Developing Chick Embryo Research Articles

Embryonic Flubendiamide Exposure Alters Expression of OTX2 and Other Early Regulators in Domestic Chick Leading to Congenital Eye Defects.

Flubendiamide, a phthalic acid diamide insecticide, has been implicated in potential teratogenic effects on non-target organisms, especially during embryonic development. This study examines the impact of flubendiamide on eye development in chick embryos, a well-established model for vertebrate development. Exposure to 0.5 µg/µL of flubendiamide significantly impaired early ocular morphogenesis, resulting in severe defects such as underdeveloped optic cups and the absence of lens and corneal structures. Histopathological analysis demonstrated disrupted optic cup differentiation, while in silico docking studies revealed strong interactions between flubendiamide and key oculogenic proteins, including OTX2, PAX6, and SOX2. These interactions were associated with altered expression patterns of these critical regulators, alongside overexpression of SHH and downregulation of BMP4, BMP7, and FGF8, which are essential for optic vesicle formation and lens differentiation. Additionally, increased CASPASE-3 expression indicated enhanced apoptosis, contributing to the observed ocular anomalies. These findings suggest that flubendiamide disrupts key signaling pathways necessary for proper eye development, potentially leading to congenital eye defects. The study highlights the need for a thorough evaluation of the molecular mechanisms driving flubendiamide-induced teratogenicity to ensure safer pesticide use and protect environmental and human health.

The Effect of Paracetamol on The Development of Chicken Embryos

Paracetamol (N-Acetylaminophenol) is the most widely used over-the-counter drug in the world. Although considered safe for pregnant mothers, there is a concern regarding the teratogenic effect of paracetamol. This study aims to observe the teratogenic effect of paracetamol developing embryos. Using chicken embryos, the embryos were incubated for 48 hours and then injected with paracetamol in 3 concentrations, namely 10 ppm, 15 ppm, and 20 ppm. The control group and treatment group consisted of 3 replicates of fertile embryos. Then, the embryos were incubated again for 48 hours in the incubator. Data analysis was carried out qualitatively by observing any developmental alterations. Results showed that paracetamol caused enlargement of the head and heart edema. Exposure to paracetamol at concentrations of 15 ppm and 20 ppm affects the morphology of chicken embryos, especially the formation of the head and disrupts the process of angiogenesis and normal heart formation, causing bleeding and edema at higher concentrations.

Proteomic and N-glycosylation analysis of fertile egg white during storage and incubation in chickens

Proteins in egg whites play vital roles in embryonic development. Simultaneously, protein modification is affected by the surrounding environment, which ultimately affects the structure and function of proteins. Here, we measured the phenotypes of eggs at different time points during storage and incubation and used 4D label-free quantitative proteomics technology and liquid chromatography/tandem mass spectrometry (LC-MS/MS)-technique to identify the differential proteins and N-glycosylation sites in egg whites during storage and incubation. We found that the differential N-glycoproteins in the early stage of storage were mainly related to protein structure changes, antibacterial activity, and cell proliferation, and that there were more protease inhibitors in egg whites, which decreased in the later stage of storage. Finally, eleven possible protein markers and N-glycosylation sites were identified to significantly change during storage and may exert an effect on hatchability, including the proteins involved in antibacterial activity (OVOA-N855, CLU-N154, ogchi-N82, PIGR-N290, WFDC2-N120), protein structure (LOC776816), and cell proliferation (ASAH1-N173). This study provides substantial insights into the physical and molecular compositional changes in egg whites under different storage times and revealed their potential effect on chick embryo development.

Real-time visualisation of developing chick embryos cultured in transparent plastic films from the blastoderm stage until hatching

Real-time visualisation of chick embryo development occurring inside an opaque eggshell is a major goal of developmental biology. This goal was partially achieved when 3-day-old embryos recovered from fertilised shelled eggs, preincubated in a conventional incubator, hatched after the egg contents had been transferred into shell-less embryo culture systems constructed of transparent plastic film placed in a plastic cup. However, the hatchable shell-less embryo culture systems described thus far cannot be used to visualise the dynamic morphological changes associated with the emergence of major organ systems during the first 3 days of embryo development, as the blastoderm area needs to be covered with an opaque membrane. Here, we present the development of a chick embryo culture system that enables omnidirectional real-time visualisation of the developing embryo, beginning from the newly laid blastoderm stage embryo until hatching.

Chlorpyrifos and cypermethrin combination disrupts sonic hedgehog signaling and associated regulatory molecules, leading to congenital eye defects in chick embryos

Pesticides are reported to be teratogenic for non-target species. Our studies have unraveled the teratogenicity of 50 % Chlorpyrifos & 5 % Cypermethrin combination (Ci) in developing chick embryos. A sub-lethal dose of this combination when administered to chick embryos, caused several developmental anomalies, with defects in eye development being frequent. Eye development begins at an early embryonic stage, with Sonic hedgehog (Shh) serving as a crucial signaling molecule. Shh plays a pivotal role in the early development of multiple organs, including the eye, by interacting with Pax6 and other regulatory molecules to guide the proper patterning of the eye. Thus, we hypothesized that Ci administration may lead to alteration in Shh expression which subsequently hampers downstream signaling molecules potentially contributing to congenital eye defects. Morphological, anatomical, histological, transcriptional and protein level analyses at various stages (Days 1,2,4 and 10) were carried out to evaluate the hypothesis. The results revealed a remarkable alteration of key regulators in treated embryos compared to control, providing insights into plausible causative mechanisms underlying Ci-induced congenital eye defects.

BENEFITS OF TEAS AND PROBIOTIC PROFILE AT SPECIFIC STAGES OF EMBRYONIC DEVELOPMEN IN CHICKEN EGGS

Introduction: The Sharr Mountain is characterized by a highly expressed biological diversity, with a particular endemism and a wide spectrum of various types of flora characteristic of this mountainous massif. Plants with nutritional and health benefits can be considered species such as: mountain tea (Sideritis scardica) and St. John's wort (Hypericum perforatum), etc. These bioproducts are characterized by special importance both in terms of their presence, quality, and health benefits. Therefore, exploration of these species would have positive cost for consumption as forms of teas or plant extracts for commercial purposes, but also for health benefits and above all for the population of the country, the region, and beyond. Research Objective: This study aims to investigate the probiotics and the effect of plant extract teas such as mountain tea (Sideritis scardica) and St. John's wort (Hypericum perforatum) by applying a specific dose of extract to chicken embryos at different stages of ontogenesis. Materials and Methods: Fertilized chicken eggs were taken for the study and were incubated in an incubator for 21 days. The eggs were treated with species such as mountain tea (Sideritis scardica) and St. John's wort (Hypericum perforatum) at certain stages of embryonic development. The eggs were opened on the seventh, fourteenth, and twenty-first day. Macroscopic and microscopic changes at certain stages of embryonic development were analyzed using stereomicroscope.The effect of the extract of these teas was studied on the chicken embryos (Gallus domesticus), by applying a specific dose of extract to the chicken embryos at different stages of embryonic development during ontogenesis. Research Results: The dose given in the form of extract has resulted in positive benefits of these teas as effective probiotics during certain stages of embryonic development in chicken embryos. Conclusions: This research will explore the effect of the given dose of plant extracts at certain stages of embryonic development during ontogenesis to observe the benefits of dose administration at specific quantities and times to detect the positive effect of these teas.

Protective effects of Spirulina (Spirulina platensis) against toxicity impacts of Imidacloprid on developing Chicken embryos

Protective effects of Spirulina (Spirulina platensis) against toxicity impacts of Imidacloprid on developing Chicken embryos

Determining the optimal level and the effect of different zinc sources on performance, egg quality and the immune system of laying hens at the end of the production period.

Trace elements, such as zinc, magnesium and copper, are essential for improving the performance and health of broiler breeders and the development of chicken embryos. These elements are integral to various proteins involved in metabolism, hormone secretion and the immune system, necessitating their inclusion in small amounts in poultry diets. This study aimed to determine the optimal level and effect of different zinc sources on performance, egg quality and the immune system of laying hens at the end of the production period. The experiment involved 520 Lohmann LSL laying hens, aged 80 weeks, divided into 13 treatments with 5 replications and 8 birds per replication. The hens were fed diets supplemented with 40, 60 and 80mg/kg of zinc from various sources: mineral zinc oxide, mineral zinc sulphate, organic zinc chelated with glycine and organic zinc chelated with an organic acid. Key parameters measured included body weight, egg weight and immune response. The basal diet contained 63.58mg/kg of zinc, with the requirement per the Lohmann LSL guideline being 80mg/kg. Zinc supplementation significantly increased body weight in the second month, with 80mg/kg being the optimal dose. Zinc oxide notably increased egg weight compared to the control. The hens utilized zinc from all sources, resulting in weight gain and improved parameters such as egg quality. Immune parameters were also positively influenced by zinc supplementation. Zinc supplementation at appropriate levels enhances the performance and egg quality of laying hens, particularly at the end of the production period. It improves bioavailability, enriches eggs and mitigates age-related declines in productivity.

Research Note: Comprehensive proteomic, phosphoproteomic, and N-glycoproteomic analysis of chicken egg yolk plasma

Chicken egg yolk plasma (EYP), the supernatant fraction of egg yolk obtained by water dilution and centrifugation, is a rich source of various bioactive substances and a significant bearer of yolk-emulsifying properties. This study utilized proteomics to conduct a comprehensive and in-depth analysis of both common and modified EYP proteins (phosphorylated proteins and N-glycosylated proteins). Total of 208 proteins were identified in EYP, including 42 phosphorylated proteins with 137 phosphorylation sites and 150 N-glycoproteins with 332 N-glycosylation sites. Among the phosphorylation sites, tyrosine accounted for 80.6%, while the N-glycosylation sites predominantly featured "N-X-T" motifs, accounting for 58.7%. Functional enrichment analysis revealed that most proteins were involved in regulating enzyme activity and inhibition with a particular focus on modulating peptidase activity. Notably, vitellogenins-2 (30 phosphorylation sites, 9 N-glycosylation sites) and apolipoprotein B (10 phosphorylation sites, 56 N-glycosylation sites) were the 2 proteins with the most modification sites. Additionally, EYP was found to contain the highly N-glycosylated complement proteins C3 and C4. These findings provide new insights into the protein composition of EYP and its roles in chicken embryo development and immune defense, offering a theoretical foundation for the application of EYP in various fields.

Supplemental L-arginine promotes hepatocyte proliferation and alters liver fatty acid metabolism in the late embryonic phase: an RNA-seq analysis

The in ovo feeding (IOF) of L-arginine (L-Arg) to chick embryos is a viable method for improving early intestinal development, subsequently leading to an acceleration in growth rate during the posthatch stage. However, the liver, being the pivotal organ for energy metabolism in poultry, the precise effects and mechanisms of L-Arg on the liver development and metabolism remain unclear. To elucidate these, the present study injected 2 doses of L-Arg (10 mg/egg and 15 mg/egg) into the embryos of Hongyao chickens at 17.5 d of incubation, subsequently incubating them until d 19 for further analysis. IOF of 15 mg L-Arg/egg significantly increased the organ indices of liver and small intestine, as well as the duodenal villus height/crypt depth. RNA-Seq analysis of liver tissues showed that the metabolism of xenobiotics, amino acid metabolism, and the fatty acid metabolism were significantly enriched in L-Arg injection group. The core differentially expressed genes (DEGs) were primarily involved in cell proliferation and fatty acid metabolism. The CCK8 assays revealed that supplemental L-Arg significantly enhanced the proliferation of primary embryo hepatocytes and leghorn male hepatoma (LMH) cells. Upregulation of core DEGs, including HBEGF, HES4, NEK3, EGR1, and USP2, significantly promoted the proliferation of liver cells. Additionally, analysis of triglyceride and total cholesterol content, as well as oil red O staining, indicated that supplemental L-Arg effectively reduced lipid accumulation. Overall, L-Arg supplementation in late chick embryos may promote early liver and small intestine development by reducing liver lipid deposition and enhancing energy efficiency, necessitating further experimental validation. This study provides profound insights into the molecular regulatory network of L-Arg in promoting the development of chicken embryos. The identified DEGs that promote cell proliferation and lipid metabolism can serve as novel targets for further developing methods to enhance early development of chicken embryos.

Pyriproxyfen-Induced Developmental Neurotoxicity and Genotoxicity Among the Developing Chick Embryos, (Gallus domesticus)

Pyriproxyfen-Induced Developmental Neurotoxicity and Genotoxicity Among the Developing Chick Embryos, (Gallus domesticus)

Enhanced vascularity in gelatin scaffolds via copper-doped magnesium–calcium silicates incorporation: In-vitro and ex-ovo insights

Addressing a critical challenge in current tissue-engineering practices, this study aims to enhance vascularization in 3D porous scaffolds by incorporating bioceramics laden with pro-angiogenic ions. Specifically, freeze-dried gelatin-based scaffolds were infused with sol-gel-derived powders of Cu-doped akermanite (Ca2MgSi2O7) and bredigite (Ca7MgSi4O16) at various concentrations (10, 20, and 30 wt%). The scaffolds were initially characterized for their structural integrity, biodegradability, swelling behavior, impact on physiological pH, and cytocompatibility with human umbilical vein endothelial cells (HUVECs). The silicate incorporation effectiveness in promoting vascularity was then assessed through HUVEC attachment, capillary tube formation, and ex-ovo chick embryo chorioallantoic membrane assays. The findings revealed significant improvements in both in-vitro and ex-ovo vascularity of the gelatin scaffolds upon the addition of Cu-doped akermanite. The most effective concentrations were determined to be 10 and 20 %, which led to notable HUVEC metabolic activity, a well-spread morphology with extensive peripheral filopodia and lamellipodia at 10 % and a cobblestone phenotype indicative of in-vivo endothelium at 20 % during cell attachment, the formation of complex networks of tubular structures, and robust vascularization in chick embryo development. Moving forward, the incorporation of Cu-doped akermanite into tissue-engineering scaffolds shows great potential for addressing the limitations of vascularization, especially for critical-sized bone defects, by facilitating the controlled release of pro-angiogenic and pro-osteogenic ions.

Developmental 6:2 FTCA exposure impairs renal development in chicken embryos via IGF signaling

6:2 fluorotelomer carboxylic acid (6:2 FTCA) is a perfluorooctanoic acid (PFOA) substitute, which is supposedly less accumulative and toxic than PFOA. However, 6:2 FTCA is structurally similar to PFOA, and there had already been reports about its toxicities comparable to PFOA. The aim of the current study is to assess potential effects of developmental exposure to 6:2 FTCA on the development of kidney in chicken embryo and to investigate underlying mechanism. Fertile chicken eggs were exposed to 1.25 mg/kg, 2.5 mg/kg or 5 mg/kg doses of 6:2 FTCA, or 2 mg/kg PFOA, then incubated to hatch. Serum and kidney of hatchling chickens were collected. Blood urea nitrogen (BUN) and creatinine (Cre) levels were measured with commercially available kits. Morphology of kidney was assessed with histopathology. To further reveal molecular mechanism of observed endpoints, IGF signaling molecules were assessed in the kidney samples with qRT-PCR, results indicated that IGFBP3 is a potentially crucial molecule. Lentiviruses overexpressing or silencing IGFBP3 were designed and applied to enhance/suppress the expression of IGFBP3 in developing chicken embryo for further verification of its role in the observed effects. Disrupted nephron formation, in the manifestation of decreased glomeruli number/area and increased serum BUN/Cre levels, was observed in the animals developmentally exposed to 6:2 FTCA. Correspondingly, IGF signaling molecules (IGF1, IGF1R and IGFBP3) were affected by 6:2 FTCA exposure. Meanwhile, overexpression of IGFBP3 effectively alleviated such changes, while silencing of IGFBP3 mimicked observed effects. In conclusion, developmental exposure to 6:2 FTCA is associated with disrupted chicken embryo renal development, in which IGFBP3 seems to be a remarkable contributor, suggesting potential health risks for human and other species. Further risk assessments and mechanistic works are necessary.

Anti-Angiogenic Activity of Sabungai (Gynura procumbens) using a Cancer-induced Chicken Embryo

Cancer has been increasing over recent years and is considered the primary cause of mortality following cardiovascular disease. Angiogenesis, the biological process by which new blood vessels are generated, plays a crucial role in the growth and spread of tumors. The objective of this study was to assess the anti-angiogenic activity of different Sabungai (Gynura procumbens) leaf extract concentrations in the Chorioallantoic Membrane (CAM) of cancer-induced chicken embryos. The results of a one-way analysis of variance (25.20 ± 2.70, 27.20 ± 1.08, and 22.80 ± 1.66) indicated a statistically significant difference in CAM vascularization between the various treatments. Post hoc analysis utilizing Tukey's Honest Significant Difference (HSD) test revealed that Treatment 2 (300ppt) significantly affected CAM vascularization, as evidenced by an average vascularization count of 27.20 ± 1.08, followed by Treatment 1 (100ppt) and Treatment 3 (500ppt). The results indicated that the extract from Sabungai leaves effectively hinders the formation of new blood vessels in a dose-dependent manner. The highest concentration of leaf extract (500 ppt) resulted in an average vascularization of 22.80 ± 1.66. However, excessively high doses can cause bleeding and embryo death. The results demonstrated that sabungai leaf extract affected blood vessel development in chicken embryos. The results of this research have various implications that contribute to scientific knowledge and potential applications in cancer treatment.

Adaptation of the diaphonization protocol and the highlight of some significant structures development in the chicken embryo (Gallus gallus) skeleton

Diaphonization is a technique used in developmental biology, anatomy, and comparative morphology to visualize and study the internal structures of small organisms. In this study, we used diaphonization to visualize the development of chicken embryos (Gallus gallus). Diaphonization was performed on chicken eggs at different stages of development, from 10 to 13 days of incubation, and the resulting specimens were analyzed using microscopy. The results suggest that for embryos older than 14 days, a longer storage time in 1% KOH is recommended (approximately 30% longer incubation time compared to the original protocol). In the case of more developed chicken embryos, it is also recommended to carry out evisceration. These results provide insight into the early stages of avian development and may have applications in the fields of developmental biology and anatomy. Keywords: diaphonization protocol, chicken embryo development, skeletal visualization, developmental biology, avian skeletal adaptation.

Effect of aripiprazole on neural tube development in early chick embryos

IntroductionAripiprazole (ARI) is a recently developed antipsychotic medication that belongs to the second generation of antipsychotics. The literature has contradictory information regarding ARI, which has been classified as pregnant use category C by the FDA. Methods125 pathogen-free fertilized eggs were incubated for 28 h and divided into five groups of 25 eggs each (including the control group), and 18 eggs with intact integrity were selected from each group. After the experimental groups were divided, ARI was administered subblastodermally with a Hamilton micro-injector at 4 different doses (1 mg/kg, 5 mg/kg, 10 mg/kg, 20 mg/kg). At the 48th hour of incubation, all eggs were hatched and embryos were removed from the embryonic membranes. And then morphologic (position of the neural tube (open or closed), crown-rump length, number of somites, embryological development status), histopathologic (apoptosis (caspase 3), cell proliferation (PCNA), in situ recognition of DNA breaks (tunnel)), genetic (BRE gene expression) analyzes were performed. ResultsAccording to the results of the morphological analysis, when the frequency of neural tube patency was evaluated among the experimental groups, a statistically significant difference was determined between the control group and all groups (p < 0.001). In addition, the mean crown-rump length and somite number of the embryos decreased in a dose-dependent manner compared to the control group. It was determined that mRNA levels of the BRE gene decreased in embryos exposed to ARI compared to the control group (p < 0.001). ConclusionMorphologically, histopathologically, and genetically, aripiprazole exposure delayed neurogenesis and development in early chick embryos. These findings suggest its use in pregnant women may be teratogenic. We note that these results are preliminary for pregnant women, but they should be expanded and studied with additional and other samples.

Transcriptomic and epigenomic insights into pectoral muscle fiber formation at the late embryonic development in pure chicken lines

Long-term intensive genetic selection has led to significant differences between broiler and layer chickens, which are evident during the embryonic period. Despite this, there is a paucity of research on the genetic regulation of the initial formation of muscle fiber morphology in chick embryos. Embryonic d 17 (E17) is the key time point for myoblast fusion completion and muscle fiber morphology formation in chickens. This study aimed to explore the genetic regulatory mechanisms underlying the early muscle fiber morphology establishment in broiler chickens of Cornish (CC) and White Plymouth Rock (RR) and layer chickens of White Leghorn (WW) at E17 using the transcriptomic and chromatin accessibility sequencing of pectoral major muscles. The results showed that broiler chickens exhibited significant higher embryo weight and pectoral major muscle weight at E17 compared to layer chickens (P = 0.000). A total of 1,278, 1,248, and 892 differentially expressed genes (DEGs) of RNA-seq data were identified between CC vs. WW, RR vs. WW, and CC vs. RR, separately. All DEGs were combined for cluster analysis and they were divided into 6 clusters, including cluster 1 with higher expression in broilers and cluster 6 with higher expression in layers. DEGs in cluster 1 were enriched in terms related to macrophage activation (P = 0.002) and defense response to bacteria (P = 0.002), while DEGs in cluster 6 showed enrichment in protein-DNA complex (P = 0.003) and monooxygenase activity (P = 0.000). ATAC-seq data analysis identified a total of 38,603 peaks, with 13,051 peaks for CC, 18,780 peaks for RR, and 6,772 peaks for WW. Integrative analysis of transcriptomic and chromatin accessibility data revealed GOLM1, ISLR2, and TOPAZ1 were commonly upregulated genes in CC and RR. Furthermore, screening of all upregulated DEGs in cluster 1 from CC and RR identified GOLM1, ISLR2, and HNMT genes associated with neuroimmune functions and MYOM3 linked to muscle morphology development, showing significantly elevated expression in broiler chickens compared to layer chickens. These findings suggest active neural system connectivity during the initial formation of muscle fiber morphology in embryonic period, highlighting the early interaction between muscle fiber formation morphology and the nervous system. This study provides novel insights into late chick embryo development and lays a deeper foundation for further research.

Effects of Nicotine on Chicken Embryo Development: A Review

Background: Studies have shown that 22.3% of the world’s population use tobacco and nicotine exposure during pregnancy remains a concern in embryonic development. Cigarette smoke contains several toxic and carcinogenic chemicals and has been known to cause pregnancy complications including premature births, low birthweights, and stillbirths. Purpose: This review aims to study nicotine exposure in chicken embryo development comprehensively. Methods: PubMed, Centers for Disease Control and Prevention (CDC), and Antpedia sites were used to search for studies using chicken embryos as a model. Studies that reported findings on nicotine&amp;apos;s effects on various developmental processes were considered for this review. Conclusion: In total, 55 published articles were included in this review to discuss findings of nicotine-induced alterations during chicken embryo development. Findings have shown that nicotine affects angiogenesis, and embryonic and chorioallantoic membrane (CAM) growth by inhibiting cell proliferation. Nicotine affects brain and cerebellar cortex development by suppressing tumor protein p53 reactions. Nicotine also causes abnormal axial rotation and incomplete formation and closure of neural tubes. The compounds like green tree extract, vitamin C, and folic acid can reduce the effects of nicotine to suppress femur growth, decrease the contractility of cardiomyocytes, and reduce survival rates. These compounds are not protective measures to completely overcome the teratogenic effects of nicotine.

Protective effects of ferulic acid on embryonic development by improving antioxidant function in broilers embryo of thermal manipulation

This study aimed to elucidate the effects of broiler embryos soaked in ferulic acid (FA) solution on alleviating the negative impact of thermal manipulation (TM) on chicken embryo development and to provide a theoretical and experimental basis for applying TM and FA in the poultry feeding industry. A total of 120 broiler fertilized eggs were randomly divided into three groups: control group, TM group, and comprehensive group (TM + FA), with 40 eggs in each group. The TM group and the comprehensive group from the 7th embryonic age to the 16th embryonic age received TM for ten days, treated with a temperature of 39.5 °C and relative humidity of 65% for 18 h a day. In the comprehensive group, broiler embryos were immersed in FA solution at a concentration of 80 mg/L for 6 min at 16:00 every day from the 6th to the 8th embryo age. They were incubated continuously after being soaked until the chicks hatched. The results showed that the rates of dead embryos and weak chicks in the TM group were significantly higher than those in the control group and comprehensive group. Chick body temperatures of the TM group and comprehensive group were significantly lower than those of the control group. The heart weights of the TM group and comprehensive group were significantly lower than those of the control group, and the leg weights of the TM group were significantly decreased compared with those of the control group and comprehensive group. The SOD activity of serum in the comprehensive group was significantly higher than that in the control group and TM group, while the CAT activity of serum in the comprehensive group and control group was significantly higher than that in the TM group; however, there was no difference between the comprehensive group and control group. The activities of SOD and CAT in the liver were significantly higher than those of the TM group; however, the MDA content of the liver in the comprehensive group and control group was significantly lower than that of the TM group. The gene expression of Nrf2 and SOD in the comprehensive group and TM group was significantly higher than that in the control group; however, there was no significant difference between the comprehensive group and TM group. Soaking broiler embryonic eggs in an FA solution can improve the antioxidant capacity of the liver by upregulating Nrf2-Keap1 signal pathway-related gene expression. FA can effectively alleviate the side effects of TM on chicken embryos and does not impact the effects of TM.

The relationship between sarcomerogenesis and the development of tissue organization of the myocardium in embryonic chicken cardiogenesis

Background. The general basis for understanding how the limited range of sarcomere contraction ensures cardiac output during systole is the analysis of the ontogenetic formation and local features of the development of the myofibrillar structure of cardiomyocytes by comparing the phase states of the myocardium. The purpose of the research is to determine phase and topological features and quantitative ultrastructural characteristics of sarcomerogenesis in cardiomyocytes of chicken embryos. Methods. Embryos of Cobb500 crossbred chickens were studied from the beginning of the 6th day to the 21st day of incubation. Ultrastructural features of contractile cardiomyocytes in different areas of ventricular and atrial myocardium in systole and diastole were studied using transmission electron microscopy. Results. At the 29th stage of development of chicken embryos in diastole, immature sarcomeres had different lengths. The average length of sarcomeres was 1.86±0.09 μm in the left ventricle and 1.91±0.21 μm in the right ventricle. At the 36th stage in the state of diastole, a significant increase in the length of sarcomeres was observed in the compact myocardium of the left ventricle and left atrium, while in the right parts of the heart, the increase in Z-Z distance was less active. In the right units of the heart, sarcomeres with unequal lengths were more often found in the compact myocardium and in the trabeculae. In different areas of the myolamella and trabeculae, the degree of relaxation of sarcomeres during simulation of maximum diastole was not the same. Incomplete relaxation of sarcomeres was noted in the initial and final sections of the muscle plates. In the middle part of the trabeculae, the length of the sarcomeres was significantly longer (1.82±0.04 μm), and in the intermediate (main) part of the muscle plates of the compact ventricular myocardium, the sarcomeres were 10.4% (p&lt;0.05) longer, than in their basis. Conclusion. By the end of prenatal cardiogenesis, the tangential orientation of the Z-discs of myofibrils and the shape of cardiomyocytes in systole was formed and strengthened due to the mutual displacement of neighboring myolamella during the counter-directional rotation of the basal and apical parts of the left ventricle during the shortening of sarcomeres to 1.83±0.04 μm. In the right ventricle and atrial myocardium, systolic contraction did not change the orthogonal orientation of telophragms and intercalated discs when sarcomeres were shortened to 1.79-1.84 μm. In the state of diastole, the orthogonal orientation of Z-discs is characteristic of contractile cardiomyocytes of all chambers when the length of sarcomeres reaches 2.17±0.07 μm in the intermediate part of the myolamella of both ventricles, 2.12±0.13 μm in the middle part of atrial and ventricular trabeculae, 2.02±0.10 μm at the base of trabeculae of all chambers and muscle plates of both ventricles.