Tissues Of Birds Research Articles

Total mercury in different egg tissues provides insights to mercury metabolisms in bird bodies

Mercury (Hg) pollution in birds has been widely reported, but the metabolism of Hg in bird bodies remains unclear. Measurement of Hg concentrations in bird tissues (muscles and organs) could provide insights into the metabolism of Hg in bird bodies, however, this approach is often invasive. To avoid invasive procedures, we conducted feeding experiments using chickens and used eggs as a proxy for understanding Hg metabolism in chicken bodies. For the control group, various THg concentrations were observed in egg whites, egg yolks, and eggshells, but the THg concentration trends for different egg tissues were not statistically different (P > 0.05). For the Hg feeding group (0.3 mg/kg body weight, feeding once), Hg peaks were observed in egg yolks and egg whites at different time periods, suggesting different response time to dietary Hg in chicken body tissues. Mercury in egg yolks peaked at Day 6, suggesting their quick response to dietary Hg. Egg whites reached Hg peak at Day 20, exhibiting a slower response to dietary Hg. Eggshells did not show a Hg peak, perhaps due to their predominant inorganic components that do not trigger Hg bioaccumulation. We measured THgyolk/THgwhite ratios in various chicken eggs purchased from three areas in Guizhou, SW China. The THgyolk/THgwhite ratios for Huaxi, Hezhang and Wuchuan were 1.33 (0.57–2.41), 7.89 (4.27–19.47) and 2.64 (1.68–4.22), respectively, to suggest different exposure history for chickens. This study provides new insights into the metabolism and lifetime of Hg in bird bodies.

Tissue distribution and association of heavy metal accumulation in a free-living resident passerine bird tree sparrow Passer montanus

Passerine birds have been increasingly used as effective sentinels of ecosystem contamination. They can provide direct evidence of the bioavailability and accumulation of heavy metal elements in the environment. In this study, the bioaccumulation of four heavy metals (Cu, Zn, Pb, and Cd) and Ca in different organs and tissues (feathers, internal organs, skeletons, and muscles) of an urban bird, tree sparrow (Passer montanus), collected from a polluted site [Baiyin (BY)] and a relatively unpolluted site [Liujiaxia (LJX)], and their associations were investigated. There were significantly higher and lower concentrations of heavy metals and Ca, respectively, in different organs and tissues of sparrows in BY than those in LJX. However, except for Pb, the heavy metal levels were below the threshold of sublethal effects. Age-dependent variations in metals were quantified, and it was found that adult bird contained higher concentration of different organs and tissue metals, except for feathers, compared with nestlings and juveniles. The tissue distribution of heavy metals in sparrows of different ages and sex was similar in the two study sites, and heavy metal elements were mainly accumulated in the feathers. This study further investigated the correlation between heavy metals in different organs and tissues and found that the correlations between them were strong in nestlings and adults but weak in juveniles. In addition, Pb and Cd in internal organs, skeletons, and muscles of young sparrows can be estimated using feathers, whereas Cu and Zn were found in adult sparrows. Altogether, our results suggest that tree sparrows will serve as valuable biomonitors of environmental heavy metal pollution and will underscore the importance of tissue types in avian ecotoxicology field studies.

Melatonin alleviates lead-induced intestinal epithelial cell pyroptosis in the common carps (Cyprinus carpio) via miR-17-5p/TXNIP axis

Lead (Pb) has been concerned as one of the most severe hazardous contaminants, because it can cause pyroptosis in multiple tissues of mammals and birds. Melatonin (Mel) has attracted much interest for its role in governing intestinal injury via microRNAs (miRNAs). To explore the effect of Mel on Pb exposure-induced intestinal epithelial cell pyroptosis in common carps by regulating miR-17-5p/TXNIP axis, the Pb exposure and Pb-Mel treated models were constructed in vivo. The results elucidated that the suppressed expression of miR-17-5p and intensified level of TXNIP were primarily detected in Pb-exposed gut tissues, and both abolished with Mel addition, along with downregulated Pb-mediated elevated expression of NLRP3, CASP1, IL1β and GSDMD. Additionally, the targeting relationship between miR-17-5p and TXNIP were demonstrated by dual-luciferase reporter assay, and on this basis, miR-17-5p NC, mimic and inhibitor cell models were established. Thereby, Thereby, the expression of TXNIP in the miR-17-5p mimic groups was significant lower in the Pb-exposure but still elevated than the Control group, and the expression of NLRP3 and NLRP3-dependent pyrotposis-related genes performed consistent alterations. Noticeably, the expression of TXNIP suppressed with Mel addition even in the miR-17-5p inhibitor cell model, resulting in the inactivation of NLRP3 inflammasome-dependent pyroptosis. Overall, we draw the conclusion as Mel attenuates Pb-induced intestinal epithelial cell pyroptosis via miR-17-5p/TXNIP axis. The present study provides a novel perspective for toxicological mechanism of Pb, and new insights for the detoxification mechanism of Mel.

Antioxidant capacity and lipid oxidative damage in muscle tissue of tropical birds

Las aves tropicales generalmente se ubican en el extremo “lento” del continuo de la historia de vida, y gran parte de su fisiología coincide con el equilibrio entre la vida útil y la reproducción. Por ejemplo, las aves demuestran tasas metabólicas basales (BMR) y tasas metabólicas máximas (PMR) de animal completo más bajas en comparación con las aves de clima templado y, a nivel celular, las aves tropicales también tienen tasas más bajas de consumo de oxígeno. El estrés oxidativo, un subproducto de la respiración aeróbica, aún no se ha dilucidado por completo para vincularlo a la teoría de la historia de vida. Sin embargo, trabajos previos sugieren que las aves tropicales pueden tener una capacidad antioxidante superior a las aves que viven en áreas templadas. En este estudio, utilizamos tejido muscular de 35 especies de aves tropicales para medir su capacidad antioxidante total (capacidad de captación de hidroxilo y capacidad de captación de peroxilo), la actividad de la enzima antioxidante catalasa (CAT), la superóxido dismutasa (SOD), la glutatión peroxidasa (GPx) y el daño de lípidos (LPO). Correlacionamos estas mediciones con la masa corporal y encontramos una correlación significativamente negativa entre la masa corporal y la LPO, y una correlación negativa marginalmente significativa con la capacidad de captación de hidroxilo. Curiosamente, también correlacionamos nuestras mediciones con mediciones de BMR encontradas en la literatura para 22 especies incluidas en nuestro estudio y no encontramos correlaciones. Una correlación negativa entre la masa corporal y el daño por LPO puede deberse a la estructura muscular celular, y al contenido y estructura mitocondrial dentro del músculo. Palabras clave: aves tropicales, estrés oxidativo, historia de vida, metabolismo basal, musculo.

First record and morphological contributions of Procyrnea leptoptera (Rudolphi, 1819) (Nematoda: Habronematidae) in the kestrel Falco tinnunculus Linnaeus (Falconiformes: Falconidae) from Egypt

BackgroundThe kestrel Falco tinnunculus, Linnaeus, 1758 is widely distributed in Europe, Asia, Africa, and East coast of North America. It is a predator species that belongs to family Falconidae. Nematode species of the genus Procyrnea infects the proventriculus and gizzard of the birds and may cause serious health hazards including inflammation, erosions, and ulcers for the infected gastric mucosa, general weakness and may lead to death. The present study aimed to improve the limited information regarding the endoparasites of Falco tinnunculus in Egypt.ResultsNine males and twenty-one female nematodes were identified as Procyrnea leptoptera, Rudolphi 1819, Chabaud 1958, isolated from the proventriculus of common kestrel; Falco tinnunculus gathered from El-Faiyum governorate, Cairo, Egypt, as a new geographical record. The isolated species has been studied morphologically by light and scanning electron microscopy. It was revealed that it is characterized by two lateral pseudolabia with dorsal and ventral labia. The pseudolabium is divided into 2 lobes at the internal side, a number of medium-size teeth (4–6) in the buccal cavity on the interior border of pseudolapia, in addition to the presence of transverse striations. Also, the histopathological effects of the isolated nematode on the liver of the infected host revealed severe damage in the bird's tissues and morphological alterations including infiltration of inflammatory cells, congestion, focal necrosis, and degeneration of hepatic cells.ConclusionsRaptors like Falco tinnunculus are infected with parasites via prey ingestion, so they are serving as intermediate hosts for many species of parasites. Due to the scarcity of studies for the helminth parasites of raptors in Egypt, further studies are needed to get additional precise data on the helminthic infection of raptors and their histopathological effects.

Alterations in connexin 43 gene and protein expression in the chicken oviduct following tamoxifen treatment

Connexins (Cxs) are a group of gap junction proteins involved in the direct exchange of small molecules between neighboring cells. Information concerning the expression and regulation of Cxs in the chicken oviduct is lacking, but likely has potential implications for functioning of the oviduct and the quality of the egg laid by commercially used hens. The present study was designed to examine whether selected Cxs are present in the chicken oviduct and, if so, whether expression of the most abundant Cx changes following tamoxifen (TMX; estrogen receptor modulator) treatment. Hy-Line Brown laying hens were injected (s.c.) daily with a vehicle (n = 6) or with TMX (n = 6), at a dose of 6 mg/kg of body weight for 7 days until complete cessation of egg laying by TMX-treated hens. All oviductal segments (infundibulum, magnum, isthmus, shell gland, and vagina) were collected from hens on day 8 of the experiment. First, the gene expression of GJA1 (i.e. Cx43 protein), GJA4 (Cx39), GJB1 (Cx32), and GJD2 (Cx36) was investigated by real-time PCR in tissues of control birds. The results demonstrated gene- and oviductal segment-dependent expression of GJB1, GJD2, GJA4, and GJA1 mRNA. Since the GJA1 transcript was the most abundant in all oviductal parts, subsequently, the Cx43 expression and localization were examined in the oviduct of all hens. The relative expression of GJA1 mRNA in control hens was highest in the infundibulum and vagina and lowest in the magnum. The pattern of Cx43 protein abundance evaluated by Western blot was similar to that of mRNA. Treatment of hens with TMX decreased the GJA1 mRNA levels in the magnum and isthmus, and Cx43 protein abundances were reduced in the isthmus and vagina. Immunofluorescence demonstrated cell- and segment-dependent localization of Cx43 protein in the oviductal wall; the most intense immunoreactivity was observed in the muscle cells of the shell gland and vagina. In TMX-treated hens, the immunoreactivity for Cx43 in all oviductal segments was slightly reduced and had a different signal pattern compared with control chickens. These results suggest that Cx43 likely takes part in the regulation of oviduct functioning, especially in the coordination of muscle contraction required for egg transport and oviposition. In addition, the results suggest a contribution of estrogen in the regulation of Cx43 expression and/or fates in the chicken oviduct. New insights into the expression and regulation of Cxs in the hen oviduct, indicating their potential involvement in the mechanisms of egg formation and transport that may affect poultry production, were obtained in this study.

Accumulation of the Toxic Metal Mercury in Multiple Tissues of Marine-Associated Birds from South Florida.

One of the best studied global "hot spots" for ecological mercury (Hg) contamination is south Florida (USA), where elevated Hg concentrations in environmental media and regional wildlife were first described over thirty years ago. While Hg contamination has lessened in this region, it is still critical to monitor Hg uptake and potential risks in south Florida wildlife, especially in marine-associated birds, which are known to accumulate potentially toxic Hg levels. In this study, total Hg (THg) concentrations were measured in liver, kidney, muscle, and feathers of 101 individuals from seven species of south Florida birds: brown pelican Pelecanus occidentalis, double-crested cormorant Phalacrocorax auratus, herring gull Larus argentatus, laughing gull Leucophaeus atricilla, northern gannet Morus bassanus, royal tern Thalasseus maximus, and osprey Pandion halietus. A sizeable proportion of individuals (> 40%) were found to contain THg concentrations in internal tissues that exceeded estimated toxicity thresholds for Hg-related effects. Certain species, especially osprey, were found to exhibit a higher rate of threshold exceedances than others and should continue to be monitored for Hg-related effects in future studies. Feather THg concentrations exhibited a lower rate of toxicity threshold exceedances (12%) and were not significantly correlated with those in internal tissues in most cases, suggesting that they may not be well suited for monitoring Hg exposure in these species unless sources of data variation can be better understood. The results of the present study contribute significantly to our understanding of trends in Hg accumulation and Hg-related health risks in south Florida marine-associated birds.

Influence of dietary vitamin E and selenium supplementation on broilers subjected to heat stress, Part II: oxidative stress, immune response, gut integrity, and intestinal microbiota

This study evaluated the effects of vitamin E (Vit E) and selenium (Se) supplementation on mRNA abundance of antioxidant, immune response, and tight junction genes, as well as taxonomic and functional profiles of ileal microbiota of broilers exposed to daily 4-h elevated temperature during d 28 to 35. A total of 640-day-old Cobb male broiler chicks were randomly allocated to 32 floor pens in a 2 × 2 factorial arrangement that included ambient temperature (thermoneutral [TN] or heat stress [HS]) and dietary treatments (basal diet or Vit E + Se). Vit E and organic Se were added to the basal diet at the rate of 250 mg/kg and 1 mg/kg, respectively. Liver and jejunum tissue samples were taken on d 27 (1 bird/pen), d 28 and d 35 (2 birds/pen) from birds for qPCR analysis. Data were subjected to a 2-way ANOVA using the GLM procedure of JMP. Ileal contents were taken on d 27 and d 35 for microbial profiling. Microbiota data were analyzed in QIIME 2 and significance between treatments identified linear discriminant analysis effect size (LEfSe, P < 0.05). Dietary Vit E/Se significantly downregulated the mRNA levels of HSPs in liver and jejunal tissues of the HS-challenged birds both on d 28 and d 35. Moreover, mRNA abundance of TLR2, TNFα, IFNγ, IL-1β, IL-10, and iNOS in the liver were significantly downregulated in birds fed the Vit E/Se diet on d 35. However, dietary treatment had no significant impact on oxidative stress, immunity, and gut integrity related genes analyzed in jejunal tissues on d 28 and d 35, except downregulation of IFNγ on d 35 (P = 0.052). LEfSe analysis revealed that Lachnospiraceae FE2018 and Ruminococcaceae NK4A214 groups was enriched in the Vit E/Se birds on d 35. Moreover, PICRUSt analysis predicted significant functional differences among the treatment groups. In conclusion, dietary supplementation of Vit E/Se mitigated the negative effects of HS potentially via improving antioxidant status, regulating cytokine responses and modifying ileal microbiota and its function.

The effect of stocking rate and supplementary selenium on the fatty acid composition and subsequent peroxidisability of poultry muscle tissues

Selenium (Se) plays a crucial role in protecting biological materials from oxidative damage through the action of the selenoprotein glutathione peroxidase (GSH-Px), and the effectiveness of this protection is often dependent upon Se supply. Recent evidence has indicated that GSH-Px mRNA expression can be upregulated in response to potential oxidative damage risk, and that this upregulation is independent of Se supply. The current study aimed to determine the effect of Se supplementation, stocking rate and tissue fatty acid profile on GSH-Px activity in breast and thigh tissue of commercial broilers. A total of 168 Ross 308 broiler chicks were enrolled onto the study. Prior to enrolment, birds were brooded as a single group and received a starter diet containing no additional Se. The study was a 2 × 2 factorial design comprising of two levels of dietary Se (high Se, 0.5 mg/kg total Se, low Se background Se only), and two stocking rates (high, 30 kg/m2, and low, 15 kg/m2). At 15 days of age, birds were blocked by live weight and randomly allocated to one of the four treatments, with six pen replicates per treatment. At 42 days of age, one bird was randomly selected from each pen replicate, euthanased and breast and thigh tissue harvested. GSH-Px activity, thiobarbituric acid reactive substances (TBARS), and fatty acid (FA) content of these tissues were determined. There was no effect (P > 0.05) of stocking rate on GSH-Px activity or TBARS. GSH-Px activity did not differ between tissue types but was greater in high Se birds (P < 0.001) compared to low Se. TBARS concentrations were greater in thigh tissue (P < 0.001), and these thigh concentrations were greater in high Se birds (P < 0.05). There were marked differences between breast and thigh tissue in most FAs (P < 0.001), with breast generally containing greater proportions of polyunsaturated FA, so that breast tissue had a higher (P < 0.001) peroxidisability index (PI) than thigh. A positive correlation between GSH-Px activity and PI in the thigh tissue of high Se birds (Pearson Correlation 0.668; P = 0.025) may indicate that increasing susceptibility to peroxidisation in lipid-rich tissues may also upregulate GSH-Px activity in Se-replete birds. This study suggests that ensuring adequate dietary selenium could be a useful tool to mitigate adverse effects on meat quality caused by oxidation, particularly in lipid-rich meat.

Enhanced levels of hazardous trace elements (Cd, Cu, Pb, Se, Zn) in bird tissues in the context of environmental pollution by Raša coal

The mining and burning of Croatian Raša coal had resulted in release of various contaminants into the local environment. They have remained in the local soil, water, and plants, and became available to animals through their consumption. In this study, tissue samples from a total of 12 birds from the Raša area and 8 birds from a control area were subjected to multi-element analysis (Al, V, Cr, Mn, Fe, Co, Cu, Zn, As, Se, Mo, Cd, Pb) by ICP-MS. The obtained results showed increased Se and Cd concentrations in some bird tissue samples compared to the control area. The highest concentrations of Cu, Zn, and Se were found in the liver, while the highest concentrations of Cd and Pb were found in the kidneys. Although some hazardous trace elements were elevated in the tissues of game species, the risk of consuming meat and offal of such species has been found to be very low.

МИКРОЭЛЕМЕНТНЫЙ СОСТАВ МЫШЕЧНОЙ ТКАНИ ЦЫПЛЯТ-БРОЙЛЕРОВ НА ФОНЕ ПРИМЕНЕНИЯ КОМПЛЕКСНОЙ КОРМОВОЙ ДОБАВКИ

The results of the influence of "Zaslon 2+" complex feed additive on the content of microelements in the muscles (breast, femur, lower leg) of broiler chickens of Ross 308 cross are presented. Two groups of birds were formed, each contained 100 birds. Birds of the control group were fed with the main ration. The main ration in the experimental group was used in combination with "Zaslon 2+" complex feed additive throughout the entire period of the study. Positive effect of the complex feed additive on concentration of microelements in the muscle tissue of broiler chickens was noted throughout the experiment. Thus, the level of iron in pectoral muscles of the birds of the experimental group increased by 9.1%, copper - by 6.7%, zinc - by 6.9% on the 38th day of the experiment, in comparison with the control group. The concentration of iron in femoral muscles of broiler chickens after application of the feed complex was higher by 18.1%, zinc - by 16.2 in relation to the parameters of the control group. The content of mineral elements in leg muscles of broiler chickens from the experimental group was higher than their concentration in the muscles of the birds from the control group. So the level of iron was higher - by 27.6%, copper - by 23.1%, zinc - by 11.8%. An increase of the content of microelements in the muscle tissue of birds indicates a positive effect of the components that make up the complex of additional nutrition.

Tolerance and safety evaluation of L-glutamic acid, N,N-diacetic acid as a feed additive in broiler diets

The novel chelator, L-glutamic acid, N,N-diacetic acid (GLDA) can be used as a dietary ingredient to safely reduce Zn supplementation in complete feed, without compromising the Zn status of farm animals. The objective of this study was to study dietary tolerance, bioaccumulation, and evaluate the safety of GLDA when supplemented in broiler diets at 0, 100, 300, 1000, 3,000, and 10,000 mg/kg. A total of 480 one-day-old Ross 308 male broilers were randomly allocated to 48 pens and fed one of the 6 experimental diets. Production performance was used to assess tolerance to the additive. At trial end, toxicity was evaluated using hematology, plasma biochemistry (n = 144) and gross necropsy (n = 48). Residue levels of GLDA were assessed in liver, kidney and breast tissue of birds used for necropsy. Performance showed an increase (P < 0.05) in body weight for GLDA inclusion at 300 mg/kg. A decrease on the measured performance parameters was found for the 10,000 mg/kg GLDA inclusion level (P < 0.05). The additive was added as a tetra-sodium salt, leading to sodium levels being 2.5 times higher in the latter treatment compared to the control diet which may have led to impaired intestinal barrier function. Mortality was not different between treatments. Residue levels for GLDA at the highest inclusion indicate that 0.0005% of total GLDA consumption is accumulated in breast tissue. Higher values of GLDA were found in kidney and liver at the highest inclusion level, potentially confirming that the small fraction of GLDA absorbed was readily excreted by the animal. At 100 and 300 mg/kg GLDA inclusion there were negligible amounts of GLDA present in all tissues measured. The present experiment demonstrated a high dietary tolerance to GLDA in broilers and indicated that GLDA does not pose a significant risk to food safety when supplemented below 3,000 mg/kg.

Heavy Metals in the Liver, Kidney, Brain, and Muscle: Health Risk Assessment for the Consumption of Edible Parts of Birds from the Chahnimeh Reservoirs Sistan (Iran)

The concentrations of four heavy metals, zinc (Zn), lead (Pb), nickel (Ni), and cadmium (Cd), were determined in the liver, kidney, muscle, and brain of nine species of birds from the Chahnimeh Sistan from Iran to assess the metal levels and the potential risk to birds and to the people who eat them. Significantly higher levels of all metals were found in the brain than in the other tissues of other birds. There were no significant gender differences in heavy metals in all tissue. The levels of Pb, Cd, Ni, and Zn in the liver and kidney varied as a function of feeding habitats; the median levels were significantly higher in invertebrate predators than they were for fish predators and omnivorous species. Short-distance migrant birds had significantly higher median levels of heavy metals in the liver and kidney than long-distance migrant birds. Ni levels in the liver and kidney tissues in 56% of birds were higher than the critical threshold levels for effects in birds. Our data indicate that environmental exposures to metals were higher in the wintering populations of birds in the Chahnimeh of Sistan from Iran than elsewhere. Concentrations of Zn, Pb, and Cd in a small percentage of birds were above toxicity levels. However, 56% of liver and kidney samples for nickel were above toxicity levels. Determining the exposure frequency and daily intake of birds, the hazard quotient for edible tissues (kidney, liver, and muscle) of these birds showed that their consumption may provide health risk to people consuming them.

Morphofunctional Features of Limphoid Tissue of the Stomach in Some Wild Bird Species

The article presents the results of histological studies of topography, microstructure and functional features of the stomach lymphoid tissue in birds. The research was carried out on 12 species of wild birds belonging to 6 orders. Classical methods of histological specimens staining with hematoxylin and eosin, according to Weigert, Van Gieson, and argentum nitrate impregnation according to Kelemen were used when performing the work. It has been confirmed that the birds' stomach has glandular (proventriculus), muscular (ventriculus, gizzard) and pyloric parts, which are not equally expressed in separate species. In all parts of the stomach, lymphoid tissue is represented by local clusters, which in birds of the orders Galliiformes (P. colchicus, B. bonasia, P. crictatus); Anseriformes (B. canadensis); Passeriformes (P. pica, C. cornix); Gruiformes (G. chloropus, F. atra); Ciconiiformes (C. ciconia) and Columbiiformes (C. livia) are located in the tunica mucosa and submucosa, and in B. canadensis, F. atra, G. chloropus also in the tunica muscularis and tunica serosa. In L. lagopus and G. glandarius, lymphoid tissue has been found only in the proventriculus and its intermediate zone. Structural levels of lymphoid tissue (diffuse form, prenodules, primary and secondary lymphoid nodules) are unequally expressed in the birds' stomach. In B. bonasia, B. canadensis, P. pica, C. cornix, C. ciconia, C. livia, only a diffuse form appears in all its parts. This form of lymphoid tissue is registered in the ventriculus of other birds species and proventriculus in L. lagopus and G. glandarius. All levels of the lymphoid tissue structural organization are detected in the proventriculus in P. crictatus, G. chloropus and in the proventriculus and pyloric part of the stomach in P. colchicus and F. atra. The content of lymphoid tissue is different in parts of the birds' stomach. Most of all it is contained in the intermediate zone of the proventriculus and the pyloric part of the stomach. Diffuse form is the most common among the levels of lymphoid tissue structural organization. The research results make it possible to more fully assess the morphofunctional status of wild birds and, accordingly, to find out the state of their immune system

Levels and profiles of perfluorinated alkyl acids in liver tissues of birds with different habitat types and trophic levels from an urbanized coastal region of South Korea

Contamination status and characteristics of perfluorinated alkyl acids (PFAAs) including perfluorinated carboxylic acids (PFCAs) and perfluorinated sulfonic acids (PFSAs) was examined using liver tissue of birds - black-tailed gulls (Larus crassirostris), domestic pigeons (Columba livia var. domestica), pacific loons (Gavia pacifica), herons (Ardea cinerea), and egrets (Egretta garzetta and Ardea alba) - with different trophic levels, habitat types and migratory behaviors from an industrialized coastal region of South Korea. A wide range of PFAAs (1.09 ng/g to 1060 ng/g; median = 52.6 ng/g) were detected in bird livers from the Korean coasts with high detection frequency. Accumulation features of PFAAs in birds indicated that primarily trophic position and secondly habitat type influence the levels and composition of PFAAs, e.g., relatively high PFAA levels and high composition of odd-numbered long carbon chain PFCAs (perfluoroundecanoic acid (PFUnDA) and perfluorotridecanoic acid (PFTriDA)) and PFOS in higher trophic and marine birds. The prevalence of long carbon chain (≥14) PFCAs likely implies a wide use of fluorotelomer-based substances in Korea. Interspecies comparison in the accumulation profile of persistent organic pollutants (including polychlorinated biphenyls (PCBs), organochlorine pesticides, polybrominated diphenylethers (PBDEs), and PFAAs) reveals relatively high load of PFAAs in inland (pigeons) and estuarine (egrets/herons) species compared to marine bird species, indicating wide use of PFAAs in the terrestrial environment.

Synchrotron microtomography‐based osteohistology ofGansus yumenensis: new data on the evolution of uninterrupted bone deposition in basal birds

AbstractMany studies of the limb bones from birds of the major clades reveal a mosaic evolution in morphological characters. From this, we assume that uninterrupted compact bone evolved independently multiple times outside of the crown group. We hypothesise that there are key intraskeletal changes in the osteohistological features, such as the organisation of the vascular network. To test these hypotheses, we analysed and described the osteohistological features of five different midshaft samples ofGansus yumenensis, a non‐ornithurine Euornithes from China, based on virtual models obtained from synchrotron microtomography scans, a less invasive method that the traditional physical cross section. We performed quantitative analyses with volume, surface area and estimated ratios. The osteohistological features ofGansus yumenensiswere compared with those of stem and crown birds. From our analyses, we discuss the pros/cons of using synchrotron microtomography scans compared to traditional physical cross section. Our analyses demonstrate thatGansus yumenensisis the fourth described extinct Euornithes to exhibit uninterrupted bone deposition in all bone samples, providing further support for multiple origins of this feature outside of the bird crown group. Finally, our osteohistological investigation ofGansus yumenensisprovides future study avenues regarding the evolution and development of bone tissue in fossil birds.

Heavy metal contamination in wild avian species inhabiting human-modified habitats.

Health of birds and heavy metal toxicity are growing concerns in Pakistan because of irresponsible industrial waste management and farming practices. Eight species of common wild birds were studied from three different study sites which varied in the type of environmental pollution (Kasur: industrial waste, Lahore city: traffic pollution and Shahdara: mixed pollution of traffic, sewerage, and industry which the Ravi River accumulates). Heavy metal analysis of six heavy metals in the various organs of birds showed that there was no evidence of organ preference for metal accumulation in birds. Shahdara and Kasur with numerous industries both showed chromium concentrations above toxicity levels in 54.16% tissues of Granivorous birds, 60% of omnivorous birds, and 33.33% in tissues of carnivorous species. Statistical analysis proved that there is no correlation between weight of birds and accumulation of metals; it depends on food preference of birds and properties of the metals as bioaccumulators or biomagnifiers.

Comparison of metal burden in different muscle tissues of Great cormorant (Phalacrocorax carbo)

Concentrations of 12 metals (As, Ba, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb and Zn) were examined in the pectoral and thigh muscle of great cormorants (Phalacrocorax carbo). The samples were collected from Central Tisza-Jászság Nature Conservation Area in Hungary. The tissue samples were analysed by inductively coupled plasma optical emission spectroscopy (ICP-OES). The aim of the study was to examine the impacts of heavy metal pollution on the water birds, determine the concentrations of the abovementioned metals in the different muscle tissues of these wetland birds, and provide the basic materials for monitoring the environmental pollution. Among the investigated elements/metals, the detected concentrations of As, Ba, Cd, Co, Cr, Mo and Ni were below the detection limit. Higher concentration of Cu, Hg, Mn and Pb was measured in the pectoral muscle compared to the thigh muscle, but only in the case of Cu and Mn were found significant differences between the tissues. In the case of the Zn concentration, the higher value was detected in the thigh muscle. There were no statistical differences between males and females in either metal concentrations.

Evaluation of chickens infected with a recombinant virulent NDV clone expressing chicken IL4

BackgroundThere is evidence that chicken IL4 (chIL4) functions similarly to its mammalian analogue by enhancing type 2 T helper (Th2) humoral immunity and promoting protection against parasitic infections; however, no studies have been performed to assess the effect of chIL4 on the pathogenesis of Newcastle disease (ND). To assess the role of chIL4 in velogenic NDV pathogenesis we created a vNDV infectious clone expressing chIL4. We hypothesized that co-expression of chIL4 during virus replication would result in decreased inflammation caused by the Th1 response and thereby increasing survival to challenge with vNDV. MethodsTo evaluate the effect of chIL4 during early infection with velogenic Newcastle disease virus (NDV) in chickens, recombinant NDV clones expressing either chIL4 (rZJ1-IL4) or a control expressing green fluorescent protein (rZJ1-GFP) were created by inserting an expression cassette in an intergenic region of the NDV genome. The pathogenesis of rZJ1-IL4 was assessed in 4-week-old specific pathogen free chickens. The extent of virus replication was evaluated by titration in mucosal secretions and immunohistochemistry in multiple tissues. Expression of chIL4 was confirmed in tissues using immunohistochemistry. ResultsInfection of birds with the rZJ1-IL4 resulted in successful viral replication in vivo and in vitro and generation of the chIL4 in tissues. All birds were clinically normal 2 DPI, with one bird in each group showing conjunctival swelling and enlarged spleens grossly. At 5 DPI, moderate or severe depression was observed in birds infected with rZJ1-GFP or rZJ1-IL4, respectively. Neurological signs and thymic atrophy were observed in one bird infected with rZJ1-IL4. Grossly, conjunctival swelling, mottled spleen and proventricular hemorrhages were observed at 5 DPI in one bird from each group. At 5 DPI, severe necrosis in the spleen, bursa and cecal tonsils were observed in birds infected with rZJ1-GFP, along with minimal evidence of chIL4 expression. In contrast, splenic atrophy, and moderate necrosis in the bursa and cecal tonsils were observed in birds infected with rZJ1-IL4. In addition, chIL4 signal was found in all tissues of rZJ1-IL4 birds at 5DPI. ConclusionsThe production of chIL4 by a recombinant NDV strain resulted in the activation of the positive feedback loop associated with IL4 production. Insertion of chIL4 into NDV may decrease necrosis to lymphoid organs while increasing the severity of lymphoid atrophy and prolonged disease. However, with a low number of birds it is difficult to determine whether these results are significant to disease outcome.

A spatial prioritization method for identifying potential eco-risk distributions of heavy metals in soil and birds

Geochemical approaches are popular for evaluations based on heavy metal concentrations in sediments or soils for eco-risk assessment. This study proposes a systematic geochemical approach (SymGeo) to explore six heavy metals in topsoils and bird tissues and organs of the target birds. We assume that the proposed approach based on field-collected heavy metals in topsoils and feathers can predict the areas with the potential risk of the heavy metals in birds. Finite mixture distribution modeling (FMDM) was used to identify background values of the heavy metal concentrations in topsoil. A spatial enrichment factor (EF), potential contamination index (PCI), contamination degree (Cod), and potential ecological risk index (PRI) based on FMDM results for topsoil, and a potential risk index (PRIbird) of heavy metals in the birds, were utilized for systematic prioritization of high eco-risk areas. Using multiple EF, PRI, and Cod results and multiple PRI-based maps of the heavy metals in feathers, we systematically prioritized risk areas where there is a high potential for heavy metal contamination in the birds. Our results indicate that heavy metal concentrations in the feather, liver, and kidney are not spatially cross-autocorrelated but are statistically significantly correlated with some heavy metals in topsoil due to external and internal depositions. Further, multiple EF, Cod, and RI distributions for topsoil, along with the PRI of the feather, showed that adequate coverages for potential risk for birds were greater than 71.05% in the top 30% and 84.69% in the top 20% potential eco-risk priority area of heavy metals in bird liver and kidney. Hence, our proposed approach suggests that assessments of heavy metals in bird feathers and topsoils without bird organs can be utilized to identify spatially high-risk areas. The proposed approach could be improved by incorporating water and sediment samples to enhance the crowdsourcing and the species-specific data.