Effects of Oxygen Gas Injection on the Subsequent Development of Chick Embryos in a Shell-Less Culture System.

The effects of oxygen gas injection starting on day 17 of incubation (D17) in a chick shell-less culture system (cSLC) on the subsequent embryo development were examined on day 19 of incubation (D19). On D19 of cSLC, the plasma phosphorus and total cholesterol concentrations of the embryos were significantly higher (P<0.05), while the plasma calcium concentrations were significantly lower (P<0.05) than those in the intact control (IC) group. However, no significant differences in embryo viability and other major blood component levels were observed among the experimental groups (P>0.05). The percutaneous oxygen saturation was lower in D17-cSLC embryos before oxygen gas supplementation than in the IC (P<0.05) embryos. Severe renal tubular degeneration of the metanephros was observed in D19-cSLC embryos despite oxygen gas injection starting from D17. These results indicate that D19-cSLC embryos are hypoxia even after injecting oxygen gas starting on D17.

Assessment of antiviral activity and mechanism of rhein on newcastle disease virus (La Sota strain IV) in vitro.

Current research is focused on the development of drug candidates from natural products. Rhein a Traditional Chinese Medicine (TCM) from Polygonaceae (rhubarb) has exhibited antioxidant, anti-inflammatory and anticancer activities, however no work has reported its antiviral potential, thus this study was performed to investigate the antiviral activities of rhein on new castle disease virus (NDV) in vitro.NDV infection of chicken embryo fibroblasts (CEFs) was prepared using 10-day-old specific pathogen free chicken embryos. Cytotoxicity and anti-viral activities of rhein were assessed using the MTT method. The interaction between NDV and cell membrane proteins were also detected using virus overlay protein binding assay (VOPBA). In addition NDV genes expressions in CEFs were measured using real-time fluorescent quantitative (RTFQ) PCR.The results showed that rhein effectively inhibit NDV activities maximal safe concentration of 0.125 mg/ml. This finding indicated that, rhein could be used as future antiviral drug against NDV.[Formula: see text].

Omics as a Window To Unravel the Dynamic Changes of Egg Components during Chicken Embryonic Development.

Chicken egg, as a completely aseptic and self-sufficient biological entity, contains all of the components required for embryonic development. As such, it constitutes not only an excellent model to study the mechanisms of early embryo nutrition and disease origin but can also be used to develop egg-based products with specific applications. Different omics disciplines, like transcriptomics, proteomics, and metabolomics, represent promising approaches to assess nutritional and functional molecules in eggs under development. However, these individual molecules do not act in isolation during the dynamic embryogenic process (e.g., migration, transportation, and absorption). Unless we integrate the information from all of these omics disciplines, there will remain an unbridged gap in the systematic and holistic assessment of the information from one omics level to the other. This integrative review of the dynamic molecular processes of the different chicken egg components involved in embryo development describes the critical interplay between the egg components and their implications in immunity, hematopoiesis, organ formation, and nutrient transport functions during the embryonic process.

The mixed application of organic and inorganic selenium shows better effects on incubation and progeny parameters.

This experiment aims to study the effects of dietary selenium (Se) sources on the production performance, reproductive performance, and maternal effect of breeder laying hens. A total of 2,112 Hyline brown breeder laying hens of 42 wk of age were selected and randomly divided into 3 groups, with 8 repeats in each group and 88 chickens per repeat. The sources of dietary Se were sodium selenite (SS, added at 0.3 mg/kg), L-selenomethionine (L-SM, added at 0.2 mg/kg), and combination of SS and L-SM (SS 0.15 mg/kg + L-SM 0.15 mg/kg). The pretest period was 7 d, and the breeding period was 49 d. Compared with 0.3 mg/kg SS, the addition of 0.2 mg/kg L-SM in the diet significantly increased the hatchability (P < 0.05) and the Se content (P < 0.05) in egg yolk and chicken embryo tissues and improved the activity of yolk glutathione peroxidase (GSH-px) effectively (P < 0.05). Treatment with 0.2 mg/kg L-SM also reduced the content of yolk malondialdehyde (P < 0.05) and significantly improved the antioxidant performance of 1-day-old chicks, as manifested by increased activity of antioxidant enzymes (GSH-px, total antioxidant capacity and the ability to inhibit hydroxyl radicals) in serum, pectoral, heart, and liver (P < 0.05). This treatment decreased the malondialdehyde content (P < 0.05) and increased the expression of liver glutathione peroxidase 4 and deiodinase 1 mRNA (P < 0.05). Adding L-SM to the diets of chickens increased the hatchability of breeder eggs as well as the amount of Se deposited and antioxidant enzyme activity in breeder eggs and embryos. Compared with SS, L-SM was more effectively transferred from the mother to the embryo and offspring, showing efficient maternal nutrition. For breeder diets, the combination of organic and inorganic Se (0.15 mg/kg SS + 0.15 mg/kg L-SM) is an effective nutrient supplementation technology program for effectively improving the breeding performance of breeders and the antioxidant performance and health level of offspring chicks.

Effects of vitamin E in a glucocorticoid induced cataract model in chicken embryos.

We investigated the antioxidant effects of vitamin E on a glucocorticoid (GC) induced model of cataracts in chick embryos. We used 70 fertilized eggs divided into seven groups as follows: phosphate-buffered saline (PBS) group, olive oil treatment (OO) group, hydrocortisone treatment (HC) group, olive oil and hydrocortisone treatment (OO + HC) group, 50 mg/kg vitamin E and hydrocortisone treatment (HC + VE (50)) group, 25 mg/kg vitamin E and hydrocortisone treatment (HC + VE (25)) group and 15 mg/kg vitamin E and hydrocortisone treatment (HC + VE (15)) group. On day 17, chick embryos were removed from the eggs and lens and liver tissues were excised. Cataract formation was evaluated and total antioxidant status (TAS), total oxidant status (TOS), malondialdehyde (MDA) and glutathione peroxidase (GPx) were measured in lens and liver tissues; MDA was measured only in liver. The lenses in the HC + VE (50) group exhibited significantly higher levels of GPx and TAS, and lower levels of TOS than for HC and OO + HC groups. The livers of the HC + VE (50) group exhibited significantly higher levels of GPx and lower levels of MDA than for the HC and OO + HC groups. The HC + VE (50) group lenses were evaluated as grade 1, because the nuclei were completely free of cataracts, likely due to the antioxidative effect of high dose VE. VE is an effective antioxidant agent that exhibits a dose-response effect, for ameliorating the negative effects of GCs.

Valproic acid effect on neural tube defects is not prevented by concomitant folic acid supplementation: Early chick embryo model pilot study.

BACKGROUND: Neural tube defect is one of the most prevalent congenital malformations and it involves a variety of malformations ranging from anencephaly to spina bifida. Folic acid supplementation during pregnancy is known to reduce risk of neural tube defects. Antiepileptic drugs have been associated with neural tube defects, one of which is valproic acid. Protective effect of folic acid on congenital malformations in patients using valproic acid or other antiepileptic medicines during pregnancy has not clearly been delineated uniformly in previous clinical series. In this experimental animal study of early chick embryo model, we would like to determine if there is any dose-response relationship between VA and NTDs and if there is any protective effect of FA on this relationship in early chick embryo period. METHODS: One hundred twenty-two fertile leghorn type chicken eggs were used in this study. Six groups, each of which composed of 20 fertilized eggs, were categorized as: group A-control, group B- folic acid, group C-low-dose valproic acid, group D-high-dose valproic acid, group E-low-dose valproic acid + folic acid, group F-high-dose valproic acid + folic acid. Eggs were hatched for 24 h and injected with destined solutions and hatched till 72th hour. RESULTS: No neural tube defect was observed in group A and B. High dose valproic acid led to significantly higher number of embryos with neural tube defects compared to low-dose valproic acid (p = 0.018). This significant difference was also present between low-dose and high dose valproic acid combined with folic acid (p = 0.031). When effect of folic acid was evaluated no significant difference observed between groups. CONCLUSIONS: Even though number of embryos with neural tube defects decreased with concomitant folic acid administration, this difference could not reach a statistical level. More experimental animal and large-scaled prospective clinical studies are in need to detect folic acid mechanism in inhibiting antiepileptic drugs, if any present.

Retinoic Acid as a Modulator of Proximal-Distal Patterning and Branching Morphogenesis of the Avian Lung.

Retinoic acid modulates numerous cellular events, namely, proliferation, differentiation, apoptosis, and patterning, hence influencing both embryo development and adult homeostasis. In vitro explant culture is a valuable technique for studying the impact of growth factors and signaling molecules, such as retinoic acid, in organ development since tissue architecture is maintained. This technique allows controlled supplementation of culture medium and straightforward analysis of its effect on morphogenesis. This chapter describes the detailed protocol for culturing embryonic chick lung explants and testing the impact of retinoic acid in branching and patterning, based on morphometric and molecular analysis.

Methodology for exposing avian embryos to quantified levels of airborne aromatic compounds associated with crude oil spills.

Oil spills on birds and other organisms have focused primarily on direct effects of oil exposure through ingestion or direct body fouling. Little is known of indirect effects of airborne volatiles from spilled oil, especially on vulnerable developing embryos within the bird egg. Here a technique is described for exposing bird embryos in the egg to quantifiable amounts of airborne volatile toxicants from Deepwater Horizon crude oil. A novel membrane inlet mass spectrometry system was used to measure major classes of airborne oil-derived toxicants and correlate these exposures with biological endpoints. Exposure induced a reduction in platelet number and increase in osmolality of the blood of embryos of the chicken (Gallus gallus). Additionally, expression of cytochrome P4501A, a protein biomarker of oil exposure, occurred in renal, pulmonary, hepatic and vascular tissues. These data confirm that this system for generating and measuring airborne volatiles can be used for future in-depth analysis of the toxicity of volatile organic compounds in birds and potentially other terrestrial organisms.

The antioxidant action and mechanism of selenizing Schisandra chinensis polysaccharide in chicken embryo hepatocyte.

The antioxidant action and mechanism of selenizing schisandra chinensis polysaccharide (sSCP) were investigated in chicken embryo hepatocyte (CEH) taking schisandra chinensis polysaccharide (SCP) and N-acetyl-L-cysteine (NAC) as control. The CEH was cultured and treated with sSCP, then exposed to H2O2. The CEHs' viability, apoptosis, ROS and antioxidase contents and the protein expression in MAPKs pathway and mitochondrion-dependence apoptotic signal pathway were assayed. The results showed that sSCP could significantly raise the cell viability and the activities of SOD, CAT and GSH-Px, decrease the cell apoptosis and the content of LDH, AST, ALT and MDA, down-regulate the protein expression of p-JNK1, p-ERK1/2, p-p38, Bax, Caspase 3 and cytochrome C, and up-regulate the protein expression of Bcl-2 in comparison with H2O2 control group. The action of sSCP were stronger than those of SCP and NAC. These results indicated that selenylation modification could significantly enhance the antioxidant activity of SCP, sSCP could significantly protect hepatocyte from oxidative damage induced by H2O2, and its mechanism was by regulating the protein expression in MAPKs and mitochondrion-dependence apoptotic signaling pathways.

Dissecting the role of regulators of thyroid hormone availability in early brain development: Merits and potential of the chicken embryo model.

Thyroid hormones (THs) are important mediators of vertebrate central nervous system (CNS) development, thereby regulating the expression of a wide variety of genes by binding to nuclear TH receptors. TH transporters and deiodinases are both needed to ensure appropriate intracellular TH availability, but the precise function of each of these regulators and their coaction during brain development is only partially understood. Rodent knockout models already provided some crucial insights, but their in utero development severely hampers research regarding the role of TH regulators during early embryonic stages. The establishment of novel gain- and loss-of-function techniques has boosted the position of externally developing non-mammalian vertebrates as research models in developmental endocrinology. Here, we elaborate on the chicken as a model organism to elucidate the function of TH regulators during embryonic CNS development. The fast-developing, relatively big and accessible embryo allows easy experimental manipulation, especially at early stages of brain development. Recent data on the characterisation and spatiotemporal expression pattern of different TH regulators in embryonic chicken CNS have provided the necessary background to dissect the function of each of them in more detail. We highlight some recent advances and important strategies to investigate the role of TH transporters and deiodinases in various CNS structures like the brain barriers, the cerebellum, the retina and the hypothalamus. Exploiting the advantages of this non-classical model can greatly contribute to complete our understanding of the regulation of TH bioavailability throughout embryonic CNS development.

Temporary prenatal hyperglycemia leads to postnatal neuronal 'glucose-resistance' in the chicken hypothalamus.

Prenatal exposures may have a distinct impact for long-term health. Exposure to maternal 'diabesity' during pregnancy increases offspring 'diabesity' risk, e.g. by malprogramming the central nervous regulation of body weight, food intake and metabolism. Critical mechanisms and concrete disrupting factors still remain unclear. Due to the independent development, from the mother, the chicken embryo could provide a valuable model to distinctively establish causal factors. Aim of this study was to determine effects of temporary prenatal hyperglycemia on postnatal hypothalamic neuronal glucose sensitivity in the chicken. To induce hyperglycemia in chicken embryos, 0.5 ml glucose solution (concentration 30 mmol/l) were daily administered via catheter into a vessel of the chorioallantoic egg membrane from days 14 to 17 of incubation. On day 21 of postnatal age, body weight, body fat content, blood glucose, neuroelectrophysiological glucose sensitivity as well as glucose transporter expression were determined in hypothalamic brain slices. No significant changes in morphometric and metabolic parameters were observed. However, strongly decreased neuronal glucose sensitivity and glucose transporter expression occurred, indicating prenatally acquired hypothalamic 'glucose-resistance'. In conclusion, temporary late prenatal hyperglycemia induces lasting changes in central glucose sensing. The prenatally glucose-treated chicken provides a valuable new model for investigating early central nervous origins of 'diabesity' and related disorders.

Phosvitin phosphorus is involved in chicken embryo bone formation through dephosphorylation.

The aim of this study was to investigate the role of phosvitin in bone formation in chicken embryos. The yolk P content, P/N ratio and secondary structure of phosvitin, alkaline phosphatase (ALP) activity of the tibia, and body length were determined during incubation. A high correlation was found between the phosphate group content of phosvitin and both secondary structure and bone metabolism (ALP activity in the tibia, body length). The ALP activity and body length growth slightly lagged behind changes in the P/N ratio and the secondary structure of phosvitin. The phosphate content of phosvitin decreased, the γ-random coil and ß-turn gradually transformed into α-helixes, and the secondary structure of protein tended to become more orderly; these changes mainly occurred on d 13 to 16. Bone formation of the chicken embryos occurred primarily on d 14 to 18, whereas ALP activity and body length growth increased substantially. The results indicate that phosvitin P is involved in chicken embryo bone formation through dephosphorylation.

The developmental toxicity of cottonseed extraction on chicken embryo

Cottonseed meal is widely used as one of the protein supplement in poultry diets. Its mechanism of toxic action on chicken embryo is poorly understood. In this study, direct effects and abnormalities of cottonseed on chicken embryo were studied. Oxidative stress, cholinergic stress, mineral analysis and microscopic lesions were analyzed in chicken embryo which injected cottonseed extraction in 0.1, 1 and 10 mg concentration (with free gossypol 0.25 ppm, 2.5 ppm and 25 ppm respectively) at day 4 of incubation. Higher group had 100 percent mortality. Serum of alive chicken embryo at day 20 of incubation were measured for FRAP (ferric reducing ability of serum), total SH groups assay, cholinesterase assay and potassium concentration. The results expressed as mean±SD show to increase oxidative stress, cholinergic stress but significant difference (p<0.05) wasn't observed between groups. The significant difference was observed in potassium concentration in serum. Some evidence of hematotoxicity such as hemorrhage and higher number of puntate reticulocytes were detected. It is concluded, hematoxicity and hyperkalemia are toxicity mechanisms that could initiate in low concentrations of cottonseed in chick embryo.