Protective effect of Sasa veitchii extract against all-trans-retinoic acid-induced inhibition of proliferation of cultured human palate cells.

Cleft palate is the most common facial birth defect worldwide. It is caused by environmental factors or genetic mutations. Environmental factors such as pharmaceutical exposure in women are known to induce cleft palate. The aim of the present study was to investigate the protective effect of Sasa veitchii extract against medicine-induced inhibition of proliferation of human embryonic palatal mesenchymal cells. We demonstrated that all-trans-retinoic acid inhibited human embryonic palatal mesenchymal cell proliferation in a dose-dependent manner, whereas dexamethasone treatment had no effect on cell proliferation. Cotreatment with Sasa veitchii extract repressed all-trans-retinoic acid-induced toxicity in human embryonic palatal mesenchymal cells. We found that cotreatment with Sasa veitchii extract protected all-trans-retinoic acid-induced cyclin D1 downregulation in human embryonic palatal mesenchymal cells. Furthermore, Sasa veitchii extract suppressed all-trans-retinoic acid-induced miR-4680-3p expression. Additionally, the expression levels of the genes that function downstream of the target genes ( ERBB2 and JADE1 ) of miR-4680-3p in signaling pathways were enhanced by cotreatment with Sasa veitchii extract and all-trans-retinoic acid compared to all-trans-retinoic acid treatment. These results suggest that Sasa veitchii extract suppresses all-trans-retinoic acid-induced inhibition of cell proliferation via modulation of miR-4680-3p expression.

Venom gland organogenesis in the common house spider.

Venom is a remarkable innovation found across the animal kingdom, yet the evolutionary origins of venom systems in various groups, including spiders, remain enigmatic. Here, we investigated the organogenesis of the venom apparatus in the common house spider, Parasteatoda tepidariorum. The venom apparatus consists of a pair of secretory glands, each connected to an opening at the fang tip by a duct that runs through the chelicerae. We performed bulk RNA-seq to identify venom gland-specific markers and assayed their expression using RNA in situ hybridisation experiments on whole-mount time-series. These revealed that the gland primordium emerges during embryonic stage 13 at the chelicera tip, progresses proximally by the end of embryonic development and extends into the prosoma post-eclosion. The initiation of expression of an important toxin component in late postembryos marks the activation of venom-secreting cells. Our selected markers also exhibited distinct expression patterns in adult venom glands: sage and the toxin marker were expressed in the secretory epithelium, forkhead and sum-1 in the surrounding muscle layer, while Distal-less was predominantly expressed at the gland extremities. Our study provides the first comprehensive analysis of venom gland morphogenesis in spiders, offering key insights into their evolution and development.

Lhx4 surpasses its paralog Lhx3 in promoting the differentiation of spinal V2a interneurons.

Paralog factors are considered to ensure the robustness of biological processes by providing redundant activity in cells where they are co-expressed. However, the specific contribution of each factor is frequently underestimated. In the developing spinal cord, multiple families of transcription factors successively contribute to differentiate an initially homogenous population of neural progenitors into a myriad of neuronal subsets with distinct molecular, morphological, and functional characteristics. The LIM-homeodomain transcription factors Lhx3, Lhx4, Isl1 and Isl2 promote the segregation and differentiation of spinal motor neurons and V2 interneurons. Based on their high sequence identity and their similar distribution, the Lhx3 and Lhx4 paralogs are considered to contribute similarly to these processes. However, the specific contribution of Lhx4 has never been studied. Here, we provide evidence that Lhx3 and Lhx4 are present in the same cell populations during spinal cord development. Similarly to Lhx3, Lhx4 can form multiproteic complexes with Isl1 or Isl2 and the nuclear LIM interactor NLI. Lhx4 can stimulate a V2-specific enhancer more efficiently than Lhx3 and surpasses Lhx3 in promoting the differentiation of V2a interneurons in chicken embryo electroporation experiments. Finally, Lhx4 inactivation in mice results in alterations of differentiation of the V2a subpopulation, but not of motor neuron production, suggesting that Lhx4 plays unique roles in V2a differentiation that are not compensated by the presence of Lhx3. Thus, Lhx4 could be the major LIM-HD factor involved in V2a interneuron differentiation during spinal cord development and should be considered for in vitro differentiation of spinal neuronal populations.

Zinc oxide nanoparticles induces cell death and consequently leading to incomplete neural tube closure through oxidative stress during embryogenesis.

The implementation of Zinc oxide nanoparticles (ZnO NPs) raises concerns regarding their potential toxic effects on human health. Although more and more researches have confirmed the toxic effects of ZnO NPs, limited attention has been given to their impact on the early embryonic nervous system. This study aimed to explore the impact of exposure to ZnO NPs on early neurogenesis and explore its underlying mechanisms. We conducted experiments here to confirm the hypothesis that exposure to ZnO NPs causes neural tube defects in early embryonic development. We first used mouse and chicken embryos to confirm that ZnO NPs and the Zn2+ they release are able to penetrate the placental barrier, influence fetal growth and result in incomplete neural tube closure. Using SH-SY5Y cells, we determined that ZnO NPs-induced incomplete neural tube closure was caused by activation of various cell death modes, including ferroptosis, apoptosis and autophagy. Moreover, dissolved Zn2+ played a role in triggering widespread cell death. ZnO NPs were accumulated within mitochondria after entering cells, damaging mitochondrial function and resulting in the over production of reactive oxygen species, ultimately inducing cellular oxidative stress. The N-acetylcysteine (NAC) exhibits significant efficacy in mitigating cellular oxidative stress, thereby alleviating the cytotoxicity and neurotoxicity brought about by ZnO NPs. These findings indicated that the exposure of ZnO NPs in early embryonic development can induce cell death through oxidative stress, resulting in a reduced number of cells involved in early neural tube closure and ultimately resulting in incomplete neural tube closure during embryo development. The findings of this study could raise public awareness regarding the potential risks associated with the exposure and use of ZnO NPs in early pregnancy.

Characteristics of unilateral and bilateral bovine twin foetuses.

Twin pregnancy in cattle is undesirable for a number of reasons, including a higher abortion risk compared to pregnancies with a single foetus. Yet, the abortion risk is significantly influenced by the intrauterine location of the foetuses, that is, the abortion risk is several times higher if they are implanted in the same uterine horn (unilateral twin pregnancy) than if they are implanted with one foetus in each uterine horn (bilateral twin pregnancy). The reason for the higher abortion risk in unilateral twin pregnancies is unknown, but it may be related to malnutrition of the outermost foetus due to a limited placental capacity, as is the case for equine twin foetuses. A slaughterhouse study was performed and the foetuses of cattle pregnant with twins were measured. We identified 65 cases of twin pregnancies, of which 35 were unilateral twin pregnancies and 30 were bilateral twin pregnancies. There was no significant difference between the outermost and the more centrally located foetus in unilateral twin pregnancies in terms of body weight and length of the metacarpal diaphysis. Growth retardation of the outermost foetus could therefore not be confirmed as the cause of the higher abortion risk in unilateral bovine twin pregnancies. Four cases of pre-slaughter foetal mortality were identified. In three of these cases, both twins were dead, of equal size and at a comparable level of degradation. In the fourth case, with approximately 40-day-old twin foetuses of equal size, only one of the foetuses showed signs of pre-slaughter death.

The effect of exogenous melatonin administration before superovulation on embryo yield in Assaf ewes.

The aim of this study was to determine the effect of exogenous melatonin administration on transferable embryos by increasing total antioxidant status before superovulation in Assaf ewes. Selected ewes were randomly divided into two equal groups: melatonin (n = 9) and control (n = 9). In the melatonin group, a melatonin implant (18 mg melatonin, Regulin®, Ceva, Turkey) was placed under the skin of the ear 7 days prior to insertion of the progesterone-containing sponge. In the control group, a physiological saline solution was injected under the skin of the ear on the same day. The same superovulation protocol was used in both groups. In addition, blood samples for determination of Glutathione peroxidase, superoxide dismutase, total antioxidant status and total oxidant status concentrations were collected on five different days, including the day of melatonin implant placement (Day-7), vaginal sponge insertion (Day 0), vaginal sponge removal (Day 11), mating (Day 12-13) and uterine flushing (Day 19). Embryos were collected by laparotomy on the 7th day after mating. Uterine flushing taken into petri dishes were scanned under a stereomicroscope, and the quality and developmental stages of the embryos were recorded. In the study, total corpus luteum count and total cell count were found to be higher in the control group than in the melatonin group (p < .05). When the results were evaluated in terms of oxidative stress index, a negative correlation was found between the total number of corpus luteum, number of cells obtained, count of transferable embryos and number of Grade 1 embryos on Day 0. There was also a positive correlation oxidative stress index and the number of unfertilized oocytes on Day-7. As a result, exogenous melatonin administration prior to superovulation during the breeding season is thought to have a negative effect on embryo yield and quality. Therefore, the use of exogenous melatonin in MOET studies during the breeding season is recommended to be investigated in new studies.

Mechanical forces remodel the cardiac extracellular matrix during zebrafish development.

The cardiac extracellular matrix (cECM) is fundamental for organ morphogenesis and maturation, during which time it undergoes remodeling, yet little is known about whether mechanical forces generated by the heartbeat regulate this remodeling process. Using zebrafish as a model and focusing on stages when cardiac valves and trabeculae form, we found that altering cardiac contraction impairs cECM remodeling. Longitudinal volumetric quantifications in wild-type animals revealed region-specific dynamics: cECM volume decreases in the atrium but not in the ventricle or atrioventricular canal. Reducing cardiac contraction resulted in opposite effects on the ventricular and atrial ECM, whereas increasing the heart rate affected the ventricular ECM but had no effect on the atrial ECM, together indicating that mechanical forces regulate the cECM in a chamber-specific manner. Among the ECM remodelers highly expressed during cardiac morphogenesis, we found one that was upregulated in non-contractile hearts, namely tissue inhibitor of matrix metalloproteinase 2 (timp2). Loss- and gain-of-function analyses of timp2 revealed its crucial role in cECM remodeling. Altogether, our results indicate that mechanical forces control cECM remodeling in part through timp2 downregulation.

Direct Somatic Embryogenesis in Carica papaya L. Genotypes for Genetic Modification Purposes.

This chapter presents an efficient protocol for regenerating Carica papaya plants via somatic embryogenesis from immature zygotic embryos from economically important papaya genotypes. To achieve regenerated plants from somatic embryos, in the present protocol, four induction cycles are required, followed by one multiplication cycle and one regeneration cycle. With this optimized protocol, 80% of somatic embryos can be obtained in only 3.5 months. At this stage, calli containing more than 50% globular structures can be used for transformation (via agrobacterium, biobalistics, or any other transformation method). Once transformed, calli can be transferred to the following steps (multiplication, elongation, maturation, rooting, and ex vitro acclimatization) to regenerate a transformed somatic embryo-derived full plant.

Transcriptomic Analysis During the Induction of Somatic Embryogenesis in Coffea canephora.

Omic tools have changed the way of doing research in experimental biology. The somatic embryogenesis (SE) study has not been immune to this benefit. The transcriptomic tools have been used to compare the genes expressed during the induction of SE with the genes expressed in zygotic embryogenesis or to compare the development of the different stages embryos go through. It has also been used to compare the expression of genes during the development of calli from which SE is induced, as well as many other applications. The protocol described here is employed in our laboratory to extract RNA and generate several transcriptomes for the study of SE on Coffea canephora.

Conservation of cis-Regulatory Syntax Underlying Deuterostome Gastrulation.

Throughout embryonic development, the shaping of the functional and morphological characteristics of embryos is orchestrated by an intricate interaction between transcription factors and cis-regulatory elements. In this study, we conducted a comprehensive analysis of deuterostome cis-regulatory landscapes during gastrulation, focusing on four paradigmatic species: the echinoderm Strongylocentrotus purpuratus, the cephalochordate Branchiostoma lanceolatum, the urochordate Ciona intestinalis, and the vertebrate Danio rerio. Our approach involved comparative computational analysis of ATAC-seq datasets to explore the genome-wide blueprint of conserved transcription factor binding motifs underlying gastrulation. We identified a core set of conserved DNA binding motifs associated with 62 known transcription factors, indicating the remarkable conservation of the gastrulation regulatory landscape across deuterostomes. Our findings offer valuable insights into the evolutionary molecular dynamics of embryonic development, shedding light on conserved regulatory subprograms and providing a comprehensive perspective on the conservation and divergence of gene regulation underlying the gastrulation process.

Global Transcriptomic and Characteristics Comparisons between Mouse Fetal Liver and Bone Marrow Definitive Erythropoiesis.

Erythropoiesis occurs first in the yolk sac as a transit "primitive" form, then is gradually replaced by the "definitive" form in the fetal liver (FL) during fetal development and in the bone marrow (BM) postnatally. While it is well known that differences exist between primitive and definitive erythropoiesis, the similarities and differences between FL and BM definitive erythropoiesis have not been studied. Here we performed comprehensive comparisons of erythroid progenitors and precursors at all maturational stages sorted from E16.5 FL and adult BM. We found that FL cells at all maturational stages were larger than their BM counterparts. We further found that FL BFU-E cells divided at a faster rate and underwent more cell divisions than BM BFU-E. Transcriptome comparison revealed that genes with increased expression in FL BFU-Es were enriched in cell division. Interestingly, the expression levels of glucocorticoid receptor Nr3c1, Myc and Myc downstream target Ccna2 were significantly higher in FL BFU-Es, indicating the role of the Nr3c1-Myc-Ccna2 axis in the enhanced proliferation/cell division of FL BFU-E cells. At the CFU-E stage, the expression of genes associated with hemoglobin biosynthesis were much higher in FL CFU-Es, indicating more hemoglobin production. During terminal erythropoiesis, overall temporal patterns in gene expression were conserved between the FL and BM. While biological processes related to translation, the tricarboxylic acid cycle and hypoxia response were upregulated in FL erythroblasts, those related to antiviral signal pathway were upregulated in BM erythroblasts. Our findings uncovered previously unrecognized differences between FL and BM definitive erythropoiesis and provide novel insights into erythropoiesis.

A comparative study of in vivo toxicity in zebrafish embryos synthesized CuO nanoparticles characterized from Salacia reticulata.

The Salacia reticulata, a medicinal woody climbing shrub, was utilized for our study, the green synthesis of CuO nanoparticles, which were analyzed through SEM, EDX, FTIR, XRD, and UV‒Vis spectroscopy. This study assessed the toxicity to zebrafish embryos and explored the antibacterial, cytotoxic, antidiabetic, and anti-inflammatory properties of the synthesized nanoparticles. In results, the UV absorption of the CuO NPs showed that the intensity of nanoparticle green colloidal suspension changed from blue to green, which also confirmed that the spectrum of the green CuO NPs changed from colorless to black. in FT-IR and XRD spectral analysis to identify functional groups and determine the particle size of CuO NPs prepared by green and chemical methods. Its showed that CuO NPs (green) had a size of approximately 42.2 nm, while CuO NPs (chemical) had a size of approximately 84 nm. The morphology of these NPs was analyzed using SEM-EDX. Compared with their chemically prepared counterparts, the green-synthesized CuO nanoparticles demonstrated superior dispersion. Additionally, both green and chemical CuO nanoparticles at a concentration of 200 µL/mL caused developmental anomalies and increased mortality in zebrafish embryos and larvae. The green and chemical CuO NPs inhibited α-glucosidase enzyme activity at concentrations between 10 and 50 µL/mL, with IC50 values of 22 µL/mL and 26 µL/mL, respectively. The extract exhibited anti-inflammatory activity, with IC50 values of 274 and 109 µL/mL. The authors concluded that this green nanoparticle method has potential as a more eco-friendly and cost-effective alternative to traditional synthetic methods. NPs are widely used in human contact fields (medicine and agriculture), hence synthesis methods that do not involve toxic substances are becoming increasingly important.

A prospective study of the proteome of equine pre-implantation embryo.

The present study was conducted to investigate the global proteome of 8-day-old equine blastocysts. Follicular dynamics of eight adult mares were monitored by ultrasonography and inseminated 24 h after the detection of a preovulatory follicle. Four expanded blastocysts were recovered, pooled, and subjected to protein extraction and mass spectrometry. Protein identification was conducted based on four database searches (PEAKS, Proteome Discoverer software, SearchGUI software, and PepExplorer). Enrichment analysis was performed using g:Profiler, Panther, and String platforms. After the elimination of identification redundancies among search tools (at three levels, based on identifiers, peptides, and cross-database mapping), 1977 proteins were reliably identified in the samples of equine embryos. Proteomic analysis unveiled robust metabolic activity in the 8-day equine embryo, highlighted by an abundance of proteins engaged in key metabolic pathways like the TCA cycle, ATP biosynthesis, and glycolysis. The prevalence of chaperones among highly abundant proteins suggests that regulation of protein folding, and degradation is a key process during embryo development. These findings pave the way for developing new strategies to improve equine embryo media and optimize in vitro fertilization techniques.

Mosaic distal 9p deletion or 46,XY,del(9)(p23)/46,XY at amniocentesis in a pregnancy associated with perinatal progressive decrease of the aneuploid cell line and a favorable fetal outcome.

OBJECTIVE: We present mosaic distal 9p deletion at prenatal diagnosis in a pregnancy associated with a favorable fetal outcome. CASE REPORT: A 34-year-old, primigravid woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 46,XY, del(9)(p23)[8]/46,XY[17]. Simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes showed 43% mosaicism for the 9p24.3p23 deletion. Prenatal ultrasound suspected hypospadias and echogenic bowel. At 23 weeks of gestation, she was referred for genetic counseling, and repeat amniocentesis revealed a karyotype of 46,XY,del(9)(p23)[10]/46,XY[10]. The parental karyotypes were normal. Molecular genetic analysis on uncultured amniocytes revealed no uniparental disomy (UPD) 9 by quantitative fluorescence polymerase chain reaction (QF-PCR) and arr 9p24.3p23 × 1.55 (40%-50% mosaicism) by aCGH. At 27 weeks of gestation, she underwent the third amniocentesis which revealed a karyotype of 46,XY,del(9)(p23)[6]/46,XY[14]. Simultaneous aCGH analysis on the DNA extracted from uncultured amniocytes revealed the result of arr 9p24.3p23 (35% mosaicism). Prenatal ultrasound was normal. She was advised to continue the pregnancy, and a 3020-g phenotypically normal male baby was delivered at 41 weeks of gestation. At birth, the karyotypes of cord blood, umbilical cord and placenta were 46,XY,del(9)(p23)[7]/46,XY[37], 46,XY,del(9)(p23)[17]/46,XY[23] and 46,XY in 40/40 cells, respectively. When follow-up at age three months, the neonate was normal in phenotype and development. The peripheral blood had a karyotype of 46,XY,del(9)(p23)[3]/46,XY[37], and interphase fluorescence in situ hybridization (FISH) analysis on buccal mucosal cells showed 13% (13/102 cells) mosaicism for the distal 9p deletion. CONCLUSION: Mosaic distal 9p deletion with a normal cell line at prenatal diagnosis can be associated with a favorable fetal outcome and perinatal progressive decrease of the aneuploid cell line.

Low-level mosaic trisomy 7 at amniocentesis in a pregnancy associated with cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes, perinatal progressive decrease of the trisomy 7 cell line and a favorable fetal outcome.

OBJECTIVE: We present low-level mosaic trisomy at amniocentesis in a pregnancy associated with cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes, perinatal progressive decrease of the trisomy 7 cell line and a favorable fetal outcome. CASE REPORT: A 40-year-old, primigravid woman underwent amniocentesis at 16 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 46,XY in cultured amniocytes. Simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes revealed the result of arr (7) × 2-3, (X,Y) × 1, consistent with 24% mosaicism for trisomy 7. Polymorphic DNA marker analysis on the DNA extracted from the uncultured amniocytes and parental bloods excluded uniparental disomy (UPD) 7. Prenatal ultrasound findings were normal. She was referred for genetic counseling at 19 weeks of gestation. No repeat amniocentesis was suggested, and continuing the pregnancy was advised. At 22 weeks of gestation, the result of soluble fms-like tyrosine kinase-1 (sFlt-1)/placental growth factor (PlGF) = 6.1 (normal < 38). She did not have preeclampsia. At 39 weeks of gestation, a 3346-g male baby was delivered without any phenotypic abnormality. aCGH analysis on the DNA extracted from cord blood and placenta revealed the result of arr (1-22) × 2, (X,Y) × 1 with no genomic imbalance in all tissues. When follow-up at age three months, the baby was normal in development and phenotype. The peripheral blood had a karyotype of 46,XY, and interphase fluorescence in situ hybridization (FISH) analysis using the bacterial artificial chromosome (BAC) probes of chromosome 7 showed disomy 7 cells in all 102/102 cells. CONCLUSION: Low-level mosaic trisomy 7 at amniocentesis can be associated with cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes, perinatal progressive decrease of the trisomy 7 cell line and a favorable fetal outcome.

[Transcription factor activator protein 2C contribute to molar development in mice].

Objective: Explore the expression pattern of transcription factor activator protein 2C (TFAP2C) and identify the roles of Tfap2c during tooth development. Methods: Real-time fluorescence quantitative PCR (RT-qPCR) was used to analyze the relative expression level of Tfap2c in various organs of embryonic day(E)14.5 mouse embryos and mouse molar germs at E12.5-E18.5 and postnatal day (P)0-P7. The expression position of Tfap2c in mouse molar germs was demonstrated by frozen section immunofluorescence staining. Cultured mandibular molar germs were transfected with control small interfering RNA (siRNA) or Tfap2c siRNA to evaluate the effect of Tfap2c on tooth molar germs development, and RT-qPCR was used to detect the relative expression level of genes related to odontoblast expression. Dental mesenchymal cells were isolated from E14.5 molar germs and transfected with control siRNA or Tfap2c siRNA, cell counting kit 8 (CCK-8) and scratch healing test were applied to detect dental mesenchymal cell viability and migration. Results: Tfap2c was highly expressed in the early development period of mouse molar germs. Tfap2c was expressed in the epithelial and mesenchymal tissues of E13.5 mouse molar germs and there was no significant difference of relative expression of Tfap2c between them (t=1.06, P=0.472). Tfap2c was expressed in mesenchymal tissues of E14.5 mouse molar germs and the relative expression of Tfap2c in mesenchymal tissues was significantly higher than epithelial tissues (t=37.29, P<0.0001). For molar germs transfected with Tfap2c siRNA, the relative height of cusps (0.708±0.171) and the ratio of cusp height and crown height (0.321±0.068) was significantly lower than control group (1.000±0.287 and 0.483±0.166) (t=2.79, P=0.012; t=2.85, P=0.015). But there was no significant difference in relative height (1.078±0.206, 0.993±0.254, t=0.83, P=0.419)and relative width (1.000±0.116, 0.999±0.122, t=0.01, P=0.992) of crowns between two groups. The relative expression level of genes related to odontoblast expression was decreased (Dspp: t=15.33, P<0.001; Dmp1: t=13.81, P<0.001). Tfap2c siRNA hinders cell migration in dental mesenchymal cells (t=29.86, P=0.001), but there was no significant difference in CCK-8 absorbance value between two groups. The relative expression level of genes related to odontoblast expression was also decreased in dental mesenchymal cells transfected with Tfap2c siRNA (Dspp: t=3.86, P=0.031; Dmp1; t=4.36, P=0.022). Conclusions: Tfap2c highly expressed in the early morphogenesis period of mouse molar germs, mainly in mesenchymal tissues. Tfap2c affected the cusps formation of mouse molar germs and migration of dental mesenchymal cells.

Transition of signal requirement in hematopoietic stem cell development from hemogenic endothelial cells.

Hematopoietic stem cells (HSCs) develop from hemogenic endothelial cells (HECs) in vivo during mouse embryogenesis. When cultured in vitro, cells from the embryo phenotypically defined as pre-HSC-I and pre-HSC-II have the potential to differentiate into HSCs. However, minimal factors required for HSC induction from HECs have not yet been determined. In this study, we demonstrated that stem cell factor (SCF) and thrombopoietin (TPO) induced engrafting HSCs from embryonic day (E) 11.5 pre-HSC-I in a serum-free and feeder-free culture condition. In contrast, E10.5 pre-HSC-I and HECs required an endothelial cell layer in addition to SCF and TPO to differentiate into HSCs. A single-cell RNA sequencing analysis of E10.5 to 11.5 dorsal aortae with surrounding tissues and fetal livers detected TPO expression confined in hepatoblasts, while SCF was expressed in various tissues, including endothelial cells and hepatoblasts. Our results suggest a transition of signal requirement during HSC development from HECs. The differentiation of E10.5 HECs to E11.5 pre-HSC-I in the aorta-gonad-mesonephros region depends on SCF and endothelial cell-derived factors. Subsequently, SCF and TPO drive the differentiation of E11.5 pre-HSC-I to pre-HSC-II/HSCs in the fetal liver. The culture system established in this study provides a beneficial tool for exploring the molecular mechanisms underlying the development of HSCs from HECs.

Evaluation of the teratogenic potency of bulk zinc oxide and its nanoparticles on embryos of the freshwater snail, Helisoma duryi.

Bulk zinc oxide (ZnO-BPs) and its nanoparticles (ZnO-NPs) are frequently used in various products for humans. Helisoma duryi embryos can serve as effective model organisms for studying the toxicity of NPs. This study aimed to compare the teratogenic potency of ZnO-BPs and ZnO NPs in the embryonic stages of H. duryi to evaluate the utility of this snail as a bioindicator for ZnO-NPs in the aquatic environment. The mechanisms of teratogenesis were evaluated by determination of the LC50, studying the effect of sub-lethal concentrations of both ZnO forms on the embryos, and studying their enzyme activity, oxidative stress, and biochemical analysis. The SDS-PAGE electrophoresis was undertaken to assess the effect of ZnO-BPs and ZnO NPs on protein synthesis. The results revealed that the veliger stage of H. duryi is the specific stage for bulk and nano ZnO. ZnO-NPs proved to be more toxic to snails' embryos than ZnO-BPs. Exposure to ZnO influences specific types of defects in development, which in the case of BPs are far less drastic than those caused by NPs. Thus, the toxicity of ZnO-NPs in embryonic development is due to their unique physicochemical properties. The observed malformations include mainly hydropic malformation, exogastrulation, monophthalmia, shell misshapen, and cell lyses. Almost all tested oxidative biomarkers significantly changed, revealing that ZnONPs display more oxidative stress than ZnO-BPs. Also, the low concentration of ZnO induces many disturbances in the organic substances of veliger larvae, such as a decrease in the total protein and total lipid levels and an increase in the glycogen level. The results indicated that ZnO-BPs increase the number of protein bands. Conversely, ZnO-NPs concealed one band from treated egg masses, which was found in the control group. Embryos of snail are an appropriate model to control freshwater snails. This study demonstrates that H. duryi embryos can serve as effective model organisms to study the toxicity of ZnO-NPs.