Search

Chicken coccidiosis causes annual losses exceeding GBP 10 billion globally. The most pathogenic species for domestic fowls including Eimeria tenella, E. acervulina, and E. maxima, can lead to gastrointestinal issues ranging from mild to fatal. In this study, stages of E. tenella and freshly isolated chicken heterophils were co-cultured for 180 min. These interactions were analyzed using live 3D holotomographic and confocal microscopy. We observed that E. tenella stages were entrapped by heterophils and heterophil extracellular traps (HETs). Notably, different HET phenotypes, specifically sprHETs and aggHETs, were induced regardless of the stage. Furthermore, the quantification of extracellular DNA release from co-cultures of heterophils and sporozoites (ratio 1:1) for 180 min demonstrated a significantly higher release (p = 0.04) compared to negative controls. In conclusion, research on the chicken innate immune system, particularly fowl-derived HETs, remains limited. More detailed investigations are needed, such as exploring the time-dependent triggering of HETs, to establish a standard incubation time for this pathogen defense mechanism. This will enhance our understanding of its role in parasite survival or death during HET confrontation. [ABSTRACT FROM AUTHOR]

The impact of supplementing glucose, glycine, or a combination of both in Ringer’s lactate egg yolk base extender to preserve the quality of semen from local Indonesian chickens has not been previously investigated. This study aimed to examine the potential of glucose and glycine on chicken semen stored at 5°C for 120 hours. In this study, five local roosters were used. The parameters under observation included semen volume, odor, pH levels, consistency, color, mass movement, concentration, motility, viability, abnormality, plasma membrane integrity, chromatin degeneration, and acrosomal cap integrity. This study was conducted using a completely randomized design (CRD) with four treatments groups and 10 replication, i.e. T1 (control without supplementation), T2 (50 mM glucose), T3 (60 mM glycine), and T4 (a combination of 50 mM glucose and 60 mM glycine), respectively. In result, semen volume was 0.54 ± 0.17 mL/ejaculate, a milky white color, distinctive odor, thick consistency, good mass movement (++/+++), pH of 7.37 ± 0.23, motility of 91.50 ± 2.42%, plasma membrane integrity of 96.85 ± 0.96%, abnormality at 2.88 ± 0.77%, the concentration of 3.04 ± 0.3 billion/mL, and viability of 96.47 ± 1.71%. Following storage at 5°C for 120 hours, the motility, viability, abnormality, and acrosomal cap integrity of local chicken spermatozoa significantly different (p < 0.05) between T3 and T4 compared to T1 and T2 groups. Moreover, the integrity of the plasma membrane and chromatin degeneration in treatment T3 significantly different (p < 0.05) from T1, T2, and T4 groups. In conclusion, local chickens exhibited fair quality fresh semen both in macroscopic and microscopic evaluations. Furthermore, the combination of 60 mM glycine and 50 mM glucose into local chicken semen stored at 5°C for 120 hours effectively preserved motility and viability, minimized abnormality, maintained plasma membrane integrity, minimized chromatin degeneration, and retained acrosomal integrity. [ABSTRACT FROM AUTHOR]

In this study, the role of chicken CD4+CD25+ cells during induced immunotolerance was tested. Properties of chicken CD4+CD25+ cells sorted by flow cytometry were analyzed. Results showed that chicken CD4+CD25+ cells express IL-10, TGF-β highly and suppress proliferation of CD4+CD25- cells in vitro. To induce immunotolerance, embryos were inoculated with bovine serum albumin (BSA) via an intravascular route on embryo incubation day 20 (EID20), and after hatching chicks experienced BSA immunization four times at 7-day intervals. Serum anti-BSA antibodies and CD4+CD25+ cell ratio was analyzed. Results showed that humoral tolerance was obtained and the CD4+CD25+ cell percentage in peripheral blood lymphocytes increased along with this progress. Injection of anti-chicken CD25 antibody via an intravascular route on EID16 is applied to block CD4+CD25+ cells, and the CD4+CD25+ cell ratio decreased significantly up to 35 d post-hatch. Based on the above, injections of anti-chicken CD25 antibody on EID16 and BSA on EID20 were carried out sequentially, and tolerance level was contrasted to the BSA-injection group. Data revealed the anti-BSA antibodies increased significantly in the CD4+CD25+ cell-blocked groups indicating that immune tolerance level was weakened. In conclusion, chicken CD4+CD25+ cells are essential in maintaining induced immune tolerance. [ABSTRACT FROM AUTHOR]

Abstract Primordial germ cells (PGCs) are promising genetic resources for avian studies including modified animals. However, chicken PGCs are slow to proliferate and gradually lose germline competency after long-term culture, which hinders their application in avian biotechnology. Thus, we developed a robust method for the isolation and rapid propagation of PGCs using an indirect co-culture system. PGCs derived from a pair of embryonic chicken gonads were expanded to 1 × 106 within 2 weeks, and no sex bias was observed in. These PGCs presented high capacity of germline transmission and produced donor-derived offspring after injection into the chicken embryos. This system allows the efficient gene-banking of chicken species and can facilitate the production of chickens bearing a desired phenotype via genomic editing. Highlights • PGCs in more than 90% of the isolations grew to one million in 2 weeks. • The deriving system in this research presented no sex bias in surviving PGC lines. • These MKO-FI derived PGCs maintain germline transmission capacity pre- or post-cryopreservation. [ABSTRACT FROM AUTHOR]

Abstract The aim of this study was to evaluate ultrastructural changes in kidney and liver tissue of chicken embryos exposed in ovo to cadmium. Embryonated eggs were injected on the 4th day of incubation with cadmium at the dose of 0, 2, 4 and 8 μg/egg (80 eggs/group). The samples of kidney and liver tissues were collected from embryos at the 14th and 18th day of incubation (E14 and E18) and at hatching day (D1). The tissue structure was evaluated by transmission electron microscopy (Tecnai G2 Spirit). The results indicate that hepatocytes responded to damage caused by toxic cadmium activity with a significant disturbance in the structure of mitochondria and a considerable expansion of the lysososmal system, while glomerular cells additionally reacted with an increased proliferation of peroxisomes. The range of changes observed on the subcellular level was dependent on the dose of cadmium, embryogenesis stage and cell type. [ABSTRACT FROM AUTHOR]

This study investigated the effects of thermal manipulation (TM) during embryonic days 12 to 18 on the cloacal temperature (Tc) and the kinetics of muscle mRNA levels of heat shock proteins 70 and 60 (Hsp70 and Hsp60) and heat shock factors 3 and 4 (HSF3 and HSF4) during the first week of life and during thermal stress (TS). One thousand five hundred fertile chicken eggs were randomly divided into 5 groups: control group (37.8°C), TM1 (38.5°C for 18 h), TM2 (39°C for 18 h), TM3 (39.5°C for 18 h), and TM4 (40°C for 18 h). On post-hatch days 14 and 28 of age, 30 randomly selected chicks from each group were thermally stressed at 41.0°C for 6 h, while another 30 randomly selected chicks from each group were kept under thermo-neutral conditions. The Tc of TM chicks was only numerically lower than that of the control during the study period. However, during TS at days 14 and 28 of age, the Tc of TM chicks was significantly lower than that of the controls. On post-hatch days 14 and 28, the basal mRNA levels of Hsps and HSFs were significantly higher than those of the control. Furthermore, during TS, rapid increases in the mRNA levels of Hsps and HSFs in the TM groups were observed. These results indicate that, as well as altering their basal mRNA levels during the first week post-hatch, TM also altered the dynamics of the mRNA expression of HSPs and HSFs, which was associated with improved acquisition of thermotolerance during TS. [ABSTRACT FROM AUTHOR]

Abstract: Metabolic disorder is a major health problem and is associated with a number of metabolic diseases. Due to native hyperglycaemia and resistance to exogenous insulin, chickens as a model had used in the studies of adipose tissue biology, metabolism and obesity. But no detailed information is available about the comprehensive changes of serum metabolites at different stages of chicken embryonic development. This study employed LC/MS‐QTOF to determine the changes of major functional metabolites at incubation day 14 (E14d), 19 (E19d) and hatching day 1 (H1d), and the associated pathways of differential metabolites during chicken embryonic development were analysed using Metabolite Set Enrichment Analysis method. Results showed that 39 metabolites were significantly changed from E14d to E19d and 68 metabolites were significantly altered from E19d to H1d in chicken embryos. Protein synthesis was promoted by increasing the concentrations of L‐glutamine and threonine, and gonadal development was promoted through increasing oestrone content from E14d to E19d in chicken embryos, which indicated that serum glutamine, threonine and oestrone contents may be considered as the candidate indicators for assessment of early embryonic development. 2‐oxoglutaric acid mainly contributed to enhancing the citric cycle, and it plays an important role in improving the growth of chicken embryos at the late development; the decreasing of L‐glutamine, L‐isoleucine and L‐leucine contents from E19d to H1d in chicken embryonic development implied their possible functions as the feed additive during early posthatch period of broiler chickens to satisfy the growth. These results provided insights into understand the roles of serum metabolites at different developmental stages of chicken embryos, it also provides available information for chicken as a model to study metabolic disease or human obesity. [ABSTRACT FROM AUTHOR]

At present, broilers reach slaughter weight at a physiologically younger age and the embryonic developmental period as well as the first week after hatching represents a larger proportion (45%) of the whole life span. Thus, pre-hatch as well as the transitional post-hatch period must be achieved efficiently. It is known that body weight is increased three to four fold during the first week and considerable changes in gut, and muscle weight and morphology are observed. The post-hatch period is critical for the digestive tract because the system is switching itself from off to on. The first day after hatch is critical for the development of body systems in the chicken and certain types of manipulation must occur during the first days after hatch in order to achieve long-term effects. Meat-type broilers are capable of achieving 70 g/day until 40 days. This achievement requires emphasis on early phase nutrition (i.e. pre-starter diets). The use of pre-starter diets assumes that starter diets are somewhat inefficient in providing balanced nutrients. Early nutritional strategies offer the promise of sustaining progress in production efficiency and welfare of commercial poultry. In order to achieve broiler potential several unconventional changes must be made: supplying nutrients to the developing embryo before hatch, supplying feed within hatchery, developing highly digestible pre-starter diets. Integrate all of the above to create a continuous feeding process from several days prior to hatch, during hatch and till farm placement where first feed is provided. [ABSTRACT FROM AUTHOR]

At hatch, the chick skeleton is a miniature of that of the adult bird. The hen deposits calcium, phosphorus, and trace minerals (copper, zinc, and manganese) along with vitamin D into the egg to allow development of the embryonic skeleton. The main source of calcium is the eggshell, whereas phosphorus, trace minerals, and vitamin D are mainly derived from the yolk. Calcium is absorbed from the eggshell and transferred to the embryo and yolk through the chorioallantoic membrane, whereas phosphorus and trace minerals are simultaneously mobilized by the yolk sac membrane. These processes start at day 12 of incubation and peak at around day 17. While the eggshell provides a steady supply of calcium until 19 d of incubation, phosphorus and trace mineral reserves decrease considerably and minimal skeletal development occurs in the last 3 d of incubation. Whether the low levels of phosphorus and trace minerals at late incubation prevent further bone growth, or some other biological control exists preventing further mineralization towards hatching is unknown. Maternal transfer of minerals and the influence of trace mineral form in the hen diet to advance the state of skeletal development at hatch have received increased research attention. Minimal effects on yolk mineral composition and bone growth were observed in the offspring of hens fed different forms of trace minerals. Embryos from young hens had inferior bone development towards the end of incubation and at hatch relative to chicks from older hens. This effect is likely a consequence of limited egg nutrient resources in eggs from young hens. The influence of maternal nutrient transfer on embryonic bone development has been clearly established. However, attempts to increase the state of skeletal development at hatch through increasing egg mineral content have met with limited success. The focus of this paper is the relationship between skeletal mineralization of the chicken embryo throughout incubation and egg mineral supply. [ABSTRACT FROM AUTHOR]

Intraepithelial corneal nerves (ICNs) help protect the cornea as part of the blink reflex and by modulating tear production. ICNs are also thought to regulate the health and homeostasis of the cornea through the release of trophic factors. Disruption to these nerves can lead to vision loss. Despite their importance little is known about how corneal nerves function and even less is known about how the cornea is initially innervated during its embryonic development. Here, we investigated the innervation of the embryonic chicken cornea. Western blot and immunohistochemistry were used to characterize the localization of the synaptic vesicle marker SV2, a molecule thought to be involved in the release of trophic factors from sensory nerves. The data show that both SV2 and synaptotagmin co-localize to ICNs. Nerves in the conjunctiva also contained SV2 and synaptotagmin, but these were localized to below the basal layers of the conjunctiva epithelium. SV2 isolated from corneal epithelium migrates in western blot at a heavier weight than SV2 isolated from brain, which suggests a role in vesicle targeting, as the deglycosylating enzyme PnGase does not affect corneal SV2. [ABSTRACT FROM AUTHOR]

Inclusion body hepatitis and hydropericardium-hepatitis syndrome caused by serotype 4 fowl adenovirus (FAdV-4) have emerged in China since 2013. FAdV is usually propagated in primary chicken embryonic liver cells or embryo yolk sac. The aim of this work was to develop an immortalized CEL cell line by stable expression of human mitochondrial ribosomal protein 18S-2, named CEL-hMRP18S-2 cells, for the propagation of FAdV-4. The maximum cell density of CEL-hMRP18S-2 cells could reach 2.65 × 10 6  cells/ml in four-days culture. According to the mRNA levels of cell-cycle related genes in CEL-hMRP18S-2 cells tested by qRT-PCR, we speculated that the transformation of hMRP18S-2 into CEL cells caused the functional inactivation of p53 and the significant down-regulation of p15 INK4b might cause the hyperphosphorylated form of Rb, releasing E2F-1 factor and enhancing the E2F-dependent transcription for cell cycle progression. It was suspected that the up-regulated c-Myc mRNA level at the initial period of immortalization might prompt transformed cells through the G0-G1 checkpoint. The normal CPE was observed in CEL-hMRP18S-2 cells infected by FAdV-4 and microcarrier suspension culture performed for FAdV-4 propagation with 9.0 lgTCID 50 /ml suggested that CEL-hMRP18S-2 cells could be a useful continuous cell line for isolation of wild FAdV and production of FAdV-inactivated vaccine. [ABSTRACT FROM AUTHOR]

Triclosan (TCS), a commonly used antimicrobial compound, has recently been detected in the eggs of wild avian species. Exposure to TCS in rodents is known to interfere with thyroid hormone (TH), disrupt immune responses and cause liver disease. However, no attempt has been made to clarify the effects of TCS in avian species. The aim of this study is therefore to evaluate the toxic effects of in ovo exposure to TCS and explore the molecular mechanism by transcriptome analysis in the embryonic liver of a model avian species, chicken ( Gallus gallus ). Embryos were treated with graded concentration of TCS (0.1, 1 and 10 μg/g egg) at Hamburger Hamilton Stage (HHS) 1 (1st day), followed by 20 days of incubation to HHS 46. At the administration of 10 μg TCS/g egg, embryo mortality increased from 20% in control to 37% accompanied with 8% attenuation in tarsus length. While liver somatic index (LSI) in TCS treatments was enhanced, statistical difference was only observed at the treatment of 0.1 μg TCS/g egg in females. The up-regulation of several crucial differentially expressed genes (DEGs) in transcriptome analysis suggested that TCS induced xenobiotic metabolism (e.g. CYP2C23a , CYP2C45 and CYP3A37 in males; CYP2C45 in females) and activated the thyroid hormone receptor (THR) - mediated downstream signaling (e.g. THRSPB and DIO2 in males; THRSPB in females). In females, TCS may further activate the lipogenesis signaling (e.g. ACSL5 , ELOVL2 ) and repress the lipolysis signaling (e.g. ABHD5 , ACAT2 ). A battery of enriched transcription factors in relation to these TCS-induced signaling and phenotypes were found, including activated SREBF1, PPARa, LXRa, and LXRb in males and activated GLI2 in females; COUP-TFII was predicted to be suppressed in both genders. Finally, we developed adverse outcome pathways (AOPs) that provide insights into the molecular mechanisms underlying the alteration of phenotypes. [ABSTRACT FROM AUTHOR]

Chicken embryonic stem cells (cESCs) obtained from stage X embryos provide a novel model for the study of avian embryonic development. A new way to maintain cESCs for a long period in vitro still remains unexplored. We found that the cESCs showed stem cell-like properties in vitro for a long term with the support of DF-1 feeder and basic culture medium supplemented with human basic fibroblast growth factor (hbFGF), mouse stem cell factor (mSCF), and human leukemia inhibitory factor (hLIF). During the long culture period, the cESCs showed typical ES cell morphology and expressed primitive stem cell markers with a relatively stable proliferation rate and high telomerase activity. These cells also exhibited the capability to differentiate into cardiac myocytes, smooth muscle cells, neural cells, osteoblast, and adipocyte in vitro. Chimera chickens were produced by cESCs cultured for 25 passages with this new culture system. The experiments showed that DF-1 was the optimal feeder and hbFGF was an important factor for maintaining the pluripotency of cESCs in vitro. [ABSTRACT FROM AUTHOR]

Complex morphogenetic events, critical for the development of normal cerebellum foliation and layering, are known to involve type III intermediate filament protein such as vimentin expressed by Bergmann glia. The present study aimed to determine aspects of intermediate and late embryonic pattern of vimentin expression during the corticogenesis of chicken cerebellum at embryonic days 10–19 (E10-E19), using single and double immunohistochemistry/immunofluorescence. Vimentin expression showed partial co-localization with the glial markers GFAP and BLBP. Within cerebellar cortex, vimentin+ fibers were first found within lobules I and X (E10) and gradually extended to all folia (E15-E17), located within the external granule (EGL) the molecular cell layer, showing a radial orientation towards the inner granular layer and the cerebellar white matter oriented longitudinally. Interestingly, within the immature fissures base of most lobules, vimentin+ fibers radiate in a fan shape. Short-term BrdU experiments revealed that EGL cell proliferation was higher in the fissure base compared to folia apex. In addition, following 24-h survival, BrdU+ cells were found in close association to vimentin+ fibers in the EGL pre-migratory zone and within immature molecular layer. Paralleling cerebellum development, vimentin expression gradually extended to all folia sub-regions (base, wall, apex), but, at day E19, it was mainly confined to the folia apex and secondary fissure base. Taken together our data further support the possible role of vimentin+ fibers in the structural events of cerebellum corticogenesis, suggesting the participation of radial/Bergmann glia in chicken cerebellum foliation, similarly to that described for mammalian cerebellum morphogenesis. [ABSTRACT FROM AUTHOR]

1. Acrylamide (ACR) is a potent neurotoxicant, although information on its toxic influence on the developing neural system is still limited. The effects of in-ovo-injected ACR on the antioxidant system activity in the brain of newly hatched chickens was examined. This model eliminated the mother’s contribution to embryonic development. It was also recognised as an adequate model for animal embryonic development. 2. ACR was injected on d 4 of embryogenesis - in doses of 1.25 and 2.50 mg/egg (n = 40 eggs/group/120 eggs). The doses corresponded well with ACR doses used in other animal studies and their concentrations in certain animal feeds. 3. Mortality and incidences of malformations were not found to increase significantly. Significant depletion of glutathione was detected in the cerebellum, cerebrum and medulla oblongata of specimens exposed to the highest doses of ACR. Enzymatic activity was affected by the highest ACR doses. Glutathione peroxidase (GPx) activity increased significantly in the cerebrum, medulla oblongata and the hypothalamus. Superoxide dismutase (SOD) activity increased significantly in hypothalamus and decreased in cerebellum and cerebrum. A significant depletion of catalase (CAT) activity was detected in cerebellum. In the hypothalamus, the increased SOD/GPx and SOD/CAT ratios suggest the risk of H2O2. 4. It was concluded that ACR significantly influences the antioxidative defence in the chicken brain at doses of 1.25 and 2.50 mg/egg. [ABSTRACT FROM AUTHOR]

Initial embryological development in avian species, consisting of cleavage and area pellucida formation, occurs prior to oviposition. In chickens, the first lineage segregation is known to occur during the last 10 hours of intrauterine development, a finding which has primarily been identified on the basis of morphological perspectives. We traced the early expression of the transcription factors NANOG, POUV and EOMES at Eyal-Giladi and Kochav (EGK) stages VI through X using in situ hybridization. At EGK.VI, NANOG and EOMES were heterogeneously expressed in a saltand- pepper manner. From EGK.VIII to EGK.X, NANOG- or EOMES-positive cells were predominantly located in the epiblast or area opaca regions, respectively. POUV-expressing cells were found in the upper layer at EGK.VIII. After oviposition, POUV mRNA was strongly expressed in the epiblast, but weakly expressed in the hypoblast at EGK.X. Furthermore, NANOG- and POUV-negative cells were located in the subgerminal cavity where layer reduction occurs during area pellucida formation. Those cells were larger and did not seem to contribute to epithelialization until EGK.X. Our results on the spatiotemporal expression of transcription factors contribute to a greater understanding of the dynamic process of intrauterine development in chickens. [ABSTRACT FROM AUTHOR]

Morphological malformations induced by tributyltin (TBT) exposure during embryonic development have already been characterized in various taxonomic groups, but, nonetheless, the molecular processes underlying these changes remain obscure. The present study provides the first genome-wide screening for differentially expressed genes that are linked to morphological alterations of gonadal tissue from chicken embryos after exposure to TBT. We applied a single injection of TBT (between 0.5 and 30 pg as Sn/g egg) into incubated fertile eggs to simulate maternal transfer of the endocrine disruptive compound. Methyltestosterone (MT) served as a positive control (30 pg/g egg). After 19 days of incubation, structural features of the gonads as well as genome-wide gene expression profiles were assessed simultaneously. TBT induced significant morphological and histological malformations of gonadal tissue from female embryos that show a virilization of the ovaries. This phenotypical virilization was mirrored by altered expression profiles of sex-dependent genes. Among these are several transcription and growth factors (e.g. FGF12, CTCF, NFIB), whose altered expression might serve as a set of markers for early identification of endocrine active chemicals that affect embryonic development by transcriptome profiling without the need of elaborate histological analyses. [ABSTRACT FROM AUTHOR]

Background: Chicken embryos are widely used as a model for studies of obesity; however, no detailed information is available about the dynamic changes of proteins during the regulation of adipose biology and metabolism. Thus, the present study used an isobaric tags for relative and absolute quantitation (iTRAQ)-based proteomic approach to identify the changes in protein abundance at different stages of chicken embryonic development. Results: In this study, the abundances of 293 hepatic proteins in 19-day old of chicken embryos compared with 14-day old and 160 hepatic proteins at hatching compared with 19-day old embryos were significantly changed. Pathway analysis showed that fatty acid degradation (upregulated ACAA2, CPT1A, and ACOX1), protein folding (upregulated PDIs, CALR3, LMAN1, and UBQLN1) and gluconeogenesis (upregulated ACSS1, AKR1A1, ALDH3A2, ALDH7A1, and FBP2) were enhanced from embryonic day 14 (E14) to E19 of chicken embryo development. Analysis of the differentially abundant proteins indicated that glycolysis was not the main way to produce energy from E19 to hatching day during chicken embryo development. In addition, purine metabolism was enhanced, as deduced from increased IMPDH2, NT5C, PGM2, and XDH abundances, and the decrease of growth rate could be overcome by increasing the abundance of ribosomal proteins from E19 to the hatching day. Conclusion: The levels of certain proteins were coordinated with each other to regulate the changes in metabolic pathways to satisfy the requirement for growth and development at different stages of chicken embryo development. Importantly, ACAA2, CPT1A, and ACOX1 might be key factors to control fat deposition during chicken embryonic development. These results provided information showing that chicken is a useful model to further investigate the mechanism of obesity and insulin resistance in humans. [ABSTRACT FROM AUTHOR]

Around the time of gastrulation in higher vertebrate embryoS' inductive interactions direct cells to form central nervous system (neural plate) or sensory placodes. Grafts of different tissues into the periphery of a chicken embryo elicit different responses: Hensen's node induces a neural plate whereas the head mesoderm induces placodes. How different are these processes? Transcriptome analysis in time course reveals that both processes start by induction of a common set of genes' which later diverge. These genes are remarkably similar to those induced by an extraembryonic tissue' the hypoblast' and are normally expressed in the pregastrulation stage epiblast. Explants of this epiblast grown in the absence of further signals develop as neural plate border derivatives and eventually express lens markers. We designate this state as "preborder"; its transcriptome resembles embryonic stem cells. Finally' using sequential transplantation experiments' we show that the node' head mesoderm' and hypoblast are interchangeable to begin any of these inductions while the final outcome depends on the tissue emitting the later signals. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) are toxic environmental pollutants that are potent teratogens. Recent research suggests that early life exposure to PAHs can affect health outcomes later in life. Some of these latent responses may be mediated by epigenetic mechanisms such as DNA methylation. The role of DNA methylation in regulating responses to PAHs in birds is currently unknown. Here, we assess the effect of in ovo exposure to the model PAH, benzo[ k ]fluoranthene (BkF), on aryl hydrocarbon receptor (AHR) mediated cytochrome P4501A ( CYP1A ) gene expression and promoter methylation in chicken embryos. Fertilized chicken eggs were injected with BkF (0–100 μg/kg) prior to incubation. BkF exposure was associated with an increase in CYP1A4 and CYP1A5 mRNA levels at mid-incubation (embryonic day 10), which dropped to baseline levels towards the end of the incubation period (embryonic day 19). The transient induction in CYP1A expression was accompanied by small but significant increases in CYP1A promoter methylation, which persisted until after shortly after hatching. Methylation within the CYP1A promoter was correlated with levels of CYP1A5 , but not CYP1A4 mRNA. Characterization of the role of DNA methylation in the AHR response pathway may increase our understanding of the effects of early life exposure to PAHs in birds. [ABSTRACT FROM AUTHOR]

The autonomic nervous system consists of sympathetic and parasympathetic nerves, which functionally antagonize each other to control physiology and homeostasis of organs. However, it is largely unexplored how the autonomic nervous system is established during development. In particular, early formation of parasympathetic network remains elusive because of its complex anatomical structure. To distinguish between parasympathetic (cholinergic) and sympathetic (adrenergic) ganglia, vesicular acetylcholine transporter ( VAChT) and choline O-acetyltransferase (Ch AT), proteins associated with acetylcholine synthesis, are known to be useful markers. Whereas commercially available antibodies against these proteins are widely used for mammalian specimens including mice and rats, these antibodies do not work satisfactorily in chickens, although chicken is an excellent model for the study of autonomic nervous system. Here, we newly raised antibodies against chicken VAChT and Ch AT proteins. One monoclonal and three polyclonal antibodies for VAChT, and one polyclonal antibody for Ch AT were obtained, which were available for Western blotting analyses and immunohistochemistry. Using these verified antibodies, we detected cholinergic cells in Remak ganglia of autonomic nervous system, which form in the dorsal aspect of the digestive tract of chicken E13 embryos. The antibodies obtained in this study are useful for visualization of cholinergic neurons including parasympathetic ganglia. [ABSTRACT FROM AUTHOR]

1. The avian embryo is an excellent model for studying embryology and the production of pharmaceutical proteins in transgenic chickens. Furthermore, chicken stem cells have the potential for proliferation and differentiation and emerged as an attractive tool for various cell-based technologies. 2. The objective of these studies is the derivation and culture of these stem cells is the production of transgenic birds for recombinant biomaterials and vaccine manufacture, drug and cytotoxicity testing, as well as to gain insight into basic science, including cell tracking. 3. Despite similarities among the established chicken stem cell lines, fundamental differences have been reported between their culture conditions and applications. Recent conventional protocols used for expansion and culture of chicken stem cells mostly depend on feeder cells, serum-containing media and static culture. 4. Utilising chicken stem cells for generation of cell-based transgenic birds and a variety of vaccines requires large-scale cell production. However, scaling up the conventional adherent chicken stem cells is challenging and labour intensive. Development of a suspension cell culture process for chicken embryonic stem cells (cESCs), chicken primordial germ cells (PGCs) and chicken induced pluripotent stem cells (ciPSCs) will be an important advance for increasing the growth kinetics of these cells. 6. This review describes various approaches and suggestions to achieve optimal cell growth for defined chicken stem cells cultures and use in future manufacturing applications. [ABSTRACT FROM AUTHOR]

Mycoplasma gallisepticum (MG) is a bacterial pathogen that causes production losses in layer chickens. To combat MG, multiage layer facilities vaccinate pullets by either spray or eye-drop vaccination. The objective in this study was to evaluate the use of in ovo vaccination as a potential alternative for MG vaccination. Layer embryos at 18 d of incubation were either not-injected (control), or were hand-injected with either commercial Marek's disease vaccine diluent alone or with a high, medium, low, or very low dosage of a live attenuated strain F (FMG) vaccine suspended in the commercial diluent. Hatch success and residual egg embryonic mortality were determined after 23 d of incubation. Six hatched chicks per treatment were swabbed for the detection of FMG at 4 different sites (trachea, mouth and esophagus, yolk sac membrane, and the lumen of the duodenal loop) via real-time PCR. Embryos were found to be administered 106 CFU per dose in the high treatment, 104 CFU/dose in the medium treatment, 102 CFU/dose in the low treatment, and between 5.06 and 5.93 CFU/dose in the very low treatment. Hatch of embryonated eggs was decreased by the medium and high doses (P = 0.02). These embryos died while pipping. No FMG was detected in the control and diluent-injected chicks. In the FMG treatments, FMG was found in all sites and dosages, with a greater number of positive chicks found in the higher FMG dosage treatments. These findings indicate the potential practicality of vaccinating layer embryos with FMG by in ovo injection based on the observed hatch success at lower dosages. Also, once injected into the amnion, the bacteria are present in the upper respiratory and gastrointestinal tracts as well the yolk sac membrane and the small intestine of hatchlings. Future research will need to ascertain the effects of FMG administered by in ovo injection on posthatch immunity and mortality. [ABSTRACT FROM AUTHOR]

Contents In the mammalian ovary, aquaporins ( AQPs) are thought to be involved in the regulation of fluid transport within the follicular wall and antrum formation. Data concerning the AQPs in the avian ovary is very limited. Therefore, the present study was designed to examine whether the AQP4 is present in the chicken ovary, and if so, what is its distribution in the ovarian compartment of the laying hen. Localization of AQP4 in the ovarian follicles at different stage of development was also investigated. After decapitation of hens the stroma with primordial follicles and white (1-4 mm), yellowish (4-8 mm), small yellow and the three largest yellow pre-ovulatory follicles F3-F1 (F3 < F2 < F1; 20-36 mm) were isolated from the ovary. The granulosa and theca layers were separated from the pre-ovulatory follicles. The AQP4 mRNA and protein were detected in all examined ovarian compartments by the real-time PCR and Western blot analyses, respectively. The relative expression of AQP4 was depended on follicular size and the layer of follicular wall. It was the lowest in the granulosa layer of pre-ovulatory follicles and the highest in the ovarian stroma as well as white and yellowish follicles. Along with approaching of the largest follicle to ovulation the gradual decrease in AQP4 protein level in the granulosa layer was observed. Immunoreactivity for AQP4 was present in the granulosa and theca cells (theca interna ≥ theca externa > granulosa). The obtained results suggest that AQP4 may take part in the regulation of water transport required for follicle development in the chicken ovary. [ABSTRACT FROM AUTHOR]

Few researchers have investigated the direction of commissural axon projections on the contralateral side of the vertebrate embryonic spinal cord, especially for comparison between its different regions. In this study, pCAGGS-GFP plasmid expression was limited to different regions of the chicken embryonic spinal cord (cervical, anterior limb, anterior thorax, posterior thorax and posterior limb) at E3 using in ovo electroporation with modified electrodes and optimal electroporation conditions. Then open-book technique was performed at E6 to analyze the direction of axon projections in different spinal cord regions. The results show that in the five investigated regions, most axons projected rostrally after crossing the floor plate while a minority projected caudally. And there was a significant difference between the rostral and caudal projection quantities ( P < 0.01). The ratio of rostral and caudal projections was significantly different between the five investigated regions ( P < 0.05), except between the cervical region and the anterior limb ( P > 0.05). The projections were most likely to be rostral for the posterior limb followed by the posterior thorax, cervical region, anterior limb and anterior thorax. Our data for the direction of the commissural axon projections will be helpful in the future analyses of axon projection mechanisms and spinal cord-brain circuit formation. [ABSTRACT FROM AUTHOR]

In amniotes, the amniotic fluid is a significant contributor to fetal development and health. While numerous studies have been conducted in mammalian amniotic fluid, the composition of amniotic and other extraembryonic fluids in avian egg along with their physiological functions remain largely unexplored. In such a context, our objective was to characterize the chicken amniotic fluid (AmF) and allantoic fluid (AlF) properties, protein composition, and some associated functions from day 8 to day 16 of incubation. SDS-PAGE combined to mass spectrometry analysis revealed common and specific proteins to each fluid, suggesting distinct properties and functions. Indeed, major AlF proteins are mostly “egg yolk” proteins involved in lipid, vitamin metabolisms, and metal ion transport, while major AmF proteins resemble those of albumen. Drastic changes in the AmF protein profiles were observed during incubation, when the albumen transfers from day 12 onwards, while few changes were detected for the AlF protein profile. The decreases in osmolality (from 231 to 183 mOsm/kg) and pH (from 8.26 to 7.26) observed in the AlF during incubation are associated with water and electrolytes reallocation for the embryo needs. In contrast, AmF pH value remained stable (≈7.5). Active proteolytic enzymes have been identified in the 2 fluids using gelatin zymography, followed by mass spectrometry analysis for protease identification. A total of 12 proteases was detected in the AlF, compared to 5 in the AmF. We have shown that AlF concentrates proteolytic enzymes assumed to participate in digestive processes: aminopeptidase N, dipeptidyl peptidase-4, meprin A, and 72 kDa type IV collagenase preproprotein. The other proteases identified in both fluids also could have a role in morphogenesis (hepatocyte growth factor activator, suppressor of tumorigenicity 14, astacin-like metalloendopeptidase) and hemostasis (prothrombin and coagulation factor X). Altogether, these data suggest that the roles of chicken AlF and AmF are not merely associated with protection of the embryo and regulation of metabolic disposable wastes, but also they could have more sophisticated roles during embryonic development. [ABSTRACT FROM AUTHOR]

The present study was carried out in six indigenous ecotypes of two divisions of Karnataka to assess association of twenty microsatellite regions of thirteen chicken autosomes with age, body weight and egg weight at sexual maturity and Forty week egg production. The general molecular technique protocols were adopted wherever required in PCR, electrophoresis, gel staining and reading. The analysis revealed significant difference (p<0.05) among genotypes combined across ecotypes for nineteen microsatellite loci for body weight at sexual maturity. The analysis revealed significant difference (P<0.05) among genotypes combined across ecotypes for eighteen microsatellite loci for EWSM. The posthoc dunnet's test conducted in one of the microsatellite region ADL0020 genotypes after excluding genotypes with only one bird at 0.05 level of significance revealed that a particular genotype A was significantly different from two of the genotypes C and D, indicating the important role of the corresponding alleles of these genotypes in influencing the Body weight at sexual maturity. The validity of using thus identified markers or alleles need further authentication by research in other populations and further proof by expression studies. [ABSTRACT FROM AUTHOR]

The article focuses on the proteomic analysis of chicken skeletal muscle during embryonic growth and development. Topics discussed include impact of development of skeletal muscle on meat production in chicken; integrative analysis of the proteome and transcriptomes data; and proteomic expression profiling of embryonic muscle in chickens.

Environmental changes during perinatal development can affect the postnatal life. In this sense, chicken embryos that experience low levels of O 2 over a specific phase of incubation can have their tissue growth reduced and the ventilatory response to hypoxia blunted, at least until hatching. Additionally, exposure to low level of O 2 after birth reduces the thermogenesis as well. In the present study, we tested the hypothesis that hypoxia over the third week of incubation affects the thermoregulation of juvenile chicks at an age when thermogenesis is already expected to be well-developed. To this end, we measured body temperature (Tb) and oxygen consumption ( V ̇ 0 2 ) under acute hypoxia or different ambient temperatures (Ta) of 1 and 10 day-old chicks that have been exposed to 21% O2 for entire incubation (Nx) or to 15% O 2 in the last week of incubation (Hx). We also assessed the thermal preference under normoxia or acute hypoxia of the older chicks from both incubation groups in a thermocline. Hypoxia over incubation reduced growth but did not affect the cold-induced thermogenesis in hatchlings. Regarding the juvenile Hx, present data indicate a catch up growth with higher resting V ̇ 0 2 , a thermal preference for warmer Tas and a possible higher thermal conductance. In conclusion, our results show that hypoxia over the third week of incubation can affect the thermoregulation at least until 10 days after hatch in chickens. [ABSTRACT FROM AUTHOR]

The metanephric kidneys of the chicken embryo, along with the chorioallantoic membrane, process water and ions to maintain osmoregulatory homeostasis. We hypothesized that changes in relative humidity (RH) and thus osmotic conditions during embryogenesis would alter the developmental trajectory of embryonic kidney function. White leghorn chicken eggs were incubated at one of 25–30% relative humidity, 55–60% relative humidity, and 85–90% relative humidity. Embryos were sampled at days 10, 12, 14, 16, and 18 to examine embryo and kidney mass, glomerular characteristics, body fluid osmolalities, hematological properties, and whole embryo oxygen consumption. Low and especially high RH elevated mortality, which was reflected in a 10–20% lower embryo mass on D18. Low RH altered several glomerular characteristics by day 18, including increased numbers of glomeruli per kidney, increased glomerular perfusion, and increased total glomerular volume, all indicating potentially increased functional kidney capacity. Hematological variables and plasma and amniotic fluid osmolalities remained within normal physiological values. However, the allantoic, amniotic and cloacal fluids had a significant increase in osmolality at most developmental points sampled. Embryonic oxygen consumption increased relative to control at both low and high relative humidities on Day 18, reflecting the increased metabolic costs of osmotic stress. Major differences in both renal structure and performance associated with changes in incubation humidity occurred after establishment of the metanephric kidney and persisted into late development, and likely into the postnatal period. These data indicate that the avian embryo deserves to be further investigated as a promising model for fetal programming of osmoregulatory function, and renal remodeling during osmotic stress. [ABSTRACT FROM AUTHOR]

Studies on the yolk and albumen content in bird eggs, and the effects of variations in their relative loads in the phenotype of the birds, have revealed multiple consequences at different levels of biological organization, from biochemical traits to behavior. However, little is known about the effect of albumen variation on energetics performance during development and early ontogeny, despite the fact that variation in energy expenditure may have consequences in terms of fitness for both feral and domestic species. In this work, we evaluated experimentally whether variations in the content of albumen of Gallus gallus eggs could generate differences in metabolic rates during embryonic development. Additionally, we assessed changes in the activity of mitochondrial enzymes (cytochrome c oxidase and citrate synthase) in skeletal muscles and liver. Finally, we evaluated the success of hatching of these embryos and their metabolic rates (MR) post-hatching. The results revealed a significant reduction in MR in the last fifth of embryonic life, and reduced catabolic activities in the skeletal muscle of chicks hatched from albumen-removed eggs. However, the same group demonstrated an increase in catabolic activity in the liver, suggesting the existence of changes in energy allocation between tissues. Besides, we found a decrease in hatching success in the albumen-removed group, suggesting a negative effect of the lower albumen content on eggs, possibly due to lower catabolic activities in skeletal muscle. We also found a compensatory phenomenon in the first week after hatching, i.e., birds from albumen-removed eggs did not show a decrease in MR either at thermoneutral temperatures or at 10°C, compared to the control group. Collectively, our data suggest that a reduction in albumen may generate a trade-off between tissue metabolic activities, and may explain the differences in metabolic rates and hatching success, supporting the immediate adaptive response (IAR) hypothesis. [ABSTRACT FROM AUTHOR]

Pluripotent cells emerging at very early stages of development are the founders of differentiated cells. It has been established in mouse that the LIF/Jak/Stat-Nanog axis acts as a positive regulator to support the pluripotent state of cells whereas Fgf/Erk signaling acts as a negative regulator to direct cells to enter the differentiating state. In chicken, although Fgf/Erk signaling is known to act as a negative regulator, positive regulators remained unknown. Here, to identify positive regulator(s) of chicken pluripotency, we selected Jak1/Stat3 signaling as a candidate based on transcriptome analyses. Jak1/Stat3 signaling was activated specifically at stages before gastrulation: Stat3 protein was localized in nuclei at blastodermal stages, but translocated to cytoplasm after gastrulation. We conducted pharmacological and gene transfection analyses in the blastoderm-derived colony formation assay, in which Nanog-positive dense colonies represent a hallmark of the undifferentiated state, and found that Jak1/Stat3 signaling supports pluripotency in chicken early embryos. Jak1 inhibition abolished the formation of dense colonies, but the colony formation was restored when Stat3ER was artificially activated. We propose that the molecular mechanisms regulating pluripotency are conserved at the signaling network level between mouse and chicken, and possibly among a wider range of species. [ABSTRACT FROM AUTHOR]

This paper presents the effects of the forage, "FARMAVET COMPLETE FEED FOR POULTRY. CRUMBLED" on embryonic development in chickens of species Gallus gallus by 6 days. The effects of this forage are tracked by quantifying the size and respectively weight, of the embryos of this species compared to 3 different groups of embryos: Control, Treated with Alcohol 20% and Treated with hidroalcolic extract of forage studied. There is a slight increase in size and weight of the embryos treated with hydro-alcoholic extract compared to other two groups of embryos, but not statistically significant. [ABSTRACT FROM AUTHOR]

Monochromatic green light-emitting diodes (LED) light stimuli influences the posthatch growth performance of chicks. This study was undertaken with the following objectives: i) to examine whether the green LED light stimuli induces an overheating effect by determining weight loss rate of fertile eggs during incubation period; ii) to look for the development of eyes and other primary organs at different ages of embryos and newly hatched chicks. Arbor Acres fertile broiler eggs (n = 480) were randomly assigned to 3 incubation groups and exposed to continuous white light, green light, or a dark environment (control) from the first day to 19 d of incubation. The light sourced from LED lamps with the intensity of 30 lx at eggshell level. The results showed that either green or white light stimuli during incubation did not significantly affect the weight loss rate of fertile eggs, hatching time, hatchability, chick embryo, or body weight (BW), the weight percentage of heart, liver, and eyes, as well as obvious systematic abnormalities in eye weight, side-toside, back-to-front, or corneal diameter from 15 d of embryogenesis to 6 d of posthatch (p>0.05). Compared with the dark condition, green light stimuli during incubation tended to increase feed intake (p = 0.080), improved the BW gain of chicks during 0 to 6 day posthatch (p<0.05), and increased the percentage of pectoral muscle to the BW on 3- and 6-day-old chicks. In addition, embryos or chicks in green light had lower weight percentage of yolk retention on 19 d of embryogenesis and 1 d of posthatch in comparison to those in dark or white group (p<0.05). These results suggest that providing 30 lx green LED light stimuli during incubation has no detrimental effect on the development of eyes, heart and liver of embryos and hatchlings, but does have potential benefits in terms of enhancement of the chick growth during the early posthatch stages. In addition, the fertile broiler eggs stimulated with 30 lx green LED light during incubation does not cause an overheating effect. [ABSTRACT FROM AUTHOR]

Canonical Wnt-signalling is well understood and has been extensively described in many developmental processes. The regulation of this signalling pathway is of outstanding relevance for proper development of the vertebrate and invertebrate embryo. Axin2 provides a negative-feedback-loop in the canonical Wnt-pathway, being a target gene and a negative regulator. Here we provide a detailed analysis of the expression pattern in the development of the chicken embryo. By performing in-situ hybridization on chicken embryos from stage HH 04+ to HH 32 we detected a temporally and spatially restricted dynamic expression of Axin2. In particular, data about the expression of Axin2 mRNA in early embryogenesis, somites, neural tube, limbs, kidney and eyes was obtained. [ABSTRACT FROM AUTHOR]

Aim: This research was conducted to determine the most affecting parameters on hatchability of indigenous and improved local chickens' eggs. Materials and Methods: Five parameters were studied (fertility, early and late embryonic mortalities, shape index, egg weight, and egg weight loss) on four strains, namely Fayoumi, Alexandria, Matrouh, and Montazah. Multiple linear regression was performed on the studied parameters to determine the most influencing one on hatchability. Results: The results showed significant differences in commercial and scientific hatchability among strains. Alexandria strain has the highest significant commercial hatchability (80.70%). Regarding the studied strains, highly significant differences in hatching chick weight among strains were observed. Using multiple linear regression analysis, fertility made the greatest percent contribution (71.31%) to hatchability, and the lowest percent contributions were made by shape index and egg weight loss. Conclusion: A prediction of hatchability using multiple regression analysis could be a good tool to improve hatchability percentage in chickens. [ABSTRACT FROM AUTHOR]

The aim of the present study was to examine the role and interrelationships between calorie restriction and obestatin in the control of hormone release by chicken ovarian tissue. For this purpose, we compared the release of progesterone (P), testosteron (T), estradiol (E), and arginine-vasotocin (AVT) by ovarian fragments isolated from chicken subjected and not subjested to food restriction, as well as the response of these ovarian fragments to obestatin additions. It was observed that food restriction promoted release of P, reduced output of T, but did not affect basal E and AVT release. Obestatin addition reduced E, promoted AVT, and did not alter P and T release by ovarian tissue isolated from ad libitum fed chicken. In ovarian fragments of fasted hens it reduced E, promoted T, and did not influence P and AVT release. The present observations demonstrate (1) that obestatin can directly control the release of avian ovarian hormones – regulators of reproduction, (2) that metabolic state can control the release of these hormones, and (3) metabolic state can alter the response of ovarian hormones to obestatin. [ABSTRACT FROM AUTHOR]

Retinal growth hormone (GH) has been shown to promote cell survival in retinal ganglion cells (RGCs) during developmental waves of apoptosis during chicken embryonic development. The possibility that it might also against excitotoxicity-induced cell death was therefore examined in the present study, which utilized quail-derived QNR/D cells as an in vitro RGC model. QNR/D cell death was induced by glutamate in the presence of BSO (buthionine sulfoxamide) (an enhancer of oxidative stress), but this was significantly reduced ( P < 0.01) in the presence of exogenous recombinant chicken GH (rcGH). Similarly, QNR/D cells that had been prior transfected with a GH plasmid to overexpress secreted and non-secreted GH. This treatment reduced the number of TUNEL-labeled cells and blocked their release of lactate dehydrogenase (LDH). In a further experiment with dissected neuroretinal explants from ED (embryonic day) 10 embryos, rcGH treatment of the explants also reduced ( P < 0.01) the number of glutamate-BSO-induced apoptotic cells and blocked the explant release of LDH. This neuroprotective action was likely mediated by increased STAT5 phosphorylation and increased bcl-2 production, as induced by exogenous rcGH treatment and the media from GH-overexpressing QNR/D cells. As rcGH treatment and GH-overexpression cells also increased the content of IGF-1 and IGF-1 mRNA this neuroprotective action of GH is likely to be mediated, at least partially, through an IGF-1 mechanism. This possibility is supported by the fact that the siRNA knockdown of GH or IGF-1 significantly reduced QNR/D cell viability, as did the immunoneutralization of IGF-1. GH is therefore neuroprotective against excitotoxicity-induced RGC cell death by anti-apoptotic actions involving IGF-1 stimulation. [ABSTRACT FROM AUTHOR]

BACKGROUND Copper (Cu) is a key trace mineral involved in a variety of physiological processes, and is commonly used in poultry production. However, regardless of the inclusion level the majority of Cu is excreted with poultry faeces. We hypothesise that in ovo administration will allow for better utilisation of Cu during embryo development than when supplied post-natally with feed to growing chickens. Thus, the objective of this study was to evaluate effects of in ovo administration of NanoCu and copper sulfate ( CuSO4) on broiler chicken performance. RESULTS The study showed the positive influences of Cu nanoparticles and CuSO4 on broiler chickens performance. Body weight, at the end of the rearing period (day 42) was significantly higher in NanoCu (2206 g) and CuSO4 (2402 g) groups compared to the control group (2000 g). Both treatment groups had significantly lower feed conversion rate and mortality, and higher percentage of breast and leg muscles in the carcass versus control. CONCLUSION The in ovo application of Cu colloids may ensure an efficient penetration of Cu into the embryonic tissue with long lasting effects on postnatal growth. The method may provide a successful alternative to using Cu as a feed additive. © 2015 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The uptake and transport of ions from the environment to the site of bone formation is only partially understood and, for the most part, based on disparate observations in different animals. Here we study different aspects of the biomineralization pathways in one system, the rapidly forming long bones of the chicken embryo. We mainly used cryo-fixation and cryo-electron imaging to preserve the often unstable mineral phases in the tissues. We show the presence of surprisingly large amounts of mineral particles located inside membrane-delineated vesicles in the bone forming tissue between the blood vessels and the forming bone surface. Some of these particles are also located inside mitochondrial networks. The surfaces of the forming bones in the extracellular space contain abundant aggregates of amorphous calcium phosphate particles, but these are not enveloped by vesicle membranes. In the bone resorbing region, osteoclasts also contain many particles in both mitochondrial networks and within vesicles. Some of these particles are present also between cells. These observations, together with the previously reported observation that CaP mineral particles inside membranes are present in blood vessels, leads us to the conclusion that important components of the bone mineralization pathways in rapidly forming chicken bone are dense phase mineral particles bound within membranes. It remains to be determined whether these mineral particles are transported to the site of bone formation in the solid state, fluid state or dissolve and re-precipitate. [ABSTRACT FROM AUTHOR]

Chicken serum has been suggested as a supplement to promote chicken cell proliferation and development. However, the molecular mechanisms by which chicken serum stimulates chicken cell proliferation remain unknown. Here, we evaluated the effects of chicken serum supplementation on chicken embryo fibroblast (CEF) and DF-1 cell proliferation. We also sought to elucidate the molecular pathways involved in mediating the effects of chicken serum on fibroblasts and DF-1 cells by overexpression of chicken 78 kDa glucose-regulated protein (chGRP78), which is important for cell growth and the prevention of apoptosis. Our data demonstrated that the addition of 5% chicken serum significantly enhanced fibroblast proliferation. Moreover, knockdown of chGRP78 using siRNA decreased fibroblast proliferation and increased apoptosis. Based on these results, we suggest that the chGRP78-mediated signaling pathway plays a critical role in chicken serum-stimulated fibroblast survival and antiapoptosis. Therefore, our findings have important implications for the maintenance of chicken fibroblast cells through the inhibition of apoptosis and may lead to the development of new treatments for avian disease. [ABSTRACT FROM AUTHOR]

To investigate the effect of inhibin gene immunization on antibody production and reproductive performance in broiler breeder females, Partridge Shank hens aged 380 days were immunized with inhibin recombinant plasmid pcISI. One hundred and twenty hens were randomly assigned to four groups and treated intramuscularly with 25, 75, or 125 μg/300-μL inhibin recombinant plasmid pcISI (T1∼T3) or 300-μL saline as control (C), respectively. Booster immunization was given with the same dosage 20 days later. Blood and egg samples were collected to detect the antibody against inhibin by enzyme-linked immunosorbent assay and to evaluate egg performance. The ovaries were collected to classify the follicles and detect the FSH receptor (FSHR) messenger RNA (mRNA) expression by reverse transcription-PCR. The results showed that immunization against pcISI could elicit antibody against inhibin in both plasma and egg yolk compared with the control (P < 0.05), whereas booster immunization did not increase the antibody level in plasma. Vaccination promoted egg lay during the first 30 days after primary vaccination (P < 0.05) with no effect on egg quality and hatching rate. Immunization increased the amounts of dominant, small yellow and large white follicles in the ovary (P < 0.05). Reverse transcription-PCR results showed that immunization increased the FSHR mRNA in the large white follicles, whereas decreased the FSHR mRNA in the small yellow follicles (P < 0.05). In conclusion, inhibin vaccine pcISI can stimulate the production of antibody against inhibin as well as the follicle development and egg laying performance in Partridge Shank hens, which provides a good foundation for the application of inhibin DNA vaccine in avian production. [ABSTRACT FROM AUTHOR]

The present experiment was carried out at El-Sabahia Poultry Research Station, Animal Production Research Institute with aiming to study the effect of chicken strain {Mandarah (M) and Gimmizah (G)}besides egg storage time (1-4 and 5-8 days) on eggshell conductance (GH2O) (mgH2O/d/torr) and eggshell conductance constant (K) and their relations with embryonic intestinal function, hatching success, some related physiological parameters and post-hatch growth. The obtained results are summarized as follows: 1. Gimmizah chickens had higher significant records compared to Mandarah ones for egg weight loss % during setting phase, hatch time and eggshell conductance. 2. Eggs stored for 5-8 days represented significant increase for egg weight loss %, GH2O, hatch time and K conductance except that for initial egg weight before incubation compared with those stored for 1-4 days. 3. Embryonic mortality during incubation was significantly increased for eggs stored for longer period compared with shorter one. Whereas, hatchability percentage, chick body weight, relative intestinal weight, lengths of duodenum, jejunum and ileum and jejunum maltase enzyme value were significantly increased for shorter period compared with longer one. 4. Relative liver weights and glycogen value were increased (P≤0.05) for embryos and hatched chicks produced from egg stored for 1-4 days compared with those stored for 5- 8 days. 5. Triiodothyronine hormone was decreased (P≤0.05) for embryos and baby chicks with the increase of storage time. 6. The results proved that longer storage period even with short period of increase had a determintal effect on K and consequently intestinal function, hatchability percentage, liver glycogen, energy availability, T3 hormone, chick body weight and post-hatch growth. [ABSTRACT FROM AUTHOR]

Cranial neural crest cells form the majority of the facial skeleton. However exactly when the pattering information and hence jaw identity is established is not clear. We know that premigratory neural crest cells contain a limited amount of information about the lower jaw but the upper jaw and facial midline are specified later by local tissue interactions. The environmental signals leading to frontonasal identity have been explored by our group in the past. Altering the levels of two signaling pathways (Bone Morphogenetic Protein) and retinoic acid (RA) in the chicken embryo creates a duplicated midline on the side of the upper beak complete with egg tooth in place of maxillary derivatives ( Lee et al., 2001 ). Here we analyze the transcriptome 16 h after bead placement in order to identify potential mediators of the identity change in the maxillary prominence. The gene list included RA, BMP and WNT signaling pathway genes as well as transcription factors expressed in craniofacial development. There was also cross talk between Noggin and RA such that Noggin activated the RA pathway. We also observed expression changes in several poorly characterized genes including the upregulation of Peptidase Inhibitor-15 (PI15). We tested the functional effects of PI15 overexpression with a retroviral misexpression strategy. PI15 virus induced a cleft beak analogous to human cleft lip. We next asked whether PI15 effects were mediated by changes in expression of major clefting genes and genes in the retinoid signaling pathway. Expression of TP63, TBX22, BMP4 and FOXE1 , all human clefting genes, were upregulated. In addition, ALDH1A2, ALDH1A3 and RA target, RARβ were increased while the degradation enzyme CYP26A1 was decreased. Together these changes were consistent with activation of the RA pathway. Furthermore, PI15 retrovirus injected into the face was able to replace RA and synergize with Noggin to induce beak transformations. We conclude that the microarrays have generated a rich dataset containing genes with important roles in facial morphogenesis. Moreover, one of these facial genes, PI15 is a putative clefting gene and is in a positive feedback loop with RA. [ABSTRACT FROM AUTHOR]

Thermal manipulation during embryogenesis has been shown to improve thermo tolerance in broilers. Heat shock proteins are a family of proteins produced in response to variety of stress and protect cells from damage. The aim of this study was to evaluate the effect of thermal manipulation (TM) during embryogenesis on HSP gene and protein expression in the embryos and in chronic heat stressed 42nd day old chicks. On 15th day of incubation, fertile eggs from two breeds-Naked neck (NN) and Punjab Broiler-2 (PB-2) were randomly divided in to two groups, namely Control (C) eggs were incubated under standard incubation conditions and Thermal Conditioning (TC) eggs were exposed to higher incubation temperature (40.5 °C) for 3 h on 15th, 16th and 17th day of incubation. The chicks so obtained from each group were further subdivided and reared from 15th–42nd day as normal (N; 25±1 °C, 70% RH) and heat exposed (HE; 35±1 °C, 50% RH) resulting in four treatment groups (CN, CHE, TCN and TCHE). Embryos of two groups (C and TC) on 17th day and birds from four treatment groups on 42nd day were sacrificed. Liver was collected for analysis of gene expression by real-time PCR and protein expression by Western blot of Heat Shock Proteins ( HSP 90 alpha, HSP 90 beta, HSP 70, HSP 60, HSP 27 and ubiquitin ). The plasma collected on 42nd day was analyzed for biochemical parameters. Thermal challenging of embryos of both the breeds caused significant ( P ≤0.05) increase in all the HSPs gene and protein expression. The TCHE chicks had significantly ( P ≤0.05) lower HSPs gene and protein expressions and oxidative stress compared to CHE groups in both NN and PB-2. Based on these findings it can be concluded that TM during incubation provides adaptation to broiler chicks during chronic heat stress. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the effects of dietary selenium (Se) supplementation on apoptosis of germ cells in the testis during spermatogenesis in roosters. Eighty 12-week-old Hy-Line Variety white roosters with an averaged body weight of 1.38 ± 0.2 kg were selected and randomly divided into four experimental groups. They were fed the basal diet (0.044 mg/kg Se dry matter) supplemented with 0 (control), 0.5, 1.0, or 2.0 mg/kg of Se dry matter (from sodium selenite). After the 45-day feeding experiment, testis samples were collected from the roosters of each treatment group to detect the population of apoptotic germ cells using the terminal deoxynucleotidy1 transferase dUTP nick end labeling assay. The protein expression of cell cycle–related genes and the messenger RNA (mRNA) expression of apoptosis and cell cycle–related genes had also been detected. The results show that the population of apoptotic germ cells in the control and 2.0 mg/kg groups was increased (P < 0.05) compared with that in the 0.5 mg/kg and 1.0 mg/kg groups. Expressions of CDC2 and CCNB1 protein in the control and 2.0 mg/kg groups were lower (P < 0.05) than those in the 0.5 mg/kg and 1.0 mg/kg groups. The mRNA level of CDC2 in the 0.5 mg/kg group was higher (P < 0.05) than that in other groups. The lowest (P < 0.05) mRNA expressions of apoptosis-related genes ( BCL-2 , CASPASE 3 , CASPASE 8 ) were also obtained in the 0.5 mg/kg group. These results show that dietary Se of roosters can affect apoptosis of germ cells by regulating the mRNA expressions of apoptosis- and cell cycle–related genes in the testis during spermatogenesis. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the infectivity of Toxocara canis eggs after interacting with isolated nematophagous fungi of the species Duddingtonia flagrans (AC001) and Pochonia chlamydosporia (VC4), and test the predatory activity of the isolated AC001 on T. canis second stage larvae after 7 days of interaction. In assay A, 5000 embryonated T. canis eggs previously in contact with the AC001 and VC4 isolated for 10 days were inoculated into domestic chickens ( Gallus gallus domesticus), and then these animals were necropsied to collect material (digested liver, intestine, muscles and lungs) at 3-, 7-, 14-, and 21-day intervals after inoculation. In assay A, the results demonstrated that the prior interaction of the eggs with isolated AC001 and VC4 decreases the amount of larvae found in the collected organs. Difference ( p < 0.01) was observed in the medium larvae counts recovered from liver, lung, intestine, and muscle of animals in the treated groups when compared to the animals in the control group. At the end of assay A, a percentage reduction of 87.1 % (AC001) and 84.5 % (VC4) respectively was recorded. In the result of assay B, the isolated AC001 showed differences ( p < 0.01) compared to the control group, with a reduction of 53.4 % in the recovery of L. Through these results, it is justified to mention that prior interaction of embryonated T. canis eggs with the tested fungal isolates were efficient in reducing the development and migration of this parasite, in addition to the first report of proven predatory activity on L. [ABSTRACT FROM AUTHOR]

During the catching of broilers for slaughter, 2 to 3 birds are grabbed per hand at one leg at the same time. From an animal welfare point of view, this procedure is under critical observation from animal welfare administration and the general public. In this paper 2 catching methods were compared: the routinely used 1-leg catching method, and a second technique whereby birds were grabbed by both legs with a maximum of 2 birds per hand (2-leg catching method). Lesions on the body, legs, and wings (hemorrhages and fractures) were recorded by a camera system located after the plucking position. Two weight classes, 2 catching teams, and 2 flocks were included in the study. Heavy animals showed more lesions than birds of the light weight class. In all investigations, lesions on the body and legs were rare, whereas wing lesions occurred at a rate of up to 15.32%. Statistical analysis showed no significant difference between the 2 methods or between the catching teams for both weight classes. A correlation between lesions and weight was observed, with a significant odds ratio (OR) of 3.6 (95% CI: 3.299- 3.957). During 2-leg catching, the animals appeared to be more restless. Workers stated that the grabbing of both legs of a bird was more difficult and that working in a crouching position for a longer time was harder. We conclude that the cautious handling of animals to reduce stress is more important than "holding animals by both legs", as has been proposed. [ABSTRACT FROM AUTHOR]

The objective of this research was to determine the optimal level of an encapsulated butyric acid (ButiPEARL) based on the performance of male Cobb broilers reared to 42 d of age and to investigate its effects on intestinal morphology. Experiment 1 (EXP 1) consisted of 4 treatments with 12 replicate pens that contained 45 broilers, and Experiment 2 (EXP 2) consisted of 6 treatments with 8 replicate pens that contained 50 broilers. Birds were weighed by pen on d 0, 21, 35, and 42. In EXP 1, the treatments were as follows: 1) control (C); 2) C + 100 g Buti- PEARL/ton; 3) C + 200 g ButiPEARL/ton; and 4) C + 300 g ButiPEARL/ton. In EXP 2, the treatments were identical to EXP 1, with 2 additional treatments: 5) C + 400 g ButiPEARL/ton and 6) C + 500 g Buti- PEARL/ton. In EXP 1, two 42-d-old broilers per pen were randomly selected for duodenal and jejunal tissue collection. Only the samples from the broilers fed the C or 300 g ButiPEARL treatments were analyzed for histology in EXP 1. For EXP 2, on d 21 and 35, two broilers per pen were randomly selected for duodenal, jejunal, and ileal tissue collection. For EXP 1 and 2, BW gain increased linearly with increasing butyric acid levels (P < 0.027 and P < 0.001, respectively). For EXP 1 and 2, feed conversion linearly improved with increasing butyric acid from 0 to 42 d (P < 0.001 and P < 0.001, respectively). In EXP 1, there were no differences in any intestinal morphology at 42 d between broilers fed the C or 300 g ButiPEARL treatments. In EXP 2, there were no differences in villus height at 21 or 35 d of age with any level of butyric acid. Based on the results of this research related to BW gain and feed conversion, the recommended optimum dosage level for ButiPEARL in broilers reared to 42 d of age is up to 500 g/ton. [ABSTRACT FROM AUTHOR]