Search Results (756)

This review aims to discuss how heat stress affects ovarian follicles and oocytes, steroidogenesis, and embryo development in ruminants. The literature shows that quiescent primordial follicles appear to be less susceptible to heat stress, but from the primary follicle stage onwards, they begin to suffer the consequences of heat stress. These adverse effects are exacerbated when the follicles are cultured in vitro. In antral follicles, heat stress reduces granulosa cell viability and proliferation in both in vivo and in vitro models. Oocyte maturation, both nuclear and cytoplasmic, is also compromised, and embryo quality declines under elevated thermal conditions. These effects are linked to intracellular disturbances, including oxidative imbalance, mitochondrial dysfunction, and altered hormonal signaling. The differences between in vivo and in vitro responses reflect the complexity of the biological impact of heat stress and emphasize the protective role of the physiological microenvironment. A better understanding of how heat stress alters the function of ovarian follicles, oocytes, and embryos is crucial. This knowledge is critical to devise effective strategies that mitigate damage, support fertility, and improve outcomes in assisted reproduction for livestock exposed to high environmental temperatures. Full article

Cacao genotypes propagation through plant tissue culture represents a strategic approach for establishing a core collection of elite plants to be used as a donor material source, necessary for increasing new planting areas of cacao. This study aimed to evaluate somatic embryo regeneration in ten native fine-aroma cacao genotypes (INDES-06, INDES-11, INDES-14, INDES-32, INDES-52, INDES-53, INDES-63, INDES-64, INDES-66, INDES-70) from the INDES-CES germplasm collection, under in vitro conditions using culture medium supplemented with different concentrations of Thidiazuron (0, 10, and 20 nM). Our results showed an average of 20 and 100% of callogenesis in all genotypes evaluated, but the callus development did not appear after early stages of its induction; however, primary somatic embryos were observed after 42 days after TDZ treatment in the INDES-52, INDES-53, INDES-64, INDES-66, INDES-70 genotypes. The INDES-52 genotype was more responsive to under 20 nM of TDZ, generating an average of 17 embryos per explant. This study contributes to the adaptation and establishment of a protocol for somatic embryo regeneration of fine-flavor cacao genotypes. Full article

Grass carp is an economically important cultured species in China. Triploid embryo production is widely applied in aquaculture to achieve reproductive sterility, improve somatic growth, and reduce ecological risks associated with uncontrolled breeding. In this study, a simple cold shock method for inducing triploid grass carp was developed. The triploid induction rate of 71.73 ± 5.00% was achieved by applying a cold treatment at 4 °C for 12 min, starting 2 min after artificial fertilization. Flow cytometry and karyotype analysis revealed that triploid individuals exhibited a 1.5-fold increase in DNA content compared to diploid counterparts, with a chromosomal composition of 3n = 72 (33m + 36sm + 3st). Additionally, embryonic transcriptome analysis demonstrated that, in the cold shock-induced embryos, genes associated with abnormal mesoderm and dorsal–ventral axis formation, zygotic genome activation (ZGA), and anti-apoptosis were downregulated, whereas pro-apoptotic genes were upregulated, which may contribute to the higher abnormal mortality observed during embryonic development. Overall, this study demonstrates optimized conditions for inducing triploidy in grass carp via cold shock and provides insights into the transcriptomic changes that take place in cold shock-induced embryos, which could inform future grass carp genetic breeding programs. Full article

Zebrafish are model organisms for drug screening owing to their transparent bodies, rapid embryonic development, and genetic similarities with humans. However, using standard polystyrene culture plates can limit the oxygen supply, potentially affecting embryo survival and the reliability of assays conducted in zebrafish. In this study, we evaluated the application of a novel, highly oxygen-permeable culture plate (InnoCell^TM) in zebrafish development and drug screening assays. Under both normal and oxygen-restricted conditions, zebrafish embryos cultured on InnoCell^TM plates exhibited significantly improved developmental parameters, including heart rate and body length, compared with those cultured on conventional polystyrene plates. The InnoCell^TM plate enabled a significant reduction in medium volume without compromising zebrafish embryo viability, thereby demonstrating its advantages, particularly in high-throughput 384-well formats. Drug screening tests using antiangiogenic receptor tyrosine kinase inhibitors (TKIs) revealed enhanced sensitivity and more pronounced biological effects in InnoCell^TM plates, as evidenced by the quantification of intersegmental blood vessels and gene expression analysis of the vascular endothelial growth factor receptor (vegfr, also known as kdrl). These results indicate that the InnoCell^TM highly oxygen-permeable plate markedly improves zebrafish-based drug screening efficiency and assay reliability, highlighting its potential for widespread application in biomedical research. Full article

Tissue remodeling of human endometrium occurs during the menstrual cycle to prepare for embryo adhesion and invasion. The ovarian steroid hormones 17β-estradiol and progesterone control the menstrual cycle to achieve the receptive state during the “window of implantation” (WOI). Here, we focus on the human endometrial epithelium and its changes in polarity, adhesion, cytoskeletal organization and the underlying extracellular matrix enabling embryo implantation. The adhesion and invasion of the trophoblast via the apical plasma membrane of epithelial cells is a unique cell biological process, which is coupled to partial epithelial–mesenchymal transition (EMT). Given the fundamental species differences during implantation, we restrict the review mainly to the human situation and focus on cell culture systems to study the interaction between human trophoblast and endometrial cells. We summarize current knowledge based on the relatively scarce in vivo data and the steadily growing in vitro observations using various cell culture systems. Full article

Bovine serum albumin (BSA), the most commonly used protein in preimplantation embryo culture media, performs a variety of physiological functions. However, its involvement in long-term effects remains largely unclear. To investigate its physiological importance in culture media, we examined the developmental and metabolic consequences of BSA deprivation during preimplantation stages in mice. Embryos cultured in BSA-free media during specific time windows exhibited impaired blastocyst formation, with continuous deprivation from the two-pronuclei (2PN) stage significantly reducing trophectoderm (TE) and inner cell mass (ICM) cell numbers (p < 0.05), indicating compromised viability. Short-term BSA deprivation similarly disrupted lineage allocation, underscoring the sensitivity of early embryos to nutrient availability during cell fate determination. Although birth rates remained unaffected, suggesting compensatory mechanisms, longitudinal analysis revealed sex-specific metabolic dysfunction. Male offspring developed progressive glucose intolerance by 16 weeks, exhibiting elevated fasting glucose levels (p < 0.05) and impaired glucose clearance, whereas females showed no significant alterations in glucose metabolism. This study demonstrates that protein restriction during the preimplantation period not only disrupts early embryonic development but also programs long-term metabolic dysfunction, underscoring the importance of optimizing culture conditions in assisted reproductive technologies to minimize future health risks. Full article

Objectives: With the development of artificial intelligence technology in medicine, an intelligent deep learning-based embryo scoring system (iDAScore) has been developed on full-time lapse sequences of embryos. It automatically ranks embryos according to the likelihood of achieving a fetal heartbeat with no manual input from embryologists. To ensure its performance, external validation studies should be performed at multiple clinics. Methods: A total of 6291 single vitrified–thawed blastocyst transfer cycles from 2018 to 2021 at the Reproductive Medicine Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology were retrospectively analyzed by the iDAScore model. Patients with two or more blastocysts transferred and blastocysts that were not cultured in a time-lapse incubator were excluded. Blastocysts were divided into four comparably sized groups by first sorting their iDAScore values in ascending order and then compared with the clinical, perinatal, and neonatal outcomes. Results: Our results showed that clinical pregnancy, miscarriage, and live birth significantly correlated with iDAScore (p < 0.001). For perinatal and neonatal outcomes, no significant difference was shown in four iDAScore groups, except sex ratio. Uni- and multivariable logistic regressions showed that iDAScore was significantly positively correlated with live birth rate (p < 0.05). Conclusions: In conclusion, the objective ranking can prioritize embryos reliably and rapidly for transfer, which could allow embryologists more time for processes requiring hands-on procedures. Full article

Malania oleifera Chun & S.K. Lee, an endemic monotypic species that belongs to the family Olacaceae, is under continuous pressure of decline owing to several ecological and physiological factors. The present study aimed to establish an efficient in vitro protocol for callus-mediated indirect somatic embryogenesis in M. oleifera by alleviating tissue browning. Internodes and leaves obtained from seedlings were used as explants. Antioxidant pre-treatment (ascorbic acid, AA) followed by different carbon sources (sucrose, maltose, glucose, and fructose) and plant growth regulators in various concentrations and combinations were employed in Woody Plant Medium (WPM) to alleviate explant browning and induce callus formation from the explants. AA pre-treatment and subsequent culture on maltose at a concentration of 116.8 mM were optimal for controlling phenolic exudation on >90% of both explants. The highest responses of 53.77% and 57.43% for embryogenic calli were induced from internode and leaf explants, respectively. The highest responses, 85.22% and 93.80%, were observed for somatic embryos that matured into the globular, heart-shaped and torpedo stages at different percentages on NAA 2.5 mg/L in combination with BA 1.0 mg/L for both explants. The matured somatic embryos were finally germinated at a maximum concentration of GA₃, 2.0 mg/L. All plantlets were successfully hardened and acclimatized under culture room conditions and then transferred to the greenhouse. The current study suggests an efficient protocol for indirect somatic embryogenesis by alleviating phenolic exudation from the explants of M. oleifera. This first successful report of in vitro culture establishment in M. oleifera may offer an effective alternative measure to conserve this species and provide a system for analyzing bioactive chemicals and for use in the oil industry. Full article

In the severe environment of Hunshandake Sandy Land, the uncommon and indigenous Chinese tree species Picea mongolica is an important biological component. Conventional seed propagation in P. mongolica is constrained by low germination rates, prolonged breeding cycles, and hybrid offspring genetic instability, limiting efficient varietal improvement. In contrast, somatic embryogenesis (SE) offers superior propagation efficiency, exceptional germination synchrony, and strict genetic fidelity, enabling rapid mass production of elite regenerants. However, SE in P. mongolica is hampered by severe genotype dependence, poor mature embryo induction rates, and loss of embryogenic potential during long-term cultures, restricting the production of high-quality seedlings. In this study, we aimed to analyze the transcriptome and metabolome of three crucial phases of SE: mature somatic embryos (MSEs), globular somatic embryos (GSEs), and embryogenic calli (EC). Numerous differentially expressed genes (DEGs) were found, especially in pathways linked to ribosomal functions, flavonoid biosynthesis, and the metabolism of starch and sucrose. Additionally, 141 differentially accumulated metabolites (DAMs) belonging to flavonoids, organic acids, carbohydrates, lipids, amino acids, and other metabolites were identified. An integrated study of metabolomic and transcriptome data indicated considerable enrichment of DEGs and DAMs in starch and sucrose metabolism, as well as phenylpropanoid biosynthesis pathways, all of which are required for somatic embryo start and development. This study revealed a number of metabolites and genes linked with SE, offering important insights into the molecular mechanisms driving SE in P. mongolica and laying the groundwork for the development of an efficient SE system. Full article

This study presents the first successful generation and comprehensive characterization of trophoblastic organoids (TOs) and the derivation of three-dimensional cavity- or sac-like structures—termed lacunoids/cystoids—from sheep intracytoplasmic sperm injection (ICSI) embryos. TOs were generated from sheep ICSI embryos for the first time and were shown to express trophoblastic markers at levels comparable to those in embryonic tissue. Detailed morphological characterization was conducted for both the TOs and the derived lacunoids/cystoids. Additionally, the TOs’ interactions with endometrial organoids (EOs), as well as those with preimplantation embryos, were investigated through co-culture experiments. The TOs expressed key trophoblastic markers, including CDX2, GATA3, syncytin-1, KRT18, KRT7, and Sox2, confirming their validity as a model for studying sheep trophoblast biology. The generation of lacunoids/cystoids from the TOs further revealed their structural and developmental characteristics, contributing valuable insights into early placental development and trophoblast-related pathologies. The TOs also supported extended embryonic development, and their co-culture with EOs induced dynamic changes in gene expression, particularly in angiogenesis-related genes, in both organoid types. This novel and reproducible in vitro model offers a reliable platform to study early placental development, effectively recapitulating the biological crosstalk between the trophectoderm and endometrium. The in-depth characterization of TOs and lacunoids/cystoids highlights their potential to advance our understanding of trophoblast differentiation and related developmental disorders. Full article

Coconut palm’s economic significance across the tropics, underpinning livelihoods and industries, is increasingly threatened by pests, diseases, genetic erosion, and natural disasters. This underscores the urgent need for efficient germplasm conservation strategies. In vitro culture of zygotic embryos provides a vital pathway for secure global conservation and exchange, particularly for elite varieties like Makapuno. However, standardized, practical protocols for the international exchange of fresh, non-cryopreserved embryos remain underdeveloped. To address this gap, this study refined a key protocol for fresh coconut embryo exchange by systematically optimizing critical parameters. The results demonstrated that an optimal culture medium containing low sucrose (10 g/L), activated charcoal (1 g/L), Gelrite (2.5 g/L), and 1 mL medium per cryotube significantly enhanced embryo size (40% increase; p < 0.05) compared to sucrose-free controls. While surface sterilization using AgNPs showed a marginal growth advantage over NaClO, rigorous transportation simulations confirmed that embryos retain high viability and regeneration potential only if delivered within seven days. These findings establish a robust, standardized framework for enhancing the global exchange and conservation of elite coconut germplasm, directly supporting genetic conservation and varietal improvement efforts. Full article

Oocyte maturation represents a fundamental biological process in bovine reproduction, establishing the physiological basis for fertilization and early embryonic development while critically determining the propagation of improved varieties and breeding efficiency. The roles of MQC in reproduction have gained substantial scientific attention. The proper maturation of oocytes fundamentally depends on adequate mitochondrial functionality. However, the intrinsic regulatory mechanisms governing MQC during bovine oocyte maturation remain incompletely characterized. Here, we discuss the most recent progress on the molecular mechanisms and roles of mitochondrial fission/fusion, biogenesis, and mitophagy in MQC. Building upon the mechanistic foundations of MQC in bovine oocyte maturation, this review identifies key mitochondrial-targeted supplements with potential applications in enhancing oocyte quality. Furthermore, we evaluate epigenetic influences on mitochondrial regulatory networks through mitochondrial–nuclear communication. Finally, we discuss the challenges in elucidating mitochondrial quality control mechanisms during oocyte maturation and propose corresponding strategies to address these obstacles. Integrating mechanistic insights, this review proposes strategies to enhance in vitro culture systems and identify oocyte quality markers, providing valuable insights for optimizing in vitro production (IVP) of bovine embryos and enhancing reproductive efficiency. Full article

Oxidative stress poses a challenge to in vitro embryo culture. As a flavonoid, galangin (GAL) has been shown to have antioxidant effects, but the effect and antioxidant capacity of GAL in the in vitro development of porcine parthenogenetic embryos are still unknown. In this study, we demonstrated that 1 µM GAL significantly increased the blastocyst rate, decreased the accumulation of intracellular reactive oxygen species (ROS), increased the glutathione (GSH) level, and enhanced mitochondrial function in early porcine embryos. Nuclear factor erythroid-2-related factor 2 (Nrf2) was identified as the target gene of GAL via network pharmacology, and the transcript levels of related antioxidant enzymes (HO-1, NQO1, SOD2, and CAT) were found to be increased. Since Nrf2 has seven domains, we constructed Nrf2 mutants lacking different domains in vitro. We found that GAL specifically binds to the Neh1 domain of Nrf2. Subsequent embryonic experiments demonstrated that the antioxidant effect of GAL was abolished after Nrf2 deletion. These results suggest that GAL can directly bind to Nrf2 to regulate the level of oxidative stress and improve mitochondrial function in embryos. Full article

Jatropha curcas L. is a shrub of the Euphorbiaceae family with non-toxic varieties found in Mexico that holds significant potential for biofuel production and other industrial applications. However, its limited in vitro regenerative capacity is a barrier to the development of productive species. Somatic embryogenesis (SE) offers a strategy to establish a regeneration system to overcome these challenges and enable genetic improvement. In this work, proteomic and gene expression analyses were utilized to identify key factors involved in SE induction in a non-toxic variety of J. curcas. Two-dimensional electrophoresis (2-DE) in combination with mass spectrometry was used to compare the proteomes of pre-globular and globular somatic embryos. RT-qPCR was used for gene expression analysis of the BBM, AGL15, SERK, IAA26 and eIF3f genes. The globular stage showed enrichment in the pathways related to carbohydrate and energy metabolism, protein folding, and stress response. In addition, the gene expression analysis of selected genes revealed a significantly elevated expression of BBM, AGL15, and IAA26 in globular embryos compared to pre-globular embryos. In contrast, SERK expression was low, and eIF3f expression remained unchanged between stages. These expression patterns may contribute to developmental arrest at the globular stage. These findings provide new insights into the molecular mechanisms regulating early SE in J. curcas and offer potential strategies for improving its propagation and industrial applications. Full article

The aims of the present study were to analyze the taxonomic profile and to evaluate the functional effects of sheep FF cultivable microbiota on prepubertal lamb oocytes PLOs developmental potential. Ovarian FFs were recovered from slaughtered adult sheep via the aspiration of developing follicles and used for microbiota propagation. Bacterial pellets underwent 16S rRNA gene sequencing and targeted culturomics, whereas cell-free supernatants were used as supplements for the in vitro maturation (IVM) of slaughtered PLOs. For the first time, bacteria presence in adult sheep FF was detected, with the first report of Streptococcus infantarius subsp. infantarius (as a species) and Burkholderia cepacia (as a genus and species) in either animal or human FF. The short- and long-term effects of bacterial metabolites on PLO maturation and embryonic development were demonstrated. As short-term effects, the addition of FF microbiota metabolites did not affect the oocyte nuclear maturation and mitochondria distribution pattern, except in one of the examined supernatants, which reduced all quantitative bioenergetic/oxidative parameters. As long-term effects, one of them reduced the total cleavage rate after in vitro embryo culture (IVC). In conclusion, microbiota/bacteria are present in adult sheep FF and may influence reproductive outcomes in vitro. Future studies may reveal the beneficial in vitro effects using the microbiome from preovulatory follicles. Full article