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1.
Nature ; 585(7826): 557-562, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32939093

RESUMO

Climate and physiology shape biogeography, yet the range limits of species can rarely be ascribed to the quantitative traits of organisms1-3. Here we evaluate whether the geographical range boundaries of species coincide with ecophysiological limits to acquisition of aerobic energy4 for a global cross-section of the biodiversity of marine animals. We observe a tight correlation between the metabolic rate and the efficacy of oxygen supply, and between the temperature sensitivities of these traits, which suggests that marine animals are under strong selection for the tolerance of low O2 (hypoxia)5. The breadth of the resulting physiological tolerances of marine animals predicts a variety of geographical niches-from the tropics to high latitudes and from shallow to deep water-which better align with species distributions than do models based on either temperature or oxygen alone. For all studied species, thermal and hypoxic limits are substantially reduced by the energetic demands of ecological activity, a trait that varies similarly among marine and terrestrial taxa. Active temperature-dependent hypoxia thus links the biogeography of diverse marine species to fundamental energetic requirements that are shared across the animal kingdom.


Assuntos
Organismos Aquáticos/classificação , Organismos Aquáticos/metabolismo , Ecossistema , Filogeografia , Aerobiose , Animais , Organismos Aquáticos/crescimento & desenvolvimento , Metabolismo Basal , Aves/metabolismo , Peso Corporal , Hipóxia/metabolismo , Hipóxia/veterinária , Mamíferos/metabolismo , Oxigênio/metabolismo , Répteis/metabolismo , Especificidade da Espécie , Temperatura
2.
Chemosphere ; 252: 126583, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32443269

RESUMO

Birds are bioindicators for research on the relationship between environmental heavy metal concentration levels and accumulation levels in bird tissues. We use roadkill samples, collected by citizen science participants, to investigate the accumulation levels and associations of seven heavy metals in internal organs (heart, liver, and kidney), feathers (primary and breast), and bones (sternum and femur) of two focal species, Amaurornis phoenicurus and Gallinula chloropus. We found that heavy metal accumulation varied by target tissue, and that variables are associated with bird species and heavy metal type. Although Zn and Cu were highest by concentration among both species, Cu was mostly accumulated in internal organs, As in feathers, and Pb in bones. Concentrations of As, Ni, and Pb in feathers of both focal species were lower than those reported in literature, whereas Cd and Cr were above toxic levels. The results also showed that spatial correlation for heavy metal concentration among bird tissues were weaker than non-spatial correlation, suggesting low spatial autocorrelations and variability. In addition, multiple regression analysis revealed significant correlation for Cr, As, and Pb estimations in A. phoenicurus heart, sternum, and kidney, respectively; and potentially Cr in G. chloropus femur by using feathers. These results support the feasibility of using feathers as indicators of As, Cr, and Pb heavy metal contamination to enhance our understanding of heavy metal accumulation in birds, although caution is required for feather-based estimations of Cd, Cu, and Ni concentration.


Assuntos
Aves/metabolismo , Monitoramento Ambiental/métodos , Metais Pesados/metabolismo , Animais , Crowdsourcing , Biomarcadores Ambientais , Plumas/química , Rim/química , Fígado/química , Metais Pesados/análise
3.
Sci Rep ; 10(1): 8684, 2020 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-32457384

RESUMO

Essential for calcium homeostasis, TRPV5 and TRPV6 are calcium-selective channels belonging to the transient receptor potential (TRP) gene family. In this study, we investigated the evolutionary history of these channels to add an evolutionary context to the already available physiological information. Phylogenetic analyses revealed that paralogs found in mammals, sauropsids, amphibians, and chondrichthyes, are the product of independent duplication events in the ancestor of each group. Within amniotes, we identified a traceable signature of three amino acids located at the amino-terminal intracellular region. The signature correlates with both the duplication events and the phenotype of fast inactivation observed in mammalian TRPV6 channels. Electrophysiological recordings and mutagenesis revealed that the signature sequence modulates the phenotype of fast inactivation in all clades of vertebrates but reptiles. A transcriptome analysis showed a change in tissue expression from gills, in marine vertebrates, to kidneys in terrestrial vertebrates. Our results highlight a cytoplasmatic structural triad composed by the Helix-Loop-Helix domain, the S2-S3 linker, and the TRP domain helix that is important on modulating the activity of calcium-selective TRPV channels.


Assuntos
Cálcio/metabolismo , Evolução Molecular , Canais de Cátion TRPV/metabolismo , Sequência de Aminoácidos , Anfíbios/metabolismo , Animais , Aves/metabolismo , Brânquias/metabolismo , Células HEK293 , Sequências Hélice-Alça-Hélice , Humanos , Rim/metabolismo , Mamíferos/metabolismo , Mutagênese Sítio-Dirigida , Filogenia , Alinhamento de Sequência , Canais de Cátion TRPV/química , Canais de Cátion TRPV/classificação , Canais de Cátion TRPV/genética
4.
J Zoo Wildl Med ; 51(1): 53-58, 2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-32212546

RESUMO

Mavacoxib is a selective cyclooxygenase-2 nonsteroidal anti-inflammatory drug that has been used for management of osteoarthritis and other inflammatory conditions in dogs. The main advantage of mavacoxib over other nonsteroidal anti-inflammatory drugs is its longer plasma half-life, leading to decreased dosing frequency. This study determined the pharmacokinetics of mavacoxib in Caribbean flamingos (Phoenicopterus ruber ruber) after a single-dose oral administration of 6 mg/kg (n = 6). Plasma mavacoxib concentrations were determined using liquid chromatography with mass spectrometry, and pharmacokinetic analysis was performed using noncompartmental methods. Mean peak plasma concentration (Cmax) was (mean; range) 2.97 (2.19--4.06) µg/ml; mean time to peak plasma concentration (Tmax) was 18.68 (4.00-48.00) hr; mean area under the curve (AUC) was 455 (292-637) hr * µg/ml; and mean terminal half-life (T1/2) was 74.47 (49.57-161.43) hr. Based on the results of this study, mavacoxib dosed at 6 mg/kg orally in Caribbean flamingos reaches plasma concentrations above the therapeutic concentration established for dogs, but further studies are needed to determine appropriate dosing recommendations in flamingos.


Assuntos
Animais de Zoológico/metabolismo , Anti-Inflamatórios não Esteroides/farmacocinética , Aves/metabolismo , Pirazóis/farmacocinética , Administração Oral , Animais , Feminino , Masculino
5.
PLoS One ; 15(3): e0229148, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32160215

RESUMO

Lake Lesser Prespa in Greece is a vital breeding habitat for the Dalmatian and Great White Pelican and a shelter for numerous rare and endemic species. However, eutrophication processes are distressing the lake system and the outbreaks of cyanobacterial blooms during the warm months may pose a threat to aquatic organisms due to the presence of microcystins (MCs). In this study we hypothesize that nutrients (eutrophication), nutrient-rich pelican droppings (guanotrophication) and warming (climate change) can affect the algal growth and MCs production in the water layer of Lake Lesser Prespa. Seston collected from three lake sites was incubated at ambient (20°C) and high (30°C) temperature with or without the addition of nutrients (nitrogen (N), phosphorus (P)), or pelican droppings. Results showed increased chlorophyll-a at higher temperature (30°C). N addition yielded higher chlorophyll-a levels than the non-treated water or when only P was added. The addition of both N and P as well as the addition of pelican dropping resulted in the highest chlorophyll-a at both temperatures. Notably, in the dropping-treatments, cyanobacteria and MCs were promoted while changes were evoked in the relative contribution of toxic MC-variants. Guanotrophication may thus influence the cyanobacterial dynamics and most likely their toxicity profile at Lesser Prespa.


Assuntos
Clorófitas , Mudança Climática , Cianobactérias , Eutrofização , Lagos , Microcistinas/metabolismo , Animais , Aves/metabolismo , Clorófitas/crescimento & desenvolvimento , Clorófitas/metabolismo , Cianobactérias/crescimento & desenvolvimento , Cianobactérias/metabolismo , Fezes , Grécia , Microcistinas/toxicidade , Temperatura
6.
Microbes Infect ; 22(4-5): 221-225, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32199943

RESUMO

SARS-CoV-2, the newly identified human coronavirus causing severe pneumonia pandemic, was probably originated from Chinese horseshoe bats. However, direct transmission of the virus from bats to humans is unlikely due to lack of direct contact, implying the existence of unknown intermediate hosts. Angiotensin converting enzyme 2 (ACE2) is the receptor of SARS-CoV-2, but only ACE2s of certain species can be utilized by SARS-CoV-2. Here, we evaluated and ranked the receptor-utilizing capability of ACE2s from various species by phylogenetic clustering and sequence alignment with the currently known ACE2s utilized by SARS-CoV-2. As a result, we predicted that SARS-CoV-2 tends to utilize ACE2s of various mammals, except murines, and some birds, such as pigeon. This prediction may help to screen the intermediate hosts of SARS-CoV-2.


Assuntos
Betacoronavirus/metabolismo , Aves/metabolismo , Infecções por Coronavirus/virologia , Mamíferos/metabolismo , Peptidil Dipeptidase A/genética , Pneumonia Viral/virologia , Sequência de Aminoácidos , Animais , Humanos , Pandemias , Filogenia , Conformação Proteica , Especificidade da Espécie
7.
Arch Environ Contam Toxicol ; 78(4): 555-567, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32008049

RESUMO

Use of pesticides continues to be indiscriminate, and birds are one of the worst affected non-targeted organisms. Information on the ill effects of pesticides on birds far from desired in India. Despite the presence of a wide variety and number of birds, there is exceedingly little data on organochlorine pesticide (OCP) residues in colonial nesting birds in sanctuaries of India. A total of 76 individuals belonging to 14 species of birds found dead between March 2008 and March 2010 were analyzed for pesticide residues in various tissues. Of all the OCPs analyzed, concentration of HCH was found to be the highest. Magnitude of contamination varied widely among species. Accumulation pattern of OCPs in colonial nesting birds was in the order ∑HCH > ∑endosulfan > ∑DDT > heptachlor epoxide > dieldrin. Pesticides, namely p,p-DDE and ß-HCH contributed most towards the total OCPs. Concentrations of DDT and its metabolites, HCH and isomers, dieldrin, and heptachlor epoxide were lower than the concentrations reported for various species of birds elsewhere in India. Although the sanctuaries presently studied have official boundaries, physical demarcations are missing and there are no proper earthen dykes particularly in Vedanthangal and Koonthankulam Bird Sanctuaries. During monsoon, runoff not only floods the Sanctuaries but also the cultivated areas nearby. Run off brings in residues of pesticides and fertilizers from the agricultural lands into the sanctuaries. Although OCP results in this study were below threshold limits, it may be noted that the long duration exposure even to low levels of pesticides could create a significant impact at population level. Hence, earthen dykes need to be built to avoid agricultural runoff entering the Sanctuary and also help to hold sufficient amount of water for breeding birds.


Assuntos
Aves/crescimento & desenvolvimento , Monitoramento Ambiental/métodos , Hidrocarbonetos Clorados/análise , Resíduos de Praguicidas/análise , Animais , Aves/metabolismo , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Cruzamento , Índia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo
8.
J Exp Biol ; 223(Pt 2)2020 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-31900347

RESUMO

Many juvenile birds turn into long-distance migrants within weeks of fledging. This transition involves upheavals in their energy management as major changes in growth and activity occur. Understanding such ontogenetic transitions in energy allocation has been difficult because collecting continuous data on energy costs in wild developing birds was previously largely impossible. Here, we continuously measured heart rate and fine-scale movements of 20 free-living juvenile white storks (Ciconia ciconia) using on-board bio-loggers to explore individual and environmental factors relating to daily mean heart rate. In addition, we explored which specific energy management strategy storks use during these crucial early life stages. We found that daily mean heart rate increased with overall movement activity, and increasing body temperature, but that it decreased with age. Further, we found that during the nestling period, when growth costs are high, activity costs are low, and post-fledging that activity costs are increased while maintenance costs are low, indicating a constraint on overall energy use in both phases. Our observations are consistent with the hypothesis that individuals invested more energy per unit time while still in the nest than after fledging despite the high costs of flight.


Assuntos
Aves/metabolismo , Metabolismo Energético , Animais , Aves/crescimento & desenvolvimento
9.
J Exp Biol ; 223(Pt 2)2020 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-31836652

RESUMO

Hummingbirds fuel their high energy needs with the fructose and glucose in their nectar diets. These sugars are used both to fuel immediate energy needs and to build fat stores to fuel future fasting periods. Fasting hummingbirds can deplete energy stores in only hours and need to be continuously replacing these stores while feeding and foraging. Whether and how hummingbirds partition dietary fructose and glucose towards immediate oxidation versus fat storage is unknown. Using a chronic stable isotope tracer methodology, we examined whether glucose or fructose is preferentially used for de novo lipogenesis in ruby-throated hummingbirds (Archilochus colubris). Potential seasonal changes were correlated with variation in the overall daily energy expenditure. We fed ruby-throated hummingbirds sucrose-based diets enriched with 13C on either the glucose or the fructose portion of the disaccharide for 5 days. Isotopic incorporation into fat stores was measured via the breath 13C signature while fasting (oxidizing fat) during the winter and summer seasons. We found greater isotopic enrichment of fat stores when glucose was labelled compared with fructose, suggesting preference for glucose as a substrate for fatty acid synthesis. We also found a seasonal effect on fat turnover rate. Faster turnover rates occurred during the summer months, when birds maintained lower body mass, fat stores and exhibited higher daily nectar intake compared with winter. This demonstrates that fat turnover rate can substantially vary with changing energy expenditure and body composition; however, the partitioning of sucrose towards de novo fatty acid synthesis remains constant.


Assuntos
Tecido Adiposo/metabolismo , Aves/metabolismo , Metabolismo Energético , Sacarose/metabolismo , Animais , Composição Corporal , Masculino , Estações do Ano
10.
Ecotoxicology ; 29(10): 1802-1814, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31729602

RESUMO

We examined how variation in MeHg concentrations through time is reflected in birds, a taxon commonly used as a biological indicator of ecosystem health. Using museum specimens collected from 1880 to 2016, we measured feather MeHg concentrations in six species of birds that breed in New York State and have distinct dietary and habitat preferences. We predicted that MeHg concentrations in feathers would mirror Hg emission patterns in New York State and increase through time until 1980 then decrease thereafter in response to increased regulation of anthropogenic Hg emissions. We found that MeHg concentrations increased with δ15N, and that MeHg feather concentrations for some individuals from four of the six species examined exceeded concentrations known to cause negative sublethal effects in birds. In contrast to our prediction, MeHg concentrations in feathers did not parallel global or local Hg emissions through time and varied by species, even after controlling for possible changes in diet and habitat. MeHg concentrations varied substantially within species and individual specimens, suggesting that high within-individual variation in feather MeHg concentrations caused by spatiotemporal variation in molt, environmental Hg exposure, or mobility decoupling Hg uptake from breeding sites, may obscure trends in MeHg through time. Our study provides a unique assessment of feather MeHg in six species not typically analyzed using this retrospective approach.


Assuntos
Aves/metabolismo , Monitoramento Ambiental , Mercúrio/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Dieta , Ecossistema , Plumas , Compostos de Metilmercúrio , Museus , New York
11.
Environ Pollut ; 256: 113280, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31718826

RESUMO

Methylmercury (MeHg) is a globally pervasive contaminant with known toxicity to humans and wildlife. Several sources of variation can lead to spatial differences in MeHg bioaccumulation within a species including: biogeochemical processes that influence MeHg production and availability within an organism's home range; trophic positions of consumers and MeHg biomagnification efficiency in food webs; and individual prey preferences that influence diet composition. To better understand spatial variation in MeHg bioaccumulation within a species, we evaluated the effects of habitat biogeochemistry, food web structure, and diet composition in the wetland-obligate California black rail (Laterallus jamaicensis coturniculus) at three wetlands along the Petaluma River in northern San Francisco Bay, California, USA. The concentration of MeHg in sediments differed significantly among wetlands. We identified three sediment and porewater measurements that contributed significantly to a discriminant function explaining differences in habitat biogeochemistry among wetlands: the porewater concentration of ferrous iron, the percent organic matter, and the sediment MeHg concentration. Food web structure and biomagnification efficiency were similar among wetlands, with trophic magnification factors for MeHg ranging from 1.84 to 2.59. In addition, regurgitation samples indicated that black rails were dietary generalists with similar diets among wetlands (percent similarity indices > 70%). Given the similarities in diet composition, food web structure, and MeHg biomagnification efficiency among wetlands, we concluded that variation in habitat biogeochemistry and associated sediment MeHg production was the primary driver of differences in MeHg concentrations among black rails from different wetlands.


Assuntos
Aves/metabolismo , Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Compostos de Metilmercúrio/metabolismo , Poluentes Químicos da Água/metabolismo , Áreas Alagadas , Animais , Bioacumulação , Dieta , Compostos Ferrosos/análise , Cadeia Alimentar , Humanos , Compostos de Metilmercúrio/análise , Rios/química , São Francisco , Poluentes Químicos da Água/análise
12.
Gen Comp Endocrinol ; 285: 113294, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31585115

RESUMO

Motilin and ghrelin were identified in the pheasant by molecular cloning, and the actions of both peptides on the contractility of gastrointestinal (GI) strips were examined in vitro. Molecular cloning indicated that the deduced amino acid sequences of the pheasant motilin and ghrelin were a 22-amino acid peptide, FVPFFTQSDIQKMQEKERIKGQ, and a 26-amino acid peptide, GSSFLSPAYKNIQQQKDTRKPTGRLH, respectively. In in vitro studies using pheasant GI strips, chicken motilin caused contraction of the proventriculus and small intestine, whereas the crop and colon were insensitive. Human motilin, but not erythromycin, caused contraction of small intestine. Chicken motilin-induced contractions in the proventriculus and ileum were not inhibited by a mammalian motilin receptor antagonist, GM109. Neither atropine (a cholinergic receptor antagonist) nor tetrodotoxin (a neuron blocker) inhibited the responses of chicken motilin in the ileum but both drugs decreased the responses to motilin in the proventriculus, suggesting that the contractile mechanisms of motilin in the proventriculus was neurogenic, different from that of the small intestine (myogenic). On the other hand, chicken and quail ghrelin did not cause contraction in any regions of pheasant GI tract. Since interaction of ghrelin and motilin has been reported in the house musk shrew, interaction of two peptides was examined. The chicken motilin-induced contractions were not modified by ghrelin, and ghrelin also did not cause any contraction under the presence of motilin, suggesting the absence of interaction in both peptides. In conclusion, both the motilin system and ghrelin system are present in the pheasant. Regulation of GI motility by motilin might be common in avian species. However, absence of ghrelin actions in any GI regions suggests the avian species-related difference in regulation of GI contractility by ghrelin.


Assuntos
Aves/metabolismo , Trato Gastrointestinal/fisiologia , Grelina/farmacologia , Motilina/farmacologia , Contração Muscular/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Atropina/farmacologia , Sequência de Bases , Galinhas , Clonagem Molecular , Feminino , Motilidade Gastrointestinal/efeitos dos fármacos , Motilidade Gastrointestinal/fisiologia , Trato Gastrointestinal/efeitos dos fármacos , Grelina/química , Grelina/genética , Humanos , Masculino , Motilina/química , Motilina/genética , Proventrículo/efeitos dos fármacos , Codorniz , Ratos , Receptores dos Hormônios Gastrointestinais/metabolismo , Receptores de Neuropeptídeos/metabolismo , Tetrodotoxina/farmacologia
13.
Artigo em Inglês | MEDLINE | ID: mdl-31669699

RESUMO

The endangered red-crowned crane (Grus japonensis) is a protected species in eastern Hokkaido and injured specimens are treated with medication. The present study aimed at understanding the expression profiles of cytochrome P450 (CYP) 1-3 genes in red-crowned crane tissues. We used 14 individuals found dead in the wild in eastern Hokkaido or in Kushiro City Zoo. Nine CYP1-3 genes expressed in the liver of the red-crowned crane were identified by high-throughput sequencing, and phylogenetically classified as CYP1A5, CYP2C23, CYP2C45, CYP2D49, CYP2G19, CYP2U1, CYP2AC1, CYP3A37, and CYP3A80. Based on the quantitative real-time PCR of 13 samples, the rank order of their median expression levels was as follows: CYP3A37 > CYP2AC1 > CYP2C45 > CYP2D49 > CYP2G19 > CYP1A5 > CYP3A80 > CYP2C23. The tissue distribution of the CYP transcripts indicated that many of the CYP1-3 genes examined were mainly expressed in the tissues where drug metabolism occurs, such as the liver, kidneys, and lungs. We found that CYP3A37 was dominant at the transcript level in the liver, indicating it might play a crucial role in liver physiology and xenobiotic metabolism. Similarly, an "orphan" CYP2AC1 was expressed at relatively high levels in the kidneys and liver, suggesting a possible role in renal and liver physiology and xenobiotic metabolism. Our results establish a foundation for future studies on red-crowned cranes aiming to further understand drug sensitivity and develop medication protocols, but also contribute to national and local projects for the conservation of red-crowned crane.


Assuntos
Aves/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Espécies em Perigo de Extinção , Fígado/enzimologia , Animais , Aves/genética , Poluentes Ambientais/metabolismo , Perfilação da Expressão Gênica , Japão , Rim/metabolismo , Pulmão/metabolismo , Distribuição Tecidual , Transcriptoma , Xenobióticos/metabolismo
14.
Ecotoxicology ; 29(10): 1794-1801, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31691906

RESUMO

Habitat degradation resulting from anthropogenic activities can threaten wildlife populations. Even wildlife existing in seemingly pristine areas are at risk of airborne pollutants and urban development. The common loon (Gavia immer), a top-trophic level predator in freshwater aquatic ecosystems, has previously experienced detrimental changes in reproductive success as a result of anthropogenic activities. However, long-term studies and large sample sizes are necessary to ascertain the impacts of various anthropogenic activities on this long-lived species. Using a multi-year dataset, we investigated the effects of multiple biotic and abiotic factors on the probability of adult male and female common loon hatching and fledging success. From 1998-2017, we banded individual loons, collected blood samples to assess mercury (Hg) exposure of the birds, and monitored their reproductive success. Adult female loon hatching success was negatively associated with the amount of rainfall received in a given year while fledging success was positively associated with the amount of shoreline development. Adult male loon hatching success was positively associated with the amount of shoreline development and fledging success was negatively associated with the number of other loon pairs on a lake.


Assuntos
Aves/metabolismo , Monitoramento Ambiental , Poluentes Químicos da Água/metabolismo , Animais , Ecossistema , Feminino , Lagos , Masculino , Mercúrio , Compostos de Metilmercúrio , New England , Reprodução
15.
Ecotoxicology ; 29(10): 1774-1785, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31691909

RESUMO

Mercury (Hg), a neurotoxic pollutant, can be transported long distances through the atmosphere and deposited in remote areas, threatening aquatic wildlife through methylation and bioaccumulation. Over the last two decades, air quality management has resulted in decreases in Hg emissions from waste incinerators and coal-fired power plants across North America. The common loon (Gavia immer) is an apex predator of the aquatic food web. Long-term monitoring of Hg in loons can help track biological recovery in response to the declines in atmospheric Hg that have been documented in the northeastern USA. To assess spatial patterns and temporal trends in Hg exposure of the common loon in the Adirondack Park of New York State, we analyzed Hg concentrations in loon blood and egg samples from 116 lakes between 1998 and 2016. We found spatially variable Hg concentrations in adult loon blood and feathers across the Park. Loon Hg concentrations (converted to female loon units) increased 5.7% yr-1 from 1998 to 2010 (p = 0.04), and then stabilized at 1.70 mg kg-1 from 2010 to 2016 (p = 0.91), based on 760 observations. Concentrations of Hg in juvenile loons also increased in the early part of the record, stabilizing 2 years before Hg concentrations stabilized in adults. For 52 individual lakes with samples from at least 4 different years, loon Hg increased in 34 lakes and decreased in 18 lakes. Overall, we found a delayed recovery of Hg concentrations in loons, despite recent declines in atmospheric Hg.


Assuntos
Aves/metabolismo , Monitoramento Ambiental , Mercúrio/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Plumas/química , Feminino , Cadeia Alimentar , Lagos , Compostos de Metilmercúrio , New York
16.
J Avian Med Surg ; 33(4): 361-368, 2019 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-31833304

RESUMO

The pharmacokinetics of danofloxacin was investigated in rehabilitated California brown pelicans (Pelecanus occidentalis californicus) after a single intramuscular injection at a dose of 15 mg/kg body weight. The concentration of the drug in plasma was assayed by high-pressure liquid chromatography. A sparse-sampling design was used to reduce the number of samples (1-4 venipunctures) obtained from 24 brown pelicans. A population pharmacokinetic analysis with nonlinear mixed-effects modeling was used to accommodate the sparse-sampling strategy. The nonlinear mixed-effects modeling approach measured both fixed effects (typical values for the population) and random effects (between-subject variability) for this population. A 1-compartment model best represented the concentration-versus-time data after injection. After injection, the elimination half-life, peak concentration, area under the curve, and volume of distribution were 2.76 hours, 2.5 µg/mL, 13.75 µg/h/mL, and 4.35 L/kg, respectively. Rate of absorption was highly variable among the birds. The intramuscular injection of danofloxacin in pelicans at this dose produced plasma concentrations that meet therapeutic targets for bacteria with a minimum inhibitory concentration of ≤0.25 µg/mL. This dose can be used for future studies to evaluate the efficacy of danofloxacin for treating susceptible bacteria.


Assuntos
Anti-Infecciosos/farmacocinética , Aves/metabolismo , Fluoroquinolonas/farmacocinética , Animais , Anti-Infecciosos/administração & dosagem , Anti-Infecciosos/sangue , Área Sob a Curva , Cromatografia Líquida de Alta Pressão/veterinária , Fluoroquinolonas/administração & dosagem , Fluoroquinolonas/sangue , Meia-Vida , Injeções Intramusculares/veterinária , Absorção Intramuscular , Testes de Sensibilidade Microbiana/veterinária , Dinâmica não Linear , Músculos Peitorais/metabolismo
17.
Int J Mol Sci ; 20(22)2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31698762

RESUMO

Muramidases/lysozymes are important bio-molecules, which cleave the glycan backbone in the peptidoglycan polymer found in bacterial cell walls. The glycoside hydrolase (GH) family 22 C-type lysozyme, from the folivorous bird Opisthocomus hoazin (stinkbird), was expressed in Aspergillus oryzae, and a set of variants was produced. All variants were enzymatically active, including those designed to probe key differences between the Hoatzin enzyme and Hen Egg White lysozyme. Four variants showed improved thermostability at pH 4.7, compared to the wild type. The X-ray structure of the enzyme was determined in the apo form and in complex with chitin oligomers. Bioinformatic analysis of avian GH22 amino acid sequences showed that they separate out into three distinct subgroups (chicken-like birds, sea birds and other birds). The Hoatzin is found in the "other birds" group and we propose that this represents a new cluster of avian upper-gut enzymes.


Assuntos
Aves/metabolismo , Muramidase/química , Trato Gastrointestinal Superior/enzimologia , Sequência de Aminoácidos , Animais , Aspergillus/metabolismo , Parede Celular/metabolismo , Concentração de Íons de Hidrogênio , Modelos Moleculares , Filogenia , Polissacarídeos/química , Eletricidade Estática
18.
Sci Rep ; 9(1): 15405, 2019 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-31659198

RESUMO

In the Arctic, sea-ice plays a central role in the functioning of marine food webs and its rapid shrinking has large effects on the biota. It is thus crucial to assess the importance of sea-ice and ice-derived resources to Arctic marine species. Here, we used a multi-biomarker approach combining Highly Branched Isoprenoids (HBIs) with δ13C and δ15N to evaluate how much Arctic seabirds rely on sea-ice derived resources during the pre-laying period, and if changes in sea-ice extent and duration affect their investment in reproduction. Eggs of thick-billed murres (Uria lomvia) and northern fulmars (Fulmarus glacialis) were collected in the Canadian Arctic during four years of highly contrasting ice conditions, and analysed for HBIs, isotopic (carbon and nitrogen) and energetic composition. Murres heavily relied on ice-associated prey, and sea-ice was beneficial for this species which produced larger and more energy-dense eggs during icier years. In contrast, fulmars did not exhibit any clear association with sympagic communities and were not impacted by changes in sea ice. Murres, like other species more constrained in their response to sea-ice variations, therefore appear more sensitive to changes and may become the losers of future climate shifts in the Arctic, unlike more resilient species such as fulmars.


Assuntos
Aves/fisiologia , Comportamento Alimentar , Óvulo/metabolismo , Elevação do Nível do Mar , Animais , Regiões Árticas , Aves/metabolismo , Carbono/metabolismo , Ecossistema , Nitrogênio/metabolismo , Oviposição , Terpenos/metabolismo
19.
Bull Environ Contam Toxicol ; 103(5): 750-755, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31555848

RESUMO

With increasing urbanization and industrialization, clean air is becoming a scarce resource. During the present investigation, concentrations of metals (Pb, Ni and Zn) in the atmosphere and their subsequent deposition in the lungs of two common avian species, common myna, Acridotheres tristis (n = 30) and bank myna, A. ginginianus (n = 20), captured from urban areas of Lahore city and semi-urban areas of Pattoki city 80 km away from main city of Lahore were determined. The obtained results were analyzed statistically using Independent sample t test and Pearson's correlation. A comparison of trace metal concentrations in air of both the cities was also carried out. Statistically, significant variations were recorded for Pb (t (7) = - 4.276, p = 0.001) while non-significant differences were observed for both Ni (t (7) = 0.049, p = 0.962) and Zn (t (7) = 1.555, p = 0.146).


Assuntos
Poluentes Atmosféricos/metabolismo , Aves/metabolismo , Monitoramento Ambiental/métodos , Pulmão/metabolismo , Metais Pesados/metabolismo , Oligoelementos/metabolismo , Animais , Bioacumulação , Cidades , Paquistão , Urbanização
20.
Artigo em Inglês | MEDLINE | ID: mdl-31476363

RESUMO

Understanding variation in physiological traits across taxa is a central question in evolutionary biology that has wide-ranging implications in biomedicine, disease ecology, and environmental protection. Sialic acid (Sia), and in particular, 5-N-acetylneuraminic acid (Neu5Ac), is chemically bound to galactose and the underlying glycan via α2-3 or α2-6 glycosidic linkage (i.e., Siaα2-3Galactose or Siaα2-6Galactose), conferring two different cell surface structures that affects cell to cell communication and interactions with foreign agents including microparasites and toxins. As an initial step towards understanding variation of Sia across the class Aves, we collected red blood cells (RBCs or erythrocytes) and measured Sia quantity in 76 species and 340 individuals using HPLC-MS/MS and glycosidic linkage type in 24 species and 105 individuals using hemagglutination assay. Although Sia quantity did not, α2-6 glycosidic linkage did exhibit a discernable phylogenetic pattern as evaluated by a phylogenetic signal (λ) value of 0.7. Sia quantity appeared to be higher in after hatch year birds than hatch year birds (P < 0.05); moreover, ~80% of the measured Sia across all individuals or species was expressed by ~20% of the individuals or species. Lastly, as expected, we detected a minimal presence of 5-N-glycolylneuraminic acid in the avian RBCs tested. These data provide novel insights and a large baseline dataset for further study on the variability of Sia in the class Aves which might be useful for understanding Sia dependent processes in birds.


Assuntos
Aves/metabolismo , Eritrócitos/metabolismo , Ácidos Siálicos/metabolismo , Animais , Aves/classificação , Eritrócitos/química , Ácidos Siálicos/química , Especificidade da Espécie
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