ooplasmic repair mechanism.

What is known already

In approximately 50% of couples with unexplained ART failure, a subtle male factor is present that is missed in a conventional semen analysis assessing concentration, motility, and morphology. Additional information on male gamete competence can be acquired by assessing Sperm Chromatin Fragmentation (SCF). Indeed, a fragmented male genome can give rise to poorly developing embryos, leading to impaired implantation, lower pregnancy, and higher miscarriage rates. It has been previously seen that an oocyte, according to its age, can repair the damaged DNA contributed by the male gamete.

Study design, size, duration

In last decade, 316 couples, who have an elevated SCF, underwent ICSI cycles and resulted in disappointing clinical outcomes. To exclude an eventual confounding female factor, couples who utilized donor oocytes were identified and clinical outcome was compared to a control. To measure the role of an impaired sperm genome and a concurrent oocyte repair mechanism, we compared clinical outcomes between cycles in the same couples who used their own and subsequently donor oocytes.

Participants/materials, setting, methods

We included 381 couples screened for SCF; 65 underwent ICSI cycles with donor oocytes; of these, 46 underwent a previous ICSI cycle with their own oocytes. Fertilization, implantation, clinical pregnancy, and delivery rates were compared between above-mentioned groups. A TUNEL assay was used to measure SCF (≥500 spermatozoa were assessed/sample at a 15% threshold). Paired t and Chi-square tests were used to compare ages and clinical outcomes, respectively.

Main results and the role of chance

We included 381 couples (maternal age, 37.8 ± 4.2; paternal age, 41.8 ± 8.2), whose male partners had the following semen parameters: average volume of 2.5 mL, concentration of 25.4x106/mL, 33% motility, and normal morphology of 1.7. Of these, 316 had elevated average DNA fragmentation of 25.5% and utilized their own oocytes in 683 ICSI cycles, resulting in a 67.5% fertilization, 12.2% implantation, 27.9% clinical pregnancy, and a 22.5% ongoing/delivery. Of the 381 couples, 65 underwent ICSI utilizing donor oocytes (SCF of 24.3%) resulting in a significantly higher fertilization (78.4%) (P &lt; 0.00001) and embryo implantation rates (34.2%) (P &lt; 0.0001). Similarly, albeit not statistically significant, the clinical pregnancy and ongoing/delivery rates increased from 27.9% to 37.1% and from 22.5% to 30.0%, respectively.

To further explore the exclusive role of the male gamete in embryo development, we identified a cohort of patients (n = 46), with an elevated average DNA fragmentation of 23.6%, who underwent an ICSI cycle using their own oocytes and a subsequent cycle using donor oocytes. Compared to cycles where couples used their own oocytes, fertilization, embryo implantation, clinical pregnancy, and ongoing/delivery rates rose from 67.5% to 76.6% (P &lt; 0.0001), 2.8% to 24.7% (P &lt; 0.00001), 8.4% to 38.8% (P &lt; 0.0001), and 1.2% to 28.6% (P &lt; 0.00001), respectively.

Limitations, reasons for caution

Although this study attempts to control for a concurrent confounding female factor, it cannot be completely excluded. It is difficult to assess the extent and contribution of the ooplasmic repair mechanisms on the male genome.

Wider implications of the findings

Ooplasmic repair mechanisms of healthy female gametes appear to repair or improve the deleterious impact of sperm DNA fragmentation on ART outcomes.

Trial registration number

not applicable

O-044 ICSI in the lab: from vintage to AI

With the advent of in vitro fertilization (IVF) by Patrick Steptoe and Bob Edwards in the late 70s, the first conception outside of the human body resulted in the birth of Louise Brown. Although a terrific success, limitations of IVF surfaced, represented by the unexpected complete fertilization failure with suboptimal or dysfunctional spermatozoa.

This prompted curiosity toward individual spermatozoa for a deeper understanding of its role aimed at enhancing the interaction between complementary gametes. Techniques were designed to manipulate the oocytes, such as stripping, partially digesting, or cracking the zona pellucida (ZP). These methods were palliative solutions to overcome fertilization failure and were often plagued by polyspermy. As a result, more direct approaches were implemented to overcome the ZP, such as subzonal injection (SUZI) that although more consistent, was still unable to overcome the shortcomings of dysfunctional spermatozoa. This laid the foundation for the utilization of ICSI that, whilst attempted by some investigators, became popular when Gianpiero Palermo serendipitously inserted one spermatozoon into the ooplasm during SUZI. Consistent fertilization then followed by injecting a cohort of oocytes by ICSI in SUZI cycles, and replacement of these embryos led to 4 pregnancies described in the first clinical ICSI report. To minimize oocyte damage, the procedure was further refined by inducing a deep invagination of the oolemma toward the 9 o’clock position, granting higher chances of post-injection survival.

What set apart ICSI from other forms of ART was that any sperm sample, regardless of quality/quantity, would yield fertilization. Indeed, ICSI is the sole insemination method used with epididymal and testicular spermatozoa and has therefore revolutionized fertility treatment of azoospermic men. Indeed, even immotile testicular spermatozoa can still fertilize and yield successful pregnancies, albeit at a lower rate than their motile counterpart. Also, for these semen sources, aggressive sperm immobilization was introduced to enhance sperm membrane permeabilization and grant optimal fertilization results.

Furthermore, ICSI has transformed the field of reproductive medicine by assisting other reproductive techniques, such as testing embryos for single gene defects to reduce the occurence of sperm DNA contamination, or overcoming the cryostress-induced changes of the ZP during cryopreservation allowing the oocyte to be fertilized at a higher rate. Oocyte cryopreservation now empowers women in their reproductive age to ordain their childbearing future.

ICSI has proven to be the ultimate technique to overcome male infertility and has broadened its indication by yielding consistent fertilization and successful pregnancies in most circumstances, ensuring that men have the chance of fathering their own progeny.

To date, ICSI is applied in several countries, and in some, is performed as the preferred/sole insemination method contributing to the birth of millions of babies worldwide. Thus far, no concerning differences have been seen in the health of ICSI versus standard IVF offspring, or even naturally conceived. In fact, it has been currently established that young adults of both genders born through ICSI retain their reproductive health.

Despite its growing popularity, ICSI does not always succeed but still provides an invaluable platform to deepen our knowledge of gamete biology and helps to investigate/overcome some of the most severe and persistent forms of infertility. For example, combined with assisted gamete treatment, ICSI allows couples plagued by sperm-bound oocyte-activation-deficiency to achieve pregnancy.

The need to increase access and curtail costs of reproductive care has led to the testing of automation in ART. This is also occurring with ICSI and to date, different automated modules have been proposed for oocyte denudation, sperm tracking, and robotic ICSI. Concurrently, there has been an interest in experimenting with artificial intelligence in the IVF laboratory to minimize human shortcomings and ensure that the best spermatozoon is chosen.

O-314 Epigenetic Profiling of Seminal Plasma in NOA Men to Predict Successful Testicular Sperm Retrieval

Study question

Can epigenetic profiling of seminal plasma be used to predict successful testicular sperm retrieval for men with non-obstructive azoospermia (NOA)?

Summary answer

Epigenetic screening of cell-free seminal RNA identified gene imbalances in NOA men, with specific correlation to those who failed to yield spermatozoa at testicular biopsy.

What is known already

Although the chance of a successful microdissection testicular sperm extraction (micro-TESE) in men with NOA can be up to 60%, the procedure may still fail to yield spermatozoa. Several factors have been proposed to predict a successful retrieval, including FSH, inhibin B, genetics, and histopathology. Although histopathology would be the most reliable of these to predict successful micro-TESE, it is equally invasive to perform. Indeed, cell-free RNA extracted from testicular biopsy specimens has been shown to be differentially expressed in infertile men according to the origin of their azoospermia, whether obstructive or nonobstructive, and in relation to a normozoospermic control.

Study design, size, duration

Over a 2-year period, we identified men in whom no spermatozoa were identified despite extensive semen analyses conducted by multiple embryologists. These patients, who were negative for Y microdeletion, subsequently underwent micro-TESE. For consenting men, we performed epigenetic analyses on their seminal plasma by RNAseq. Significant differentially expressed gene (DEG) profiles were then assessed and compared according to whether surgical sperm retrieval successfully yielded spermatozoa (+TESE) or not (-TESE).

Participants/materials, setting, methods

RNA was isolated from the ejaculates for RNAseq using a commercially available spin column kit. RNA isolates were sequenced by Illumina HiSeq at 2x150bp. An absolute log2fold change of &gt; 1 and a P-value of &lt; 0.05 was considered significant. DEG profiles were compared within, as well as between, the +TESE and -TESE cohorts in comparison to a donor control.

Main results and the role of chance

All 12 men (37.3±6yrs) had normal peripheral karyotypes. Six (38.0±7yrs) underwent successful testicular sperm retrievals, defining the +TESE cohort. These men exclusively shared 10 significantly imbalanced genes involved in processes such as spermatogenesis (n = 4), sperm function (n = 2), and testis development (n = 1).

For the 6 men (36.6±5 yrs) who underwent testicular sperm retrievals that failed to yield spermatozoa (-TESE), we identified 16 significantly imbalanced genes, exclusively shared by these patients. These genes are mainly involved in spermatogenesis (n = 9), sperm maturation (n = 1), and cell cycle regulation (n = 4).

We then compared the DEG profiles between the +TESE and -TESE cohorts and identified 8 imbalanced genes that were shared among all 12 NOA men.

Of interest, TPTE2 was partially (67%) expressed in patients from the +TESE group, while IGSF11-AS1 was underexpressed in all men from the -TESE group. Both of these genes are implicated in spermatogenic defects and are normally highly expressed in the testis.

Interestingly, we identified a gene (NA) that was solely and specifically underexpressed in all men from the -TESE group, yet simultaneously overexpressed in all men from the +TESE group. NA, which is well known for its role in sialic acid metabolism, is also present on the sperm acrosome.

Limitations, reasons for caution

Using non-invasive RNAseq on the seminal plasma of NOA men, we were able to identify DEGs according to whether spermatozoa were successfully retrieved or had failed retrieval with micro-TESE. Although intriguing, these are preliminary results that should be further validated in a larger study cohort.

Wider implications of the findings

RNAseq identified genes shared within the same prognostic cohort. Moreover, differential expression of some specific genes predicted micro-TESE outcome. This epigenetic assessment, carried out on the ejaculate, can therefore be used as a non-invasive biomarker tool to predict loss of spermatogenesis in NOA men, sparing them from unnecessary surgery.

Trial registration number

N/A

P-112 Utilizing surgical sperm retrieval to improve clinical outcomes for men with high sperm chromatin fragmentation in their ejaculates

Study question

In men with elevated sperm chromatin fragmentation (SCF), can surgical sperm retrieval from the proximal area of the male genital tract improve clinical outcomes?

Summary answer

Spermatozoa retrieved from the epididymis or testes demonstrate higher genomic integrity and are associated with enhanced embryo implantation, clinical pregnancy, and delivery rates.

What is known already

Sperm genomic integrity is a key factor in achieving a successful pregnancy. During spermiogenesis, alteration of DNA topology involving nuclease and ligase mechanisms is required for supercoiling and DNA compaction. If a proper DNA repair mechanism fails during this intricate process, spermatozoa with DNA fragmentation should be picked up by the epididymis and phagocytized. When this mechanism fails, along with the presence of superimposed reactive oxygen species in the male genital tract, spermatozoa with DNA fragmentation may reach the ejaculates. We have previously demonstrated that retrieving spermatozoa directly from the epididymis and testes yields gametes with higher conserved genomic integrity.

Study design, size, duration

In a nine-year timespan, we identified over 1,000 men with high SCF in their ejaculates; 144 patients consented to undergo surgical retrieval of spermatozoa. In a preliminary assessment, their clinical outcomes were compared to those from men with normal SCF (n = 539). Of these men, 53 consented to undergo subsequent ICSI cycles with their female partners using surgically retrieved spermatozoa from the epididymis (n = 15) or testes (n = 38). Fertilization and clinical outcomes were compared.

Participants/materials, setting, methods

Ejaculated, epididymal, and testicular specimens were screened by terminal deoxynucleotidyl dUTP nick-end labeling (TUNEL) to assess SCF using a commercially available kit. A total of 500 spermatozoa/sample were screened with a normal threshold of 15%. Surgical samples from the epididymis and testes were cryopreserved in multiple vials for subsequent ICSI cycles.

Main results and the role of chance

In the preliminary assessment, ICSI outcomes utilizing ejaculated spermatozoa were compared between men with normal (n = 539, 9.3±3%) and abnormal (n = 144, 28.2±13%) SCF. Although fertilization did not differ, implantation (24.1% vs. 7.8%) and clinical pregnancy rates (CPR, 35.8% vs. 14.6%) were significantly impaired (P &lt; 0.001) in men with elevated SCF.

SCF assessment on surgically retrieved spermatozoa revealed a decreasing trend from 28.2±13% in the ejaculate to 16.6±9.2% in the epididymis and 10.1±5.7% in the testes.

A total of 53 men underwent 79 subsequent ICSI cycles using surgically retrieved spermatozoa. Compared to their historical cycles using ejaculates (n = 65), ICSI with surgically retrieved sperm substantially improved implantation (18.8% vs. 2.1%; P &lt; 0.001), CPR (36.5% vs. 5.3%; P &lt; 0.0001), and ongoing/delivery rates (33.8% vs. 4.1%; P &lt; 0.0001).

Among these couples, 15 underwent 21 ICSI cycles utilizing epididymal spermatozoa with a mean SCF of 16.6±9%. Implantation (26.5% vs. 3.7%; P &lt; 0.05), CPR (68.4% vs. 4.2%; P &lt; 0.0001), and ongoing/delivery rates (57.1% vs. 4.2%; P &lt; 0.0001) were significantly improved compared to the historical cycles.

The remaining 38 patients underwent ICSI with testicular spermatozoa with an average SCF of 10.1±6%. Implantation (15.0% vs. 2.6%; P &lt; 0.01), CPR (25.5% vs. 6.1%; P &lt; 0.01), and ongoing/delivery rates (23.6% vs. 3.0%; P &lt; 0.05) were higher when compared to historical cycles.

Limitations, reasons for caution

Although surgically retrieved spermatozoa can be used to enhance clinical outcomes in couples with high SCF, epididymal spermatozoa yielded higher pregnancy rates despite the higher level of SCF in these specimens compared to testicular spermatozoa. This can be explained by the corrective action of the ICSI procedure itself.

Wider implications of the findings

Our study demonstrated that sperm DNA integrity progressively increases through the journey of the male genital tract. In couples with a compromised sperm genome, surgically retrieved spermatozoa can be beneficial. Therefore, assessing SCF might be used a routine tool to evaluate the male gamete.

Trial registration number

N/A

P-270 Assisted gamete treatment to pinpoint acquired meiotic maturity and overcome oocyte activation deficiency contributed by both gametes

Study question

How can we treat couples with complete and persistent fertilization failure with ICSI linked to a combination of oocyte- and sperm-related oocyte activation deficiency (OAD)?

Summary answer

By targeting spindle presence, we optimized oocyte response to chemical activation and enhanced fertilization. Genomic assessment confirmed gamete contribution.

What is known already

Total fertilization failure occurs in 1-3% of all intracytoplasmic sperm injection (ICSI) cases. In sperm-factor OAD, the lack of phospholipase C zeta (PLCζ) prevents the spermatozoon from initiating downstream calcium oscillation in the oocyte. In these cases, assisted gamete treatment (AGT), which exposes gametes to calcium ionophore, has been adopted to artificially trigger the influx of calcium ions and has been shown to effectively improve fertilization. However, AGT is limited to triggering an intracytoplasmic calcium influx and still requires optimal ooplasmic maturity.

Study design, size, duration

Over the past 17 months, we identified couples with compromised PLCζ and reported persistent fertilization failure with ICSI despite AGT treatment. We then devised a treatment plan comprising an extended in vitro culture (IVC) to pinpoint meiotic oocyte maturity confirmed by the presence of a meiotic II spindle and followed by AGT post-ICSI. Genomic assessment was also carried out.

Participants/materials, setting, methods

Two couples with recurrent and total fertilization failure even after AGT were included. PLCζ expression was assessed using immunofluorescence on ≥ 200 cells/specimen with a 30% threshold. In the follow-up cycles, IVC was extended for at least 8 hours between retrieval and ICSI. Metaphase II spindles were visualized by Oosight®. AGT was performed by exposing both spermatozoa and oocytes to calcium ionophore. NGS was performed on spermatozoa to identify gene mutations involved in fertilization.

Main results and the role of chance

We identified 2 couples (couple A: 37-year-old female, 39-year-old male; couple B: 32-year-old female, 33-year-old male) with the following semen parameters: average volume of 2.6 ml, concentration of 82.0x106/ml, 44% motility, and normal morphology of 3%. The oocyte maturation rate was 76.3% (45/59) but resulted in zero fertilized out of a total of 45 MII oocytes injected. In-house PLCζ assessment revealed a deficiency of oocyte activation factor at 12.9%. AGT treatment alone failed to enhance fertilization on a subsequent cycle, resulting in 0% (0/8) and 5.6% (1/18) fertilization rates for couples A and B, respectively. Couple A then underwent 3 ICSI cycles with extended IVC and AGT; upon examination of nuclear maturity, 91.4% (32/35) of oocytes displayed normal metaphase II spindle and achieved an overall fertilization rate of 43.8% (14/32). To date, 12 blastocysts were cryopreserved. In couple B, 27 oocytes out of 34 retrieved presented normal metaphase II spindles after extended IVC; ICSI with AGT yielded a fertilization rate of 63.0% (17/27). All 17 zygotes were cryopreserved. Overall, our treatment improved fertilization to an overall rate of 52.5% (31/59, P  &lt;0.00001). Genomic assessment of spermatozoa identified gene mutations involved in fertilization (ADAM15, ADAM30) and calcium channel activity (CATSPER1).

Limitations, reasons for caution

Assisted gamete treatment can enhance fertilization in cases of deficiency in PLCζ. However, chemical activation requires a responsive ooplasm that has reached meiotic maturity. These rare cases require precise diagnoses and tailored treatment techniques to address each aspect of sperm- and/or oocyte-factor OAD.

Wider implications of the findings

Our study has demonstrated the usefulness of extended IVC by targeting spindle presence to enhance chemical responses to AGT. Our findings show that although calcium ionophore can trigger the release of intracellular calcium and allow fertilization, a fully mature ooplasm is required.

Trial registration number

N/A

A Novel Risk-Scoring System to Identify the Potential Population Benefiting From Adjuvant Chemotherapy for Node-Negative TNBC Patients With Tumor Size Less Than 1 cm

Background and Objectives

Whether chemotherapy is needed in node-negative triple-negative breast cancer (TNBC) patients with tumor size less than 1 cm is still controversial. In our research, we constructed a novel risk-scoring system to identify the potential TNBC patients benefiting from adjuvant chemotherapy in T1miN0M0, T1aN0M0, and T1bN0M0 stages.

Methods

Relevant data were extracted from the SEER database. We applied Kaplan-Meier curves and the Cox hazards model for survival analysis and developed a nomogram of overall survival. The X-tile software was used for risk stratification. The information of TNBC patients treated in the First Affiliated Hospital of Xi’an Jiaotong University was used for the application of the model.

Results

A total of 4266 patients who met the criteria of our study were included. T stage, age, race, surgery, and radiotherapy state were used to create the nomogram of overall survival. According to the total risk score, the patients were divided into high-risk (score g 73), median-risk (38 ≤ score &lt; 73), and low-risk (score &lt;38) groups. Chemotherapy can prolong the overall survival of patients in the median-risk and high-risk groups, while patients in the low-risk group can be exempted from chemotherapy. In addition, we also used the risk-scoring system in real-world patients as application and verification.

Conclusion

We constructed a novel risk-scoring system that can be used as a chemotherapy decision-making tool for node-negative TNBC patients with tumor size less than 1 cm. Tumor size should not be the only criterion for chemotherapy treatment decision-making.

Bioinformatics analysis for the role of CALR in human cancers

Cancer is one of the most important public health problems in the world. The curative effect of traditional surgery, radiotherapy and chemotherapy is limited and has inevitable side effects. As a potential target for tumor therapy, few studies have comprehensively analyzed the role of CALR in cancers. Therefore, by using GeneCards, UALCAN, GEPIA, Kaplan-Meier Plotter, COSMIC, Regulome Explorer, String, GeneMANIA and TIMER databases, we collected and analyzed relevant data to conduct in-depth bioinformatics research on the CALR expression in Pan-cancer to assess the possibility of CALR as a potential therapeutic target and survival biomarker. We studied the CALR expression in normal human tissues and various tumors of different stages, and found that CALR expression was associated with relapse free survival (RFS). We verified the expression of CALR in breast cancer cell lines by vitro experiments. Mutations of CALR were widely present in tumors. CALR interacted with different genes and various proteins. In tumors, a variety of immune cells are closely related to CALR. In conclusion, CALR can be used as a biomarker for predicting prognosis and a potential target for tumor molecular and immunotherapy.

A novel immune subtype classification of ER-positive, PR-negative and HER2-negative breast cancer based on the genomic and transcriptomic landscape

BACKGROUND

The diversity and plasticity behind ER+/PR-/HER2- breast cancer have not been widely explored. It is essential to identify heterogeneous microenvironment phenotypes and investigate specific genomic events driving the formation of these phenotypes.

METHODS

Based on the immune-related gene expression profiles of 411 ER+/PR-/HER2- breast cancers in the METABRIC cohort, we used consensus clustering to identify heterogeneous immune subtypes and assessed their reproducibility in an independent meta-cohort including 135 patients collected from GEO database. We further analyzed the differences of cellular and molecular characteristics, and potential immune escape mechanism among immune subtypes. In addition, we constructed a transcriptional trajectory to visualize the distribution of individual patient.

RESULTS

Our analysis identified and validated five reproducible immune subtypes with distinct cellular and molecular characteristics, potential immune escape mechanisms, genomic drivers, as well as clinical outcomes. An immune-cold subtype, with the least amount of lymphocyte infiltration, had a poorer prognosis. By contrast, an immune-hot subtype, which demonstrated the highest infiltration of CD8+ T cells, DCs and NK cells, and elevated IFN-γ response, had a comparatively favorable prognosis. Other subtypes showed more diverse gene expression and immune infiltration patterns with distinct clinical outcomes. Finally, our analysis revealed a complex immune landscape consisting of both discrete cluster and continuous spectrum.

CONCLUSION

Overall, this study revealed five heterogeneous immune subtypes among ER+/PR-/HER2- breast cancer, also provided important implications for clinical translations.

Effect of Akt activation on apoptosis-related gene expression in the crop tissues of male and female pigeons (Columba livia)

The current study investigated whether the expression of apoptosis genes in the pigeon crops was affected by the Akt signaling pathway during crop milk formation. First, 78 pairs of adult White King pigeons were randomly assigned to 7 groups, and the expression of apoptosis-related genes and Akt signaling pathway-related proteins in the crop tissues during different breeding stages were examined. The results showed that the mRNA levels of Bak, caspase-3, caspase-6, and caspase-9 in female crops all increased and reached their highest levels at d 17 of incubation (I17). In male crops, the levels of caspase-3 and caspase-9 gene expression peaked at d 1 of chick rearing (R1). The lowest level of Bcl-2 gene expression in females was observed at I17. The expression ratios of p-Akt (Ser473)/Akt and p-Akt (Thr308)/Akt in male crops decreased to their minimum at R1, while it was observed at d 7 of chick rearing (R7) in females. Second, 36 pairs of adult pigeons were divided into 3 groups and were subjected to SC79 injections with dosages of 0, 0.02, or 0.04 mg/kg bodyweight. The SC79 injections resulted in a considerable decrease in growth performance of pigeon squabs. In male crops, the expression ratios of p-Akt (Ser473)/Akt and p-Akt (Thr308)/Akt were significantly elevated in the 0.02 mg/kg SC79 group, while in female crops, they were higher in the 0.04 mg/kg SC79 group (P < 0.05). The SC79 injection inhibited the gene expression of Bak in female crops, but enhanced the gene expression of Bcl-2 in both male and female crops. In the 0.04 mg/kg SC79 group, a 50.7 to 75.7% decrease was observed in the expression of caspase-3, caspase-6, and caspase-9 in male and female pigeon crops. Expression of the caspase-8 gene and total Akt protein in pigeon crops was not changed in different breeding stages or after SC79 injection. In conclusion, the expression of genes related to mitochondria-dependent apoptosis can be regulated by the Akt signaling pathway, which may play a potential role in pigeon milk formation.

O-206 Meiotic segregation analysis for reciprocal translocation carriers: Assessment of factors influencing meiotic segregation patterns

Study question

To analyze factors that could influence meiotic segregation patterns for reciprocal translocation carriers.

Summary answer

Involvement of an Acr-ch, female gender, and lower TAR1 (ratio of translocated segment 1 over the chromosome arm) were independent risk factors for alternate segregation.

What is known already

Reciprocal translocation is one of the more common structural rearrangements of chromosomes, which is associated with reproductive risks, such as infertility, spontaneous abortion and the delivery of babies with mental retardation or developmental delay. Extensive studies on meiotic segregation patterns of sperm, blastomere, and blastocysts have identified several factors that may influence the generation of unbalanced rearrangement of reciprocal translocations, including carrier’s gender and age, location of breakpoints, chromosome type, and the quadrivalent structure. However, some results are controversial.

Study design, size, duration

A retrospective study from October 2013 to December 2019, a total of 10846 blastocysts originating from 2871 oocyte retrieval cycles from 2253 couples with one of the partners carrying reciprocal were investigated. The mean maternal age was 29.97±4 years (20 –47years).

Participants/materials, setting, methods

Trophectoderm biopsy of blastocysts was performed on the 5th or 6th day of development. Whole genome amplification (WGA) was performed on all samples, and the WGA was analyzed with SNP array or NGS. Segregation patterns of quadrivalent in 10846 blastocysts were analyzed. Risk factors for segregation patterns were explored through analyzing carriers’ demographic and cytogenetic characteristics using multivariate generalized linear mixed models (GLMMs).

Main results and the role of chance

The percentage of normal/balanced blastocysts was 34.3%, and 2:2 segregation was observed in 90.0% of blastocysts. Increased TAR1 (the ratio of translocated segment 1 over the chromosome arm) was noted as an independent protective factor for the proportion of alternate segregation (P = 0.004). The female gender and involvement of an Acr-ch were found independent risk factors for alternate segregation (P &lt; 0.001). A higher TAR1 reduced the risk of adjacent-1 segregation; longer translocated segment and female gender increased the risk of adjacent-2 segregation (P = 0.009 and P &lt; 0.001, respectively). Female gender and involvement of an Acr-ch enhanced the risk of 3:1 segregation (P &lt; 0.001 and P = 0.012, respectively).

Limitations, reasons for caution

About 1400 blastocysts were not diagnosed in the 2871 cycles, which might cause bias in the results. Secondly, the interchromosomal effect of reciprocal translocations was not analyzed in this study.

Wider implications of the findings

In conclusion, a carrier’s gender, involvement of an Acr-ch, and location of breakpoints may influence the segregation patterns. Besides, involvement of an Acr-ch, female gender, and lower TAR1 are independent risk factors for alternate segregation. These results may provide more appropriate genetic counseling for couples with balanced translocation.

Trial registration number

no

P-805 Artificial oocytes: from somatic cells to fertile pups

Study question

We analyzed the efficacy of generating artificial oocytes using somatic cells (SCs) from two mouse strains (B6D2F1 and FVB) and followed their full pre-/post-implantation development.

Summary answer

While artificial oocytes generated from the new strain (FVB) had higher fertilization rates, those from the standard strain (B6D2F1) provided expanded blastocysts and fertile pups.

What is known already

B6D2F1 is a popular hybrid mouse strain for cloning and transgenic creation due to its geno-/pheno-typic uniformity and high oocyte yield and quality. Indeed, B6D2F1 oocytes have a distinct metaphase II (MII) spindle complex, making them an ideal candidate to generate ooplasts used in SC nuclear transfer (SCNT). However, because they lack genetic variance, they are less suitable for reciprocal SCNT studies. In contrast, FVB mice have single nucleotide polymorphisms and indels on each chromosome that can aid in tracing the pedigree of progeny.

Study design, size, duration

A total of 10 experiments were performed over the course of 3 months, using 30 stimulated mice. SCs were retrieved from cumulus oophorus harvested from FVB and B6D2F1 mice. SCs from both strains were injected into enucleated MII B6D2F1 oocytes. Unmanipulated B6D2F1 oocytes were piezo-ICSI inseminated, serving as controls. The occurrence of haploidization, fertilization, and full preimplantation development was compared. Some blastocysts were transferred into pseudo-pregnant CD-1 mice to obtain offspring.

Participants/materials, setting, methods

Oocyte enucleation was performed under Oosight™ visualization and cytochalasin B exposure. An FVB or B6D2F1 SC was transferred into the perivitelline space of the ooplast with Sendai virus to promote fusion. Haploidization was monitored by pseudo-meiotic spindle formation followed by extrusion of a pseudo-polar body after insemination. Conceptuses were cultured in a time-lapse imaging system, with piezo-ICSI controls. Expanded blastocysts were transferred into uterine horns of pseudo-pregnant mice. Offspring were mated to test their fertility.

Main results and the role of chance

FVB (n = 278) and B6D2F1 (n = 905) SCs at G0 phase, with a diameter &lt;10 mm, were chosen for SCNT and transferred into enucleated B6D2F1 ooplasts. Enucleation of 1,212 oocytes yielded a survival rate of 97.6%. Both FVB and B6D2F1 SCNT resulted in similar survival rates of 100% and 98.5%, respectively. Successful haploidization, determined by the presence of a pseudo-meiotic spindle 2 hours after SCNT, was also comparable, with 59.9% of FVB and 63.7% of B6D2F1. Survival after piezo-ICSI was also comparable between FVB- and B6D2F1-reconstituted oocytes, with rates of 64.3% and 60.3%, respectively, albeit lower than the control (75.2%, P&lt;0.00001). FVB embryos fertilized at a rate of 88.7%, comparable to the control zygotes at 85.8%, while B6D2F1 conceptuses demonstrated a lower fertilization rate (70.8%, P &lt; 0.00001). Blastulation of FVB- and B6D2F1-derived embryos was 15.1% and 24.0%, respectively, while the control was 80.7% (P&lt;0.00001). Whole-genome karyotyping of 9 B6D2F1-derived blastocysts confirmed 5 of the samples to be euploid. FVB blastocysts (N = 8) and B6D2F1 blastocysts (N = 81) were transferred into pseudo-pregnant mice, resulting in 3 fertile offspring only from the B6D2F1 conceptuses.

Limitations, reasons for caution

This is still a limited number of observations, and pups were delivered only from the B6D2F1 strain. The utilization of a strain with higher genetic variance may help facilitate offspring fingerprinting.

Wider implications of the findings

This study demonstrates the ability to generate artificial genotyped conceptuses, yielding live offspring. The identification of a feasible donor cell, together with optimization of cell cycle stage and standardization of post-implantation development, will help promote this technique for human reproduction in couples with age-related infertility or poor ovarian reserve.

Trial registration number

N/A

P–119 The correlation between sperm chromatin fragmentation and intrauterine insemination outcome

Study question

Does sperm genomic integrity affect the intrauterine insemination (IUI) outcomes in couples with unexplained infertility and young maternal age?

Summary answer

Spermatozoa with higher genomic integrity are correlated with higher clinical pregnancy rates in couples with unexplained infertility undergoing IUI.

What is known already

It is known that elevated sperm chromatin fragmentation (SCF) on the male gamete affects embryo development and implantation. This is particularly relevant in IVF as well as programmed intercourse and IUI. By complementing the standard semen analysis with an SCF assay, we can assess the competence of the male gamete and its ability to generate euploid embryos and healthy offspring. Elevated SCF has been used as a way to identify subtle male factor infertility in couples undergoing IUI with poor pregnancy outcomes in order to plan for further treatments.

Study design, size, duration

This is a retrospective cohort study of IUI outcomes of couples with young maternal age and a negative infertility workup treated at our center from 2016–2020. Terminal deoxynucleotidyl dUTP transferase nick-end labeling (TUNEL) assay was used to assess sperm genomic integrity. Couples were grouped based on SCF level: normal (≤15%) or abnormal (&gt;15%). Rates of clinical pregnancy, defined as the presence of a fetal heartbeat, were compared between the groups following IUI.

Participants/materials, setting, methods

A total of 189 consenting couples, in which the female partner had a normal uterine cavity and patent fallopian tubes, underwent 454 IUI attempts. Only women ≤37 years old were included to control for age-related confounding factors. At least 500 spermatozoa were assessed per patient, and a threshold of ≤ 15% was considered normal. Women were either untreated for natural cycle IUI or stimulated with clomiphene citrate, gonadotropins, or Letrozole.

Main results and the role of chance

A total of 454 IUI cycles were reported at our center; 302 of these were carried out in 132 couples in which the male partner had normal SCF averaged at 9.29%. The average maternal age was 34.1±3 years, and the average paternal age was 37.1±5 years. These men had the following semen parameters: a concentration of 46.2±5x106/mL, 43.8±3% motility, and an average SCF of 9.3±3%. There were 45 documented clinical pregnancies (45/302, 14.9%) as confirmed by the presence of at least one fetal heartbeat detected by ultrasound; 26 delivered, 9 are ongoing, 5 were spontaneous abortions, and 5 were lost to follow-up. A total of 57 couples in which the male partner (37.2±5.9 years) had abnormal SCF underwent 152 IUI cycles (maternal age, 34.0±2.7 years). The men had the following semen parameters: an average SCF of 23.8±10 (p &lt; 0.0001), a concentration of 26.0±10 x106/ml, and 40.1±4% motility. These IUI attempts yielded a clinical pregnancy rate of only 4.6% (7/152; P &lt; 0.0001); 4 delivered and 3 were spontaneous abortions.

Limitations, reasons for caution

This study is a retrospective cohort analysis of a relatively small number of patients. Furthermore, most patients were screened for SCF due to at least one prior IUI failure. A prospective, randomized trial, in which men are concurrently screened for SCF levels at the first IUI attempt, would be ideal.

Wider implications of the findings: Assessment of SCF at the initial male infertility screening can be a useful tool to investigate the competence of the male gamete. Screening couples with idiopathic infertility for a subtle male factor would guide those with higher SCF toward alternative reproductive treatments to avoid unnecessary IUI treatments.

Trial registration number

Not applicable

P–804 Morphokinetic development by time-lapse imaging of conceptuses generated from artificial oocytes

Study question

What are the ideal culture conditions to enhance full preimplantation development of embryos generated by FVB somatic cell haploidization (SCH) in the mouse model?

Summary answer

The presence of a histone deacetylase inhibitor yielded the best morphokinetic development of expanded blastocysts generated by FVB SCH, comparable to control blastocysts.

What is known already

Various culture conditions and medium supplements have been proposed to promote preimplantation development of embryos generated by SCH, including supplementation with trichostatin A (TSA), fasudil, scriptaid, and RAD–51 stimulatory compound–1 (RS–1). TSA and scriptaid, both histone-deacetylase inhibitors, have been found to improve embryo development following nuclear transfer by enhancing histone acetylation and cellular reprogramming. Additionally, fasudil is a Rho-associated kinase inhibitor that has been shown to reduce apoptosis and promote cell proliferation. Finally, RS–1 stimulates RAD51 activity, which promotes the repair of DNA damage and increases the efficacy of somatic cell reprogramming.

Study design, size, duration

B6D2F1 mouse metaphase II (MII) oocytes underwent enucleation and nuclear transfer, or were ICSI inseminated serving as controls. Reconstituted oocytes showing development of a meiotic-like spindle demonstrated successful SCH, and were ICSI inseminated. SCH conceptuses were cultured in one of three groups: KSOM, KSOM supplemented with TSA (TSA), or KSOM supplemented with fasudil, scriptaid, and RS–1 (Cocktail). ICSI controls (ICSIC) were cultured in KSOM medium. Fertilization and full preimplantation development were compared among all groups.

Participants/materials, setting, methods

Ooplasts were generated from MII oocytes by removing spindle complexes under OosightÔ visualization and cytochalasin B exposure. A single FVB mouse cumulus cell was transferred into the perivitelline space and fused with the ooplast, facilitated by Sendai virus. Reconstructed oocytes with novel pseudo-meiotic spindles underwent piezo-ICSI and were cultured in different media conditions in a time-lapse imaging system up to 96h. TSA and Cocktail embryos had media changed to regular KSOM 10 hours after insemination.

Main results and the role of chance

A total of 274 B6D2F1 MII oocytes were enucleated, resulting in a 95.9% survival rate. All ooplasts survived nuclear transfer and 62.1% successfully haploidized after 2 hours. ICSIC and reconstituted SCH oocytes survived piezo-ICSI at rates of 81.5% and 57.0%, respectively (P &lt; 0.01). SCH embryos were then allocated into KSOM, TSA supplied, and Cocktail media. Fertilization rates for ICSIC, KSOM, and TSA embryos were 92.4%, 90.7%, and 94.4%, respectively, while the rate for embryos cultured in Cocktail was only 71.9% (P &lt; 0.03). While embryos cultured in Cocktail had a comparable 2-cell timing to ICSIC, embryos in TSA reached developmental milestones with a closer timing to the ICSIC, having minor delays at the 3-, 4-, and 6-cell stages (P &lt; 0.05). KSOM- and Cocktail-cultured embryos were delayed at most of the stages (P &lt; 0.01), except for the two-pronuclei appearance. Although the TSA group displayed the best embryo developmental pattern, the final rate of blastocyst development was somewhat homogeneous with rates of 15.4%, 23.5%, and 13.0% for the KSOM, TSA, and Cocktail groups, respectively (P &lt; 0.001), and remarkably lower than the ICSIC (81.6%).

Limitations, reasons for caution

Although live pups have been obtained using BDF cumulus cells, embryos generated by FVB cumulus cells show a remarkably lower blastocyst development, but maintain morphokinetic characteristics similar to ICSIC in the presence of TSA.

Wider implications of the findings: While using different strains to enhance genetic variance, the morphokinetic analysis of preimplantation embryos in ideal culture conditions is paramount to the progress of neogametogenesis. The implementation of this technique may soon help create genotyped oocytes for women with compromised ovarian reserve.

Trial registration number

N/A

P-525 Analysis of segregation patterns of trivalent structure and the effect on genome stability in Robertsonian translocation carriers

Study question

What are the factors that affect the separation pattern of Robertsonian translocation trivalent, and whether the structure of the trivalent affected the chromosome stability?

Summary answer

The meiotic segregation modes can be affected by the carrier’s sex and special chromosome, and a trivalent structure can affect the stability of the genome.

What is known already

Robertson translocation occurs when two proximal acrocentric chromosomes fuse at the centromere, and forms a trivalent structure during meiosis. This structure will affect the fertility of Robertsonian translocation carriers, and may destroy the stability of the genome by affecting the separation of other chromosomes, which is called Inter-Chromosomal Effect (ICE). Previous research have confirmed that the use of PGT in Robertsonian translocation carriers can effectively reduce abortion and increase live birth. But some studies dispute this conclusion and the existence of ICE. However, there is no large data study to verify these controversies.

Study design, size, duration

PGT results of 928 oocyte retrieval cycles in 763 couples(one of the couples is a Robertsonian translocation carrier) were analysied from December 2012 to June 2020. A total of 1492 couples who received PGT-A were collected as control group, and matched according to age and testing time stage. The study was approved by the ethics committee(LL-SC-SG-2006-008 and LL-SC-SG-2014-016).

Participants/materials, setting, methods

Cytogenetic analysis was performed using GTG standard method (trypsin and GiemsaG banding) to analyze the chromosomes of peripheral blood lymphocytes. Blastocysts obtained by standard IVF procedure were biopsied on the 5th or 6th morning after fertilization, and the trophoblast cells were amplified by PicoPLEX whole genome amplification kit (Rubicon Genology) or Repli-g Single Cell Kit(Qiagen). PGT-SR was performed using SNP array or NGS as previously described.

Main results and the role of chance

In this study, a total of 3423 blastocysts from 763 couples were analysed using SNP-array or NGS. Among them, the rate of alternate segregation of male Robertsonian translocation carriers was significantly higher than that in female carriers (82.26% vs 59.96%, P &lt; 0.001), and meiotic segregation modes could be affected by the special chromosome such as 13 in female(P = 0.042) and 15 in male(P = 0.045) involved. A trivalent structure can affect the stability of the genome during mitosis, which is associated with an increase in the propotion of chromosome mosaic compared with the PGT-A control group(1.18% vs 0.53%, P &lt; 0.01). In addition, we found an interesting phenomenon: in the meiotic segregation of female Robertsonian translocation carriers associated with chromosomes 21 and 22, the chromosome 21 or 22 of the two chromosomes involved in translocation are more likely to be abnormal, and according to our results, the effect of chromosome 21 seems to be greater.

Limitations, reasons for caution

(1) Limitations of retrospective analysis; (2) The results are not fully representative of the general population; (3) PGT-A patients always had repeated implantation failure or recurrent aboration, which may cause deviation to the results.

Wider implications of the findings

This study analyzed the influencing factors of the separation patterns of trivalent, and verified the existence of ICE. This suggest that PGT-SR can have a better outcome in patients with Robertsonian translocation, especially in male carriers. These results will provide carrier couple with more appropriate genetic counseling.

Trial registration number

no

P–806 Neogametogenesis via oocyte replication

Study question

Can full preimplantation embryo development be achieved from artificial oocytes created through nuclear transfer of a haploid pseudo-blastomere (HpB) into a recipient ooplast?

Summary answer

It is feasible to replicate the female genome and generate novel sibling oocytes that can yield full preimplantation embryo development, albeit at a reduced rate.

What is known already

A limitation of assisted reproduction is the number of available oocytes for embryo creation. It is feasible to utilize a somatic cell nucleus to construct novel oocytes through a process known as haploidization, in which a reverse meiosis occurs after SCNT. Similarly, producing haploid parthenogenetic constructs can generate HpBs, useful for genetic testing at the pre-fertilization level or for reproduction. It is feasible to use a HpB as a nuclear donor since it has already completed homologue segregation.

Study design, size, duration

This is prospective translational animal model study. Over 6 months, 556 oocytes were manipulated for the experimental group, and 158 control oocytes were employed. B6D2F1 HpBs were used to establish the procedure and acquire expertise. FVB HpBs were subsequently introduced for genetic variance. Experimental and control embryos were cultured in a time-lapse incubator (up to 96h). Cleavage parameters were compared to control. Two-sample T-tests and one-way ANOVA with Bonferroni correction were employed for statistical analysis.

Participants/materials, setting, methods

A cohort of oocytes was harvested from B6D2F1 or FVB superovulated mice and artificially activated by 8% ethanol. At the 8-cell stage, HpBs were exposed to nocodazole. Another cohort of B6D2F1 oocytes was enucleated for recipient ooplasts. HpBs were individually transferred into the perivitelline space of the ooplasts alongside inactivated Sendai virus. After fusion, reconstructed oocytes with spindle development were fertilized by piezo-actuated ICSI using B6D2F1 spermatozoa. Unmanipulated and fertilized B6D2F1 oocytes served as control.

Main results and the role of chance

A total of 158 control oocytes underwent ICSI with a 67.7% survival rate; of these, 65.4% developed to the blastocyst stage. For artificial oocyte activation (AOA), up to 10 oocytes were activated for each experiment, yielding 8 HpBs per activated oocyte. For the experimental group, 556 oocytes underwent enucleation with a 96.4% survival rate. Nuclear transfer of HpBs resulted in a 93.2% survival rate, consistent for those derived from BDF and FVB. Reconstructed oocytes showed appropriate development of a novel pseudo-meoitic spindle at a rate of 63.7% for B6D2F1 HpBs and 75.5% for FVB HpBs, and ICSI yielded a 67.1% and 57.7% survival rate, respectively. The fertilization rate for the reconstructed oocytes was 64%. Control oocytes underwent ICSI with a 67.7% survival rate. When evaluating time-lapse parameters, reconstructed embryos created via blastomere nuclear transfer showed asynchrony compared to controls beginning as early as the stage of pronuclear fading. While the majority of reconstructed embryos arrested at the 4-cell stage, of those that progressed, 11.3% of those using BDF HpBs and 14.6% of those using FVB HpBs developed to the fully expanded blastocyst stage. This corresponds to a total of 23 reconstructed embryos that developed to the morula or blastocyst stage.

Limitations, reasons for caution

While we used single-well embryoscope culture for morphokinetic data collection, group culture is superior to single-embryo culture for mice. Thus, developmental rates may be underestimated by this protocol. Implantation and successful pregnancy are also needed to support the clinical utility of this method in generating gametes.

Wider implications of the findings: For women with diminished ovarian reserve, oocyte yield and age-related aneuploidy are limitations to achieving genotyped offspring. Nuclear transfer of HpB can generate sibling oocytes while maintaining genetic information. This model represents a promising path for expanding oocyte yield, allowing genetic assessment of sibling oocytes, and enhancing chances of procreation.

Trial registration number

none

P–800 Generation of artificial oocytes by two distinct mechanisms

Study question

Are haploid genome replication and somatic cell haploidization feasible mechanisms for generating parentally genotyped oocytes?

Summary answer

Artificial oocytes can be generated by haploid genome replication and somatic cell haploidization. The latter is more efficient and capable of generating live offspring.

What is known already

A low number of mature oocytes is one of the major limitations to treating infertile women who have impaired ovarian reserve. Although it has been proposed that competent oocytes can be created by a phenomenon known as somatic cell haploidization (SCH), its clinical value has yet to be examined due to its poorly understood mechanism. On the other hand, spindle transfer has been clinically applied for mitochondrial replacement therapy. Therefore, we propose to utilize G2-phase haploid pseudo-blastomere (HpB), generated by parthenogenesis, as a nuclear donor to create oocyte replica.

Study design, size, duration

In the past 7 months, individual G0 phase cumulus cells (CCs) were transferred into 1,066 ooplasts for SCH. HpBs obtained from the activation of 80 oocytes were transferred into 464 ooplasts. Both cohorts were ICSI-inseminated and placed in the time lapse for embryo development. Another 379 unmanipulated oocytes were ICSI-inseminated, serving as control. Pre-implantation development was monitored and compared for both neogametogenesis techniques. Fully expanded blastocysts were transferred to obtain live pups.

Participants/materials, setting, methods

CCs were isolated from the cumulus oophorus of B6D2F1 mice. HpBs were obtained via oocyte activation, cultured to the 8-cell stage, and subsequently treated by nocodazole to synchronize at the G2-phase. In two experimental groups, CCs or HpBs were individually transferred into the perivitelline space of the ooplasts with inactivated Sendai virus. Reconstructed oocytes presenting with a pseudo-meiotic spindle were fertilized by piezo-actuated ICSI. Blastocysts were transferred into a pseudo-pregnant CD–1 surrogate to obtain pups.

Main results and the role of chance

A total of 1,769 oocytes underwent enucleation to generate ooplasts, with a survival rate of 97%. Survived ooplasts were allocated to SCH (n = 1,034) and HpB-SCNT (n = 458). To generate HpBs, 80 unmanipulated oocytes were activated; 58 of them progressed to the 8-cell stage and generated 464 HpB for SCNT. For SCH, CCs were selected based on morphology with a diameter &lt;10 micron. Nuclear transfer of CCs and HpB yielded survival rates of 98.6% and 93.2%, respectively. Following SCH and HpB-SCNT, spindle development for SCH and HpB-SCNT was comparable at 63.5% for SCH and 66.7% for HpB-SCNT. The ICSI survival rates for SCH and HpB-SCNT were 58.9% and 64.9%, respectively, but lower than the control at 73.9% (P &lt; 0.001). Fertilization rates for SCH and HpB-SCNT were also comparable at 61.3% and 64.3%, respectively, but lower than the control at 89.6% (P &lt; 0.00001). Full pre-implantation development was achieved for both experimental groups. While the SCH group yielded a development rate of 24.6% (n = 94), the HpB-SCNT group yielded a lower rate at 12.4% (n = 23) (P &lt; 0.001), both lower than the control (71.7%, P &lt; 0.00001); however, the morphokinetics of the embryo development was retained. To date, only 3 live pups were obtained from SCH group.

Limitations, reasons for caution

While these techniques to manufacture oocytes are very new and highly experimental, our findings show a lower blastulation rate for oocytes generated by HpB. Both techniques require refinement and improvement of reliability and consistency before they can be considered a feasible technique for human reproduction.

Wider implications of the findings: The study confirms the potential to create artificial oocytes capable of supporting full pre-implantation development and, in some cases, live pups. If further streamlining of both procedures demonstrates their safety, they may both represent a viable option to generate de novo gametes

Trial registration number

N/A

O-124 Contact-free oocyte denudation in a chip-scale ultrasonic microfluidic device

Study question

To design and test an automated microfluidic device to revolutionize the cumulus-oocyte-complex (COC) denudation procedure for intracytoplasmic sperm injection (ICSI) using murine oocytes.

Summary answer

Oocyte exposure to temperature variation, mechanical stress, and prolonged chemical treatment during denudation was mitigated using our microfluidic device based on surface acoustic waves (SAWs).

What is known already

COC denudation is a prerequisite for many ART procedures such as ICSI. However, this procedure is based on manual pipetting (MP), which lacks standardization and requires experienced embryologists to perform. Inadequate MP may damage oocytes through prolonged enzymatic treatment or high fluidic stresses and may jeopardize gamete competence. The use of microfluidic devices based on porous membranes or microchannels has been adopted by many laboratories for sperm selection. Of these, microchannel devices may also be adapted for denudation with minimal mechanical stress in a controlled microenvironment. However, oocyte manipulation and extraction have proven difficult to achieve.

Study design, size, duration

We developed a novel ultrasonic microfluidic device based on a microwell design manufactured with Polydimethylsiloxane (PDMS). The SAWs were generated by 4 interdigitated transducers (IDTs) arranged in an orthogonally symmetric pattern. A non-toxic dosage of ultrasonic waves, similar to those used in gynecology and obstetrics, was applied. COCs were denuded by induced acoustic streaming and acoustic radiation force. Denudation rate, embryo development, and pregnancy outcomes were assessed and compared to control oocytes denuded by MP.

Participants/materials, setting, methods

For each run, up to 10 individual COCs from super-ovulated B6D2F1 mice were loaded into the microwell alongside diluted hyaluronidase (20 IU/ml) and denuded by 80 or 200 MHz SAWs. Denuded oocytes were fertilized by piezo-actuated ICSI using spermatozoa from the same strain. Pre-implantation embryo development was assessed in a time-lapse incubator for up to 96 h. High-quality blastocysts were transferred to 2.5-dpc pseudo-pregnant CD-1 surrogates. Pregnancy and offspring health were observed.

Main results and the role of chance

Using alternating frequency sweep in a pulse-repetition mode, we swirled the fluid inside the microwell consistently and tumbled COCs inside the microwell to expose them to acoustic steaming-induced drag forces and acoustic radiation force. Using a high-speed camera and particle-tracking technique, we observed that the drag force generated by the SAWs fulfilled the denudation mechanism. Additionally, due to the small attenuation coefficient in water, thermal absorption heating remains minuscule, preventing any thermal-induced damage.

Our device significantly reduced the time and labor of the denudation process. It also yielded proper denudation quality without oocyte loss. To ensure that SAWs do not damage oocytes, 40 oocytes denuded by 80 MHz SAWs, 25 oocytes denuded by 200 MHz SAWs, and 30 oocytes denuded by MP were inseminated by piezo-actuated ICSI. The 80-MHz, 200-MHz, and MP groups yielded comparable post-ICSI survival (82.5% vs. 84.0% vs. 83.3%, respectively), fertilization (80.0% vs. 80.0% vs. 83.3%,respectively), and blastulation rates (72.5% vs. 82.0% vs. 66.7%, respectively). Embryo morphokinetics were also not impacted. After transferring all blastocysts into recipient mice, 8 live births were achieved from the 80-MHz group, while 5 were achieved from the 200-MHz group.

Limitations, reasons for caution

Although PDMS is a popular material due to its high optical transparency and biocompatibility, adverse effects due to gas permeability and small-molecule adsorption cannot be excluded. Large-scale mouse embryo assays should be performed to assess the teratogenicity of PDMS. Operation parameters must be optimized for human COCs in clinical application.

Wider implications of the findings

Adopting widely used ultrasound techniques with emerging SAW technology is a major step toward advancing and standardizing oocyte denudation—a laborious yet delicate procedure. We predict it will be further integrated with AI and miniaturized robotics, modules specialized in gamete assessment, ICSI, and embryo evaluation in the near future.

Trial registration number

‘not applicable’

P–805 Artificial oocytes: from somatic cells to fertile pups

Study question

We analyzed the efficacy of generating artificial oocytes using somatic cells (SCs) from two mouse strains (B6D2F1 and FVB) and followed their full pre-/post-implantation development.

Summary answer

While artificial oocytes generated from the new strain (FVB) had higher fertilization rates, those from the standard strain (B6D2F1) provided expanded blastocysts and fertile pups.

What is known already

B6D2F1 is a popular hybrid mouse strain for cloning and transgenic creation due to its geno-/pheno-typic uniformity and high oocyte yield and quality. Indeed, B6D2F1 oocytes have a distinct metaphase II (MII) spindle complex, making them an ideal candidate to generate ooplasts used in SC nuclear transfer (SCNT). However, because they lack genetic variance, they are less suitable for reciprocal SCNT studies. In contrast, FVB mice have single nucleotide polymorphisms and indels on each chromosome that can aid in tracing the pedigree of progeny.

Study design, size, duration

A total of 10 experiments were performed over the course of 3 months, using 30 stimulated mice. SCs were retrieved from cumulus oophorus harvested from FVB and B6D2F1 mice. SCs from both strains were injected into enucleated MII B6D2F1 oocytes. Unmanipulated B6D2F1 oocytes were piezo-ICSI inseminated, serving as controls. The occurrence of haploidization, fertilization, and full preimplantation development was compared. Some blastocysts were transferred into pseudo-pregnant CD–1 mice to obtain offspring.

Participants/materials, setting, methods

Oocyte enucleation was performed under Oosight™ visualization and cytochalasin B exposure. An FVB or B6D2F1 SC was transferred into the perivitelline space of the ooplast with Sendai virus to promote fusion. Haploidization was monitored by pseudo-meiotic spindle formation followed by extrusion of a pseudo-polar body after insemination. Conceptuses were cultured in a time-lapse imaging system, with piezo-ICSI controls. Expanded blastocysts were transferred into uterine horns of pseudo-pregnant mice. Offspring were mated to test their fertility.

Main results and the role of chance

FVB (n = 278) and B6D2F1 (n = 905) SCs at G0 phase, with a diameter &lt;10 mm, were chosen for SCNT and transferred into enucleated B6D2F1 ooplasts. Enucleation of 1,212 oocytes yielded a survival rate of 97.6%. Both FVB and B6D2F1 SCNT resulted in similar survival rates of 100% and 98.5%, respectively. Successful haploidization, determined by the presence of a pseudo-meiotic spindle 2 hours after SCNT, was also comparable, with 59.9% of FVB and 63.7% of B6D2F1. Survival after piezo-ICSI was also comparable between FVB- and B6D2F1-reconstituted oocytes, with rates of 64.3% and 60.3%, respectively, albeit lower than the control (75.2%, P &lt; 0.00001). FVB embryos fertilized at a rate of 88.7%, comparable to the control zygotes at 85.8%, while B6D2F1 conceptuses demonstrated a lower fertilization rate (70.8%, P &lt; 0.00001). Blastulation of FVB- and B6D2F1-derived embryos was 15.1% and 24.0%, respectively, while the control was 80.7% (P &lt; 0.00001). Whole-genome karyotyping of 9 B6D2F1-derived blastocysts confirmed 5 of the samples to be euploid. FVB blastocysts (N = 8) and B6D2F1 blastocysts (N = 81) were transferred into pseudo-pregnant mice, resulting in 3 fertile offspring only from the B6D2F1 conceptuses.

Limitations, reasons for caution

This is still a limited number of observations, and pups were delivered only from the B6D2F1 strain. The utilization of a strain with higher genetic variance may help facilitate offspring fingerprinting.

Wider implications of the findings: This study demonstrates the ability to generate artificial genotyped conceptuses, yielding live offspring. The identification of a feasible donor cell, together with optimization of cell cycle stage and standardization of post-implantation development, will help promote this technique for human reproduction in couples with age-related infertility or poor ovarian reserve.

Trial registration number

N/A

O-094 Utilization of ultrastructural analysis and genomics of spermatozoa to better characterize subtle forms of male factor infertility

Study question

Can sequencing the sperm genome provide insight into the various forms of male factor infertility caused by sperm organelle ultrastructural defects?

Summary answer

A comprehensive genomic assessment of spermatozoal DNA is able to identify genetic causes of ultrastructural defects visualized by transmission electron microscopy (TEM).

What is known already

To evaluate a man’s reproductive potential, a conventional semen analysis through the assessment of concentration, motility, and morphology can indicate the proficiency of male gametes. Among those, conventional morphology assay can only provide indirect information on the different components of the sperm cell. The assessment of nanoscopic details such as chromatin, centriolar, mitochondrial, and axonemal components can only be observed by TEM. Indeed, TEM has been used to identify defects in the acrosome, chromatin compaction, and axonemal/periaxonemal structures. Furthermore, exome sequencing of spermatozoal DNA may identify novel causes and candidate genes for these ultrastructural defects.

Study design, size, duration

In the past 2 years, 20 men with history of fertilization failure or severe astheno-/terato-zoospermia were selected for TEM analysis of their spermatozoa, while 3 fertile men served as controls. Sperm head characteristics, intactness of fibrous sheath, and axonemal/periaxonemal structure were examined by diagnostic TEM. For consenting patients, NGS assessment was concurrently performed to identify mutations responsible for the structural abnormalities identified by TEM.

Participants/materials, setting, methods

TEM was performed on the ejaculates of 20 infertile patients and 3 fertile controls. Post-centrifugation cell pellets were resuspended, fixed, and dehydrated to be infiltrated and embedded onto the resin. Fixed specimens were sliced by ultramicrotome to 100-nm sections, then viewed by JEOL-1400 electron microscope at 300,000X magnification. At least 100 spermatozoa were evaluated by TEM. For consenting patients, DNA was extracted and amplified from at least 500 spermatozoa for concurrent NGS analysis.

Main results and the role of chance

Four types of sperm ultrastructural defects were observed, including globozoospermia, dysplasia of fibrous sheath (DFS), proximal centriole defect, and primary ciliary dyskinesia (PCD). One combined case of globozoospermia and DFS was identified. In globozoospermic patients (n = 13), 97-100% of the spermatozoa displayed characteristic spherical heads with absence of acrosomes, dispersed chromatin, and perinuclear theca deformities. Centrosomal and axonemal structures were conserved. NGS identified gene deletions (DPY19L, PICK1, SPATA16) directly related to the globozoospermic phenotype. In patients with DFS (n = 4), complete absence of flagellum was observed in 90-100% of spermatozoa. These defective gametes also displayed mitochondria disorganization, microtubular deformities, and cytoplasmic residues containing coiled flagellum with deformed capitulum within the plasma membrane. Contrary to the globozoospermia, acrosomes and nuclei appeared normal, indicating incomplete late spermiogenesis. Indeed, NGS confirmed gene deletions involved in flagellar development/function (AKAP4, SPAG16, CATSPER1). For the patient with proximal centriole defect (n = 1), sperm nucleus, fibrous sheath, and flagellar structure were conserved. However, 90% of proximal centrioles assessed exhibited microtubular disorganization, confirmed by ODF2 mutation per NGS. In the PCD patient (n = 1), chaotic flagellar microtubule arrangement and absence of outer dynein arms were prevalent in 90% of axonemal cross-sections examined, which was explained by a DNAH5 gene deletion.

Limitations, reasons for caution

While TEM can overcome the limitations of conventional semen analysis by providing direct visualization of the inner organelle arrangement of spermatozoa to accurately diagnose rare sperm pathologies, it is not routinely applied in clinics due to its high cost and technical specifications. Therefore, confirmatory NGS can provide additional diagnostic value.

Wider implications of the findings

Ultrastructural analysis with a concurrent genomic assessment characterized phenotypes and genotypes of rare sperm pathologies in infertile men. The utilization of TEM, corroborated by genomic assay, is therefore crucial for clinical and translational reproductive medicine to better characterize male factor infertility.

Trial registration number

N/A

P–120 Selecting spermatozoa with the highest genomic integrity in order to enhance clinical outcomes in men with high DNA fragmentation levels

Study question

What are the best methods of selecting spermatozoa with the highest genomic integrity in order to improve embryo implantation and term pregnancy rates with ICSI?

Summary answer

Testicular or ejaculate spermatozoa isolated by microfluidic sperm selection (MFSS) were characterized by superior genomic integrity with improved clinical pregnancy and delivery rates.

What is known already

In couples with unexplained infertility, a subtle male factor can often be identified. Both single-strand (ss) and double-strand (ds) DNA nicks and breaks hinder the ability of the male gamete to support embryonic development. Surgical retrieval of spermatozoa from the proximal male genital tract can prevent their exposure to oxidative stress. Moreover, use of membrane-based microfluidics chips has been shown to allow for selection of the most progressively motile spermatozoa with higher genomic integrity.

Study design, size, duration

Over the course of 48 months, 86 consenting men presenting with high sperm chromatin fragmentation (SCF) in their ejaculate with prior ART failure underwent a subsequent cycle with specimens retrieved by testicular biopsy or ejaculate processed by MFSS. A concurrent TUNEL assay was performed on samples collected or selected by each method. Sperm specimens of both origins were utilized for ICSI cycles. Semen parameters, chromatin integrity, and pregnancy outcomes were compared between the two methods.

Participants/materials, setting, methods

Fresh ejaculates from consenting men were collected for standard semen analysis (WHO 2010). Testicular biopsy and MFSS were used to isolate spermatozoa with a higher genomic integrity after previous ART failure. SCF was assessed by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) on at least 500 spermatozoa under a fluorescent microscope with a threshold of ≥ 15%. MFSS was carried out by Zymot® chips. ICSI was performed in the standard fashion.

Main results and the role of chance

A total of 86 men (36.5±5 years) had the following semen parameters: volume of 2.6 ±1mL, concentration of 27.0±33 x 106/mL, 35.6±15% motility, and high SCF (24.1±10%). They underwent 146 ICSI cycles with their partners (maternal age, 33.7±3) resulting in a high incidence of pregnancy loss (100%; 13/13). Of those who failed to conceive, 22 couples used surgically retrieved spermatozoa (SRS) with a concentration of 1.8 ± 4 x 106/mL (P &lt; 0.01), 5.0±11% motility (P &lt; 0.01), and an SCF of 12.6 ± 6% (P &lt; 0.0001). SRS was used in 37 ICSI cycles, yielding a fertilization rate of 61.6% (204/331, P &lt; 0.01), an implantation rate of 10.6% (9/85, P &lt; 0.01), a CPR of 23.5% (8/34, P &lt; 0.01), and a delivery rate of 17.6% (6/34, P &lt; 0.01). Another 24 couples underwent ICSI cycles with ejaculated spermatozoa processed by MFSS with a concentration of 1.8±3 x 106/mL (P &lt; 0.01), but an increased motility of 99±1% (P &lt; 0.01) and an SCF of 1.2 ±1%, lower than both the raw and testicular specimens (P &lt; 0.0001). MFSS-processed specimens resulted in a fertilization rate of 76% (335/441, P &lt; 0.01), an implantation rate of 26.3% (15/57, P &lt; 0.05), and a CPR of 67.9% (19/28, P &lt; 0.01), of which 15 patients delivered and 2 pregnancies are ongoing (89.5%; P &lt; 0.01).

Limitations, reasons for caution

This is a preliminary study on a small number of subjects. A randomized prospective study conducted on a larger cohort would be required to confirm our findings.

Wider implications of the findings: SCF severely affects pregnancy by impairing embryonic development, consequently promoting implantation failure. While retrieving spermatozoa from the germinal epithelium is a viable option, MFSS provides an alternative. Although MFSS requires an adequate number of sperm with good kinetic characteristics, it provides a more palatable option, reducing surgical risk and costs.

Trial registration number

Not applicable

P–525 Analysis of segregation patterns of trivalent structure and the effect on genome stability in Robertsonian translocation carriers

Study question

What are the factors that affect the separation pattern of Robertsonian translocation trivalent, and whether the structure of the trivalent affected the chromosome stability?

Summary answer

The meiotic segregation modes can be affected by the carrier’s sex and special chromosome, and a trivalent structure can affect the stability of the genome.

What is known already

Robertson translocation occurs when two proximal acrocentric chromosomes fuse at the centromere, and forms a trivalent structure during meiosis. This structure will affect the fertility of Robertsonian translocation carriers, and may destroy the stability of the genome by affecting the separation of other chromosomes, which is called Inter-Chromosomal Effect (ICE). Previous research have confirmed that the use of PGT in Robertsonian translocation carriers can effectively reduce abortion and increase live birth. But some studies dispute this conclusion and the existence of ICE. However, there is no large data study to verify these controversies.

Study design, size, duration

PGT results of 928 oocyte retrieval cycles in 763 couples(one of the couples is a Robertsonian translocation carrier) were analysied from December 2012 to June 2020. A total of 1492 couples who received PGT-A were collected as control group, and matched according to age and testing time stage. The study was approved by the ethics committee(LL-SC-SG–2006–008 and LL-SC-SG–2014–016).

Participants/materials, setting, methods

Cytogenetic analysis was performed using GTG standard method (trypsin and GiemsaG banding) to analyze the chromosomes of peripheral blood lymphocytes. Blastocysts obtained by standard IVF procedure were biopsied on the 5th or 6th morning after fertilization, and the trophoblast cells were amplified by PicoPLEX whole genome amplification kit (Rubicon Genology) or Repli-g Single Cell Kit(Qiagen). PGT-SR was performed using SNP array or NGS as previously described.

Main results and the role of chance

In this study, a total of 3423 blastocysts from 763 couples were analysed using SNP-array or NGS. Among them, the rate of alternate segregation of male Robertsonian translocation carriers was significantly higher than that in female carriers (82.26% vs 59.96%, P &lt; 0.001), and meiotic segregation modes could be affected by the special chromosome such as 13 in female(P = 0.042) and 15 in male(P = 0.045) involved. A trivalent structure can affect the stability of the genome during mitosis, which is associated with an increase in the propotion of chromosome mosaic compared with the PGT-A control group(1.18% vs 0.53%, P &lt; 0.01). In addition, we found an interesting phenomenon: in the meiotic segregation of female Robertsonian translocation carriers associated with chromosomes 21 and 22, the chromosome 21 or 22 of the two chromosomes involved in translocation are more likely to be abnormal, and according to our results, the effect of chromosome 21 seems to be greater.

Limitations, reasons for caution

(1) Limitations of retrospective analysis; (2) The results are not fully representative of the general population; (3) PGT-A patients always had repeated implantation failure or recurrent aboration, which may cause deviation to the results.

Wider implications of the findings: This study analyzed the influencing factors of the separation patterns of trivalent, and verified the existence of ICE. This suggest that PGT-SR can have a better outcome in patients with Robertsonian translocation, especially in male carriers. These results will provide carrier couple with more appropriate genetic counseling.

Trial registration number

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Heterotrimeric G protein signalling in plant biotic and abiotic stress response

Heterotrimeric G proteins act as molecular switches to participate in transmitting various stimuli signals from outside of cells. G proteins have three subunits, Gα, Gβ and Gγ, which function mutually to modulate many biological processes in plants, including plant growth and development, as well as biotic and abiotic stress responses. In plants, the number of Gγ subunits is larger than that of the α and β subunits. Based on recent breakthroughs in studies of plant G protein signal perception, transduction and downstream effectors, this review summarizes and analyses the connections between different subunits and the interactions of G proteins with other signalling pathways, especially in plant biotic and abiotic stress responses. Based on current progress and unresolved questions in the field, we also suggest future research directions on G proteins in plants.