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Riboflavin deficiency (RD) induces liver damage, abnormal embryonic development, and high mortality. We hypothesized that the phenotype could be rescued by inhibiting ER stress. The objectives of the present study were to investigate the underlying molecular mechanisms of RD-induced embryonic defects using in vitro and in vivo models. Primary duck embryonic hepatocytes were treated with an ER stress inhibitor (4-PBA) or transfected with CHOP siRNA , and cultured in RD medium and riboflavin-sufficient (CON) medium for 8 days. Laying ducks (n = 20 cages/diet, 1 bird/cage) were fed an RD diet or CON diet for 14 wk, and the eggs were collected for hatching. At day 7 of incubation, the fertilized RD eggs were injected with or without 4-PBA into the yolk. RD decreased cell number and cell viability compared to the CON group, induced oxidative stress and apoptosis in primary duck embryonic hepatocytes. However, after being treated with an ER stress inhibitor (4-PBA) or transfected with CHOP siRNA , the apoptosis rate in RD hepatocytes decreased by 60.6 % and 86.1 %, respectively, being equal to the CON. These results indicated that RD-induced hepatocyte apoptosis is mediated by ER stress and the CHOP pathway. In vivo , RD embryos showed low hatchability, abnormal development, liver damage, ER stress, and apoptosis compared to the CON group. However, 4-PBA administration, as a model of ER stress inhibition, substantially restored embryonic development and alleviated liver damage in the RD group, including ER stress and apoptosis. Notably, hatchability in the RD group increased from 21.7 % to 72.7 % after 4-PBA treatment, though it remained less than the CON group (87.7 %). These results implicated ER stress-CHOP-apoptosis pathway as molecular mechanisms underlying RD-induced abnormal embryonic development and death, this target with potential for therapy or intervention. [Display omitted] • RD leads to liver damage, abnormal embryonic development, and increased mortality in duck embryos. • Riboflavin may modulate ER stress and apoptosis, offering a novel perspective for treating related diseases. • ER stress-CHOP-apoptosis pathways may represent a novel target for regulating embryonic development. [ABSTRACT FROM AUTHOR]

Although supplementation with docosahexaenoic acid (DHA) during porcine oocyte IVM is well-established, the available data are limited due to the lack of consistency. Moreover, to our knowledge, the anti-oxidant effects of DHA on porcine oocytes have not been reported. Hence, this study aimed to examine the effects of DHA supplementation on the regulation of energy metabolism during porcine oocyte maturation to improve oocyte maturation and embryonic development. By supplementing the IVM medium with various DHA concentrations, 25 μM DHA was identified as the optimal concentration which improved intraoocyte glutathione content and enhanced embryonic development after parthenogenesis. Compared to embryos derived from the control group, those derived from SCNT or IVF showed significantly improved blastocyst formation upon DHA supplementation during IVM. In addition, various transcription factors associated with oocyte development and apoptosis in mature oocytes were beneficially regulated in the DHA-treated oocytes. Moreover, DHA improved the AMP-activated protein kinase (AMPK)-regulatory ability of porcine oocytes and ameliorated nuclear maturation and embryonic development, which were decreased by artificially downregulating AMPK. To our knowledge, this is the first study to examine the effects of DHA as an AMPK regulator on oocyte maturation and embryo development in pigs. Furthermore, DHA addition to the IVM medium upregulated the relative expression of genes associated with mitochondrial potential and lipid metabolism. Therefore, the membrane potential of mitochondria (evaluated based on the JC-1 aggregate/JC-1 monomer ratio) and the levels of fatty acids and lipid droplets in matured oocytes increased, resulting in increased ATP synthesis. In conclusion, the DHA treatment of porcine oocytes with 25 μM DHA during IVM enhances the homeostasis of energy metabolism by improving mitochondrial function and lipid metabolism, leading to improved quality of matured oocytes and enhanced embryonic developmental potential of in vitro produced (IVP) embryos. Thus, 25 μM DHA supplementation could serve as a tool for improving the quality of IVP embryos. The study findings provide a basis for further research on improving the production efficiency of cloned animals by securing high-quality matured oocytes and enhancing energy metabolism in mammalian oocytes, including those of pigs. • DHA (25 μM) optimally improves porcine oocyte quality and embryonic development. • DHA maintains the homeostasis of energy metabolism of porcine oocytes. • DHA improves pivotal functions of mitochondria in matured porcine oocytes. • DHA supplementation during porcine oocyte maturation improves lipid metabolism. [ABSTRACT FROM AUTHOR]

Iron death is a novel type of programmed cell death caused by excessive accumulation of iron-dependent lipid peroxidation products; however, the function of iron death during porcine oocyte maturation and embryo growth is poorly understood. This study was conducted to investigate the mechanism of ferric ammonium citrate (FAC) in regulating iron death in mature oocytes in vitro through the NRF2 signaling pathway, and subsequent embryonic development. The experiment was divided into four groups: 0 (control group), 2, 5, and 10 μM FAC. Western blotting (WB), reactive oxygen species (ROS)assays, mitochondrial membrane potential (MMP) assays, and Quantitative real-time polymerase chain reaction (qRT-PCR) were used to detect the maturation of porcine oocytes in vitro , the protein content of nuclear transcription factor E2-related factor 2 (Nrf2), the distribution of mitochondria, the level of oxidative stress, and the development of embryos fertilized in vitro. The results showed that with increasing FAC concentrations, the oocyte maturation rate in vitro , Nrf2 protein content, MMP, and cleavage rates of in vitro fertilized embryos decreased (significantly in the 5 μM group); the oxidative stress level was significantly increased; the transcript levels of Nrf2 , GPX4, and FTH1 mRNAs were significantly decreased; the expression of ACSL4 was significantly upregulated (P < 0.05); and the blastocyst rate of embryos fertilized in vitro was reduced (significantly in the 2 μM group). In conclusion, FAC can regulate Nrf2 protein levels in porcine oocytes matured in vitro to induce iron death, affecting the maturation rate of oocytes, distribution of mitochondria, level of oxidative stress, expression of iron-death-related genes, and development of embryos after in vitro fertilization. • FAC reduces Nrf2 protein levels in mature porcine oocytes in vitro , resulting in iron death due to reduced cell maturation. • FAC regulates oocyte oxidative stress, mitochondrial membrane potential and iron death-related gene expression. • FAC affects embryonic development after in vitro fertilization. [ABSTRACT FROM AUTHOR]

Post-translational modifications (PTMs) are critical for early development in mice because early cleavage-stage embryos are characterized by transcriptional inactivity. Neddylation is an important ubiquitin-like PTM that regulates multiple biophysical processes. However, the exact roles of neddylation in regulating early embryonic development remain largely unknown. In the present study, we found that inhibition of neddylation by specific inhibitor MLN4924 led to severe arrest of early embryonic development. Transcriptomic analysis showed that neddylation inhibition changed the expression of 3959 genes at the 2-cell stage. Importantly, neddylation inhibition blocked zygotic genome activation and maternal mRNA degradation, thus disrupting the maternal-to-zygotic transition. Moreover, inhibition of neddylation induced mitochondrial dysfunction including aberrant mitochondrial distribution, decreased mitochondrial membrane potential, and reduced ATP content. Further analysis showed that inhibition of neddylation resulted in the accumulation of reactive oxygen species and superoxide anion, thereby resulting in oxidative stress and severe DNA damage at the 2-cell stage. Overall, this study demonstrates that neddylation is vital for early embryonic development in mice. Our findings suggest that proper neddylation regulation is essential for the timely inter-stage transition during early embryonic development. Neddylation inhibitor MLN4924 treatment disrupted maternal-to-zygotic transition (MZT) by altering the expression of genes related to the zygotic genome activation (ZGA) and maternal genes degradation (MGD), resulting in early embryonic developmental arrest, and the arrested 2-cell embryos exhibited abnormal mitochondrial function, oxidative stress, and DNA damage. [Display omitted] • Neddylation inhibition disrupted the maternal-to-zygotic transition in mice. • Neddylation inhibition induced mitochondrial dysfunction and reduced ATP content in 2-cell embryos. • Neddylation inhibition caused oxidative stress and DNA damage in 2-cell embryos. [ABSTRACT FROM AUTHOR]

Endoplasmic reticulum (ER) stress induced by agents such as tunicamycin (TM) substantially impedes the developmental progression of porcine embryos. Lignan compounds such as Schisandrin B (Sch-B), may have the potential to mitigate this stress. However, there are few studies on the effects of Sch-B on embryo development. To address this research gap, this study evaluates the protective efficacy of Sch-B against TM-induced ER stress during pivotal stages of porcine embryogenesis. Notably, embryos treated with Sch-B exhibited pronounced resistance to TM-induced developmental arrest, particularly at the 4-cell stage, facilitating progression to the 8-cell stage and subsequent blastocyst formation. It was also observed that Sch-B effectively reduced reactive oxygen species (ROS) levels and improved mitochondrial membrane potential (MMP). Furthermore, Sch-B positively influenced the expression of several stress-related genes. These findings highlight the promising role of Sch-B in improving porcine embryo development and mitigating ER stress. • Schisandrin B promotes porcine embryonic development by mitigating Tunicamycin-induced 4-cell stage arrest and reducing apoptosis levels in blastocysts. • Schisandrin B mitigates the elevation of reactive oxygen species levels in porcine embryos treated with tunicamycin. • Schisandrin B improves mitochondrial membrane potential in porcine embryos treated with tunicamycin. • Schisandrin B positively influences the expression of several stress-related genes. [ABSTRACT FROM AUTHOR]

Vitrification of porcine immature oocytes at the germinal vesicle (GV) stage reduces subsequent embryo yield and changes at the molecular level may occur during embryonic development. Therefore, the present study used porcine parthenogenetic embryos as a model to investigate the effect of GV oocyte vitrification on the transcriptional profiles of the resultant embryos at the 4-cell and blastocyst stages using the Smart-seq2 RNA-seq technique. We identified 743 (420 up-regulated and 323 down-regulated) and 994 (554 up-regulated and 440 down-regulated) differentially expressed genes (DEGs) from 4-cell embryos and blastocysts derived from vitrified GV oocytes, respectively. Functional enrichment analysis of DEGs in 4-cell embryos showed that vitrification of GV oocytes influenced regulatory mechanisms related to transcription regulation, apoptotic process, metabolism and key pathways such as the MAPK signaling pathway. Moreover, DEGs in blastocysts produced from vitrified GV oocytes were enriched in critical biological functions including cell adhesion, cell migration, AMPK signaling pathway, GnRH signaling pathway and so on. In addition, the transcriptomic analysis and quantitative real-time PCR results were consistent. In summary, the present study revealed that the vitrification of porcine GV oocytes could alter gene expression patterns during subsequent embryonic developmental stages, potentially affecting their developmental competence. • This study provided transcriptional profiles of 4-cell embryos and blastocysts derived from vitrified porcine GV oocytes. • We identified 743 and 994 differentially expressed genes in resultant 4-cell embryos and blastocysts, respectively. • The results could help us understand the molecular mechanisms of oocyte cryodamages from embryonic transcriptome perspective. [ABSTRACT FROM AUTHOR]

Endogenous retroviruses (ERVs) have long been thought as 'junk DNA' or 'fossil records' of ancestral retrovirus invasions. ERVs can be transcriptionally active and critical for human development and health. ERVs are involved in pathological processes such as virus infection, immune response, and aging. Various emerging strategies target human ERVs (HERVs) for the treatment of cancers and aging-associated diseases. Endogenous retroviruses (ERVs) are evolutionary remnants of retroviral infections in which the viral genome became embedded as a dormant regulatory element within the host germline. When ERVs become activated, they comprehensively rewire genomic regulatory networks of the host and facilitate critical developmental events, such as preimplantation development and placentation, in a manner specific to species, developmental stage, and tissues. However, accumulating evidence suggests that aberrant ERV transcription compromises genome stability and has been implicated in cellular senescence and various pathogenic processes, underscoring the significance of host genomic surveillance mechanisms. Here, we revisit the prominent functions of ERVs in early development and highlight their emerging roles in mammalian post-implantation development and organogenesis. We also discuss their implications for aging and pathological processes such as microbial infection, immune response. Furthermore, we discuss recent advances in stem-cell-based models, single-cell omics, and genome editing technologies, which serve as beacons illuminating the versatile nature of ERVs in mammalian development and health. [ABSTRACT FROM AUTHOR]

The purpose of this study was to perform morphological and immunohistochemical (IHC) analysis of the submandibular glands (SMGs) in early development in Apert syndrome model mice (Ap mice). ACTB-Cre homozygous mice were mated with fibroblast growth factor receptor 2 (Fgfr2 +/Neo-S252W ) mice; ACTB-Cre heterozygous mice (ACTB-Cre mice) at embryonic day (E) 13.5 served as the control group, and Fgfr2 +/S252W mice (Ap mice) served as the experimental group. Hematoxylin and eosin (H&E) staining was performed on SMGs; Total SMG area and epithelial area were determined, and the epithelial occupancy ratio was calculated. Immunostaining was performed to assess the localization of FGF signaling-related proteins. Next, bromodeoxyuridine (BrdU)-positive cells were evaluated to assess cell proliferation. Finally, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was performed to assess apoptosis in SMGs. The epithelial occupancy ratio was significantly higher in SMGs of Ap mice compared with that in SMGs of controls. FGF7 and bone morphogenetic protein 4 (BMP4) exhibited different localizations in SMGs of Ap mice compared with SMGs of controls. Cell proliferation was higher in SMGs of Ap mice compared with that of controls; however, apoptosis did not different significantly between the two groups. Our results suggest that enhanced FGF signaling conferred by missense mutations in FGFR2 promotes branching morphogenesis in SMGs of Ap mice. • The missense mutation S252W in FGFR2 causes hyperplasia of the submandibular gland epithelium. • The missense mutation S252W in FGFR2 causes ectopic localization of FGF7 and BMP4. • The missense mutation S252W in FGFR2 causes increased cell proliferation. [ABSTRACT FROM AUTHOR]

Extracellular vesicles (EVs) play an active role in regulating different physiological events, however, endocrine control of EVs cargo contents remain poorly understood. In this study, we aimed to isolate EVs from the porcine oviductal epithelial cells (POECs) that were primed with steroid hormones including estradiol (E 2) and progesterone (P 4), mimicking the in vivo conditions of the reproductive cycle and studied their effects on in vitro produced embryonic development. For this purpose, POECs were treated either with 0 concentration (control) or two different combinations of E 2 and P 4 including 50 pg/mL E 2 + 0.5 ng/mL P 4 (group H1), and 10 pg/mL E 2 + 35 ng/mL P 4 (group H2). Embryos were prepared after in vitro maturation either by parthenogenetic activation or somatic cell nuclear transfer (SCNT) technique. Treating parthenogenetic embryo with EVs, led a significantly higher rate of the blastocyst formation in the group supplemented with each EVs, compared to the control group. In addition, TUNEL assay and gene expression level analysis revealed that apoptosis was significantly reduced in the H2 EVs group. Furthermore, EVs from hormone-primed POECs improved the formation rate of porcine SCNT embryos compared to the control group. While in each EVs supplemented group (control EVs, H1 EVs, H2 EVs), the expression of cell reprogramming-related genes in cloned embryos showed a tendency of increase, the effect was stronger in H1 EVs and H2 EVs. In conclusion, EVs derived from POECs cultured in hormonal conditions simulating the in vivo environment had a positive effect on porcine blastocysts formation, which will likely facilitate in the production of cloned embryos. • The in vivo environment of the oviduct of pigs during the estrous cycle was mimicked. • Extracellular vesicle was extracted from oviduct epithelial cell exposed to E 2 and P 4 dominant environments. • The effects of oviduct-derived extracellular vesicles on porcine embryonic development were investigated. • Steroid hormones regulate protein expression of oviduct-derived extracellular vesicles. • The extracellular vesicles in the P 4 dominant environment have a positive effect on embryonic development. [ABSTRACT FROM AUTHOR]

O-GlcNAcylation is a dynamic and reversible post-translational modification (PTM) controlled by the enzymes O- GlcNAc transferase (OGT) and O- GlcNAcase (OGA). Changes in its expression lead to a breakdown in cellular homeostasis, which is linked to several pathological processes. Placentation and embryonic development are periods of high cell activity, and imbalances in cell signaling pathways can result in infertility, miscarriage, or pregnancy complications. O- GlcNAcylation is involved in cellular processes such as genome maintenance, epigenetic regulation, protein synthesis/degradation, metabolic pathways, signaling pathways, apoptosis, and stress response. Trophoblastic differentiation/invasion and placental vasculogenesis, as well as zygote viability and embryonic neuronal development, are all dependent on O- GlcNAcylation. This PTM is required for pluripotency, which is a required condition for embryonic development. Further, this pathway is a nutritional sensor and cell stress marker, which is primarily measured by the OGT enzyme and its product, protein O- GlcNAcylation. Yet, this post-translational modification is enrolled in metabolic and cardiovascular adaptations during pregnancy. Finally, evidence of how O-GlcNAc impacts pregnancy during pathological conditions such as hyperglycemia, gestational diabetes, hypertension, and stress disorders are reviewed. Considering this scenario, progress in understanding the role of O - GlcNAcylation in pregnancy is required. • O -GlcNAc promotes blastocyst implantation, trophoblastic invasion, and placentation. • Placental O -GlcNAc is a marker of maternal/fetal health. • Aberrant O -GlcNAc is linked to gestational diabetes, hypertension, and stress. [ABSTRACT FROM AUTHOR]

Understanding early patterning events in the extracellular matrix (ECM) formation can provide a blueprint for regenerative strategies to better recapitulate the function of native tissues. Currently, there is little knowledge on the initial, incipient ECM of articular cartilage and meniscus, two load-bearing counterparts of the knee joint. This study elucidated distinctive traits of their developing ECMs by studying the composition and biomechanics of these two tissues in mice from mid-gestation (embryonic day 15.5) to neo-natal (post-natal day 7) stages. We show that articular cartilage initiates with the formation of a pericellular matrix (PCM)-like primitive matrix, followed by the separation into distinct PCM and territorial/interterritorial (T/IT)-ECM domains, and then, further expansion of the T/IT-ECM through maturity. In this process, the primitive matrix undergoes a rapid, exponential stiffening, with a daily modulus increase rate of 35.7% [31.9 39.6]% (mean [95% CI]). Meanwhile, the matrix becomes more heterogeneous in the spatial distribution of properties, with concurrent exponential increases in the standard deviation of micromodulus and the slope correlating local micromodulus with the distance from cell surface. In comparison to articular cartilage, the primitive matrix of meniscus also exhibits exponential stiffening and an increase in heterogeneity, albeit with a much slower daily stiffening rate of 19.8% [14.9 24.9]% and a delayed separation of PCM and T/IT-ECM. These contrasts underscore distinct development paths of hyaline versus fibrocartilage. Collectively, these findings provide new insights into how knee joint tissues form to better guide cell- and biomaterial-based repair of articular cartilage, meniscus and potentially other load-bearing cartilaginous tissues. Successful regeneration of articular cartilage and meniscus is challenged by incomplete knowledge of early events that drive the initial formation of the tissues' extracellular matrix in vivo. This study shows that articular cartilage initiates with a pericellular matrix (PCM)-like primitive matrix during embryonic development. This primitive matrix then separates into distinct PCM and territorial/interterritorial domains, undergoes an exponential daily stiffening of ≈36% and an increase in micromechanical heterogeneity. At this early stage, the meniscus primitive matrix shows differential molecular traits and exhibits a slower daily stiffening of ≈20%, underscoring distinct matrix development between these two tissues. Our findings thus establish a new blueprint to guide the design of regenerative strategies to recapitulate the key developmental steps in vivo. [Display omitted] [ABSTRACT FROM AUTHOR]

A series of changes occur in the early embryo that are critical for subsequent development, and the pig is an excellent animal model of human disease, so understanding the regulatory mechanisms of early embryonic development in the pig is of very importance. To find key transcription factors regulating pig early embryonic development, we first profiled the transcriptome of pig early embryos, and confirmed that zygotic gene activation (ZGA) in porcine embryos starts from 4 cell stage. Subsequent enrichment analysis of up-regulated gene motifs during ZGA revealed that the transcription factor ELK1 ranked first. The expression pattern of ELK1 in porcine early embryos was analyzed by immunofluorescence staining and qPCR, and the results showed that the transcript level of ELK1 reached the highest at the 8 cell stage, while the protein level reached the highest at 4 cell stage. To further investigate the effect of ELK1 on early embryo development in pigs, we silenced ELK1 in zygotes and showed that ELK1 silencing significantly reduced cleavage rate, blastocyst rate as well as blastocyst quality. A significant decrease in the expression of the pluripotency gene Oct4 was also observed in blastocysts from the ELK1 silenced group by immunofluorescence staining. Silencing of ELK1 also resulted in decreased H3K9Ac modification and increased H3K9me3 modification at 4 cell stage. To investigate the effect of ELK1 on ZGA, we analyzed transcriptome changes in 4 cell embryos after ELK1 silencing by RNA seq, which revealed that ELK1 silencing resulted in significant differences in the expression of a total of 1953 genes at the 4 cell stage compared with their normal counterparts, including 1106 genes that were significantly upregulated and 847 genes that were significantly downregulated. Through GO and KEGG enrichment, we found that the functions and pathways of down-regulated genes were concentrated in protein synthesis, processing, cell cycle regulation, etc., while the functions of up-regulated genes were focused on aerobic respiration process. In conclusion, this study demonstrates that the transcription factor ELK1 plays an important role in regulation of preimplantation embryo development of pigs and deficiency of ELK1 leads to abnormal epigenetic reprogramming as well as zygotic genome activation, thus adversely affecting embryonic development. This study will provide important reference for the regulation of transcription factors in porcine embryo development. • Knockdown of ELK1 causes developmental barrier of porcine preimplantation embryos and impaires blastocyst quality. • Absence of transcription factor ELK1 results in abnormal H3K9 modification of porcine 4 cell embryos. • Absence of transcription factor ELK1 leads to abnormal transcription profile of porcine 4 cell embryos. [ABSTRACT FROM AUTHOR]

Strategies for improving the quality of oocytes have important theoretical and practical significance for increasing the efficiency of livestock breeding. In this respect, the accumulation of reactive oxygen species (ROS) is a major factor affecting the development of oocytes and embryos. This study investigated the effects of Dendrobium nobile extract (DNE) on the in vitro maturation of bovine oocytes and embryonic development after IVF. DNE is an extract from Dendrobium rhizomes that contains alkaloids with anti-inflammatory, anti-cancer and anti-ageing functions. Various concentrations of DNE (0, 5, 10, 20 and 50 μmol/L) were added during oocyte maturation in vitro, and we found that 10 μmol/L of DNE remarkably increased the oocyte maturation rate, the subsequent blastocyst formation rate and embryo quality. Further, we found that DNE treatment decreased the frequency of spindle/chromosome defects and ROS and increased the oocyte glutathione and mitochondrial membrane potential in oocytes. Moreover, DNE upregulated the expression of oxidative stress-related genes (Sirt1, Sirt2, Sirt3 and Sod1) in oocytes and apoptosis-related genes (Caspase-3, Caspase-4, Bax, Bcl-xl and Survivin) in blastocysts. These results suggest that DNE supplementation can promote oocyte maturation and subsequent embryonic development by regulating redox reactions and inhibiting embryonic apoptosis. • DNE promotes oocyte maturation and embryo development. • DNE decreases ROS and increases MMP. • DNE has an inhibitory effect on embryonic apoptosis. [ABSTRACT FROM AUTHOR]

In mammals, E2 factor (E2F) acts as a cell cycle regulator. E2F transcription factor 4 (E2F4) is a member of the E2F family of transcription factors and usually represents predominant E2F activity in cells. The E2F4 gene has been extensively studied in animals and is associated with multiple functions, such as cell cycle regulation and apoptosis; however, little is known about its role during embryonic development. In this study, we investigated the function of E2F4 and its mechanism of action in porcine embryo development. For this purpose, we knocked down E2F4 by microinjecting double-stranded RNA of E2F4 at the 1-cell stage. The results showed that E2F4 knockdown in porcine embryos led to a significant decrease in the blastocyst rate and total cell number. Defective E2F4 expression reduced the level of G1/S checkpoints (cyclin E-cyclin-dependent kinase 2) and cell cycle-related gene expression at the 4-cell embryo stage and blastocyst. Moreover, a decrease in E2F4 expression increased phosphorylated H2A.X variant histones and activated ataxia telangiectasia mutated (ATM) and p53-p21 pathway. In addition, E2F4 depletion caused a significant decrease in histone acetylation. Taken together, E2F4 plays a critical role as a transcriptional activator in the development of porcine embryos, an observation that contradicts its well-established role as a transcription repressor. • E2F4 affected porcine embryonic development. • E2F4 induced DNA damage and G1/S arrest in porcine embryos. • E2F4 decreased histone acetylation in porcine embryos. [ABSTRACT FROM AUTHOR]

Aberrant epigenetic nuclear reprogramming, especially imprinting pattern disorders, is one of the major causes of failure of clone development from somatic cell nuclear transfer (SCNT). Previous studies showed that ZFP57 is a key protein required for imprint maintenance after fertilization. In this study, we found that imprinting control regions in several imprinted genes were significantly hypomethylated in cloned embryos compared with in vitro fertilization embryos, indicating a loss of imprinted gene methylation. The ZFP57 expression was capable of maintaining the correct degree of methylation at several imprinting control regions and correcting abnormal hypomethylation. Moreover, we successfully obtained bovine fetal fibroblasts overexpressing ZFP57, which were used as donors for SCNT. Our results demonstrated that overexpression of ZFP57 increased total and trophectoderm cell numbers and the ratio of inner cell mass to total cells, reduced the apoptosis rate and significantly enhanced the development of SCNT blastocysts in vitro, ultimately achieving a degree of methylation similar to that in in vitro fertilization embryos. We concluded that overexpression of ZFP57 in donor cells provided an effective method for enhancing nuclear reprogramming and developmental potential in SCNT embryos. The ZFP57 protein played a key role in maintaining the methylation of imprinted genes during early embryonic development, which may be effective for enhanced SCNT in cattle. [ABSTRACT FROM AUTHOR]

Polymesoda arctata is a Caribbean estuarine clam commercially important that currently is considered threatened. The reproductive conditioning, spawning and early development were evaluated under laboratory conditions using organisms collected in the lagoon system of Ciénaga Grande de Santa Marta (Colombian Caribbean) between December 2020 and May 2021. Two reproductive conditioning experiments were conducted over 7 weeks, examining the frequency of mature animals in the natural environment (controls) and in the laboratory under two water temperatures (26 and 29 °C) and different salinity regimes (constant at 5 and 15 ppt, increasing from 5 to 15 ppt, and decreasing from 15 to 5 ppt). One spawning experiment was done, comparing the spawning response of adult clams exposed to various stimuli (changes in water temperature and salinity, flow of seawater irradiated with UV light, addition of a high concentration of food and sperm to the water, as well as injections of serotonin and KCl into the foot and/or adductor muscle). Higher frequencies of mature clams were observed after 2 to 5 weeks of reproductive conditioning at a low temperature (26 °C) and under a constant salinity regime (at 5 or 15 ppt). Higher percentages of spawning and post-stimulation survival as well as spawning response speed were observed in specimens injected in the foot with a low concentration of serotonin (0.4 mL at 20 μM). The time of spawning response onset was shorter in males than in females. The fecundity increased with the live weight of the females, showing an average value of 3.4 × 106 oocytes per female. The early development of the estuarine clam from oocyte to juvenile stage was described in detail. The growth rates of larvae and spat were relatively high but their survival values were low, showing the need for additional research on the larval and post-larval rearing. • First report on the juvenile hatchery-production of the estuarine clam, P. arctata. • Reproductive conditioning of P. arctata improves its gonadal maturity. • Pedal-injection of serotonin induces the spawning of P. arctata. • Growth rates of spat were higher than larvae, but its survival values were lower. [ABSTRACT FROM AUTHOR]

What is the impact of maternal and paternal alcohol consumption in the periconception period on embryonic and fetal development assessed using three-dimensional ultrasound and virtual reality techniques? This prospective observational study was embedded in the Rotterdam periconception cohort (Predict study). Participating women received longitudinal three-dimensional transvaginal ultrasound examinations from week 7 to week 12 of gestation to measure crown–rump length and embryonic volume. Mid-pregnancy fetal size parameters and birth weight were retrieved from medical files. Participants completed a periconception exposure questionnaire and a validated food frequency questionnaire. Linear mixed models were used to analyse the association between parental alcohol consumption, and embryonic and fetal developmental parameters. In total, 1141 female and 987 male participants were included in the analyses. Moderate maternal alcohol consumption in the periconception period resulted in a smaller head circumference (β = -1.85, SE = 0.84, P = 0.03), abdominal circumference (β = -2.65, SE = 0.93, P = 0.004), femur length (β = -0.56, SE = 0.22, P = 0.01) and estimated fetal weight (β = -9.36, SE = 4.35, P = 0.03) at 20 weeks of gestation. Paternal alcohol consumption showed significant positive associations, mainly with fetal size parameters (abdominal circumference: β = 0.033, SE = 0.01, P = 0.008; estimated fetal weight: β = 0.131, SE = 0.06, P = 0.03). Moderate maternal alcohol consumption is negatively associated with fetal growth parameters. Moreover, alcohol is proven to be a strong teratogen, and its consumption before and during pregnancy should be discouraged in both women and men as it affects several parameters of embryonic and fetal development. [ABSTRACT FROM AUTHOR]

Monobutyl phthalate (MBP) is the primary active metabolite of dibutyl phthalate (DBP), the key plasticizer component. A substantial body of evidence from studies conducted on both animals and humans indicates that MBP exposure could result in harmful impacts on toxicity pathways. In addition, it can seriously affect human and animal reproductive health. In our present study, we showed that exposure to MBP causes abnormal epigenetic modifications in porcine oocytes and failure of early embryonic development. However, glycine (Gly) can protect oocytes and early embryos from damage caused by MBP. Our study indicated a significant decrease in the percentage of porcine oocytes that reached the metaphase II (MII) phase when exposed to MBP. SET-domain-containing 2(SETD2)-mediated H3K36me3 histone methylation was detected, and the results showed that MBP significantly decreased the protein expression of H3K36me3 and SETD2. Moreover, the expression of the DNA break markers γH2AX and the mRNA expression of Asf1a, and Asf1b increased in the MBP group. The detection of DNA methylation marker proteins showed that MBP significantly increased the fluorescence intensity of 5-methylcytosine (5mC). The results from our RT-qPCR analysis demonstrated a significant decrease in the mRNA expression of the DNA methylation-related genes Dnmt1 and Dnmt3a , as well as the embryonic developmental potential-related genes Oct4 and Nanog , in porcine oocytes following exposure to MBP. Additionally, the mRNA expression of p53 significantly increased. Subsequently, the effects of MBP on early embryonic development were examined via parthenogenesis activation (PA) and in vitro fertilization (IVF). Exposure to MBP significantly impacted the development of embryos in both PA and IVF processes. The TUNEL staining data showed that MBP significantly increased embryonic apoptosis. However, Gly can ameliorate MBP-induced defects in oocyte epigenetic modifications and early embryonic development. • MBP exposure significantly compromised early embryonic evelopment in porcine. • Glycine rescues epigenetic modifications altered in porcine oocytesby MBP exposure. • Glycine mitigates the accumulation of DNA damage induced by MBPexposure in porcine oocytes. [ABSTRACT FROM AUTHOR]

Are there (sex-specific) differences in first-trimester embryonic growth and morphological development between two culture media used for IVF and intracytoplasmic sperm injection (ICSI) treatment? A total of 835 singleton pregnancies from a prospective hospital-based cohort study were included, of which 153 conceived after IVF/ICSI treatment with Vitrolife G-1™ PLUS culture medium, 252 after culture in SAGE 1-Step™ and 430 were naturally conceived. Longitudinal three-dimensional ultrasound examinations were performed at 7, 9 and 11 weeks of gestation for offline biometric (crown rump length, CRL), volumetric (embryonic volume) and morphological (Carnegie stage) measurements. Embryos cultured in SAGE 1-Step grew faster than those cultured in Vitrolife G-1 PLUS (beta EV 0.030 3√ml [95% CI 0.008–0.052], P = 0.007). After stratification for fetal sex, male embryos cultured in SAGE 1-Step demonstrated faster growth than those cultured in Vitrolife G-1 PLUS (beta EV 0.048 3√ml [95% CI 0.015–0.081], P = 0.005). When compared with naturally conceived embryos, those cultured in SAGE 1-Step grew faster (beta EV 0.040 3√ml [95% CI 0.012–0.069], P = 0.005). This association was most pronounced in male embryos (beta EV 0.078 3√ml [95% CI 0.035–0.120], P < 0.001). This study shows that SAGE 1-Step culture medium accelerates embryonic growth trajectories compared with Vitrolife G-1 PLUS and naturally conceived pregnancies, especially in male embryos. Further research should focus on the impact of culture media on postnatal development and the susceptibility to non-communicable diseases. [ABSTRACT FROM AUTHOR]

Pyruvate is an important energy substance during early embryonic development of mammals. However, the underlying mechanisms of pyruvate during early embryonic development in pigs and its role in zygotic genome activation (ZGA) are not fully understood. Here, based on a previous RNA-seq dataset of porcine early embryos, we found that pyruvate metabolism-related genes started to be expressed at the 4-cell stage and that pyruvate metabolism-related genes were correlated with porcine ZGA marker genes. To determine the function of pyruvate in porcine embryos, in vitro fertilization (IVF) embryos were cultured in PZM-3 medium (control group); modified PZM-3 medium that only contains pyruvate and lactate plus salts (+P group); or modified PZM-3 medium lacking pyruvate (-P group). The 4-cell arrest rate at 72 h was significantly increased in the -P group compared to the +P group (P < 0.05). In addition, we observed that the reactive oxygen species (ROS) level was significantly increased and that the adenosine triphosphate (ATP) level was significantly (P < 0.05) decreased in the -P group compared to the +P group. Moreover, the expression of ZGA marker genes and SIRT1 protein in embryos was significantly decreased in the -P group compared to the +P group (P < 0.05). Furthermore, the acetylation level of H3K9 was significantly decreased (P < 0.05) and the methylation level of H3K9 was significantly increased (P < 0.05) in the -P group compared to the +P group. In summary, our findings demonstrate that pyruvate affects early embryonic development in pigs by promoting ZGA and reducing oxidative stress levels. • Genes related to pyruvate metabolism were correlated with porcine zygotic genome activation marker genes. • Pyruvate can reduce 4-cell arrest and oxidative stress levels in porcine embryos. • Pyruvate can promote ZGA by affecting H3K9 modification levels in porcine embryos. [ABSTRACT FROM AUTHOR]

Embryo development is essential for seed yield and post-germination growth. Glucose-6-phosphate dehydrogenase (G6PD), the rate-limiting enzyme in oxidative pentose phosphate pathway (OPPP), is widely involved in plant development and stress tolerance by providing nicotinamide adenine dinucleotide phosphate (NADPH). In this study, the double mutant (g6pd5/6), overexpression line (G6PD5/6OE) and complementation line (g6pd5/6 Comp) of cytosolic glucose-6-phosphate dehydrogenases (Cyt-G6PD) were used to investigate Cyt-G6PD roles in embryo development of Arabidopsis. The results showed that the germination rate of g6pd5/6 seeds was delayed in comparison with that of Col-0; moreover, 11.5% of g6pd5/6 seeds did not germinate. The dysfunction of Cyt-G6PD resulted in decreased fresh weight and primary root length of g6pd5/6 seedlings. The height and silique length of g6pd5/6 plants were also decreased. Moreover, the abortion rate of siliques and seeds of g6pd5/6 plants were increased compared with those of Col-0, G6PD5/6OE and g6pd5/6 Comp lines. However, the dysfunction of Cyt-G6PD did not affect pollen activity; but in g6pd5/6 , the embryo development was partially delayed or inhibited. The contents of fatty acids and storage proteins, two main storage materials in Arabidopsis seeds, were decreased in g6pd5/6 seeds. Exogenous application of fatty acids (C18:2; C18:3) alleviated the delayed germination of g6pd5/6 seeds. RT-qPCR results further demonstrated that the early embryo development genes were down-regulated in g6pd5/6. Taken together, Cyt-G6PD plays a pivotal role in plant seed development by regulating the transcriptions of early embryo development genes and the accumulation of storage materials (especially fatty acids). • Cyt-G6PD mutation affects the transcription of genes involved in embryonic development in Arabidopsis. • Cyt-G6PD mutation decreases the contents of fatty acids and storage proteins in g6pd5/6 seeds. • Cyt-G6PD dysfunction reduces seed yield and delays post-embryonic development of Arabidopsis seedlings. [ABSTRACT FROM AUTHOR]

The microbial community associated with aquatic animals begins to assemble from the embryonic stage and plays a vital role in their growth and survival. However, the microbial community of the swimming crab Portunus trituberculatus during its embryonic period has not yet been studied. In this study, we investigated the embryonic bacterial community (EBC) of this species across the developmental cycle to elucidate its longitudinal dynamics and biotic sources. The results showed that the diversity of the EBC decreased with host development. The composition of the EBC varied across embryonic development, with a high percent of persistent bacteria and the gradual replacement of γ-Proteobacteria (mainly Oceanospirillaceae and Colwelliaceae) by α-Proteobacteria (Rhodobacteraceae and Flavobacteriaceae) as the major signatures of the succession patterns. Moreover, the unique amplicon sequence variants (ASVs) exhibited the highest functional potentials at the cleavage stage, whereas the shared ASVs did so at the later stages. Furthermore, maternal tissue, mainly the ovary and abdominal setae, contributed the most to the EBC, while rearing water contributed minimally. Overall, our results reveal succession patterns and biotic sources of EBC during the developmental cycle, highlighting that the dominance of embryonic bacteria starts from the early stage of embryo and bacterial vertical transmission is of significance during embryonic development. We also suggest the necessity of microbial management from maternal crabs. • The EBC exhibited a decreased α-diversity and a U-shaped succession trajectory of β-diversity across the developmental cycle. • The persistent bacteria dominated EBC with a gradual replacement of γ-Proteobacteria by α-Proteobacteria. • The unique and shared ASVs exhibited respective functional potentials at the cleavage and later stages. • The EBC was mainly sourced from the ovary and abdominal setae of maternal crab. • Bacterial vertical transmission indicates the necessity of microbial management from the maternal crabs. [ABSTRACT FROM AUTHOR]

This study aimed to investigate how maternal asthma during pregnancy disrupts fetal lung development by altering lipid metabolism in the amniotic fluid, which is crucial for fetal development. A pregnancy-induced asthma model was established in female rats using house dust mite (HDM) as a common allergen. The fetuses were divided into four groups based on whether the mother and fetus were exposed to the allergen: PBS+PBS, PBS+HDM, HDM+PBS, and HDM+HDM. Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was employed to analyze changes in the lipid profile of the amniotic fluid and bronchoalveolar lavage fluid (BALF). Principal component analysis (PCA) and ChemRICH methods were used to explore the potential relationship between lipid metabolism abnormalities and impaired fetal lung development. The results indicate that maternal asthma exacerbates asthma-related inflammatory markers in fetuses, leading to pathological changes in the lungs and elevated levels of cytokines IL-5, IL-13, and IgE. Additionally, 18 differential lipids, primarily oxygenated lipids, were identified in the amniotic fluid after modeling, suggesting an enhanced oxidative stress environment for the fetus. This environment causes metabolic disturbances in various lipid groups in fetal lungs, with the HDM+HDM group showing significant abnormalities in lipids critical for lung development, including phosphatidylethanolamine (PE), phosphatidylglycerol (PG), and fatty acids (FA). In conclusion, gestational asthma can reshape the lipid profile in the amniotic fluid and BALF, significantly disrupting fetal growth and lung development. Restoring normal lipid metabolism in the amniotic fluid and fetal lungs may offer a potential therapeutic approach to managing aberrant fetal lung development in asthmatic mothers. [Display omitted] • LC-MS studies asthma's impact on lipid metabolism in amniotic fluid and fetal lavage fluid. • Uncontrolled asthma disrupts lipid metabolism, explaining fetal lung function decline. • Maternal asthma increases fetal airway sensitivity, causing severe lung development deficits. • Study highlights asthma effects, offers innovative approach for future metabolite research. [ABSTRACT FROM AUTHOR]

SRY (Sex Determining Region) box 2 (SOX2) is an essential transcription factor that plays crucial roles in activating genes involved in pre- and post-embryonic development, adult tissue homeostasis, and lineage specifications. SOX2 maintains the self-renewal property of stem cells and is involved in the generation of induced pluripotency stem cells. SOX2 protein contains a particular high-mobility group domain that enables SOX2 to achieve the capacity to participate in a broad variety of functions. The information about the involvement of SOX2 with gene regulatory elements, signaling networks, and microRNA is gradually emerging, and the higher expression of SOX2 is functionally relevant to various cancer types. SOX2 facilitates the oncogenic phenotype via cellular proliferation and enhancement of invasive tumor properties. Evidence are accumulating in favor of three dimensional (higher order) folding of chromatin and epigenetic control of the SOX2 gene by chromatin modifications, which implies that the expression level of SOX2 can be modulated by epigenetic regulatory mechanisms, specifically, via DNA methylation and histone H3 modification. In view of this, and to focus further insights into the roles SOX2 plays in physiological functions, involvement of SOX2 during development, precisely, the advances of our knowledge in pre- and post-embryonic development, and interactions of SOX2 in this scenario with various signaling pathways in tumor development and cancer progression, its potential as a therapeutic target against many cancers are summarized and discussed in this article. [Display omitted] [ABSTRACT FROM AUTHOR]

The maintenance of normal pregnancy requires appropriate maturation and transformation of various cells, which constitute the microenvironmental regulatory network at the maternal-fetal interface. Interestingly, changes in the cellular components of the maternal-fetal immune microenvironment and the regulation of epigenetic modifications of the genome have attracted much attention. With the development of epigenetics (DNA and RNA methylation, histone modifications, etc.), new insights have been gained into early embryonic developmental stages (e.g., maternal-to-zygotic transition, MZT). Understanding the various appropriate modes of transcriptional regulation required for the early embryonic developmental process from the perspective of epigenetic modifications will help us to provide new targets and insights into the pathogenesis of embryonic failure during further natural fertilization. This review focuses on the loci of action of epigenetic modifications from the perspectives of female germ cell development and embryo development to provide new insights for personalized diagnosis and treatment of abortion. • Mechanisms of epigenetic modifications in embryonic development and early maintenance stages of pregnancy. • Epigenetic modifications provide new ideas for clinical treatment of pregnancy complications. • The impact of transcription factors on the pattern of transcriptional regulation. • Recent developments in genetic imprinting are briefly summarized. [ABSTRACT FROM AUTHOR]

Zig-zag eel (Mastacembelus armatus (2 n = 48)) and Spiny eel (Sinobdella sinensis (2 n = 48)) are two species of the Mastacembelidae family commonly found in southern China. Hybridization between the two has a very high deformity rate and a very low hatching rate. In order to investigate the reasons for this, the first hybridization between M. armatus and S. sinensis was carried out using artificial insemination, and the embryonic development of the hybrid offspring was examined using microphotography, and the malformations of the hybrid offspring were investigated by transcriptomics. The experiments showed that the average egg production was 4265.7 ± 322.94 (Mean ± SD), the average fertilization rate of hybrid offspring was 98.67 ± 0.58 % (Mean ± SD), the hatching rate was 12.06 ± 3.44 % (Mean ± SD), the deformity rate was 98.15 ± 3.21 % (Mean ± SD), and the embryonic development successively went through the five main stages of fertilized egg, egg cleavage, embryo formation, organogenesis, and exertion of membranes. Transcriptomics showed that the expression of NAD(P)H-related enzyme activity DEGs was increased, and many DEGs related to cell signaling molecule transmission and metabolic regulation are enriched in KEGG pathways, such as IL-17 signaling pathway, Osteoclast differentiation, TNF signaling pathway and MAPK signaling pathway. etc. The major types of DEGs corresponded to those coding for proteins. This study suggests that the high malformation rate in hybrid offspring may be caused by impaired synthesis of proteins during embryonic development. • For the first time, the embryonic development of the offspring of a hybrid between Mastacembelus armatus and Sinobdella sinensis was observed. • Abnormalities in the NAD(P)H enzyme system were potential factors leading to embryonic malformations. • Protein-coding related DEGs were significantly enriched in hybrid embryos. [ABSTRACT FROM AUTHOR]

The sustainability of aquarium trade relies on successful captive breeding and seed production practices to prevent the long-term consequences of wild collection, which can result in irreversible damage to natural populations. To establish comprehensive breeding and seed production protocols, it is imperative to gain a deep understanding of the reproductive characteristics of the fish, encompassing aspects such as sexual dimorphism, spawning behavior, embryogenesis, and the crucial period of larval survival. Hence, in this study, we document the captive breeding, spawning behavior, embryonic development, and early larval stages of Chromis viridis , a highly sought-after marine ornamental fish that plays a prominent role in the aquarium trade. Fish were sourced from Agatti Island, Lakshadweep, and reared in controlled conditions. Mature fish (6–9 cm) were kept in 500 L FRP tanks with regulated salinity (35.4 ± 0.5 g/L), temperature (27.1 ± 0.54 °C), and a 12-h light-dark photoperiod. After four months in captivity, spawning commenced, characterized by intense substrate cleaning and rapid swimming motions of the male. Each spawning event yielded 3562 to 20,651 eggs. Egg development included five stages over three days at 27.1 ± 0.54 °C, with hatching on the third day. Egg dimensions varied along both axes and egg volume changed over three days. Newly hatched larvae lacked eye pigments and paired fins, with an average total length (TL) of 1.97 ± 0.35 mm. Larval mouth opening occurred at 38 h, and yolk absorption was complete by the third day post-hatch. Continuous captive reproduction was observed with a spawning frequency of 5.59 ± 0.96 days. This study offers valuable insights for standardizing captive propagation techniques and advancing marine ornamental aquaculture for C. viridis by documenting its breeding, embryonic development, and early larval stages in captivity. • Chromis virdis is being exploited for tuna bait and aquarium trade. • First report on sexual dimorphism, spawning, and embryogenesis of C. viridis. • Vital data on the mating system, egg incubation, and early larval development. • The species is a year-round spawner but exhibits a very low larval survival rate. [ABSTRACT FROM AUTHOR]

The sum of nonspecific physiological responses exhibited by mammals in response to the disruption of thermal balance caused by high-temperature environments is referred to as heat stress (HS). HS affects the normal development of mammalian oocyte and embryos and leads to significant economic losses. Therefore, it is of great importance to gain a deep understanding of the mechanisms underlying the effects of HS on oocyte and embryonic development and to explore strategies for mitigating or preventing its detrimental impacts in the livestock industry. This article provides an overview of the negative effects of HS on mammalian oocyte growth, granulosa cell maturation and function, and embryonic development. It summarizes the mechanisms by which HS affects embryonic development, including generation of reactive oxygen species (ROS), endocrine disruption, the heat shock system, mitochondrial autophagy, and molecular-level alterations. Furthermore, it discusses various measures to ameliorate the effects of HS, such as antioxidant use, enhancement of mitochondrial function, gene editing, cultivating varieties possessing heat-resistant genes, and optimizing the animals'rearing environment. This article serves as a valuable reference for better understanding the relationship between HS and mammalian embryonic development as well as for improving the development of mammalian embryos and economic benefits under HS conditions in livestock production. • This article offers a systematic overview of recent effects and mechanisms of heat stress on mammalian oocyte and embryo development. • The article discusses recent measures to ameliorate HS effects, including antioxidant use, mitochondrial function enhancement, gene editing, and environment management. • This article serves as a valuable reference for enhancing mammalian embryo development and economic benefits under HS in animal production. [ABSTRACT FROM AUTHOR]

Present study describes the spawning induction of striped Snakehead, Channa striata using carp pituitary extract (CPE) and LH-RH agonist i.e. Buserelin (Glp-His-Trp-Ser-Tyr-Ser-tBu-Leu-Arg-Pro-NHEt). Total four treatments were designed under both hormones trail and treated as control group, T 1 , T 2 , and T 3 with three replications of each treatment. While breeders under all hormone treatments showed spawning performances, no spawning performance was observed in control group. Latency time after hormonal treatment was lowest (20–24 hrs) in case of CPE than Buserelin (25–30 hrs). Regarding to CPE, spawning, fertilization and hatching rate were higher with the increasing doses of CPE in different treatments. The highest mean ± Standard deviation spawning, fertilization and hatching rate were 85.60±8.58 %, 79.38±4.89 % and 64.33±6.60 % respectively in T 3 where dose of CPE was 80 mg kg−1. Similarly, in case of Buserelin hormone highest spawning rate was found in T 3 (80.61±5.59) where dose of Buserelin was 0.80 µg kg−1 body weight. Fertilization rate was on the level 48.57±5.99, 70.62±5.33 and 90.32±4.79 respectively for T 1 , T 2 , and T 3.Whilst, hatching rate was found 20.81±4.91, 37.11±4.50 and 61.33±6.61 in T 1 , T 2 , and T 3 treatments respectively. However, T 3 exhibited best performance regarding spawning, fertilization and hatching rate which were significantly higher than other two treatments.The current study revealed that spawning induction using carp pituitary extract and Buserelin is effective and might be useful for artificial breeding of Channa striata. Regarding to dose application i.e. 80 mg kg−1 of CPE and 0.80 µg kg−1 of Buserelin may be successfully applied to ovulation stimulation of Channa striata. • Carp pituitary extract (CPE) and Buserelin were efficient in spawning induction. • Spawning performances were higher with the increasing doses of hormones. • Most effective doses were 80 mg kg−1 and 0.80 µg kg−1 for CPE and Buserelin. • The result will be helpful to design induced breeding of Channa striata. [ABSTRACT FROM AUTHOR]

DNA methylation has long been considered the primary epigenetic mediator of genomic imprinting in mammals. Recent epigenetic profiling during early mouse development revealed the presence of domains of trimethylation of lysine 27 on histone H3 (H3K27me3) and chromatin compaction specifically at the maternally derived allele, independent of DNA methylation. Within these domains, genes are exclusively expressed from the paternally derived allele. This novel mechanism of noncanonical imprinting plays a key role in the development of mouse extraembryonic tissues and in the regulation of imprinted X-chromosome inactivation, highlighting the importance of parentally inherited epigenetic histone modifications. Here, we discuss the mechanisms underlying H3K27me3-mediated noncanonical imprinting in perspective of the dynamic chromatin landscape during early mouse development and explore evolutionary origins of noncanonical imprinting. Trimethylation of lysine 27 of histone H3 (H3K27me3) is a novel DNA-methylation-independent mediator of genomic imprinting in mice. H3K27me3-mediated noncanonical imprinting underlies imprinted paternal X chromosome inactivation during preimplantation of mouse development and is essential for proper development of extraembryonic tissues. Lack of H3K27me3-mediated noncanonical imprinting in somatic cells impedes post-implantation development of embryos derived from somatic cell nuclear transfer (SCNT). Noncanonical imprinting in mouse embryos is likely associated with the relative slow dynamics with which H3K27me3 equalizes between both parental alleles after fertilization. H3K27me3-mediated imprinting as observed in mice and plants seems to have evolved convergently. [ABSTRACT FROM AUTHOR]

The effects of herbicide Roundup (based on glyphosate) on the embryonic development, survival and hatching of common carp (Cyprinus carpio L.) larvae and alteration in foxr1 and hsp70 gene expression were determined. The eggs (obtained from 6 females) were fertilised and incubated in water containing 0; 1 or 10 μl L−1 of Roundup formulation. During early embryonic development (24 and 48 h post-fertilisation – hpf), Roundup caused a statistically important decrease in the embryonic survival rate of common carp. Moreover, retardation of the hatching rate was observed in the group treated with the higher concentration of Roundup at 81 to 99 hpf. At the end of the experiment (99 hpf), an important increase in number of deformed larvae was observed in both groups treated with Roundup in comparison to the control group (52.06; 16.02 and 5.08%, respectively). Significant differences in transcript of the gene foxr1 were found in Roundup-intoxicated groups in comparison to the controls. In the case of hsp70 transcripts, no important changes in exposed groups were observed. These results showed that even small, environmentally relevant amount of Roundup present in the aquatic environment is able to affect the early life stages of common carp and change the transcripts of foxr1 , which may have an adverse effect on the later proper development of the reproductive system. • Effect of the herbicide Roundup on common carp early life stages was studied. • Embryonic exposure to Roundup induced developmental abnormalities and increased mortality in common carp larvae. • Early life exposure led to alteration in foxr1 gene expression. • Roundup is a potential ecotoxicant for developing common carp embryos and larvae. [ABSTRACT FROM AUTHOR]

The beneficial effect of glutathione (GSH) on the in vitro maturation (IVM) of bovine/porcine oocytes has been confirmed; however, the antioxidant effect of exogenous GSH supplementation on the IVM of ovine oocytes has not been determined. In this study, ovine cumulus oocyte complexes (COCs) were classified into three groups according to the layer number of cumulus cells (the Grade A group has more than five layers, the Grade B group has three to four layers and the Grade C group has less than three layers). After in vitro culture of COCs in the presence of exogenous GSH, the meiotic competence of ovine oocytes was assessed by analyzing nuclear maturation to metaphase II (MII) stage, cortical granules (CGs) dynamics, astacin like metalloendopeptidase (ASTL) distribution, histone methylation pattern, reactive oxygen species (ROS) production, mitochondrial activities and genes expression. After in vitro fertilization (IVF), assessments of embryonic development were conducted to confirm the effects of exogenous GSH supplementation. The results showed that exogenous GSH not only enhanced the maturation rates of the Grade B and Grade C groups but also promoted CGs dynamics and ASTL distribution of the Grade A, B and C groups (p < 0.05). Exogenous GSH increased the mitochondrial activities of the Grade A, B and C groups and decreased the ROS production levels of oocytes (p < 0.05), regardless of the layer number of cumulus cells. Moreover, exogenous GSH promoted the expression levels of genes related with oocyte maturation, antioxidant activity and antiapoptotic effects in the Grade B and Grade C groups (p < 0.05). The expression levels of H3K4me3 and H3K9me3 in the Grade B and Grade C groups were promoted after exogenous GSH supplementation (p < 0.05), consistent with the expression levels of genes related with histone methylation (p < 0.05). In addition, exogenous GSH strongly promoted the embryonic developmental competence of Grade B and Grade C groups (p < 0.05). Taken together, our findings provide foundational evidence for the free radical scavenging potential of exogenous GSH in the in vitro developmental competence of ovine oocytes, especially oocytes from COCs lacking cumulus cells. These findings, which demonstrated the potential for improving the quality of ovine oocytes during IVM, will contribute to researches on GSH applications and the efficiency of assisted reproductive technology for ovine breeding. • Exogenous GSH supplementation promoted the in vitro developmental competence of ovine oocyte. • Exogenous GSH supplementation during ovine IVM enhanced the embryonic developmental competence and blastocyst quality. • Exogenous GSH supplementation promoted the developmental competence of ovine oocyte via the inhibition of oxidative stress. [ABSTRACT FROM AUTHOR]

• Gastruloids are a new in vitro platform for teratogenicity testing. • Teratogens disrupt gastruloid gene expression and morphology with imaging readout. • Medium-throughput gastruloid cultures are quantifiable with statistical robustness. • Mouse and human gastruloids recapitulate species-specific sensitivities to teratogens. • Proof-of-concept as a predictive assay with scope for automation. Pharmaceuticals intended for use in patients of childbearing potential need to be tested for teratogenicity before marketing. Several pharmaceutical companies use animal-free in vitro models which allow a more rapid selection of lead compounds and contribute to 3Rs principles ('replace, reduce and refine') by streamlining the selection of promising compounds submitted to further regulatory studies in animals. Currently available in vitro models typically rely on adherent monolayer cultures or disorganized 3D structures, both of which lack the spatiotemporal and morphological context of the developing embryo. A newly developed 3D 'gastruloid' model has the potential to achieve a more reliable prediction of teratogenicity by providing a robust recapitulation of gastrulation-like events alongside morphological coordination at relatively high-throughput. In this first proof-of-concept study, we used both mouse and human gastruloids to examine a panel of seven reference compounds, with associated in vivo data and known teratogenic risk, to quantitatively assess in vitro teratogenicity. We observed several gross morphological effects, including significantly reduced elongation or decreased size of the gastruloids, upon exposure to several of the reference compounds. We also observed aberrant gene expression using fluorescent reporters, including SOX2 , BRA , and SOX17, suggestive of multi-lineage differentiation defects and disrupted axial patterning. Finally, we saw that gastruloids recapitulated some of the known in vivo species-specific susceptibilities between their mouse and human counterparts. We therefore suggest that gastruloids represent a powerful tool for teratogenicity assessment by enabling relevant physiological recapitulation of early embryonic development, demonstrating their use as a novel in vitro teratogenic model system. [ABSTRACT FROM AUTHOR]

Objective: To explore the development and pregnancy potential of non-pronuclear (0PN) zygote-derived embryos in conventional in vitro fertilization (IVF) cycles.Study Design: Embryonic development in 1039 oocyte retrieval cycles and clinical outcomes of 659 frozen-thawed blastocyst transfer cycles were retrospectively studied.Results: Developmental potential of embryos with different blastomere numbers on day 3 were inconsistent in 0PN and 2PN groups. For 0PN-derived embryos, blastocyst rate of fast developing embryos (75.4%) was similar to that of intermediately developing embryos (72.9%), but good quality blastocyst rate of the former (49.2%) was significantly higher than that of the later (39.6%). In 2PN group, intermediately developing embryos had the highest blastocyst rate (77.9%) and good quality blastocyst rate (51.5%) (statistically significant). Comparison of frozen-thawed transfer was carried out between 0PN- and 2PN-derived blastocysts. For both single (SBT) and double blastocyst transfer (DBT) groups, no statistical differences existed between 0PN- and 2PN-derived blastocysts in clinical pregnancy rates (45.2% and 49.1% in SBT group, 64.7% and 66.4% in DBT group), implantation rates (45.2% and 49.1% in SBT group, 41.2% and 47.7% in DBT group) and live birth rates (35.5% and 36.8% in SBT group, 52.9% and 51.2% in DBT group).Conclusion: The developmental characteristic of 0PN-derived embryos was different from that of 2PN-derived embryos in IVF cycles. 0PN-derived blastocysts could obtain acceptable clinical pregnancy and live birth, but more studies are needed to confirm the safety.. [ABSTRACT FROM AUTHOR]

Induced pluripotent stem cell (iPSC)-based technology provides limitless resources for customized development of organs without any ethical concerns. In theory, iPSCs generated from terminally differentiated cells can be induced to further differentiate into all types of organs that are derived from the embryonic germ layers. Since iPSC reprogramming technology is relatively new, extensive efforts by the researchers have been put together to optimize the protocols to establish in vitro differentiation of human iPSCs (hiPSCs) into various desirable cell types/organs. In the present study, we review the potential application of iPSCs as an efficient alternative to primary cells for modulating signal molecules. Furthermore, an efficient culture system that promotes the differentiation of cell lineages and tissue formation has been reviewed. We also summarize the recent studies wherein tissue engineering of the three germ layers has been explored. Particularly, we focus on the current research strategies for iPSC-based tooth regeneration via molecular modulation. In recent decades, robust knowledge regarding the hiPSC-based regenerative therapy has been accumulated, especially focusing on cellular modulation. This review provides the optimization of the procedures designed to regenerate specific organs. [ABSTRACT FROM AUTHOR]

Are there differences in prenatal growth trajectories and birth outcomes between singleton pregnancies conceived after IVF treatment with frozen–thawed extended culture embryo transfer at day 5, fresh embryo transfer at day 3 or naturally conceived pregnancies? From a prospective hospital-based cohort, 859 singleton pregnancies were selected, including 133 conceived after IVF with frozen–thawed embryo transfer, 276 after fresh embryo transfer, and 450 naturally conceived pregnancies. Longitudinal 3D ultrasound scans were performed at 7, 9 and 11 weeks of gestation for offline crown–rump length (CRL) and embryonic volume measurements. Second trimester estimated fetal weight was based on growth parameters obtained during the routine fetal anomaly scan at 20 weeks of gestation. Birth outcome data were collected from medical records. No differences regarding embryonic growth trajectories were observed between frozen–thawed and fresh embryo transfer. Birthweight percentiles after fresh embryo transfer were lower than after frozen–thawed embryo transfer (38.0 versus 48.0; P = 0.046, respectively). The prevalence of non-iatrogenic preterm birth (PTB) was significantly lower in pregnancies resulting from fresh embryo transfer compared with frozen–thawed embryo transfer (4.7% versus 10.9%; P = 0.026, respectively). Compared with naturally conceived pregnancies, birthweight percentiles and percentage of non-iatrogenic PTB were significantly lower in pregnancies after fresh embryo transfer and gestational age at birth was significantly higher. This study shows that embryonic growth is comparable between singleton pregnancies conceived after fresh and frozen–thawed embryo transfer. The lower relative birthweight and PTB rate in pregnancies after fresh embryo transfer than after frozen–thawed embryo transfer and naturally conceived pregnancies warrants further investigation. [ABSTRACT FROM AUTHOR]

Background Context: Low back pain is commonly attributed to intervertebral disc (IVD) degeneration. IVD resembles articular cartilage in its biochemical and cellular composition in many ways. For articular cartilage, degeneration stage-specific characteristic spatial chondrocyte patterns have recently been described.Purpose: This study addresses how spatial chondrocyte organization in the IVD changes from early embryonic development to end stage degeneration.Study Design: Ex vivo immunohistochemical analysis.Methods: We immunohistochemically investigated bovine IVD-tissue (n=72) from early embryonic development to early disc degeneration and human adult IVD-tissue (n=25) operated for trauma or degeneration for cellular density and chondrocyte spatial organization. IVD samples were sectioned along the main collagen fiber orientation. Nuclei were stained with DAPI and their number and spatial patterns were analyzed in an area of 250,000 µm² for each tissue category.Results: The initially very high cellular density in the early embryonic bovine disc (11,431 cells/mm²) steadily decreases during gestation, growth and maturation to about 71 cell/mm² in the fully grown cattle. Interestingly, in human degenerative discs, a new increase in this figure could be noted (184 cells/mm). The IVD chondrocytes appear to be predominantly present as single cells. Especially in the time after birth, string-formations represent up to 32% of all cells in the anulus fibrosus, although single cells are the predominant spatial pattern (>50%) over the entire time. With increasing degeneration, the relative proportion of single cells in human IVDs continuously decreases (12%). At the same time, the share of cells organized in clusters increases (70%).Conclusion: Similar to articular cartilage, spatial chondrocyte organization appears to be a strong indicator for local tissue degeneration in the IVD.Clinical Significance: In the future these findings may be important for the detection and therapy of IVD degeneration in early stages. [ABSTRACT FROM AUTHOR]

Embryogenesis requires substantial coordination to translate genetic programs to the collective behavior of differentiating cells, but understanding how cellular decisions control tissue morphology remains conceptually and technically challenging. Here, we combine continuous Cas9-based molecular recording with a mouse embryonic stem cell-based model of the embryonic trunk to build single-cell phylogenies that describe the behavior of transient, multipotent neuro-mesodermal progenitors (NMPs) as they commit into neural and somitic cell types. We find that NMPs show subtle transcriptional signatures related to their recent differentiation and contribute to downstream lineages through a surprisingly broad distribution of individual fate outcomes. Although decision-making can be heavily influenced by environmental cues to induce morphological phenotypes, axial progenitors intrinsically mature over developmental time to favor the neural lineage. Using these data, we present an experimental and analytical framework for exploring the non-homeostatic dynamics of transient progenitor populations as they shape complex tissues during critical developmental windows. [Display omitted] • Molecular recording in embryoids reconstructs high-resolution cellular phylogenies • Progenitor cells share transcriptional similarities with their recent progeny • Single axial progenitors make plastic decisions that converge to a robust form • Axial progenitors functionally resolve toward a single fate over time Bolondi, Law, et al. engineer a single-cell recorder to reconstruct progenitor dynamics within mouse stem cell-derived embryoids. They characterize the variable fates of axial progenitors as they contribute to neural and somitic lineages, including how cellular decisions relate to transcriptional heterogeneity, the signaling microenvironment, and differentiation potential over developmental time. [ABSTRACT FROM AUTHOR]

Redox control seems to be indispensable for proper embryonic development. The ratio between glutathione (GSH) and its oxidized disulfide (GSSG) is the most abundant cellular redox circuit. We used zebrafish harboring the glutaredoxin 1-redox sensitive green fluorescent protein (Grx1-roGFP) probe either in mitochondria or cytosol to test the hypothesis that the GSH:GSSG ratio is strictly regulated through zebrafish embryogenesis to sustain the different developmental processes of the embryo. Following the GSSG:GSH ratio as a proxy for the GSH-dependent reduction potential (E h GSH) revealed increasing mitochondrial and cytosolic E h GSH during cleavage and gastrulation. During organogenesis, cytosolic E h GSH decreased, while that of mitochondria remained high. The similarity between E h GSH in brain and muscle suggests a central regulation. Modulation of GSH metabolism had only modest effects on the GSSG:GSH ratios of newly hatched larvae. However, inhibition of GSH reductase directly after fertilization led to dead embryos already 10 h later. Exposure to the emerging environmental pollutant Perfluorooctane Sulfonate (PFOS) disturbed the apparent regulated E h GSH as well. Mitochondrial and cytosolic GSSG:GSH ratios are almost identical in different organs during zebrafish development indicating that the E h GSH might follow H 2 O 2 levels and rather indirectly affect specific enzymatic activities needed for proper embryogenesis. Our data confirm that vertebrate embryogenesis depends on strictly regulated redox homeostasis. Disturbance of the GSSG:GSH circuit, e.g. induced by environmental pollution, leads to malformation and death. [Display omitted] • No organ specific mitochondrial and cytosolic GSH:GSSG ratios in zebrafish larvae. • Almost no effects of manipulated GSH metabolism on E h GSH in older zebrafish larvae. • Inhibition of GSH reductase in young larvae leads to malformation and death. • The environmental pollutant Perfluorooctane Sulfonate affects E h GSH in larvae. [ABSTRACT FROM AUTHOR]

• PFBS uptake in zebrafish larvae was 20.4 % higher compared to GenX. • Zebrafish larvae exhibited distinct metabolic responses to GenX and PFBS exposure. • Exposure to GenX and PFBS significantly impacted global amino acid pathways. Short chain per- and polyfluoroalkyl substances (PFAS), including hexafluoropropylene oxide dimer acid (GenX) and perfluorobutane sulfonate (PFBS), are replacement chemicals for environmentally persistent, long-chain PFAS. Although GenX and PFBS have been detected in surface and ground water worldwide, few studies provide information on the metabolic alterations or risks associated with their exposures. In this study, larval zebrafish were used to investigate the toxicity of early-life exposure to GenX or PFBS. Zebrafish were chronically exposed from 4 h post-fertilization (hpf) to 6 days post-fertilization (dpf) to 150 µM GenX or 95.0 µM PFBS. Ultra-high-performance liquid chromatography paired with high-resolution mass spectrometry was used to quantify uptake of GenX and PFBS into zebrafish larvae and perform targeted and untargeted metabolomics. Our results indicate that PFBS was 20.4 % more readily absorbed into the zebrafish larvae compared to GenX. Additionally, PFBS exposure significantly altered 13 targeted metabolites and 21 metabolic pathways, while GenX exposure significantly altered 1 targeted metabolite and 17 metabolic pathways. Exposure to GenX, and to an even greater extent PFBS, resulted in a number of altered metabolic pathways in the amino acid metabolism, with other significant alterations in the carbohydrate, lipid, cofactors and vitamins, nucleotide, and xenobiotics metabolisms. Our results indicate that GenX and PFBS impact the zebrafish metabolome, with implications of global metabolic dysregulation, particularly in metabolic pathways relating to growth and development. [ABSTRACT FROM AUTHOR]

The elevated salinity in freshwater causes a serious threat to the survival and reproduction of freshwater organisms. The effect of salinity on embryonic development of freshwater turtles is little known. In this study, we investigated the embryonic morphology and underlining mechanism of red-eared slider (Trachemys scripta elegans) in different salinities incubated environment (2.5 ppt and 5 ppt). Results showed that salinity caused various forms of malformed embryos, including brain hypoplasia, eye defects, skeletal dysplasia, deformities of carapace, plastron, limb in the embryo. Severely, salinity could lead to embryos decease. Transcriptome analysis showed that differentially expressed genes induced by salinity primarily enriched in development pathways, metabolism pathways, disease pathways as well as cell processes through KEGG enrichment analysis. In addition, in early and middle embryonic developmental stages, the mRNA expression of apoptotic genes (p38 and bax) significantly increased, whereas anti-apoptotic gene bcl-2 decreased in salinities incubated environment. These findings demonstrated that salinity inhibited the process of embryonic development and damaged organogenesis of turtles through promoting apoptotic pathways. [Display omitted] • Salinity stress resulted in aberrant morphology and embryonic mortality of red-eared turtle embryos. • Salinity exposure influenced the pathways associated with embryonic development of red-eared turtles. • Salinity stress led to notable variations in the expression of apoptotic genes. [ABSTRACT FROM AUTHOR]

Fish have common neurotransmitter pathways with humans, exhibiting a significant degree of conservation and homology. Thus, exposure to fluoxetine makes fish potentially susceptible to biochemical and physiological changes, similarly to what is observed in humans. Over the years, several studies demonstrated the potential effects of fluoxetine on different fish species and at different levels of biological organization. However, the effects of parental exposure to unexposed offspring remain largely unknown. The consequences of 15-day parental exposure to relevant concentrations of fluoxetine (100 and 1000 ng/L) were assessed on offspring using zebrafish as a model organism. Parental exposure resulted in offspring early hatching, non-inflation of the swimming bladder, increased malformation frequency, decreased heart rate and blood flow, and reduced growth. Additionally, a significant behavioral impairment was also found (reduced startle response, basal locomotor activity, and altered non-associative learning during early stages and a negative geotaxis and scototaxis, reduced thigmotaxis, and anti-social behavior at later life stages). These behavior alterations are consistent with decreased anxiety, a significant increase in the expression of the monoaminergic genes slc6a4a (sert), slc6a3 (dat) , slc18a2 (vmat2), mao , tph1a, and th2 , and altered levels of monoaminergic neurotransmitters. Alterations in behavior, expression of monoaminergic genes, and neurotransmitter levels persisted until offspring adulthood. Given the high conservation of neuronal pathways between fish and humans, data show the possibility of potential transgenerational and multigenerational effects of pharmaceuticals' exposure. These results reinforce the need for transgenerational and multigenerational studies in fish, under realistic scenarios, to provide realistic insights into the impact of these pharmaceuticals. [Display omitted] • Parental exposure to fluoxetine affected the offspring; • Parental exposure impaired the embryonic development of the offspring; • Offspring early age behavior was affected; • The expression of monoaminergic genes and neurochemical profiles were altered; • Behavioral, genetic, and neurochemical alterations persisted in offspring adulthood. [ABSTRACT FROM AUTHOR]

During oocyte maturation and early embryogenesis, changes in mRNA poly(A)-tail lengths strongly influence translation, but how these tail-length changes are orchestrated has been unclear. Here, we performed tail-length and translational profiling of mRNA reporter libraries (each with millions of 3′ UTR sequence variants) in frog oocytes and embryos and in fish embryos. Contrasting to previously proposed cytoplasmic polyadenylation elements (CPEs), we found that a shorter element, UUUUA, together with the polyadenylation signal (PAS), specify cytoplasmic polyadenylation, and we identified contextual features that modulate the activity of both elements. In maturing oocytes, this tail lengthening occurs against a backdrop of global deadenylation and the action of C-rich elements that specify tail-length-independent translational repression. In embryos, cytoplasmic polyadenylation becomes more permissive, and additional elements specify waves of stage-specific deadenylation. Together, these findings largely explain the complex tapestry of tail-length changes observed in early frog and fish development, with strong evidence of conservation in both mice and humans. [Display omitted] • UUUUA, influenced by contextual features, specifies most cytoplasmic polyadenylation • Stage-specific 3′ UTR elements drive waves of tail-length shortening in embryos • UUUUA and C-rich motifs can direct tail-length-independent translational repression • Tail-length control is conserved in oocytes of frogs, mice, and humans Xiang et al. analyze millions of different mRNA reporters to identify 3′ UTR sequence elements and their contextual features that control poly(A)-tail length and translation during early development of frogs and fish. These insights provide a unified paradigm for the translational control of early development of vertebrate animals. [ABSTRACT FROM AUTHOR]

• Histone deacetylase inhibitors can cause craniofacial developmental toxicity. • The ceratohyal angle is a quantitative measure of this developmental toxicity. • The ceratohyal angle assay is a simple in vivo tool for chemical risk assessment. Many bony features of the face develop from endochondral ossification of preexisting collagen-rich cartilage structures. The proper development of these cartilage structures is essential to the morphological formation of the face. The developmental programs governing the formation of the pre-bone facial cartilages are sensitive to chemical compounds that disturb histone acetylation patterns and chromatin structure. We have taken advantage of this fact to develop a quantitative morphological assay of craniofacial developmental toxicity based on the distortion and deterioration of facial cartilage structures in zebrafish larvae upon exposure to increasing concentrations of several well-described histone deacetylase inhibitors. In this assay, we measure the angle formed by the developing ceratohyal bone as a precise, sensitive and quantitative proxy for the overall developmental status of facial cartilages. Using the well-established developmental toxicant and histone deacetylase-inhibiting compound valproic acid along with 12 structurally related compounds, we demonstrate the applicability of the ceratohyal angle assay to investigate structure-activity relationships. [ABSTRACT FROM AUTHOR]

• mtDNA mutations do not affect quality or viability of human embryos. • A pathogenic mtDNA mutation does not modify the mtDNA metabolism in human cleavage-stage embryos. • mtDNA mutations might be associated with diminished ovarian reserves. Mitochondrial DNA (mtDNA) mutations cause severe maternally inherited disorders, although mechanisms regulating mother-to-offspring transmission have not yet been elucidated. To investigate if mtDNA mutations affect embryonic development, we compared morphology, viability and mtDNA content in control (n = 165) and mitochondrial (n = 16) human embryos at the cleavage-stage. mtDNA copy number (CN) was assessed in one or two embryonic cells, by real-time PCR. The presence of a maternal or embryonic mtDNA mutation did not impact on either embryonic quality or viability. mtDNA CN was not altered by mtDNA mutations, suggesting that mtDNA defects do not modify mtDNA metabolism at this early stage. [ABSTRACT FROM AUTHOR]

Copper (Cu) ions have redox activity and act as cofactors of enzymes related to respiration, radical detoxification, and iron metabolism. In this study, we aimed to examine the effects of copper (II) chloride dihydrate (CuCl2·2H2O) on porcine oocytes during in vitro maturation (IVM) and subsequent embryonic development following parthenogenetic activation (PA). Nuclear maturation, intracellular glutathione (GSH) and reactive oxygen species (ROS) levels, cumulus expansion, the mRNA expression levels of various genes, and developmental competence were analyzed. During IVM, the maturation medium was supplemented with various concentrations of Cu (0, 0.7, 1.4, and 2.8 μg/mL). After 42 h of IVM, Cu supplementation significantly increased the number of oocytes in the metaphase II stage. Further, the 1.4 μg/mL Cu group showed significantly higher intracellular GSH levels than the control group. However, Cu supplementation increased intracellular ROS levels regardless of their concentration. Additionally, the mRNA levels of Has-2 , the cumulus cell expansion-related gene, were higher in all the Cu-treated groups than in the control group. The cumulus cell expansion index was higher in the 0.7 and 1.4 μg/mL Cu groups than in the other groups. In the 0.7 μg/mL Cu group, the mRNA expression levels of PCNA, Zar1 , and NPM2 , which are related to developmental competence, were significantly higher than those in the control group. Moreover, increased levels of Sod1 transcript, correlated with the antioxidative response, were observed in the 0.7 and 1.4 μg/mL Cu groups. The apoptosis rate in Cu-treated cumulus cells and oocytes was decreased compared to that in the corresponding control groups. Upon evaluation of subsequent embryonic development after PA, the 0.7 μg/mL Cu group showed significantly improved cleavage and blastocyst formation rate compared to the control group. In conclusion, our results suggest that Cu supplementation at appropriate concentrations in IVM medium improves porcine oocyte maturation and the subsequent embryonic potential of PA embryos by reducing oxidative stress and apoptosis. • Cu significantly improved the cleavage and blastocyst formation rate of embryos. • Cu reduced the oxidative stress and apoptosis by increasing the expression of SOD1. • Addition of Cu can improve oocyte maturation efficiency and embryonic development. [ABSTRACT FROM AUTHOR]

In vivo, mammalian oocytes are surrounded by granulosa cells (GCs) that exist in a three-dimensional (3D) microenvironment with soft stiffness. The GCs play an important role for the in vivo growth and development of oocytes, through bidirectional communication between oocytes and GCs. To mimic the cellular microenvironment of a 3D organized follicle, this study designed a co-culture system using porcine ovarian GCs (pGCs) encapsulated in agarose matrix for in vitro maturation (IVM) of pig oocytes. We report the effects of our newly designed co-culture system on IVM and development of pig oocytes. Immature cumulus-oocyte-complexes (COCs) were matured on a 1% (w/v) agarose matrix encapsulated without or with pGCs. The number of pGCs within the agarose matrix was optimized by analyzing the in vitro development of parthenogenetic embryos. Moreover, the role of the ovarian stromal pGCs as feeder cells was assessed by analyzing the PA embryonic development. Subsequently, the effect of pGCs encapsulated in a 3D agarose matrix was evaluated for the developmental competence of pig oocytes by analyzing blastocyst formation after parthenogenetic activation (PA), intra-oocyte GSH and ROS contents, expression levels of BMP15 and BAX , TUNEL (terminal deoxynucleotidyl transferase-mediated d-UTP nick end-labeling) assay, protein expression levels of BMP15, and intra-oocyte ATP levels. The optimized number of pGCs (5 × 104 cells/well) in a 3D agarose matrix led to a significantly higher blastocyst formation, increased BMP15 gene and protein expression, and intra-oocyte ATP levels; moreover, it induced significantly lower intra-oocyte ROS contents, pro-apoptotic BAX gene expression, and apoptotic index, compared to control. Our results demonstrate that application of pGCs as feeder cells encapsulated in the agarose matrix for IVM effectively increases the developmental competence of porcine oocytes. • Effects of IVM on agarose matrix with granulosa cells on oocyte maturation and embryonic development were evaluated in pigs. • IVM under the granulosa cells (pGCs) in a 3D agarose matrix significantly increased BMP15 gene and protein expression. • IVM under the pGCs in agarose matrix increased intra-oocyte ATP levels and reduced ROS contents and apoptotic index. • Application of the agarose matrix with pGCs for IVM effectively increased the developmental competence of pig oocytes. [ABSTRACT FROM AUTHOR]

[Display omitted] • In vivo administration of 5-FU lead to small ovarian size and ovulation failure. • Exposure to 5-FU reduced oocyte competency for in vitro maturation. • 5-FU was detrimental for developmental progression of the pre-implantation embryos. • Reproductive toxicity of 5-FU in female mice was mostly eliminated after one week. 5-Fluorouracil (5-FU) is a "cytotoxic" drug used for cancer chemotherapy, which inhibits cells division via affecting DNA synthesis. Although being widely used for cancer treatment, 5-FU has non-negligible side effects. In the present study, the effects of 5-FU on oocyte and early embryonic development were investigated. Multiple intraperitoneal administration of 5-FU (50 mg/kg/day) in female mice resulted in small ovarian size and reduced number of corpus luteum in the ovary, and lead to ovulation failure. However, these defects could be recovered after one week. In vitro experiments further indicated that exposure to 5-FU inhibited oocytes maturation and reduced developmental potential of pre-implantation embryos. Our data suggested that 5-FU has negative impact on ovarian function, oocyte and early embryonic development, but the adverse effect could be reversed after withdrawal of 5-FU administration. [ABSTRACT FROM AUTHOR]

We developed an incremental growth-at-temperature model to predict hatch timing for lake whitefish under varying incubation temperatures. The model extends earlier approaches by incorporating a temperature-dependence for development stage at hatching. Testing using experimentally reared embryos from Lakes Huron and Simcoe demonstrates improved predictive accuracy compared to previous models for asymmetrically varying thermal regimes that mimic aspects of those encountered under real-world conditions. The simple calibration of the model to different populations and its ability to predict observed phenomena such as thermally-induced mass hatching and hatching synchronization makes it a useful tool for the evaluation of thermal impacts from industrial discharges and climate change. [ABSTRACT FROM AUTHOR]