Female Embryos Research Articles

XIST dampens X chromosome activity in a SPEN-dependent manner during early human development.

XIST (X-inactive specific transcript) long noncoding RNA (lncRNA) is responsible for X chromosome inactivation (XCI) in placental mammals, yet it accumulates on both X chromosomes in human female preimplantation embryos without triggering X chromosome silencing. The XACT (X-active coating transcript) lncRNA coaccumulates with XIST on active X chromosomes and may antagonize XIST function. Here, we used human embryonic stem cells in a naive state of pluripotency to assess the function of XIST and XACT in shaping the X chromosome chromatin and transcriptional landscapes during preimplantation development. We show that XIST triggers the deposition of polycomb-mediated repressive histone modifications and dampens the transcription of most X-linked genes in a SPEN-dependent manner, while XACT deficiency does not significantly affect XIST activity or X-linked gene expression. Our study demonstrates that XIST is functional before XCI, confirms the existence of a transient process of X chromosome dosage compensation and reveals that XCI and dampening rely on the same set of factors.

Curcumin Affects the Proliferation and Neurogenesis of Embryonic Neural Stem Cells in Rats

Background: Curcumin, found in the rhizome of Curcuma longa, demonstrates anti-inflammatory and neuroprotective properties. Objectives: This study aims to assess its effects on the proliferation and differentiation of embryonic neural stem cells (NSCs). Methods: Female rats (n = 36) became pregnant, resulting in the formation of embryos (n = 176). Neural stem cells from female embryos (n = 50, embryonic day 15.5, E15.5) were cultured in a serum-free medium with growth factors (FGF-2 and EGF). Curcumin was then added at doses of 0.1, 0.5, and 1 µM. The proliferation of NSCs was assessed using the MTT colorimetric assay, nestin immunofluorescence labeling, and RT-PCR. NSC differentiation was compared using immunocytochemistry (ICC) and RT-PCR for nestin, glial fibrillary acidic protein (GFAP), and class III β-tubulin (Tuj-1). Results: Curcumin at concentrations of 0.1 and 0.5 µM increased the proliferation of NSCs, as indicated by an increase in neurosphere diameter. Similarly, the MTT assay showed that curcumin at doses of 0.1 and 0.5 µM enhanced the viability of NSCs. In the differentiation condition, no significant difference was observed. However, RT-PCR analysis showed that nestin and GFAP expressions reached their highest levels in cells treated with curcumin at a dose of 0.5 µM, while Tuj-1 expression significantly increased in cells treated with curcumin at a dose of 1 µM. Conclusions: Curcumin at lower doses may regulate the proliferation and differentiation of NSCs. Treating NSCs with curcumin could provide a promising option for pre-differentiation before cell therapy.

Man and embryo: Historicizing ideas about humanity in the study of reproduction, 18th–19th centuries

AbstractThis article is concerned with historicizing the idea that all people belong to a single collective of biological human beings. It analyzes implications and changes in the concept of “Man” over the 18th and 19th centuries, particularly in the study of reproduction and embryos. Examining gendered assumptions in 18th‐century generation systems shows how these theories described the formation of male more than female embryos. This asymmetry matched the idea that only rational males, standing above nature, were determinant for the concept of Man. In the 19th century, new studies pushed Man closer to the rest of the natural world, provoking a readjustment in definitions of Man and understandings of the human embryo. However, far from equalizing humanity, the 19th‐century concept of Man introduced a hierarchy in the human species based on different levels of embryonic and evolutionary development.

Ovum Pick Up and in vitro Embryo Production using Sex Sorted Semen in Cows

Background: Ovum pick-up, a technique for extracting immature oocytes from antral follicles, with in vitro embryo production, is a way to produce large number of embryos from live donors. Methods: By transvaginal ultrasound-guided ovum pick-up, oocytes were collected from large (9-19 mm), medium (4-8 mm) and small (2-3 mm) ovarian follicles of donor cows (n=8). The recovered oocytes were classified as A, B, C, D and E grades. Oocytes were subjected toin vitro maturation, fertilization (with sex sorted semen) and culture. Cleavage and blastocyst rates were recorded on day 4 and day 7 of culture respectively. Result: Total of 278 follicles were aspirated. The follicles aspirated per cow per OPU session was 12.67±1.86. The oocyte recovery rate was 45.31±7.35. Mean percentage of grade A, B, C, D and E oocytes was 15.69±3.91, 24.97±3.02, 37.53±3.45, 19.44±3.76 and 2.38±2.38 respectively. In vitro maturation rate (IVM%) was 91.71±2.38% and fertilization rate was 90.18±1.52%. Cleavage and blastocyst rates observed was 55.1±5.90 and 24.81±2.95% respectively. The mean percentages of different grades of embryos observed was, code 1: 21.13±2.78, code 2: 14.41±3.25, code 3: 19.56±4.11 and code 4: 44.9±5.90%. Transvaginal ovum pick up can be performed repeatedly without hormonal stimulation. Sex sorted semen can be used for in vitro production of female embryos.

Gonadal Transcriptome Analysis Reveals that SOX17 and CYP26A1 are Involved in Sex Differentiation in the Chinese Soft-Shelled Turtle (Pelodiscus sinensis).

The Chinese soft-shelled turtle (Pelodiscus sinensis) is an important aquaculture animal in China and exhibits growth dimorphism. Single-male cultures are often selected for higher economic efficiency. However, the mechanism of sex differentiation in P. sinensis is not well-known. In this study, a comparative transcriptome analysis of male (ZZ)- and 17β-oestradiol (E2)-induced pseudo-female (ZZ + E2)-stage embryonic gonads of P. sinensis was performed. A total of 420 differentially expressed genes (DEGs), which included 271 upregulated genes and 149 downregulated genes, were identified. These DEGs were mainly involved in several sex-related pathways, such as "ovarian steroidogenesis", "steroid hormone biosynthesis", "PPAR signalling pathway", and "metabolism of xenobiotics by cytochrome P450". In addition, 50 known and novel candidate genes involved in sex differentiation, such as the male-biased genes AMH, DMRT1, TBX1, and CYP26A1 and the female-biased genes CYP1A1, RASD1, and SOX17, were investigated and identified. For further verification, the full-length cDNAs of SOX17 and CYP26A1 were obtained. SOX17 contains a 1218-bp ORF and encodes 405 amino acids containing an HMG functional domain unique to the Sox superfamily. CYP26A1 contains a 1485-bp ORF and encodes 494 amino acids. Different expression levels of SOX17 and CYP26A1 could be detected in all the tested tissues of males and females. Notably, the expression of CYP26A1 was markedly greater in the gonads of male embryos (P < 0.05) than in those of female embryos, whereas the expression of SOX17 showed the opposite trend (P < 0.05). Taken together, the RNA-seq and qRT‒PCR results suggested potential roles for SOX17 and CYP26A1 in promoting female and male gonadal development, respectively, in P. sinensis. Our results provide new evidence for the mechanism of sex differentiation in P. sinensis.

Identification of potential candidate genes for the Huoyan trait in developing Wulong goose embryos by transcriptomic analysis

ABSTRACT 1. The Wulong goose is a Chinese breed and a source of high-quality meat and eggs. A characteristic of the Wulong goose is that a proportion of the birds do not have eyelids, known as the Huoyon trait. 2. Wulong geese exhibiting the Huoyan trait at embryonic stages of 9 days (E9), 12 days (E12) and 14 days (E14) were selected alongside those with normal eyelids for comprehensive transcriptome sequencing. Differentially expressed gene (DEG) and functional enrichment analyses were performed and finally, eight DEG were chosen to verify the accuracy of qPCR sequencing. 3. Overall, 466, 962 and 550 DEG were obtained from the three control groups, D9 vs. N9, D12 vs. N12 and D14 vs. N14, respectively, by differential analysis (p < 0.05). CDKN1C, CRH, CROCC and TYSND1 were significantly expressed in the three groups. Enrichment analysis revealed the enrichment of CROCC and TYSND1 in pathways of cell cycle process, endocytosis, microtubule-based process, microtubule organising centre organisation, protein processing and protein maturation. CDKN1C and CRH were enriched in the cell cycle and cAMP signalling pathway. 4. Some collagen family genes were detected among the DEGs, including COL3A1, COL4A5, COL4A2 and COL4A1. FREM1 and FREM2 genes were detected in both Huoyan and normal eyelids. There was a significant difference (p < 0.01) in FREM1 expression between ED9 and ED14 in female embryos, but this difference was not observed in male embryos.

Contribution of the seminal microbiome to paternal programming.

The field of Developmental Origins of Health and Disease has primarily focused on maternal programming of offspring health. However, emerging evidence suggests that paternal factors, including the seminal microbiome, could potentially play important roles in shaping the developmental trajectory and long-term offspring health outcomes. Historically, the microbes present in the semen were regarded as inherently pathogenic agents. However, this dogma has recently been challenged by the discovery of a diverse commensal microbial community within the semen of healthy males. In addition, recent studies suggest that the transmission of semen-associated microbes into the female reproductive tract during mating has potentials to not only influence female fertility and embryo development but could also contribute to paternal programming in the offspring. In this review, we summarize the current knowledge on the seminal microbiota in both humans and animals followed by discussing their potential involvement in paternal programming of offspring health. We also propose and discuss potential mechanisms through which paternal influences are transmitted to offspring via the seminal microbiome. Overall, this review provides insights into the seminal microbiome-based paternal programing, which will expand our understanding of the potential paternal programming mechanisms which are currently focused primarily on the epigenetic modifications, oxidative stresses, and cytokines.

Correlation between selenium protein-1 levels and the quality of oocytes and embryos in females undergoing in-vitro fertilization

Correlation between selenium protein-1 levels and the quality of oocytes and embryos in females undergoing in-vitro fertilization

Effect of baseline prolactin levels on the pregnancy outcomes after fresh embryo transfer.

There is clinical disagreement on whether to treat hyperprolactinemia with medication before embryo transfer. The aim of this study is to identify the impact of basal prolactin (PRL) levels on pregnancy outcomes in fresh embryo transfer cycles. This retrospective study involved 2,648 women who underwent basal PRL level testing and fresh embryo transfer between January 2015 and December 2020 at our Hospital's Department of Assisted Reproduction. Basal PRL levels can be classified into three categories:<30 (n=2339), 30‑60 (n=255), and ≥60 (n=54) µg/l. Pregnancy outcome was defined as the primary outcome measure, and the live birth rate was defined as the second outcome measure. Subsequently, univariate and multivariable logistic regression analysis was used to reveal the association between basal PRL levels and pregnancy outcomes after considering several potential confounding factors. Elevated basal PRL levels were found not a risk factor for pregnancy outcomes in patients receiving good-quality embryo transfer (p>.05). For pregnancy or not, female age (OR: 1.03; 95% CI: 1.01-1.05), embryos transferred (OR: 0.52; 95% CI: 0.41-0.65), and normal fertilization rate (OR: 0.68; 95% CI: 0.48-0.97) were found to be an independent risk factor. For ongoing pregnancy or not, female age (OR: 1.07; 95% CI: 1.03-1.11), embryos transferred (OR: 0.57; 95% CI: 0.37-0.88), and menstrual cycle (OR: 1.76; 95% CI: 1.22-2.54) were also independent risk factors. There is no adverse impact on pregnancy outcomes during embryo transfer cycles with good-quality embryos when PRL levels are elevated.

Identification of gene isoforms and their switching events between male and female embryos of the parthenogenetic crustacean Daphnia magna

The cladoceran crustacean Daphnia exhibits phenotypic plasticity, a phenomenon that leads to diverse phenotypes from one genome. Alternative usage of gene isoforms has been considered a key gene regulation mechanism for controlling different phenotypes. However, to understand the phenotypic plasticity of Daphnia, gene isoforms have not been comprehensively analyzed. Here we identified 25,654 transcripts derived from the 9710 genes expressed during environmental sex determination of Daphnia magna using the long-read RNA-Seq with PacBio Iso-Seq. We found that 14,924 transcripts were previously unidentified and 5713 genes produced two or more isoforms. By a combination of Illumina short-read RNA-Seq, we detected 824 genes that implemented switching of the highest expressed isoform between females and males. Among the 824 genes, we found isoform switching of an ortholog of CREB-regulated transcription coactivator, a major regulator of carbohydrate metabolism in animals, and a correlation of this switching event with the sexually dimorphic expression of carbohydrate metabolic genes. These results suggest that a comprehensive catalog of isoforms may lead to understanding the molecular basis for environmental sex determination of Daphnia. We also infer the applicability of the full-length isoform analyses to the elucidation of phenotypic plasticity in Daphnia.

Sexual dimorphic miRNA-mediated response of bovine elongated embryos to the maternal microenvironment.

A skewed male-to-female ratio in cattle is believed to be due to the biased embryo losses during pregnancy. The changes in biochemical secretion such as miRNAs by the embryo due to altered maternal environment could cause a sex biased selective implantation resulting in a skewed male to female ratio at birth. Nevertheless, it is still not clear whether the male and female embryos could modify their miRNA expression patterns differently in response to altered physiological developmental conditions. Therefore, this study was focused on identifying sex specific miRNA expression patterns induced in the embryo during the elongation period in response to the maternal environment. For this, in vitro produced day female and male embryos were transferred to Holsteins Frisian cows and heifers. The elongated female and male embryos were then recovered at day 13 of the gestation period. Total RNA including the miRNAs was isolated from each group of elongated embryo samples were subjected to the next generation miRNA sequencing. Sequence alignment, identification and quantification of miRNAs were done using the miRDeep2 software package and differential miRNA expression analyses were performed using the edgeR bioconductor package. The recovery rate of viable elongating embryos at day 13 of the gestation period was 26.6%. In cows, 2.8 more viable elongating male embryos were recovered than female embryos, while in heifers the sex ratio of the recovered elongating embryos was close to one (1.05). The miRNA analysis showed that 254 miRNAs were detected in both male and female elongated embryos developed either in cows or heifers, of which 14 miRNAs including bta-miR-10b, bta-miR-148a, bta-miR-26a, and bta-miR-30d were highly expressed. Moreover, the expression level of 32 miRNAs including bta-let-7c, bta-let-7b, bta-let-7g, bta-let-7d and bta-let-7e was significantly different between the male and female embryos developed in cows, but the expression level of only 4 miRNAs (bta-miR-10, bta-mR-100, bta-miR-155 and bta-miR-6119-5p) was different between the male and female embryos that were developed in heifers. Furthermore, 19 miRNAs including those involved in cellular energy homeostasis pathways were differentially expressed between the male embryos developed in cows and heifers, but no significantly differentially expressed miRNAs were detected between the female embryos of cows and heifers. Thus, this study revealed that the sex ratio skewed towards males in embryos developed in cows was accompanied by increased embryonic sexual dimorphic miRNA expression divergence in embryos developed in cows compared to those developed in heifers. Moreover, male embryos are more sensitive to respond to the maternal reproductive microenvironment by modulating their miRNA expression.

Evaluation of blastocyst re-expansion, quality in relation to storage temperature, and sexing using blastocoel fluid after manual perforation with a hand-held needle involving in vivo produced equine embryos

The present study was designed to evaluate equine blastocyst re-expansion rate, quality, and sex following perforation of the blastocoel, collection of blastocoel fluid (BF), and PCR amplification of free DNA. Experiment 1 tested the feasibility of the BF sample collection with a hand-held, small-gauged needle (26g) and subsequent PCR amplification of the TSP-Y gene for males and AMEL-Y gene for males and AMEL-X gene for females. Experiment 2 tested the application of the technique. Equine embryos were collected via uterine flushes 8d after ovulation. Thereafter, embryos (n = 19) were initially assessed and transferred to a 50 μL droplet of holding medium in which the blastocoel was manually perforated as in Experiment 1. Within 1 min of detecting a diameter decrease or collapse, the entire volume of each droplet of medium was collected and stored at −20 °C until PCR. In Experiment 1, amplification of the TSP-Y gene was positive for males at 60% (9/15) and negative for females at 40% (6/15). In Experiment 2, a total of 42 embryos were randomly assigned to a collapsed embryo (CE) or intact embryo (IE) groups and stored at room temperature (RT, 25 °C) or cold temperature (CT, 5 °C) for 24h as follows: 1) CERT, n = 11; 2) CECT n = 11; 3) IERT, n = 10; and 4) IECT, n = 10. After 24h, embryo diameter and quality were reassessed. For all collapsed embryos (n = 19), blastocoel fluid was subjected to double PCR amplification of the TSPY gene with blood from adult male and female horses as controls. Positive gene amplification indicated 57.9% (11/19) of embryos were male and negative amplification indicated 31.6% (6/19) of embryos were female. Relative to the least diameter (0%) after perforation of collapsed embryos or fullest diameter (100%) of intact embryos at T0, percentage change in diameter and quality Grade 1 or 2 embryos after 24h of storage for all groups were, respectively: 31.2% and 54% for CERT group, 28.2% and 0% for CECT group, 25.9% and 100% for IERT group, 4.3% and 80% for IECT group, respectively. Thus, needle-induced leakage and collapse of the blastocoel at T0 resulted in a high rate of blastocyst re-expansion (69%) with many embryos (54%) achieving good quality at T24 with potential for transfer as either male or female embryos. For both collapsed and intact embryos, it was observed that storage for 24h at room temperature (25 °C) was associated with improved embryo growth and morphological quality compared to storage at cold temperature (5 °C).

Developing and validating a prediction model of live birth following single vitrified–warmed blastocyst transfer

Research questionCan the developed clinical prediction model offer an accurate estimate of the likelihood of live birth, involving blastocyst morphology and vitrification day after single vitrified–warmed blastocyst transfer (SVBT), and therefore assist clinicians and patients? Study designRetrospective cohort study conducted at a Spanish university-based reproductive medicine unit (2017–2021) including consecutive vitrified–warmed blastocysts from IVF cycles. A multivariable logistic regression incorporated key live birth predictors: vitrification day, embryo score, embryo ploidy status and clinically relevant variables, i.e. maternal age. ResultsThe training set involved 1653 SVBT cycles carried out between 2017 and 2020; 592 SVBT cycles from 2021 constituted the external validation dataset. The model revealed that female age and embryo characteristics, including overall quality and blastulation day, is linked to live birth rate in SVBT cycles. Stratification by vitrification day and quality (from day-5A to day-6 C blastocysts) applied to genetically tested and untested embryos. The model's area under the curve was 0.66 (95% CI 0.64 to 0.69) during development and 0.65 (95% CI 0.61 to 0.70) in validation, denoting moderate discrimination. Calibration plots showed strong agreement between predicted and observed probabilities. ConclusionBy incorporating essential predictors such as vitrification day, embryo morphology grade, age and preimplantation genetic testing for aneuploidy usage, this predictive model offers valuable guidance to clinicians and patients, enabling accurate forecasts of live birth rates for any given vitrified blastocyst within SVBT cycles. Additionally, it serves as a potentially indispensable laboratory tool, aiding in selecting the most promising blastocysts for optimal outcomes.

Asymmetric growth-limiting development of the female conceptus.

Sex differences in prenatal growth may contribute to sex-dependent programming effects on postnatal phenotype. We integrated for the first time phenotypic, histomorphological, clinico-chemical, endocrine and gene expression analyses in a single species, the bovine conceptus at mid-gestation. We demonstrate that by mid-gestation, before the onset of accelerated growth, the female conceptus displays asymmetric lower growth compared to males. Female fetuses were smaller with lower ponderal index and organ weights than males. However, their brain:body weight, brain:liver weight and heart:body weight ratios were higher than in males, indicating brain and heart 'sparing'. The female placenta weighed less and had lower volumes of trophoblast and fetal connective tissue than the male placenta. Female umbilical cord vessel diameters were smaller, and female-specific relationships of body weight and brain:liver weight ratios with cord vessel diameters indicated that the umbilico-placental vascular system creates a growth-limiting environment where blood flow is redistributed to protect brain and heart growth. Clinico-chemical indicators of liver perfusion support this female-specific growth-limiting phenotype, while lower insulin-like growth factor 2 (IGF2) gene expression in brain and heart, and lower circulating IGF2, implicate female-specific modulation of key endocrine mediators by nutrient supply. This mode of female development may increase resilience to environmental perturbations in utero and contribute to sex-bias in programming outcomes including susceptibility to non-communicable diseases.

The recipient metabolome explains the asymmetric ovarian impact on fetal sex development after embryo transfer in cattle.

In cattle, lateral asymmetry affects ovarian function and embryonic sex, but the underlying molecular mechanisms remain unknown. The plasma metabolome of recipients serves to predict pregnancy after embryo transfer (ET). Thus, the aim of this study was to investigate whether the plasma metabolome exhibits distinct lateral patterns according to the sex of the fetus carried by the recipient and the active ovary side (AOS), i.e., the right ovary (RO) or the left ovary (LO). We analyzed the plasma of synchronized recipients by 1H+NMR on day 0 (estrus, n = 366) and day 7 (hours prior to ET; n = 367). Thereafter, a subset of samples from recipients that calved female (n = 50) or male (n = 69) was used to test the effects of embryonic sex and laterality on pregnancy establishment. Within the RO, the sex ratio of pregnancies carried was biased toward males. Significant differences (P < 0.05) in metabolite levels were evaluated based on the day of blood sample collection (days 0, 7 and day 7/day 0 ratio) using mixed generalized models for metabolite concentration. The most striking differences in metabolite concentrations were associated with the RO, both obtained by multivariate (OPLS-DA) and univariate (mixed generalized) analyses, mainly with metabolites measured on day 0. The metabolites consistently identified through the OPLS-DA with a higher variable importance in projection score, which allowed for discrimination between male fetus- and female fetus-carrying recipients, were hippuric acid, l-phenylalanine, and propionic acid. The concentrations of hydroxyisobutyric acid, propionic acid, l-lysine, methylhistidine, and hippuric acid were lowest when male fetuses were carried, in particular when the RO acted as AOS. No pathways were significantly regulated according to the AOS. In contrast, six pathways were found enriched for calf sex in the day 0 dataset, three for day 7, and nine for day 7/day 0 ratio. However, when the AOS was the right, 20 pathways were regulated on day 0, 8 on day 7, and 13 within the day 7/day 0 ratio, most of which were related to amino acid metabolism, with phenylalanine, tyrosine, and tryptophan biosynthesis and phenylalanine metabolism pathways being identified throughout. Our study shows that certain metabolites in the recipient plasma are influenced by the AOS and can predict the likelihood of carrying male or female embryos to term, suggesting that maternal metabolism prior to or at the time of ET could favor the implantation and/or development of either male or female embryos.

Individualized luteal phase support in frozen-thawed embryo transfer after intramuscular progesterone administration might rectify live birth rate.

The serum P concentrations are suggested to have an impact on pregnancy outcome. However there is no consensus about the optimal progesterone cut-off during the luteal phase. Few studies evaluated the effectiveness of a "rescue protocol" for low serum P concentrations and most of these studies used vaginal progesterone administration. There is paucity of data on the effectiveness of rescue protocol using intramuscular progesterone (IM-P) in frozen-thawed embryo transfer (FET). This study is a retrospective cohort study included 637 single or double blastocyst FETs with artificially prepared endometrium receiving 100 mg IM progesterone (P) after incremental estrogen treatment. Serum P concentrations were evaluated using blood samples obtained 117-119 hours after the first IM-P administration and 21 ± 2 hours after the last IM-P administration. Patients with serum P concentrations <20.6 ng/ml on the ET day were administrated 400 mg vaginal progesterone for rescue. Demographic and cycle characteristics were similar between patients receiving rescue vaginal P (embryo transfer (ET)-day P concentration < 20.6 ng/ml) and patients who did not need rescue vaginal P (ET-day P concentration ≥ 20.6 ng/ml). Clinical pregnancy, miscarriage, and live birth rates were similar between two groups: 52.9%(45/85) vs 59.6%(326/552), p=0.287; 11.1%(5/45) vs 14.1%(46/326), p=0.583; and 47.1%(40/85) vs 50.7%(280/552), p=0.526, respectively. Logistic regression analysis revealed that the female age (p = 0.008, OR=0.942, 95% CI = 0.902-0.984) and embryo quality (ref: good quality for moderate: p=0.02, OR=0.469, 95% CI =0.269-0.760; for poor: p=0.013, OR= 0.269, 95% CI = 0.092-0.757) were independent variables for live birth. Following rescue protocol implementation, ET-day P concentration was not a significant predictor of live birth. Rescue vaginal P administration for low ET day serum P concentrations following IM-P yields comparable live birth rates.

Biological characteristics and functions of a novel glutamate dehydrogenase from Trichinella spiralis.

Glutamate dehydrogenase (GDH) plays an important role in the metabolism of organisms. Its high abundance in mitochondria in particular highlights its core role in cellular physiological processes. GDH catalyzes the mutual conversion between L-glutamic acid and α-ketoglutaric acids. At the same time, this transformation is accompanied by the oxidation-reduction of NAD(H) or NADP(H). This process not only helps to link amino acid metabolism with sugar metabolism, but also helps maintain the balance of intracellular pH and nitrogen homeostasis. In this study, a novel Trichinella spiralis glutamate dehydrogenase (TsGDH) was cloned, expressed and identified. The results revealed that TsGDH was expressed at various stages of development of the nematode T. spiralis, with higher expression levels in the adult worm stage, and was mainly localized in the cuticle, muscular layer, stichosome and female intrauterine embryos. After RNAi treatment, larval natural TsGDH enzyme activity was obviously reduced, and metabolism, molting, growth and reproduction were also significantly inhibited. The results indicate that TsGDH plays an important role in the development and survival of T. spiralis, and it may be a potential molecular target of anti-Trichinella vaccines and drugs.

Sex-specific transcriptome of the chicken chorioallantoic membrane

Dimorphism between male and female embryos has been demonstrated in many animal species, including chicken species. Likewise, extraembryonic membranes such as the chorioallantoic membrane (CAM) are likely to exhibit a sex-specific profile. Analysis of the previously published RNA-seq data of the chicken CAM sampled at two incubation times, revealed 783 differentially expressed genes between the CAM of male and female embryos. The expression of some of these genes is sex-dependant only at one or other stage of development, while 415 genes are sex-dependant at both developmental stages. These genes include well-known sex-determining and sex-differentiation genes (DMRT1, HEGM, etc.), and are mainly located on sex chromosomes. This study provides evidence that gene expression of extra-embryonic membranes is differentially regulated between male and female embryos. As such, a better characterisation of associated mechanisms should facilitate the identification of new sex-specific biomarkers.

#116 : Prevalence of Aneuplodies in Chromosomes 13, 18, 21, X and Y in Embryos Generated by ICSI of Fertile Couples

Background and Aims: It has previously been reported that up to 70% of the embryos generated in an ART lab are chromosomally abnormal. Abnormalities in chromosomes 13, 18, 21, X and Y have been observed to be as common as 63% in embryos of sub-fertile couples. The aim of this study was to find if these abnormalities are just as common in embryos of fertile couples who have no history of an affected child. Method: A retrospective cohort study was conducted on 409 embryos obtained from 113 couples undergoing preimplantation genetic testing at an ART center in Pakistan, between 1 January 2021 and 31 December 2022. The inclusion criteria was that fertile couples who had come for gender selection for family balancing. Age range of female partners was 28 years to 38 years. Male partners had normal semen parameters as per the World Health Organization (WHO) guidelines. Results: A total of 70.7% (289/409) were unaffected by aneuploides in the five chromosomes. There was a significant difference in the ratio of normal to abnormal embryos. Out of the normal embryos, there was no significant difference in the male (34.5%) and female (36.1%) embryos. There was no significant difference in the number of abnormal female and male embryos (p=0.127). Among the aneuploidies in the five chromosomes, trisomy 21 was the most common (n=27; 6.6%). Conclusion: Approximately 20% of sub-fertile couples have an unknown etiology. Our results indicate that the five commonly known aneuploidies found in embryos of sub-fertile patients have a low prevalence in fertile patients. It is worth noting that this study is limited by the fact that abnormalities in sub-fertile couple were not analyzed and statistics from other already published studies was relied upon. Nonetheless, this data has provided perspectives for counselling couples of unexplained sub-fertility.

Maternal physical activity affects yolk sac size and growth in early pregnancy, but girls and boys use different strategies

This longitudinal study investigated the impact of actigraphy-measured maternal physical activity on yolk sac size during early development. The yolk sac, a transient extraembryonic organ, plays a crucial role in embryonic development and is involved in metabolism, nutrition, growth, and hematopoiesis. Prospectively collected data from 190 healthy women indicated that their total daily physical activity, including both light and moderate-vigorous activity, was associated with yolk sac growth dynamics depending on embryonic sex and gestational age. Higher preconception maternal physical activity was linked to a larger yolk sac at 7 weeks (95% CI [0.02–0.13 mm]) and a smaller yolk sac at 10 weeks’ gestation (95% CI [− 0.18 to − 0.00]) in male embryos; in female embryos, the yolk sac size was increased at 10 weeks’ gestation (95% CI [0.06–0.26]) and was, on average, 24% larger than that in male embryos (95% CI [0.12–0.38]). Considering the pattern of other maternal effects on yolk sac size—e.g., body composition and sleep duration—we suggest that physiological yolk sac adaptations occur in short, sex-specific time windows and can be influenced by various maternal factors.