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1.
Chemosphere ; 262: 127520, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32791363

RESUMO

Although climate change occurs alongside other anthropogenic ecosystem impacts, little is known about how sea-surface temperature variability influences the ecotoxicology of persistent organic pollutants (POPs). We analyzed POP contaminant levels, and stable isotopes δ15N and δ13C as measures of trophic position, in eggs collected from the Gulf of Alaska and Bering Sea between 1999 and 2010 from two similar avian species with different trophic positions: common murres (Uria aalge) and thick-billed murres (Uria lomvia). The ebb and flow of the Pacific Decadal Oscillation (PDO), a long-lived El Niño-like pattern of climate variability in the Pacific Ocean, predicted both trophic position and polychlorinated biphenyl (PCB) levels in thick-billed murres, but not in common murres. There was a similar pattern of association of the PDO with organochlorine pesticide levels in thick-billed murres, but not in common murres. The magnitude of association in thick-billed murres of PDO with the level of a specific PCB congener was a function of the number of chlorine groups on the PCB congener. Although this statistical analysis does not account for all factors contributing to climate variation, this contrast between the species suggests that facultative changes in foraging behavior, reflected in trophic position, can determine how POPs flow through and thereby alter ecosystems under climate change.


Assuntos
Charadriiformes , Monitoramento Ambiental , Poluentes Ambientais/análise , Óvulo/química , Alaska , Animais , Aves , Ecossistema , Ovos/análise , Hidrocarbonetos Clorados/análise , Oceano Pacífico , Praguicidas/análise , Bifenilos Policlorados/análise
2.
Arch Insect Biochem Physiol ; 105(2): e21728, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32710467

RESUMO

Re-nd, which was induced from the wild-type C108 by the chemical mutagen N-methane-N-methylnitrourea, is a nondiapause red-egg mutant of silkworm Bombyx mori. The special significance of the Re-nd mutant is that it is an independent dominant mutant. The aim of this study was to establish the type of pigment responsible for the red coloration in the Re-nd mutant eggs in silkworm. We compared the eggs of Re-nd mutants with those of the other B. mori egg color strains and confirmed that the Re-nd mutant is the only strain with red color and red pigment granules in nondiapause, showing this mutant belongs to the pigmentation in the serosa. We speculated that the red substance, which contributed to the bright red pigmentation for nondiapause eggs of the Re-nd mutant, could potentially be a novel pigment according to its solubility, optimum absorption peak, and oxidation-reduction reaction. Moreover, we have successfully constituted the system for enrichment, extraction, and purification of the red substance responsible for the Re-nd mutant, providing a new method for the separation and purification of other known and unknown pigments or substances.


Assuntos
Bombyx/química , Óvulo/química , Pigmentos Biológicos/química , Animais , Bombyx/genética , Cromatografia Líquida de Alta Pressão/métodos , Extração Líquido-Líquido/métodos , Mutação , Pigmentação/genética
3.
Nat Commun ; 11(1): 3063, 2020 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-32541780

RESUMO

Symmetric or asymmetric positioning of intracellular structures including the nucleus and mitotic spindle steers various biological processes such as cell migration, division, and embryogenesis. In typical animal cells, both a sparse actomyosin meshwork in the cytoplasm and a dense actomyosin cortex underneath the cell membrane participate in the intracellular positioning. However, it remains unclear how these coexisting actomyosin structures regulate the positioning symmetry. To reveal the potential mechanism, we construct an in vitro model composed of cytoplasmic extracts and nucleus-like clusters confined in droplets. Here we find that periodic centripetal actomyosin waves contract from the droplet boundary push clusters to the center in large droplets, while network percolation of bulk actomyosin pulls clusters to the edge in small droplets. An active gel model quantitatively reproduces molecular perturbation experiments, which reveals that the tug-of-war between two distinct actomyosin networks with different maturation time-scales determines the positioning symmetry.


Assuntos
Actomiosina/química , Actomiosina/metabolismo , Divisão Celular , Óvulo/citologia , Actomiosina/genética , Animais , Fenômenos Biomecânicos , Membrana Celular/química , Membrana Celular/genética , Membrana Celular/metabolismo , Tamanho Celular , Citoplasma/química , Citoplasma/metabolismo , Óvulo/química , Xenopus
4.
Bull Entomol Res ; 110(5): 638-644, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32381143

RESUMO

Telenomus podisi Ashmead (Hymenoptera: Scelionidae) is the most important egg parasitoid of Euschistus heros (Fabricius) (Hemiptera: Pentatomidae), and its successful parasitism is related to their searching ability to find suitable hosts under a complex chemical environment using host-reliable cues. Thus, the objective of this study was to elucidate chemical substances on the external layer of E. heros eggs and report its potential kairomonal activity on T. podisi. We tested female wasps in olfactometer system to synthetic compounds obtained from a chemical identification of E. heros egg masses. The synthetic blend was also evaluated in parasitism tests under laboratory and semi-field conditions. We identified 31 substances from egg surface extracts, including monoterpenes, aldehydes and alkanes. Among those compounds, a synthetic solution including camphene, ß-pinene, limonene and benzaldehyde-induced chemotaxic behaviour on the wasps and increased the parasitism on E. heros eggs, either in laboratory or semi-field test, suggesting its potential use to T. podisi manipulation and parasitism improvement.


Assuntos
Heterópteros/química , Óvulo/química , Feromônios/farmacologia , Vespas/efeitos dos fármacos , Animais , Comportamento Animal/efeitos dos fármacos , Feminino , Heterópteros/parasitologia , Óvulo/parasitologia
5.
Poult Sci ; 99(5): 2608-2615, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32359596

RESUMO

This study was conducted to determine the effects of 25-hydroxycholecalciferol (25-OH-D3) on performance, egg quality, tibia quality, and serum hormones concentration in laying hens reared under high stocking density. A total of 800 45-week-old Lohmann laying hens were randomly allotted into a 2 × 2 factorial design with 2 levels of dietary 25-OH-D3 levels (0 and 69 µg/kg) and 2 rates of stocking densities [506 (low density) and 338 (high density) cm2/hen]. Laying hens were monitored for 16 wk. High stocking density decreased laying rate, egg weight, and feed intake compared with low stocking density (P < 0.01) during 1 to 8 wk and 1 to 16 wk. Overall, high stocking density increased eggshell lightness value and decreased shell redness and yellowness value, strength, thickness, and relative weight compared with low stocking density (P < 0.05). Dietary supplementation with 25-OH-D3 reduced the value of the eggshell lightness and increased its yellowness and eggshells weight (P ≤ 0.05). The increase in eggshell thickness was more pronounced when 25-OH-D3 was supplemented to layers under high stocking density (interaction, P < 0.05). Layers under high stocking density had lower ash content and calcium content in the tibia than layers under low stocking density (P = 0.04); dietary 25-OH-D3 increased tibia strength compared with no addition (P = 0.05). Layers under high stocking density had higher serum concentrations of 25-OH-D3, corticosterone (CORT), lipopolysaccharide (LPS), and osteocalcin (OC; P < 0.05), lower content of parathyroid hormone (PTH) compared with layers under low stocking density (P < 0.01). Dietary 25-OH-D3 increased serum concentration of 25-OH-D3, carbonic anhydrase (CA), and calcitonin (CT) (P < 0.01) and reduced corticosterone, lipopolysaccharide and osteocalcin concentration (P ≤ 0.05). The increase effect in PTH was more pronounced when 25-OH-D3 was supplemented to layers under high stocking density (interaction, P = 0.05). Overall, the results gathered in this study indicate that high stocking density result in reducing production performance, shell color and quality, and tibia health, whereas dietary 25-OH-D3 was able to maintain tibia health and to mitigate the negative impact of high stocking density on productive performance.


Assuntos
Calcifediol/metabolismo , Galinhas/fisiologia , Óvulo/química , Tíbia/química , Ração Animal/análise , Animais , Calcifediol/administração & dosagem , Galinhas/crescimento & desenvolvimento , Dieta/veterinária , Suplementos Nutricionais/análise , Feminino , Densidade Demográfica , Distribuição Aleatória
6.
Environ Pollut ; 260: 113811, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32369891

RESUMO

Decades of large-scale production of per- and polyfluoroalkyl substances (PFASs) have resulted in their ubiquitous presence in the environment worldwide. Similarly to other persistent and bioaccumulative organic contaminants, some PFASs, particularly the long-chain congeners, can be biomagnified via food webs, making top predators vulnerable to elevated PFAS exposure. In this study, we measured seven classes of PFASs in bald eagle (Haliaeetus leucocephalus) eggs for the first time. The eggs (n = 22) were collected from the North American Great Lakes in 2000-2012. The ranges of total concentrations of perfluoroalkyl sulfonic acids (∑PFSAs) and perfluoroalkyl carboxylic acids (∑PFCAs) were 30.5-1650 and 5.4-216 ng/g wet weight (ww), respectively. In addition to these traditional PFAS compounds, 6:2 fluorotelomer sulfonic acid (6:2 FTS; median: 15.7 ng/g ww), perfluoro-4-ethylcyclohexanesulfonic acid (PFECHS; 0.22 ng/g ww), and 8-chloro-perfluorooctanesulfonic acid (Cl-PFOS, detected in wildlife for the first time; 0.53 ng/g ww) were also frequently detected. Bald eagle eggs from breeding areas located less than 8 km from a Great Lake shoreline or tributary had significantly greater total PFAS concentrations (∑PFASs) than those from breeding areas located further than 8 km (p < 0.05). In these samples, ∑PFASs rivalled the total concentration of brominated flame retardants, and were significantly greater than those of several other organic contaminants, such as dechlorane-related compounds, organophosphate esters, and flame retardant metabolites.


Assuntos
Águias , Fluorcarbonetos/química , Hidrocarbonetos Clorados/química , Óvulo/química , Animais , Monitoramento Ambiental , Great Lakes Region , Hidrocarbonetos Clorados/análise , Lagos , Óvulo/metabolismo , Poluentes Químicos da Água
7.
Environ Sci Technol ; 54(12): 7504-7512, 2020 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-32459094

RESUMO

Using omics approaches to monitor complex environmental mixtures is challenging. Previously, we evaluated in vitro transcriptomic effects of complex organic extracts derived from avian eggs. However, there is a lack of studies using wild species that are naturally exposed to contaminant mixtures. Here, we examined polychlorinated biphenyl (PCB) and polybrominated diphenyl ether (PBDE) residues and gene expression in embryonic liver tissue of double-crested cormorants (Phalacrocorax auritus) collected from six variably contaminated colonies. Colonies near industrialized areas were distinguished from less contaminated sites based on their PCB and PBDE concentrations. The most variably expressed genes between sites were involved in pathways including, xenobiotic metabolism (e.g., Cyp1a4), lipid/bile acid homeostasis (e.g., Lbfabp), and oxidative stress (e.g., Mt4). Hierarchical clustering, based on relative gene expression, revealed a grouping pattern similar to chemical residue concentrations. Further, partial least squares regression analysis was used to estimate chemical concentrations from transcriptomics data. PCB 155 and BDE 47 showed the highest slopes (0.77 and 0.69, respectively) fitted by linear regression of measured and estimated chemical concentrations. The application of transcriptomics to a wild avian species, naturally exposed to complex chemical mixtures and other stressors, represents a promising means to distinguish and prioritize variably contaminated sites.


Assuntos
Lagos , Bifenilos Policlorados , Animais , Aves/genética , Monitoramento Ambiental , Óvulo/química , Bifenilos Policlorados/análise , Bifenilos Policlorados/toxicidade , Toxicogenética
8.
Mar Pollut Bull ; 154: 111126, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32319936

RESUMO

The Persian Gulf, the most important marine ecosystem, and its islands are negatively impacted by development and pollution. Different types of pollution, especially heavy metals in these habitats, may create risks to birds, influencing reproductive performance, survival, and behaviors. Heavy metals (Cd, Pb, Cr) were analyzed in two long-lived and top food web-level sea birds, Lesser (Thalasseus bengalensis) and Greater Crested Tern (Thalasseus bergii). The research was carried out during 2018 on Nakhiloo Island, located in Dayyer-Nakhiloo Marine National Park, northeastern Persian Gulf, Iran. The nests were selected randomly, and 40 eggs of colonially-nesting terns (20 eggs T. bengalensis and 20 eggs T. bergii; a single egg per nest) were collected. The concentration of heavy metals in eggshells and egg contents was studied to investigate whether bioaccumulation varies between the eggshells and egg contents and also varies in both species. There were significant differences in the amounts of Cd between eggshell and egg content in the Greater and Lesser Crested Tern. This difference was not significant in the concentrations of Pb between the eggshell and egg content in the Tern species. Concentration of Cr did not appear to accumulate in the egg content and was below detection limit. There were significant differences in the concentrations of Cd in the eggshells and egg content between the Greater and Lesser Crested Tern. The results serve to improve understanding and to evaluate the dynamics of heavy metals in eggshells and egg content in various avian species.


Assuntos
Charadriiformes , Poluentes Ambientais/análise , Metais Pesados/análise , Animais , Bioacumulação , Aves , Ecossistema , Casca de Ovo/química , Monitoramento Ambiental , Oceano Índico , Irã (Geográfico) , Óvulo/química
9.
Food Chem ; 320: 126612, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32197124

RESUMO

In this work, in-syringe membrane solid-phase extraction (MSPE) device was fabricated for the on-site sampling of sulfamethoxazole (SMX) in food samples followed by solid-phase fluorescence spectra analysis. The samples and fluorescamine (FA) were added to a syringe for derivation. Then, the derivative of SMX was extracted by a membrane in the syringe SPE device. Subsequently, the derivative on the membrane was measured immediately without additional elution procedure. The method was successfully applied in plasma, milk, and egg samples for the trace SMX detection, with the recovery of 98%-102%, RSDs from 1% to 6%. Compared with liquid chromatography, direct detection of the concentrated analyte significantly improved the sensitivity. Moreover, fluorescamine made it unnecessary to separate SMX from the interference. Consequently, it was a time-saving, low-cost, and easy-operation method, which demonstrated the potential of in-syringe SPE as a promising candidate for on-site analysis.


Assuntos
Sulfametoxazol/análise , Animais , Galinhas , Cromatografia Líquida de Alta Pressão , Análise de Alimentos , Leite/química , Óvulo/química , Soro/química , Extração em Fase Sólida/instrumentação , Espectrometria de Fluorescência , Seringas , Fatores de Tempo
10.
Poult Sci ; 99(2): 1038-1051, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32036961

RESUMO

There is limited information on feeding egg-type chick breeders n-3 polyunsaturated fatty acids (PUFA) and its impact on hatching egg quality and embryonic fatty acid (FA) utilization. We investigated the effects of feeding brown and white egg-type chick breeders diets containing sources of n-3 PUFA on egg composition, apparent embryonic FA utilization, and intestinal FA transporter in hatchlings. Twenty-six-week-old ISA brown and Shaver white breeders were fed either 1) control (CON); 2) CON + 1% of microalgae (DMA, Aurantiochytrium limacinum) fermentation product, as a source of docosahexaenoic acid (DHA); or 3) CON + 2.60% of coextruded full-fat flaxseed and pulse mixture (FFF, 1:1 wt/wt) as a source of α-linolenic acid (ALA). Test diets had similar total n-3 and n-6:n-3 ratio. Eggs were hatched, and residual yolk (RY) samples taken for FA analyses. Apparent embryonic FA utilization was calculated by subtracting concentration of FA in RY from concentration of FA in yolk before incubation. There was an interaction between strains and diets (P < 0.05) on DHA in phospholipid and triglyceride fractions of yolk. Both n-3 PUFA sources increased DHA to a greater extent in Shaver white than in ISA brown. The interactive effect of strains and diets (P = 0.019) on embryonic utilization of ALA was such that DMA and FFF reduced ALA utilization, and this pattern was more prevalent in Shaver white birds than in ISA brown birds. There was no interaction between strains and diets on DHA utilization (P > 0.05). Embryos from hens fed n-3 PUFA sources used less total FA in phospholipid fraction (P < 0.001), and they preferentially used more DHA than CON embryos. Shaver white embryos used more (P < 0.05) ALA and DHA than ISA brown embryos. Although data suggested Shaver white had higher propensity of depositing DHA than ISA brown, irrespective of strain, feeding n-3 PUFA modified embryonic pattern of FA utilization toward utilization of DHA.


Assuntos
Embrião de Galinha/metabolismo , Galinhas/metabolismo , Ácido Eicosapentaenoico/metabolismo , Microalgas/química , Ração Animal/análise , Animais , Dieta/veterinária , Suplementos Nutricionais/análise , Ácido Eicosapentaenoico/administração & dosagem , Proteínas de Transporte de Ácido Graxo/metabolismo , Feminino , Fígado/química , Malondialdeído/metabolismo , Óvulo/química , Óvulo/efeitos dos fármacos , Estramenópilas/química
11.
Soft Matter ; 16(7): 1714-1721, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-32031549

RESUMO

Females of some Asian salamanders of the genus Hynobius deposit in streams their eggs embedded in a translucent envelope called an 'egg sac'. The edges of the envelope exhibit a spectacular blue-to-yellow iridescent glow, which instantaneously disappears when the sac is removed from water. First, our scanning electron microscopy analyses reveal that the inner surface of the 100 µm-thick envelope displays striations (length scale of about 3 µm), which are themselves covered by much smaller (190 ± 30 nm) and quasi-periodic corrugations. The latter could constitute a surface diffraction grating generating iridescence by light interference. Second, our transmission electron microscopy and focused-ion-beam scanning electron microscopy analyses show that the bulk of the egg sac wall is composed of meandering fibres with a quasi-periodic modulation of 190 ± 60 nm along the thickness of the envelope, generating a photonic crystal. Third, Fourier power analyses of 450 electron microscopy images with varying incident angles indicate that changing the surrounding medium from water to air shifts most of the backscattered power spectrum to the ultraviolet range, hence, explaining that the egg sac loses visible iridescence when removed out of the water. Fourth, the results of our photography and optical spectroscopy experiments of submerged and emerged egg sacs rule out the possibility that the iridescence is due to a thin film or a multilayer, whereas the observed non-specular response is compatible with the backscattering expected from surface diffraction gratings and volumetric photonic crystals with spatial 1D modulation. Finally, although we mention several potential biological functions of the egg sac structural colours and iridescence, we emphasise that these optical properties might be the by-products of the envelope material internal structure selected during evolution for its mechanical properties.


Assuntos
Iridescência , Óvulo/ultraestrutura , Urodelos/anatomia & histologia , Água/química , Ar , Animais , Feminino , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Óvulo/química , Óvulo/crescimento & desenvolvimento , Fotografação , Urodelos/metabolismo , Urodelos/fisiologia
12.
Proc Natl Acad Sci U S A ; 117(4): 2056-2064, 2020 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-31888995

RESUMO

Offspring ornamentation typically occurs in taxa with parental care, suggesting that selection arising from social interactions between parents and offspring may underlie signal evolution. American coot babies are among the most ornamented offspring found in nature, sporting vividly orange-red natal plumage, a bright red beak, and other red parts around the face and pate. Previous plumage manipulation experiments showed that ornamented plumage is favored by strong parental choice for chicks with more extreme ornamentation but left unresolved the question as to why parents show the preference. Here we explore natural patterns of variation in coot chick plumage color, both within and between families, to understand the context of parental preference and to determine whose fitness interests are served by the ornamentation. Conspecific brood parasitism is common in coots and brood parasitic chicks could manipulate hosts by tapping into parental choice for ornamented chicks. However, counter to expectation, parasitic chicks were duller (less red) than nonparasitic chicks. This pattern is explained by color variation within families: Chick coloration increases with position in the egg-laying order, but parasitic eggs are usually the first eggs a female lays. Maternal effects influence chick coloration, but coot females do not use this mechanism to benefit the chicks they lay as parasites. However, within families, chick coloration predicts whether chicks become "favorites" when parents begin control over food distribution, implicating a role for the chick ornamentation in the parental life-history strategy, perhaps as a reliable signal of a chick's size or age.


Assuntos
Aves/fisiologia , Seleção Genética , Animais , Evolução Biológica , Aves/classificação , Aves/genética , Cruzamento , Cor , Feminino , Masculino , Comportamento de Nidação , Óvulo/química , Óvulo/fisiologia , Linhagem
13.
Chemosphere ; 243: 125424, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31995877

RESUMO

Trace metal and metalloid levels were measured in eggs of the NW Atlantic leatherback turtle (Dermochelys coriacea) from nesting grounds in the Bocas del Toro province, Panama, to infer exposure and associated risks to local communities. Samples were analyzed for a set of 26 essential and non-essential elements using inductively coupled plasma techniques. Median concentrations of Fe, Zn, As, Se and Sr in D. coriacea eggs were higher than previously reported for this species, which likely reflects differential contamination levels of specimens during foraging. The evaluation of non-carcinogenic human health risks from ingesting leatherback eggs has revealed potential deleterious effects due to high concentrations of As, Se and Sr for all examined age and gender groups, while Hg and Zn levels were above international standards for children. Hazard index (HI) values exceeded unity in all cases indicating serious health impacts related to possible additive effects of multiple metals co-occurring in the eggs. Our findings suggest that exposure to high (inorganic) As and Cr(VI) levels is associated with an increased carcinogenic risk, significantly exceeding the acceptable lifetime risk of 10-6 for both adults and children. Despite some limitations, such as unclear As and Cr speciation, our results demonstrated that the ingestion of D. coriacea eggs poses considerable health risks to local communities, and their consumption should not exceed 3.4 × 10-4 g (5.0 × 10-6 eggs) kg BW d-1. Resource managers and conservationists should focus their attention to human health effects as an alternative tool to address egg poaching and consumption.


Assuntos
Contaminação de Alimentos/análise , Metais Pesados/análise , Óvulo/química , Oligoelementos/análise , Tartarugas/metabolismo , Animais , Região do Caribe , Feminino , Panamá
14.
J Fish Biol ; 96(1): 168-174, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31713867

RESUMO

Changes in the proportions of river- and lake-produced eggs of a landlocked amphidromous fish, ayu (Plecoglossus altivelis altivelis) in the Lake Biwa water system, Japan, were monitored by stable isotope analysis, based on different δ15 N and δ13 C values of prey organisms between the lake and its tributaries. During the 3 month reproduction season, the δ15 N values of spawned eggs decreased with time. This result implies that there was a shift from lake-produced eggs to river-produced eggs within a reproductive season, based on the observation that adult fish in the lake had previously been shown to have eggs with distinctly higher δ15 N values in their ovaries than those in the tributaries. This explanation was also supported by the change in δ13 C values of the spawned eggs. Furthermore, eggs with lower δ15 N and higher δ13 C values tended to be spawned at less variable depths, suggesting that females spawning river-produced eggs selected the spawning sites from a narrower range. We conclude that stable isotope ratios of spawned eggs can be indicators of the relative contributions of different food chains and can enable comparisons of reproductive characteristics between types of egg.


Assuntos
Migração Animal , Monitorização de Parâmetros Ecológicos/métodos , Osmeriformes , Animais , Isótopos de Carbono , Feminino , Cadeia Alimentar , Japão , Lagos , Isótopos de Nitrogênio , Óvulo/química , Rios , Estações do Ano
15.
Mikrochim Acta ; 187(1): 12, 2019 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-31802244

RESUMO

A fluorometric method is described for the determination of fipronil, a frequently-used insecticide. It exploits the blue fluorescence of carbon quantum dots (CQDs) and the selectivity of molecularly imprinted silica (MIS). The MIS was prepared via the sol-gel method by using fipronil as the template, 3-aminopropyltriethoxysilane as functional monomer, and tetraethoxysilane as cross-linker in the presence of CQDs. The blue fluorescence of the CQD@MIS, with excitation/emission peaks at 340/422 nm, is quenched by fipronil. The assay works in the 0. 70 pM to 47 µM fipronil concentration range, and the limit of detection is 19 pM. The method was successfully applied to the quantitation of fipronil in spiked eggs, milk, and tap water. Recoveries between 83.8 and 114.0% were achieved. The corresponding relative standard deviations (RSD) are less than 6.67%. Graphical abstractSchematic representation of a high sensitivite and selectivite fluorescence nanoprobe constructed by combining the excellent fluorescence property of carbon quantum dots and the predicted selectivity of molecularly imprinted silica. It was applied to analyze fipronil in egg, milk and tap water, respectively.


Assuntos
Carbono/química , Fluorometria/métodos , Impressão Molecular , Pirazóis/análise , Pontos Quânticos/química , Dióxido de Silício/química , Animais , Calibragem , Água Potável/química , Contaminação de Alimentos/análise , Inocuidade dos Alimentos , Limite de Detecção , Leite/química , Óvulo/química , Propilaminas/química , Pirazóis/química , Silanos/química
16.
Biochem J ; 476(24): 3791-3804, 2019 12 23.
Artigo em Inglês | MEDLINE | ID: mdl-31808793

RESUMO

Oxidative DNA damage represents one of the most abundant DNA lesions. It remains unclear how DNA repair and DNA damage response (DDR) pathways are co-ordinated and regulated following oxidative stress. While XRCC1 has been implicated in DNA repair, it remains unknown how exactly oxidative DNA damage is repaired and sensed by XRCC1. In this communication, we have demonstrated evidence that XRCC1 is dispensable for ATR-Chk1 DDR pathway following oxidative stress in Xenopus egg extracts. Whereas APE2 is essential for SSB repair, XRCC1 is not required for the repair of defined SSB and gapped plasmids with a 5'-OH or 5'-P terminus, suggesting that XRCC1 and APE2 may contribute to SSB repair via different mechanisms. Neither Polymerase beta nor Polymerase alpha is important for the repair of defined SSB structure. Nonetheless, XRCC1 is important for the repair of DNA damage following oxidative stress. Our observations suggest distinct roles of XRCC1 for genome integrity in oxidative stress in Xenopus egg extracts.


Assuntos
Extratos Celulares/química , Genoma , Óvulo/metabolismo , Proteína 1 Complementadora Cruzada de Reparo de Raio-X/metabolismo , Xenopus/metabolismo , Animais , Cromatina , Dano ao DNA , Reparo do DNA , Regulação da Expressão Gênica , Masculino , Óvulo/química , Estresse Oxidativo , Plasmídeos , Espermatozoides , Proteína 1 Complementadora Cruzada de Reparo de Raio-X/química , Proteína 1 Complementadora Cruzada de Reparo de Raio-X/genética , Xenopus/genética
17.
Food Funct ; 10(12): 8240-8249, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31710072

RESUMO

Asn-Asp-Glu-Glu-Leu-Asn-Lys (NDEELNK), derived from a sea cucumber ovum, has shown a prominent calcium-binding ability. In this study, the formation mechanism of a NDEELNK-calcium nanocomposite and its digestion and absorption behavior were investigated. Results indicated that calcium ions specifically bound to two carboxyl oxygen atoms of Asp and Glu on the NDEELNK peptide in its monomeric form, and that the binding mode was referred to as the "bidentate" mode. Calcium coordination induced the self-assembly of the NDEELNK peptide dominated by an α-helix and a random coil structure, resulting in the formation of nanoparticles with a crystal structure. NDEELNK possessed a good digestive stability of 90.21 ± 1.11% in the gastrointestinal (GI) tract; moreover, two other fragments (DEELNK and EELNK) and seven modified variants were identified by nano-LC-ESI-MS/MS in the GI digests. Nevertheless, the GI digests of the NDEELNK-calcium complex could significantly enhance calcium absorption across the Caco-2 cell monolayers as compared to the initial complex.


Assuntos
Cálcio/química , Óvulo/química , Peptídeos/química , Pepinos-do-Mar/química , Animais , Células CACO-2 , Cálcio/metabolismo , Digestão , Trato Gastrointestinal/metabolismo , Humanos , Óvulo/metabolismo , Peptídeos/metabolismo , Pepinos-do-Mar/metabolismo , Espectrometria de Massas em Tandem
18.
J Agric Food Chem ; 67(48): 13353-13361, 2019 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-31682436

RESUMO

Protein phosphorylation plays an important role in protein structure and function. To investigate the role of egg protein phosphorylation in chicken embryonic development, a comparative and quantitative phosphoproteomic analysis of fertilized chicken egg white and yolk was performed during incubation. Overall, 215 phosphosites mapped onto 205 phosphopeptides corresponding to 100 phosphoproteins were identified. Among these phosphoproteins, 123 phosphosites from 62 egg proteins were found significantly changed (p < 0.05) at day 12 during incubation. Furthermore, GO analysis suggested that these differentially phosphorylated proteins were associated with various molecular functions, primarily including binding, molecular function regulator, and transport activity. Such findings in this study improved our understanding of the protein molecular functions involved in chicken embryonic development from a protein phosphorylation perspective.


Assuntos
Galinhas/metabolismo , Proteínas do Ovo/química , Óvulo/química , Fosfoproteínas/química , Animais , Galinhas/genética , Galinhas/crescimento & desenvolvimento , Proteínas do Ovo/metabolismo , Óvulo/crescimento & desenvolvimento , Óvulo/metabolismo , Fosfoproteínas/metabolismo , Fosforilação , Proteômica , Espectrometria de Massas em Tandem
19.
Ecotoxicology ; 28(10): 1160-1168, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31624990

RESUMO

The breeding population of peregrine falcons (Falco peregrinus) in Norway was almost exterminated by the early 1970's. Long-term monitoring of breeding pairs has been conducted since 1976 up to present. Peregrine falcons were first established at breeding sites in coastal habitats, where they remained at stable low numbers until the early 1990's. Starting around 2000, numbers began to increase steadily, and current numbers have now reached historical population levels from the pre-DDT era. We documented a range expansion with increasing numbers of peregrines nesting in the fjords and inland valleys. We found that once a territory was colonized, the probability that a territory remained occupied was high (S > 0.958). During early stages of population recovery, the transitional probabilities of becoming or remaining a breeding territory were high (ψN-B > 0.40, ψB-B > 0.65) but declined over time, especially in coastal habitats. Moreover, the productivity per nest has also decreased over time at sites in coastal habitats in the former stronghold of the population. The levels of environmental pollutants in eggs of the peregrines have dropped sharply over the last few decades, and contaminant levels now seem to be below critical levels. Eggshells were relatively thin throughout the 1970s, 1980s, and 1990s, but have increased to almost normal levels during the last 2 decades. Reductions in levels of organochlorine pollutants, especially DDT, appear to have been the main factor in explaining the population recovery. The territory dynamics are consistent with density-dependence and the low breeding success of the coastal-breeding peregrines is believed to be caused by declining numbers of colonial seabirds and other prey species.


Assuntos
Conservação dos Recursos Naturais , DDT/análise , Monitoramento Ambiental , Poluentes Ambientais/análise , Falconiformes/fisiologia , Distribuição Animal , Animais , DDT/efeitos adversos , Ecossistema , Poluentes Ambientais/efeitos adversos , Óvulo/química , Crescimento Demográfico , Reprodução
20.
J Exp Zool A Ecol Integr Physiol ; 331(10): 552-561, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31625280

RESUMO

Trade-offs among the key life-history traits of reproduction and immunity have been widely documented. However, the currency in use is not well-understood. We investigated how reproducing female side-blotched lizards, Uta stansburiana, allocate lipids versus proteins when given an immune challenge. We tested whether lizards would invest more in reproduction or immunity depending on reproductive stage. Females were given stable isotopes (15 N-leucine and 13 C-1-palmitic acid), maintained on a regular diet and given either a cutaneous biopsy or a sham biopsy (control). Stable isotopes were monitored and analyzed in feces and uric acid, skin biopsies, eggs, and toe clips. We found that lizards deposited both proteins and lipids into their healing wounds (immune-challenged), skin (control), and eggs (all) and that catabolism of proteins exceeded incorporation into tissue during wound-healing. Specifically, we found that healed biopsies of wounded animals had more leucine and palmitic acid than the nonregrown skin biopsies taken from unwounded control animals. Earlier in reproduction, lizards invested relatively more labeled proteins into healing their wound tissue, but not into unwounded skin of control animals. Thus, reproduction is sometimes favored over self-maintenance, but only in later reproductive stages. Finally, we documented positive relationships among the amount of palmitic acid deposited in the eggs, the amount of food eaten, and the amount of palmitic acid excreted, suggesting higher turnover rates of lipids in lizards investing highly in their eggs.


Assuntos
Lagartos/imunologia , Lagartos/metabolismo , Reprodução/fisiologia , Aminoácidos/metabolismo , Animais , Biópsia , Ácidos Graxos Essenciais/metabolismo , Feminino , Leucina , Óvulo/química , Ácido Palmítico , Pele/lesões , Pele/metabolismo , Cicatrização/fisiologia
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