ABSTRACT
The antioxidant protection of the chicken (Gallus gallus) embryo during incubation and early postnatal development plays an important role in chick viability. To assess the antioxidant capacity of the newly hatched chick, we determined the concentrations of vitamin A, vitamin E, carotenoids and coenzyme Q10 in the major tissues of chicks which had been held in an incubator for up to 36 h post-hatch. Concentrations of total carotenoids and free retinol and retinol esters in the tissues did not differ significantly over the 36 h period post-hatch (p>0.05). In contrast concentrations of vitamin E (α-tocopherol, γ-tocopherol, and α-tocotrienol and γ-tocotrienol) in various tissues (liver, heart, brain and leg muscle) decreased significantly in chicks that had been held in the incubator for 36 h when compared to younger chicks that were held for up to 18 h. Comparatively high concentrations of coenzyme Q10 were detected in the yolk sac membrane, liver and heart, the concentrations being dependent on age of chicks, the highest value being recorded 18 h post-hatch. In most of the tissues studied, coenzyme Q10 concentrations decreased substantially between 18 and 36 h post-hatch. This study demonstrated that there are tissue-specific changes in the concentrations of the major antioxidants (vitamin E and coenzyme Q10) during the 36 h post-hatch.
Subject(s)
Antioxidants/metabolism , Chickens/metabolism , Ubiquinone/analogs & derivatives , Vitamin E/metabolism , Age Factors , Animals , Body Weight , Carotenoids/metabolism , Cell Membrane/metabolism , Chromatography, High Pressure Liquid/methods , Incubators , Liver/metabolism , Time Factors , Ubiquinone/metabolism , Vitamin A/metabolism , Yolk Sac/metabolismABSTRACT
A cDNA encoding a 174-amino-acid orthologue of a tick histamine release factor (HRF) was identified from the haematophagous poultry red mite Dermanyssus gallinae. The predicted D. gallinae HRF protein (Dg-HRF-1) sequence is highly conserved with the tick HRFs (identity 52-54%) and to a lesser degree with translationally controlled tumour proteins (TCTP) from mammals and other invertebrates (range 38-47%). Phylogenetically, Dg-HRF-1 partitions with the tick HRF clade suggesting a shared linage and potentially similar function(s). A recombinant Dg-HRF-1 protein (rDg-HRF-1) was produced and shown to induce degranulation of rat peritoneal mast cells in vitro, confirming conservation of the histamine-releasing function in D. gallinae. Polyclonal antibodies were generated in rabbits and hens to rDg-HRF-1. Western blotting demonstrated that native Dg-HRF is a soluble protein and immunohistochemical staining of mite sections revealed that the distribution of Dg-HRF, although ubiquitous, is more common in mite reproductive, digestive and synganglion tissues. A survey of hens housed continuously in a mite-infested commercial poultry unit failed to identify IgY specific for recombinant or native Dg-HRF, indicating that Dg-HRF is not exposed to the host during infestation/feeding and may therefore have potential as a vaccine using the concealed antigen approach. To test the protective capability of rDg-HRF-1, fresh heparinised chicken blood was enriched with yolk-derived anti-Dg-HRF IgY antibodies and fed to semi-starved mites using an in vitro feeding system. A statistically significant increase in mortality was shown (P=0.004) in mites fed with anti-Dg-HRF IgY after just one blood meal. The work presented here demonstrates, to our knowledge for the first time, the feasibility of vaccinating hens with recombinant D. gallinae antigens to control mite infestation and the potential of rDg-HRF-1 as a vaccine antigen.
Subject(s)
Biomarkers, Tumor/immunology , Histamine Release , Mites/immunology , Poultry Diseases/immunology , Allergens/immunology , Animals , Blotting, Western/veterinary , Chickens/parasitology , DNA, Complementary/analysis , Eggs/parasitology , Immunohistochemistry , Mite Infestations/veterinary , Molecular Sequence Data , Poultry Diseases/prevention & control , Rabbits , Rats , Tumor Protein, Translationally-Controlled 1ABSTRACT
The aim of this study was to evaluate carotenoid and vitamin E distribution in egg and tissues of newly hatched chicks from wild mallard (Anas platyrhynchos), game pheasant (Phasianus colchicus), free-range guinea fowl (Numida meleagris), hen (Gallus domesticus) and domestic duck (Anas platyrhynchos) and intensively housed hens. Carotenoid concentrations in the egg yolk of free-range guinea fowl, pheasant and wild mallard were similar (61.3-79.2 microg/g). Egg yolks from ducks and intensively housed hens were characterised by the lowest carotenoid concentration comprising 11.2-14.8 microg/g. However, carotenoid concentration in eggs from free-range ducks and hens was less than half of that in free-range guinea fowl or pheasant. Depending on carotenoid concentration in the livers of species studied could be placed in the following descending order: free living pheasant>free-range guinea fowl>>free-range hen>>intensively housed hen>wild mallard>>housed duck>free-range duck. The carotenoid concentrations in other tissues of free-range guinea fowl and pheasant were substantially higher than in the other species studied. Egg yolk of housed hens was characterised by the highest alpha- and gamma-tocopherol concentrations. In accordance with the alpha-tocopherol concentration in the egg yolk, the birds can be placed in the following descending order: intensively housed hen>wild mallard>free-living pheasant>free-range duck>free-range hen=free-range guinea fowl>housed duck. The main finding of this work is species- and tissue-specific differences in carotenoid and vitamin E distribution in the various avian species studied.
