Developing Chick Embryo Research Articles

Physiological Regulation of Growth, Hematology and Blood Gases in Chicken Embryos in Response to Low and High Incubation Humidity.

Variations from a relative humidity (RH) of ∼50–60% can unfavorably alter chicken embryo development, but little is known of whether the embryo can mitigate these effects through physiological regulation. We examined effects of Low RH (25–35%), and High RH (85–93%) compared to Control RH (50–60%) on hatchability, embryonic growth, hematology and blood gases and pH. Mean hatchability was not affected by RH. Yet, Low RH decreased wet body mass of advanced embryos (days 17–19; d17-19), with lowered body water content compared with embryos of Control and High RH. However, dry body mass of developing (d11-19) embryos was not different between the three RH groups. Mean blood osmolality across development was higher in Low RH embryos and lower in High RH embryos compared with Control embryos. Mean blood lactate was higher in both Low and High RH embryos compared to Control embryos. Unexpectedly, hematological respiratory variables (Hct, [RBC], MCV, [Hb]) and blood gas variables (Po2, Pco2, pH, [HCO3 −]) across development were not affected by RH. Mean wet body mass at hatch (d20-22) was larger in High RH embryos compared with Low RH embryos, but mean wet and dry body mass upon euthanasia on d22 was unaffected. The ability of the three populations to physiologically regulate blood respiratory variables and blood acid-base balance was then examined by observing their responses to intrinsic hypoxemia and hypercapnia created by controlled partial egg submersion in water. Hct and [RBC] responses were less disturbed by submersion in High RH embryos compared with both Control and Low RH embryos, which showed major disturbance. Acid-base regulatory responses did not differ between RH groups. We conclude that, while different incubation RHs cause large differences in tissue water content and body mass, most hematological and acid-base regulatory capabilities are regulated near Control values.

Chicken Incubation Conditions: Role in Embryo Development, Physiology and Adaptation to the Post-Hatch Environment.

The chicken hatching egg is a self-contained life-supporting system for the developing embryo. However, the post-hatch performance of birds depends on several factors, including the breeder management and age, egg storage conditions and duration before incubation, and the incubation conditions. Studies have determined the effect of incubation factors on chick post-hatch growth potential. Therefore, chick physical quality at hatch is receiving increasing attention. Indeed, although incubation temperature, humidity, turning and ventilation are widely investigated, the effects of several variables such as exposure of the embryo to high or low levels, time of exposure, the amplitude of variations and stage exposures on embryo development and post-hatch performance remain poorly understood. This review paper focuses on chick quality and post-hatch performance as affected by incubation conditions. Also, chick physical quality parameters are discussed in the context of the parameters for determining chick quality and the factors that may affect it. These include incubation factors such as relative humidity, temperature, turning requirements, ventilation, in ovo feeding and delay in feed access. All these factors affect chick embryo physiology and development trajectory and consequently the quality of the hatched chicks and post-hatch performance. The potential application of adapted incubation conditions for improvement of post-hatch performance up to slaughter age is also discussed. It is concluded that incubation conditions affect embryo parameters and consequently post-hatch growth differentially according to exposure time and stage of exposure. Therefore, classical physical conditions are required to improve hatchability, chick quality and post-hatch growth.

The m6A methylation regulates gonadal sex differentiation in chicken embryo

BackgroundAs a ubiquitous reversible epigenetic RNA modification, N6-methyladenosine (m6A) plays crucial regulatory roles in multiple biological pathways. However, its functional mechanisms in sex determination and differentiation during gonadal development of chicken embryos are not clear. Therefore, we established a transcriptome-wide m6A map in the female and male chicken left gonads of embryonic day 7 (E7) by methylated RNA immunoprecipitation sequencing (MeRIP-seq) to offer insight into the landscape of m6A methylation and investigate the post-transcriptional modification underlying gonadal differentiation.ResultsThe chicken embryonic gonadal transcriptome was extensively methylated. We found 15,191 and 16,111 m6A peaks in the female and male left gonads, respectively, which were mainly enriched in the coding sequence (CDS) and stop codon. Among these m6A peaks, we identified that 1013 and 751 were hypermethylated in females and males, respectively. These differential peaks covered 281 and 327 genes, such as BMP2, SMAD2, SOX9 and CYP19A1, which were primarily associated with development, morphogenesis and sex differentiation by functional enrichment. Further analysis revealed that the m6A methylation level was positively correlated with gene expression abundance. Furthermore, we found that YTHDC2 could regulate the expression of sex-related genes, especially HEMGN and SOX9, in male mesonephros/gonad mingle cells, which was verified by in vitro experiments, suggesting a regulatory role of m6A methylation in chicken gonad differentiation.ConclusionsThis work provided a comprehensive m6A methylation profile of chicken embryonic gonads and revealed YTHDC2 as a key regulator responsible for sex differentiation. Our results contribute to a better understanding of epigenetic factors involved in chicken sex determination and differentiation and to promoting the future development of sex manipulation in poultry industry.

Cellular and Biochemical Studies on Risperidone Induced Teratogenesis in Developing Chick Embryos

Risperidone is a second-generation antipsychotic drug that exhibits D2, 5-HT2A, α1, α2, and H1 receptor affinity. Patients suffering from Schizophrenia are prescribed with this drug. It is mostly used for controlling the overactivity of the central mesolimbic and mesocortical pathways of the patients. According to the studies conducted it has been found that Risperidone possesses teratogenic actions on various model organisms. Consumption of this antipsychotic drug is not only associated with behavioural changes but also with physical alterations. It increases the risk by elevating nitric oxide levels and activating macrophages which leads to apoptotic events in the viable cells. Furthermore, it has been established that Risperidone toxicity caused due to overdose induces neurological as well as cardiovascular defects. Risperidone has the ability to cross the placental barrier and reach the foetal bloodstream intuitively. In addition, Risperidone also gets distributed in the milk of a lactating mother leading to undesirable changes in the breastfed babies. Here in this study, we have shown that Gallus gallus domesticus embryos (HH 23-26) treated with a minimum dose of Risperidone (1000 ppm) altered the protein and enzyme biochemistry with respect to total protein content, alkaline phosphatase (ALP), and Acetylcholinesterase levels. Cell viability studies conducted using flowcytometry have indicated its possible role in the induction of apoptosis as well as necrosis in a developing chick embryo. The present study provides insight into the effects of Risperidone that it may possess on gestating and lactating women. The study also explains the teratogenic potential of Risperidone on target and non-target organisms.

Does Cell Proliferation Affect Embryonic Flexure and Torsion?

Two vital and simultaneous morphogenetic events that occur during early embryo development are the flexure and torsion (F&T) of the embryonic body axis. Both contribute to development of the fetal position, which can be observed in avian and mammalian embryos. Correct progression of F&T is crucial for the proper development of the heart and other organs. Embryonic flexure can be divided into three segments: cranial, cervical, and thoracic. In this study, we focus on cervical flexure and torsion of the embryonic body axis. Differential cell proliferation, the difference in the rate of division of cells between regions in the developing embryo, is one mechanism that could influence F&T. Goodrum & Jacobson (1981) observed thickening of the dorsal midbrain relative to the ventral midbrain during cranial flexure. Miller & White (1998) have shown using mouse embryos that differential growth could cause torsion of an axis confined to an attached sphere.We performed studies inhibiting cell proliferation. Fertile white leghorn chick eggs were incubated to approximately Hamburger and Hamilton (HH) Stage 12 or 13. At these stages, F&T have just begun. We then added aphidicolin, a mitotic inhibitor, to whole embryo culture. Embryos were observed at 0, 5, and 10 hours to see if F&T were repressed. We hypothesized that the addition of aphidicolin would inhibit progression of F&T. We developed quantitative schemes to score the extent of F&T progression from HH 12 to HH 15. Embryos were scored from 0 to 4 based on the degree of cervical flexure and were also scored from 0 to 4 based on the degree of torsion. Afterward, the difference in F&T scores of same embryos at time t=0 h and t=10 h was calculated to determine the extent of both. These scores were then averaged for multiple embryos.Compared with controls (n=46), embryos incubated in 400 µM aphidicolin (n=18) flexed and rotated at a significantly lower rate. For flexion, the mean difference in scores for control and treated embryos were 1.85 and 1.22, respectively. For torsion, the mean difference in scores for control and treated embryos were 1.62 and 1.25, respectively. These differences were statistically significant. It is noted that global application of aphidicolin did impact the overall health of embryos. However, our preliminary results indicate that differential cell proliferation could play a role in rotation and flexure progression in the developing chicken embryo.

The Role of Sox9 in Regulating Joint Development through a Gdf5 Enhancer

Sox transcription factors are involved in a number of developmental processes including joint formation. Sox9, Sox5, and Sox6 (the Sox‐trio) form a complex that promotes chondrogenesis. In joint‐associated cells, Sox9 may give rise to a subpopulation of cells expressing growth differentiation factor 5 (Gdf5). Gdf5, a secreted morphogen critical to joint development, regulates cartilage growth and tissue differentiation. Osteoarthritis (OA) is condition characterized by articular cartilage degradation and is a leading cause of disability worldwide. Gdf5 dysregulation has been identified as a risk factor for OA, and in the joints of OA patients, the Sox‐trio are downregulated. The link between Sox, Gdf5, and joint development is not fully understood. We previously identified an enhancer for Gdf5, known as Gdf5‐Associated Regulatory Region (GARR), and have identified possible Sox9 and 5/6 binding sites within GARR by in silico analysis. Thus, we hypothesized that Sox9 is required for Gdf5 upregulation through GARR, while other Sox transcription factors (Sox5/6) enhance or stabilize this interaction. To test this hypothesis, we analyzed publicly available single cell RNA sequencing (scRNA‐seq) data from mouse embryo (E12‐5‐E15.5) knee joints. Analysis revealed a strong correlation between Gdf5 and Sox9. Sox9 was upregulated in Gdf5 positive cells. Sox5 and 6 were upregulated in Gdf5 positive cells but had a lower correlation to Gdf5 expression indicating a weaker or indirect/secondary role in Gdf5 regulation. We also compared the activity of the wildtype GARR enhancer‐reporter construct to constructs with mutated Sox binding sites in developing chicken limbs to determine the role of these sites on enhancer activity. We found that in developing chicken embryo limbs, constructs with mutated Sox9 binding sites had a marked decrease in enhancer activity in the elbow but not in the autopod. Mutation of predicted Sox5/6 binding sites did not seem to affect activity relative to the non‐mutated control in the forelimb joints. Our findings suggest that Sox9 is a key regulator of elbow development through GARR‐mediated expression of Gdf5. The correlations identified in the transcriptomic data may be relevant only to the elbow and knee joints. Alternatively, the Sox transcription factors may be acting though other Gdf5‐associated enhancers in the autopod joints. Further investigation of enhancer activity in the presence of various combinations of Sox5/6/9 will throw more light on how they collectively affect Gdf5 expression as well as joint development and OA progression.

Reptile to chicken enhancer swaps to understand the molecular basis underlying morphological diversity in the vertebrate lung

The lung is one of the most morphologically diverse organs among vertebrate species. Phylogenetically, much of this diversity appears to arise from the way epithelial tubes branch and change shape ranging from very saccular to highly branched structures. We are interested in understanding the genetic mechanisms that underlie this range in morphology. Fgf10 signaling has been demonstrated to play a critical role in regulating whether the lung epithelium undergoes branching morphogenesis (through low, graded levels of Fgf10) or forms sacs (high, uniform exposure to Fgf10). We hypothesize therefore that interspecies differences in Fgf10 expression may be a mechanism to underlie morphological diversity that exists in the vertebrate lung. To test this hypothesis, we have been performing enhancer swap experiments taking reptilian Fgf10 enhancers and knocking them into orthologous loci in the genome of chicken primordial germ cells (cPGCs). These targeted cPGCs are introduced into the gonad of developing chicken embryos where they will ultimately develop into germ cells in the adult chicken. These germ line chimeras can then be bred to generate fully transgenic chicks to determine if enhancer swaps are sufficient to drive a reptilian pattern of lung morphogenesis in an avian. I will discuss the gene editing approaches my laboratory is taking to knock in reptilian Fgf10 enhancers into the orthologous locus in in the chicken.

Reflections of hands-on dissection and virtual dissection experiences of pre-service science teachers

ABSTRACT It is a controversial issue in education that students perform dissection experiments. Different opinions have been noted in studies on this subject, and various applications are recommended according to education levels. This case study aimed to determine pre-service science teachers’ views of hands-on dissection and virtual dissection. The study group consisted of 36 students, 29 female, and seven male. An open-ended question form and student diaries were used as data collection tools. The implementation started with observing the chicken embryo development process that the students actively carried out. Then, due to the COVID-19 pandemic, the frog dissection experiment was conducted as a virtual dissection. The content analysis method was used in the analysis of the data. According to the findings, the observations made during the chicken embryo development process emerged negatively due to ethical and moral concerns as the development process progressed. The frog dissection experiment applied in the virtual environment was accepted by the majority of the pre-service teachers who stated that they would prefer virtual dissection tools.

Al2O3 nanoparticles trigger the embryonic hepatotoxic response and potentiate TNF-α-induced apoptosis-modulatory effect of p38 MAPK and JNK inhibitors.

Recent evidences illustrated that the release of aluminum oxide nanoparticles (Al2O3-NPs) into the biosphere may pose risk to the environment and cause adverse effects on living organisms including humans. The current study assessed the hepatotoxic effects of Al2O3-NPs on developing chicken embryo and cell culture models. Results demonstrated that Al2O3-NPs exposure causes histological abnormalities and increased the level of tissue damage markers (ALP, AST, and ALT) in the embryonic liver. Furthermore, increased oxidative stress (TBARS) and impaired function of antioxidant enzymes (SOD, CAT, and GPx) were also observed. Moreover, it adversely affects red blood cells (RBC) morphology, liver metabolism, and stress response gene expression (HO-1 and NQO-1). Dose-dependent ROS generation and cytotoxic response in addition to potentiating effect on tumor necrosis factor alpha (TNF-α)-induced apoptosis (caspase-3 activity) were also observed. Inhibition of p38 mitogen-activated protein kinase (p38 MAPK) and c-Jun N-terminal kinase (JNK) pathways modulates Al2O3-NPs-induced apoptosis in HepG2 cells. Novel mechanisms behind embryonic hepatotoxicity, cytotoxic potentiating effects, and possible prevention strategies have been explored.

Time-Course Transcriptional and Chromatin Accessibility Profiling Reveals Genes Associated With Asymmetrical Gonadal Development in Chicken Embryos.

In birds, male gonads form on both sides whereas most females develop asymmetric gonads. Multiple early lines of evidence suggested that the right gonad fails to develop into a functional ovary, mainly due to differential expression of PITX2 in the gonadal epithelium. Despite some advances in recent years, the molecular mechanisms underlying asymmetric gonadal development remain unclear. Here, using bulk analysis of whole gonads, we established a relatively detailed profile of four representative stages of chicken gonadal development at the transcriptional and chromatin levels. We revealed that many candidate genes were significantly enriched in morphogenesis, meiosis and subcellular structure formation, which may be responsible for asymmetric gonadal development. Further chromatin accessibility analysis suggested that the transcriptional activities of the candidate genes might be regulated by nearby open chromatin regions, which may act as transcription factor (TF) binding sites and potential cis-regulatory elements. We found that LHX9 was a promising TF that bound to the left-biased peaks of many cell cycle-related genes. In summary, this study provides distinctive insights into the potential molecular basis underlying the asymmetric development of chicken gonads.

Effect of the In Ovo Injection Site of Electrolytes on Some Biochemical Blood Parameters and Quality of Layer Chicks.

Simple SummaryIn ovo technology is a unique method, the primary goal of which is to administer bioactive substances to eggs during the embryonic development of the bird. Therefore, it is necessary to develop optimal techniques for the implementation of in ovo feeding technology in practical poultry production. This preliminary study may open a window for future research on the site/location of manipulation and solutions and carriers of nutrients used for in ovo injection of laying hen embryos.The effects of the in ovo injection site of electrolytes on selected biochemical blood parameters and the quality of layer chicks were investigated. A total of 120 fertile eggs from Rhode Island Red breeders were randomly distributed into 4 groups, with each group including 30 birds. The groups were as follows: untreated control and groups with different injection sites/locations of 500 µL of 0.9% saline (NaCl) on day 18 of incubation, i.e., into the air cell (AC), through the air cell into the amniotic fluid (AFA), and directly into the amniotic fluid (AF). Measurement at 1 day of age showed that regardless of the injection site, embryos injected with 500 µL of saline had significantly higher Tona score (95/100 points) compared to the control group (90/100 points). Chick length was similar among the injected groups (mean 14.7 cm) and shorter in the control group (13.9 cm). There was no significant effect of in ovo injection on the biochemical blood parameters: total protein, cholesterol, high-density lipoprotein, low-density lipoprotein, glucose, urea, and uric acid. The highest concentration of sodium was noted in the control group (141.59 mmol/L). Regardless of the injection site/location, chicks treated with 500 µL of NaCl were characterized by a significantly lower blood sodium concentration (by 7.45% (AC), 7.90% (AFA), and 4.84% (AF) compared with birds from the control group (p ≤ 0.01)). The influence of saline solution administration in ovo on the blood potassium content of chicks was demonstrated. The concentration of potassium in the control group was significantly higher (by 11.36%) than in the AC group (p ≤ 0.01). In conclusion, the injection of 500 µL of saline solution into the developing chick embryo during the last days of incubation may have a positive effect on the quality of day-old chicks.

Dynamic MicroRNA Expression Profiles During Embryonic Development Provide Novel Insights Into Cardiac Sinus Venosus/Inflow Tract Differentiation.

MicroRNAs have been explored in different organisms and are involved as molecular switches modulating cellular specification and differentiation during the embryonic development, including the cardiovascular system. In this study, we analyze the expression profiles of different microRNAs during early cardiac development. By using whole mount in situ hybridization in developing chick embryos, with microRNA-specific LNA probes, we carried out a detailed study of miR-23b, miR-130a, miR-106a, and miR-100 expression during early stages of embryogenesis (HH3 to HH17). We also correlated those findings with putative microRNA target genes by means of mirWalk and TargetScan analyses. Our results demonstrate a dynamic expression pattern in cardiac precursor cells from the primitive streak to the cardiac looping stages for miR-23b, miR-130a, and miR-106a. Additionally, miR-100 is later detectable during cardiac looping stages (HH15-17). Interestingly, the sinus venosus/inflow tract was shown to be the most representative cardiac area for the convergent expression of the four microRNAs. Through in silico analysis we revealed that distinct Hox family members are predicted to be targeted by the above microRNAs. We also identified expression of several Hox genes in the sinus venosus at stages HH11 and HH15. In addition, by means of gain-of-function experiments both in cardiomyoblasts and sinus venosus explants, we demonstrated the modulation of the different Hox clusters, Hoxa, Hoxb, Hoxc, and Hoxd genes, by these microRNAs. Furthermore, we correlated the negative modulation of several Hox genes, such as Hoxa3, Hoxa4, Hoxa5, Hoxc6, or Hoxd4. Finally, we demonstrated through a dual luciferase assay that Hoxa1 is targeted by miR-130a and Hoxa4 is targeted by both miR-23b and miR-106a, supporting a possible role of these microRNAs in Hox gene modulation during differentiation and compartmentalization of the posterior structures of the developing venous pole of the heart.

The Neonicotinoid Thiacloprid Interferes with the Development, Brain Antioxidants, and Neurochemistry of Chicken Embryos and Alters the Hatchling Behavior: Modulatory Potential of Phytochemicals.

Simple SummaryThe present experiment was performed to investigate the toxic impact of thiacloprid (TH) on the brain of developing chicken embryos and also to measure its influence on the behavioral responses of hatchlings. The role of chicoric acid (CA) and rosmarinic acid (RA) in modulating the resulted effects was also investigated. TH resulted neurotoxic to chicken embryos and possibly neurotoxic to embryos of other vertebrates. Moreover, CA and RA exerted both an antioxidant and a neuroprotective effect on embryos.The present experiment was performed to investigate the toxic impact of thiacloprid (TH) on the brain of developing chicken embryos and also to measure its influence on the behavioral responses of hatchlings. The role of chicoric acid (CA) and rosmarinic acid (RA) in modulating the resulted effects was also investigated. The chicken eggs were in ovo inoculated with TH at different doses (0.1, 1, 10, and 100 ug/egg). TH increased the mortality and abnormality rates and altered the neurochemical parameters of exposed embryos dose-dependently. TH also decreased the brain level of monoamines and amino acid neurotransmitters and decreased the activities of acetylcholine esterase (AchE) and Na+/K+-ATPase. The brain activity of catalase (CAT) and superoxide dismutase (SOD) was diminished with downregulation of their mRNA expressions in the brain tissue. When TH was co-administered with CA and RA, the toxic impacts of the insecticide were markedly attenuated, and they showed a complementary effect when used in combination. Taken together, these findings suggested that TH is neurotoxic to chicken embryos and is possibly neurotoxic to embryos of other vertebrates. The findings also demonstrated the antioxidant and neuroprotective effects of CA and RA. Based on the present findings, the CA and RA can be used as invaluable ameliorative of TH-induced toxicity.

Effects of Calcium Lactate on the Development of Chicken Embryos in a Shell-less Culture System up to Day Seventeen of Incubation.

This study examined the effects of calcium lactate on the development of chicken embryos in a shell-less culture system (cSLCS) up to the seventeenth day of incubation. In the presence of calcium lactate, a significant reduction in embryo viability was observed during the first week of incubation in cSLCS. On day 17 of embryo development, no significant difference was observed in the blood plasma calcium concentration or tibia bone density between cSLCS and intact control embryos, whereas the tibia length was significantly shorter in cSLCS embryos than in the intact control. These results suggest that calcium lactate supplementation in cSLCS supports bone formation in developing chicken embryos, but has adverse effects on the viability of embryos, particularly during the first week of embryo development.

Effects of Zinc Oxide Nanoparticles on Neural Tube Development in Early Chicken Embryos.

In recent years, Zinc oxide nanoparticles (ZnO-NPs) have been widely used as a mineral filter in cosmetics. Therefore, the possible exposure of pregnant women to ZnO-NPs is gradually increasing. Thus, we aimed to investigate the effect of ZnO-NPs on neural tube development in early chicken embryos. Fifty pathogen-free fertilized eggs were initially incubated for thirty hours. The eggs were divided into 5 groups. In the control group (C) the egg's apex was opened and closed without any administration. In the distilled water group (DW), 10 microliters of distilled water were injected into the sub-blastodermic area. ZnO-NP suspensions were prepared in distilled water and injected sub-blastodermically into the low, medium and high dose ZnO-NP groups (10 mg/kg, 30 mg/kg, and 50 mg/kg, respectively). Incubation was completed in 72 hours, and embryological and neural tube development was evaluated histologically with a light microscope. Embryos in all groups were evaluated according to the Hamburger-Hamilton (HH) staging. It was observed that the staging progressed by the developmental process between 68-72 hours, which is equivalent to the 19-20th stage of HH. Differentiated otic vesicle, optic cup, lens vesicle, pharynx, and Rathke\'s pouch were all observed in embryo sections. Both forebrain and hindbrain vesicles were easily distinguished in the sections by cranial flexion. Neural tube closure defect was not detected in any of the groups. In our observations, ZnO-NPs did not affect neural tube development at the applied dose ranges. We believe that additional studies with higher doses using a higher number of subjects will help clarify the conflicting data in the literature.

Mitigating properties of vitamin E and olive oil on the teratomorphogenic impacts of lambda-cyhalothrin in developing chick embryos

Embryonic toxicity of lambda-cyhalothrin (LCH) and the mitigating properties of extra virgin olive oil (EVO) and vitamin E were investigated in golden black variety of chick embryos. Fifty fertilized eggs distributed in 5 groups received their respective group treatments at zero days of incubation were recovered after 14 days of incubation and fixed in fixative for 48 h for further studies. Results showed that treatment with LCH caused embryonic death, growth retardation and developmental abnormalities such as limbic developments, reduced muscular growth, and embryonic cataract. Post treatment with vitamin E and EVO alone significantly improved all these developmental defects. Morphometric readings also showed that embryos treated with combined dose of vitamin E and EVO had more resemblance towards the control group embryo. These findings suggested that the use of vitamin E and EVO together during pregnancy have the potential to curtail these accidental, environmental and work place exposures of LCH.

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.

Histopathological Changes in Kidneys of Developing Chick Embryo on Exposure to Artesunate

Introduction: Chick embryo is one of the most commonly used animals to study the adverse effects of various drugs for research purpose. In India, Malaria imposes incredible socio-economic burden on humankind. India reports approximately two million cases of malaria yearly, with large number of deaths. Surveys have demonstrated that the rates of treatment failure are higher than 50% due to Chloroquine resistance and poor efficacy of Sulphadoxine Pyrimethamine. Artesunate is a concentrate of Artemisia plant found in China, also called as Qinghaosu. It is a subordinate of a group of drugs artemisinin that have the most rapid action of all current drugs against Chloroquine resistant Plasmodium vivax and Plasmodium falciparum malaria. Aim: To understand the adverse effects of Artesunate on kidney of developing chick embryo. Materials and Methods: The present study was an experimental study which comprised of steps like selection and sampling of eggs in groups (control and experimental), selection and preparation of drug (dose titration), drug administration, incubation of eggs, manual hatching to obtain chick embryo, isolation of kidney, sectioning of kidney and staining for slide preparation, microscopical analysis of the slides. In this study, the fertilised eggs used were of White Leghorn chicken and were procured from King and King poultry farm Hapur, Uttar Pradesh, India. Hundred fertilised chicken eggs were divided into five experimental groups denoted by A, B, C, D, and E and five control groups denoted by a, b, c, d and e one for each experimental group respectively. Each experimental and control group had 10 eggs. Experimental groups A, B, C, D and E were exposed to artesunate with dose of 0.0004 mg, 0.0005 mg, 0.0006 mg, 0.0007 mg and 0.0008 mg respectively and control group a, b, c, d and e were treated with same concentration of normal saline as artesunate. The eggs were broken by scalpel on 18th day of incubation and chick embryos were obtained. The kidneys were removed sectioned, stained and studied using light and compound microscope. Results: Histopathological changes like tubular degeneration, vacuolation in the cytoplasm of epithelium lining of Proximal Convoluted Tubules (PCT) and Distal Convoluted Tubules (DCT), congestion in Glomeruli, haemorrhage in urinary space and mild lymphocytic infiltration were observed. Conclusion: Exposure to artesunate increases the risk of nephrotoxicity with increase of embryonic age.

Enzymatic and Toxicological Analysis of Vranaharin Ayurvedic Oil: An Experimental Study from a Clinical Perspective for Topical Applications on Necrotic Wounds

Vranaharin, an ayurvedic oil manufactured by MMCA Remedies Pharmaceuticals, Karnataka, India, is a red-colored drug, prepared from several traditionally used plant ingredients and is used in postoperative dressings, bedsores, burns, cuts, wounds, diabetic ulcers, abscesses, skin infections, nail fungus, herpes and so on. This research aims to investigate Vranaharin oil, to understand its side-effects such as antioxidant enzymes alteration in the cerebral cortex of the brain and liver of developing chick embryos, pathological effect/antimicrobial nature, antioxidant ability and hemolytic activity. This study is designed to give an overall toxicological analysis of the selected drug. The oil which is used for topical applications of necrotic wounds is observed to cause angioneogenesis in necrotic wound bed within a short span of application. The oil has been investigated for the first time to assess the systemic effect of local application in terms of possible genotoxicity and embryonic toxicity. The study concludes that the oil can be effectively applied over the necrotized wound bed for a short period and its long-term application needs to be further investigated. Setting of maximum dose needs to be standardized as it caused notable fluctuations to enzyme equilibrium and variations in superoxide dismutase, catalase, glutathione peroxidase and glutathione- S-transferases levels when higher concentrations were used in chick embryos. Its topical application is highly recommended, especially in necrotizing wounds due to its excellent antioxidant, and antimicrobial potential. The angiogenic potential of the oil in avascular wounds is a very interesting phenomenon that is being investigated in our laboratory.

Genotoxic and cytotoxic potential of Bisphenol A in the early developing stages of chick embryo (Gallus gallus domesticus) evidenced by HET-MN and Comet assay

Bisphenol-A (BPA) is ubiquitously present in the environment and consumer products and is a crucial environmental contaminant known to cause significant health risks to various organisms. The present study aims to evaluate the genotoxicity effect of BPA in developing chick embryos. Fertile chicken eggs were treated with increasing concentrations of BPA (1, 10, 20, 30, 40 and 50 mM/egg) on embryonic days (ED) 8, 9 and 10. On ED11, the number of viable embryos was recorded and LD50 values were calculated for 24 h (ED 10), 48 h (ED 9) and 72 h (ED 8). HET-MN (Hens egg test for micronucleus assay) and comet assay were performed on the 11th-day to evaluate the cytotoxicity and genotoxicity potential of BPA. Experiments were performed in three different time points i.e. 24 h, 48 h and 72 h of exposure. Results showed an increased mortality rate in a dose and time-dependent manner. Significant alterations of cellular dynamics erythropoiesis and PCE/NCE ratio were observed. Also, significant induction of total MN and other nuclear abnormalities was observed. A decrease in head DNA content, increase in tail DNA, olive tail moment and damage indexes were detected upon exposure. Thus, the results confirmed the genotoxic and cytotoxic potential of Bisphenol-A that caused genetic alterations extensively during the early development of embryos.