Accumulation Of Eggs Research Articles

Population Pharmacokinetics and Absolute Oral Bioavailability of Lasalocid after Single Intravenous and Intracrop Administration in Laying Hens.

Lasalocid sodium is a polyether carboxylic ionophore agent authorized by the EU for use as a coccidiostat in broilers, turkeys, and pullets up to 16 weeks of age, except for laying hens. However, laying hens are the most common nontarget species exposed to lasalocid sodium, mainly due to cross-contamination from feed mills. This exposure may result in potential drug residue deposition in eggs, which could potentially expose consumers to the drug. The breeds commonly used for commercial egg production in Poland are Isa Brown and Green-legged Partridge hens, which have been found to significantly differ in egg-laying performance. This variability may also affect the pharmacokinetics of lasalocid. Data on lasalocid plasma pharmacokinetics in laying hens are lacking. In this study, we aimed to determine typical population pharmacokinetic parameters, absolute oral bioavailability, and how breed may influence the pharmacokinetics of lasalocid. Twenty-layer hens of the two breeds were used in this study. Lasalocid was administered orally at a single dose of either 1 mg or 5 mg/kg body weight or intravenously at a dose of 1 mg/kg body weight, in a crossover design with a three-week washout period between study periods. Blood samples were collected for 72 h, and lasalocid concentrations were measured using high-performance liquid chromatography with fluorescence detection. A population pharmacokinetic analysis was conducted using nonlinear mixed effects modeling. Standard numerical and graphical criteria were used to select the best model, and a stepwise covariate modeling approach was used to determine any influencing factors. The best model was a three-compartment mammillary model with first-order absorption, transit compartments, and linear elimination. The estimated absolute oral bioavailability was low (36%). It was found that breed significantly influenced not only absorption but also the elimination of lasalocid. This study revealed that lasalocid absorption and elimination varied between the two breeds. This variability in pharmacokinetics may result in breed-related differences in drug residue accumulation in eggs, and ultimately, the risk associated with consumer exposure to drug residues may also vary.

Large dinosaur egg accumulations and their significance for understanding nesting behaviour

The accurate identification of dinosaur egg accumulations as nests or clutches is crucial for understanding the reproductive behaviour of these extinct species. However, existing methods often rely on the presence of complete eggs and embryo remains, and sedimentological criteria that are only applicable to well-structured sediments. In this study, we introduce an innovative approach to characterize egg accumulations in structureless sediments, where traditional nest structures may not be preserved. Our methodology employs a unique combination of sedimentological, taphonomic, geochemical, and geophysical proxies for the study of egg accumulations. We applied this approach to the egg accumulation from Paimogo (Jurassic, Portugal), traditionally interpreted as a nest. Our findings reveal that the Paimogo egg assemblage is a secondary deposit, resulting from a flooding event in a fluvial plain that dismantled several allosauroid and crocodylomorph clutches. The eggshell vapor conductance results, coupled with sedimentological evidence, suggest that allosauroid dinosaurs buried their eggs in the dry terrain of overbank areas close to a main channel during the breeding season, likely during the dry season to prevent the embryos from drowning. This research underscores the necessity of multidisciplinary approaches in interpreting egg accumulations and offers a novel methodology for studying these accumulations in structureless sediments. Our findings provide new insights into the breeding behaviour and nesting preferences of these extinct organisms, contributing to our understanding of dinosaur ecology.

The Role of BmTMED6 in Female Reproduction in Silkworm, Bombyx mori.

Transmembrane emp24 domain (TMED) proteins have been extensively studied in mammalian embryonic development, immune regulation, and signal transduction. However, their role in insects, apart from Drosophila melanogaster, remains largely unexplored. Our previous study demonstrated the abundant expression of BmTMED6 across all stages and tissues of the silkworm. In this study, we investigate the function of BmTMED6 in reproduction. We observe significant differences in the expression of BmTMED6 between male and female silkworms, particularly in the head and fatboby, during the larval stage. Furthermore, qRT-PCR and WB analysis reveal substantial variation in BmTMED6 levels in the ovaries during pupal development, suggesting a potential association with silkworm female reproduction. We find that reducing TMED6 expression significantly decreases the number of eggs laid by female moths, leading to an accumulation of unlaid eggs in the abdomen. Moreover, downregulation of BmTMED6 leads to a decrease in the expression of BmDop2R1 and BmDop2R2, while overexpression of BmTMED6 in vitro has the opposite effect. These indicate that BmTMED6 plays a role in oviposition in female moths, potentially through the dopamine signaling pathway. This study provides a new regulatory mechanism for female reproduction in insects.

Field investigation combined with modeling uncovers the ecological heterogeneity of Aedes albopictus habitats for strategically improving systematic management during urbanization

BackgroundAedes albopictus is an invasive vector of serious Aedes-borne diseases of global concern. Habitat management remains a critical factor for establishing a cost-effective systematic strategy for sustainable vector control. However, the community-based characteristics of Ae. albopictus habitats in complex urbanization ecosystems are still not well understood.MethodsA large-scale investigation of aquatic habitats, involving 12 sites selected as representative of four land use categories at three urbanization levels, was performed in Guangzhou, China during 2015–2017. The characteristics and dynamics of these Ae. albopictus habitats were assessed using habitat-type composition, habitat preference, diversity indexes and the Route index (RI), and the temporal patterns of these indexes were evaluated by locally weighted scatterplot smoothing models. The associations of RI with urbanization levels, land use categories and climatic variables were inferred using generalized additive mixed models.ResultsA total of 1994 potential habitats and 474 Ae. albopictus-positive habitats were inspected. The majority of these habitats were container-type habitats, with Ae. albopictus showing a particularly higher habitat preference for plastic containers, metal containers and ceramic vessels. Unexpectedly, some non-container-type habitats, especially ornamental ponds and surface water, were found to have fairly high Ae. albopictus positivity rates. Regarding habitats, the land use category residential and rural in Jiangpu (Conghua District, Guangzhou) had the highest number of Ae. albopictus habitats with the highest positive rates. The type diversity of total habitats (H-total) showed a quick increase from February to April and peaked in April, while the H-total of positive habitats (H-positive) and RIs peaked in May. RIs mainly increased with the monthly average daily mean temperature and monthly cumulative rainfall. We also observed the accumulation of diapause eggs in the winter and diapause termination in the following March.ConclusionsEcological heterogeneity of habitat preferences of Ae. albopictus was demonstrated in four land use categories at three urbanization levels. The results reveal diversified habitat-type compositions and significant seasonal variations, indicating an ongoing adaptation of Ae. albopictus to the urbanization ecosystem. H-positivity and RIs were inferred as affected by climatic variables and diapause behavior of Ae. albopictus, suggesting that an effective control of overwintering diapause eggs is crucial. Our findings lay a foundation for establishing a stratified systematic management strategy of Ae. albopictus habitats in cities that is expected to complement and improve community-based interventions and sustainable vector management.Graphical

The Arabidopsis thioredoxin TRXh5regulates the S-nitrosylation pattern of the TIRK receptor being both proteins essential in the modulation of defences to Tetranychus urticae

The interaction between plants and phytophagous arthropods encompasses a complex network of molecules, signals, and pathways to overcome defences generated by each interacting organism. Although most of the elements and modulators involved in this interplay are still unidentified, plant redox homeostasis and signalling are essential for the establishment of defence responses. Here, focusing on the response of Arabidopsis thaliana to the spider mite Tetranychus urticae, we demonstrate the involvement in plant defence of the thioredoxin TRXh5, a small redox protein whose expression is induced by mite infestation. TRXh5 is localized in the cell membrane system and cytoplasm and is associated with alterations in the content of reactive oxygen and nitrogen species. Protein S-nitrosylation signal in TRXh5 over-expression lines is decreased and alteration in TRXh5 level produces changes in the JA/SA hormonal crosstalk of infested plants. Moreover, TRXh5 interacts and likely regulates the redox state of an uncharacterized receptor-like kinase, named THIOREDOXIN INTERACTING RECEPTOR KINASE (TIRK), also induced by mite herbivory. Feeding bioassays performed withTRXh5 over-expression plants result in lower leaf damage and reduced egg accumulation after T. urticae infestation than in wild-type (WT) plants. In contrast, mites cause a more severe injury in trxh5 mutant lines where a greater number of eggs accumulates. Likewise, analysis of TIRK-gain and -loss-of-function lines demonstrate the defence role of this receptor in Arabidopsis against T. urticae. Altogether, our findings demonstrate the interaction between TRXh5 and TIRK and highlight the importance of TRXh5 and TIRK in the establishment of effective Arabidopsis defences against spider mite herbivory.

Muscle-directed mechanosensory feedback activates egg-laying circuit activity and behavior in Caenorhabditis elegans

Mechanosensory feedback of the internal reproductive state drives decisions about when and where to reproduce.1 For instance, stretch in the Drosophila reproductive tract produced by artificial distention or from accumulated eggs regulates the attraction to acetic acid to ensure optimal oviposition.2 How such mechanosensoryfeedback modulates neural circuits to coordinate reproductive behaviors is incompletely understood. We previously identified a stretch-dependent homeostat that regulates egg laying in Caenorhabditis elegans. Sterilized animals lacking eggs show reduced Ca2+ transient activity in the presynaptic HSN command motoneurons that drive egg-laying behavior, while animals forced to accumulate extra eggs show dramatically increased circuit activity that restores egg laying.3 Interestingly, genetic ablation or electrical silencing of the HSNs delays, but does not abolish, the onset of egg laying,3,4,5 with animals recovering vulval muscle Ca2+ transient activity upon egg accumulation.6 Using an acute gonad microinjection technique to mimic changes in pressure and stretch resulting from germline activity and egg accumulation, we find that injection rapidly stimulates Ca2+ activity in both neurons and muscles of the egg-laying circuit. Injection-induced vulval muscle Ca2+ activity requires L-type Ca2+ channels but is independent of presynaptic input. Conversely, injection-induced neural activity is disrupted in mutants lacking the vulval muscles, suggesting "bottom-up" feedback from muscles to neurons. Direct mechanical prodding activates the vulval muscles, suggesting that they are the proximal targets of the stretch-dependent stimulus. Our results show that egg-laying behavior in C.elegans is regulated by a stretch-dependent homeostat that scales postsynaptic muscle responses with egg accumulation in the uterus.

Knockdown of the salivary protein gene NlG14 caused displacement of the lateral oviduct secreted components and inhibited ovulation in Nilaparvata lugens.

Saliva plays important roles in insect feeding, but its roles in insect reproduction were rarely reported. Here we reported that the knockdown of a salivary gland-specific gene NlG14 disrupted the reproduction through inhibiting the ovulation of the brown planthopper (BPH), Nilaparvata lugens (Stål), one of the most devastating rice pests in Asia. NlG14 knockdown caused the displacement of the lateral oviduct secreted components (LOSC), leading to the ovulation disorder and the accumulation of mature eggs in the ovary. The RNAi-treated females laid much less eggs than their control counterparts, though they had the similar oviposition behavior on rice stems as controls. NlG14 protein was not secreted into the hemolymph, indicating an indirect effect of NlG14 knockdown on BPH reproduction. NlG14 knockdown caused the malformation of A-follicle of the principal gland and affected the underlying endocrine mechanism of salivary glands. NlG14 reduction might promote the secretion of insulin-like peptides NlILP1 and NlILP3 from the brain, which up-regulated the expression of Nllaminin gene and then caused the abnormal contraction of lateral oviduct muscle. Another explanation was NlG14 reduction disrupted the ecdysone biosynthesis and action through the insulin-PI3K-Akt signaling in ovary. Altogether, this study indicated that the salivary gland specific protein NlG14 indirectly mediated BPH ovulation process, which established a connexon in function between insect salivary gland and ovary.

Maternal Transfer and Apical and Physiological Effects of Dietary Hexabromocyclododecane Exposure in Parental Fathead Minnows (Pimephales promelas).

Hexabromocyclododecane (HBCD) is a persistent organic pollutant that has been characterized as an endocrine disruptor, undergoes maternal transfer, and hinders development and growth in oviparous organisms. The present study examined the apical effects of dietary HBCD (11.5, 36.4, 106 mg/kg, wet wt) on adult fathead minnow exposed for 49 days and the subsequent accumulation and maternal transfer kinetics in adult tissue and eggs, respectively. Exposed adults displayed a significant increase in egg production in the medium treatment group, but no other significant effects were noted. Maternal transfer of dietary HBCD had a similar egg-to-muscle ratios (EMR) in the low and medium treatment groups (1.65 and 1.27 [wet wt], respectively). However, the high treatment group deviated from other treatments with an EMR of 4.2 (wet wt), potentially due to differences in total lipid content in food and/or reaching diffusion/lipid saturation limits in adult tissue, resulting in lower accumulation in the adult muscle tissue. A positive correlation was observed between egg HBCD concentration and time of exposure, which indicates that maternal transfer of HBCD is of concern in fish, and further studies should be conducted to fully elucidate the potential adverse effects that may be observed in the early life stage of oviparous organisms. Environ Toxicol Chem 2023;42:143-153. © 2022 SETAC.

Abstract 15005: Tlr4/py14-Caveolin-1-Mediated Endothelial C-iap2 Expression During Schistosomiasis-Associated Pulmonary Arterial Hypertension

Introduction: During schistosomiasis-associated pulmonary arterial hypertension (Sch-PAH), hyperproliferation of abnormal endothelial cells (ECs) contributes to development of severe vascular lesions within the lungs; a life-threatening phenomenon that remains with no target therapy. Hypothesis: Here, we found that antigenic molecules from the major etiological agent of Sch-PAH, i.e., S. mansoni , amplify the secretion of the antiapoptotic protein c-IAP2 via TLR4-pY14Cav-1 signaling pathway, which we hypothesized to contribute to generation of an EC memory of survival and severity of PAH. Methods/Results: Cav-1 deficiency via shedding of extracellular vesicles (EVs) leads to survival of an apoptosis-resistant EC phenotype during idiopathic PAH. Similarly, S. mansoni egg antigens also reduced lung EC-Cav-1 expression, suggesting that Cav-1 also plays a role during pathogen-associated PAH. Cav-1 depletion via EVs precedes its phosphorylation at residue Tyr14 (pY14Cav-1), which in turn, contributes to EV loading. Among apoptotic regulators, IAPs have been found as a cargo of EVs in different conditions, including in TLR4-activated cells. Accordingly, our data indicates that S. mansoni egg antigen p40 also activated TLR4/NFkB-mediated signaling, inducing c-IAP2 expression and a time-dependent phosphorylation of Cav-1 in human lung microvascular EC (HMVEC-L: 228.2 +/- 38.28% of control; p<0.05; n=4). Moreover, although Sm-p40 alone was unable to induce shedding of EVs, combination with NFkB-associated proinflammatory mediators (TNF-α, IL-6, and ATP), significantly increased EV shedding by HMVEC-L, suggesting that S. mansoni may epigenetically prime ECs, but co-factors are required to induce EV shedding. Finally, Sch-PAH model using EC- Cav1 -/- mice ( End-scl.Cre ERT2 ;Rosa mt/mg ;Cav1 fl/fl ) revealed that Cav-1 absence led to accumulation of eggs within the lungs and loss of eGFP+ cells, indicating that EC-Cav-1 phosphorylation may be required to development of Sch-PAH. Conclusions: Our data suggest that S. mansoni -induced pY14Cav-1 is associated to expression of the anti-apoptotic c-IAP2 protein, which may be critical for prolonged survival of a pathogenic EC phenotype during the development of Sch-PAH.

Use of zeolite for the elimination of heavy metals from chicken eggs

The publication materials reflect the results of scientific research conducted under the conditions of the vivarium of the State Research Control Institute of Veterinary Medicines and Feed Additives. It was established that the introduction of chromium sulfate in the amount of 2 mg/kg and cadmium sulfate in the amount of 3 mg/kg of live weight into the body of laying hens caused their significant accumulation in eggs compared to their content in the control group. To reduce the concentration of heavy metals in chicken eggs, zeolite 3 % of the feed mass was fed in the form of 1–3 mm grain size (TU 05792908.002-97. “Feed Zeolite”, produced at the Sokyrnytskyi Zeolite Plant of the Ministry of Emergency Situations of Ukraine, Khust District, Zakarpattia Region. It was established that the natural mineral contributed to eliminating Chromium and Cadmium from egg components (yolk, white, shell) relative to the control. When zeolite was introduced into the diet of poultry, 3 % of the feed weight to all experimental groups, compared with groups without its introduction, contributed to a decrease in the content of heavy metals in the studied samples of egg components. With a chromium load, a 1.7-fold decrease was noted in the white (Р < 0.05) and yolk, and a 1.8-fold (Р < 0.01) decrease in the shell, and samples with a cadmium load, a decrease of this metal in the protein, yolk, and shell was, respectively, 1.5 (Р < 0.05); 1.6 (Р < 0.05) and 3.2 (Р < 0.001) times the indicator of the experimental group without a sorbent. A similar tendency to decrease the content of heavy metals is observed with the combined introduction of toxicants. They found a slight increase in the weight of the egg in the test groups after correction with zeolite, namely: in the first group by 3.7 %, respectively, in the third – by 1.9 % against the background of a decrease in the indicator in the second group by 1.6 %. Eggs of hens of the first experimental group exceeded their control counterparts by 0.9 % in terms of shell thickness. In contrast, those of the second and third groups, on the contrary, were inferior in terms of shell thickness by 1.2 and 0.6 %, respectively. In the experimental groups, there is a tendency to increase the percentage of the shell by 1.9 in the first group, by 2.8 % in the second, and by 4.0 % in the third group relative to the control. Introducing the first group of natural zeolite into birds' diet contributes to the thickening of eggshells by 6.6 % compared to the indicator without the mineral. The same trend is observed in the second and third groups, respectively – by 7.1 % and 5.0 %; however, the difference between the groups is unlikely. A tendency to increase in the experimental groups with the use of zeolite in the percentage of egg mass in the first group by 1.9 %, in the second group by 1.8, and in the third group by 2.3, relative to the indicator without the mineral, was also revealed. In the experimental groups, there are changes in the components of the egg compared to the control indicator: an increase in the shelling percentage in the first, second and third groups, respectively, by 1.0, 4.0, and 1.9 %. Regarding egg productivity, a decrease is observed relative to the control in experimental groups with chromium-cadmium total and separate load, which was 19.6, respectively; 40.2 and 29.7 %. An increase in egg production has been established when mineral sorbent is used in the diet of poultry. Gross egg production in hens of the second group with chromium load increased by 11.1 % when consumed with zeolite compound feed. The lowest number of eggs during the experimental period was obtained from hens of the second group with cadmium load. The introduction of natural minerals into the diet increased their number during the experimental period by 8.3 %. In the third group, the number of eggs increased by 10.7 % during the experimental period with the combined load of heavy metals and zeolite. A similar trend is observed in the experimental groups regarding the number of eggs obtained per average laying hen. The results of the conducted research confirm that chromium and cadmium ions affect the productivity and quality of chicken products, and the introduction of fodder zeolite in the amount of 3 % of the mass of compound feed into the diet of poultry improves the level of their mineral nutrition, laying and the indicator of the marketable quality of eggs.

Protein storage and reproduction increase in grasshoppers on a diet matched to the amino acids of egg yolk protein.

The diets of animals are essential to support development, and protein is key. Accumulation of stored nutrients can support developmental events such as molting and initiation of reproduction. Agricultural studies have addressed how dietary protein quality affects growth, but few studies have addressed the effects of dietary protein quality on developmental transitions. Studies on how dietary quality may affect protein storage and development are possible in arthropods, which store proteins in the hemolymph. We hypothesized that diets with a composition of amino acids that matches the precursor of egg yolk protein (vitellogenin, Vg) will be high quality and support both egg production and accumulation of storage proteins. Grasshoppers were fed one of two isonitrogenous solutions of amino acids daily: Vg-balanced (matched to Vg) or Unbalanced (same total moles of amino acids, but not matched to egg yolk). We measured reproduction and storage protein levels in serial hemolymph samples from individuals. The Vg-balanced group had greater reproduction and greater cumulative levels of storage proteins than did the Unbalanced group. This occurred even though amino acids fed to the Vg-balanced group were not a better match to storage protein than were the amino acids fed to the Unbalanced group. Further, oviposition timing was best explained by a combination of diet, age at the maximum level of storage protein hexamerin-270 and accumulation of hexamerin-90. Our study tightens the link between storage proteins and commitment to reproduction, and shows that dietary protein quality is vital for protein storage and reproduction.

Особенности паразито-хозяинных взаимоотношений Calodium sp. (Nematoda: Capillariidae) – обыкновенная бурозубка Sorex araneus

ematodes of the genus Calodium Dujardin, 1845 (syn. Capillaria, Hepaticola) are parasites and cause hepatic capillariasis in rodents and other mammals, including humans. The life cycle of Calodium spp. may be completed in a single host species. However, the eggs, which are laid in the liver, must mature outside of the host body (in the environment) prior to infecting a new host. The death of the host in which the adults reach sexual maturity, either by being eaten or dying and decomposing, is necessary for completion of the life cycle [Moravec, 1982]. For the first time, we described the feature of the host-parasite relationship – the nematode Calodium sp. – common shrew. During monitoring studies of the parasite fauna of rodents and insectivores on the Baikal territory, we found the parasite Calodium sp. In some individuals, we noted fibrous formations on the surface of the liver, which were noticeable with the naked eye. Histological examination revealed the presence of petrified helminth fragments in the fibrous focus and eggs surrounded by connective tissue fibers. No inflammatory response of host to Calodium sp. was noted. Eggs of Calodium sp. translucent, oval in shape, covered with villi and located under a thin shell. Their length is 69.66±1.86 (63.88–72.88); width with shell 38.3±0.89 (35.49–41.11); width without shell 31.92±0.72 (29.48– 34.93). Caps are located on the poles of the eggs. Developing larvae are clearly visible, which are brightly stained with hematoxylin-eosin and Ziehl-Neelsen. The eggs are located compactly, the liver parenchyma at the site of localization is replaced by connective tissue. Connective tissue strands surround each egg and delimit it from the surrounding tissue. Perl’s staining did not reveal the content of hemosiderin and macrophages in the liver. No liver edema was observed. The structures of the liver were destroyed, destruction of the hepatic lobules was revealed near the accumulation of parasite eggs, but without the destruction of hepatocytes. The areas occupied by the parasite accounted for almost a quarter of the volume of the liver: this is an extensive fibrous formation with a dead nematode inside and massive accumulations of eggs in a network of connective tissue fibers. No histopathological changes were found in the rest of the liver. Due to the lack of a mature specimen of the parasite, it was not possible to determine the nematode to the species level. Although C. soricidae is a specific parasite for the common shrew, the size of the eggs in this species is smaller than in the parasite we studied. With regard to the widespread nematode C. hepatica, the nature of the hostparasite relationship has been studied in some detail. In most studies, in rats Rattus rattus and Rattus norvegicus, parasite encapsulation and an inflammatory reaction around the nematode and eggs are expressed, the extent of liver fibrosis is not as significant as in the shrews we observed [De Andrade and Andrade, 2004; Millán et al., 2014; Fuehrer, 2014].

Juvenile hormone signaling promotes ovulation and maintains egg shape by inducing expression of extracellular matrix genes

It is well documented that the juvenile hormone (JH) can function as a gonadotropic hormone that stimulates vitellogenesis by activating the production and uptake of vitellogenin in insects. Here, we describe a phenotype associated with mutations in the Drosophila JH receptor genes, Met and Gce: the accumulation of mature eggs with reduced egg length in the ovary. JH signaling is mainly activated in ovarian muscle cells and induces laminin gene expression in these cells. Meanwhile, JH signaling induces collagen IV gene expression in the adult fat body, from which collagen IV is secreted and deposited onto the ovarian muscles. Laminin locally and collagen IV remotely contribute to the assembly of ovarian muscle extracellular matrix (ECM); moreover, the ECM components are indispensable for ovarian muscle contraction. Furthermore, ovarian muscle contraction externally generates a mechanical force to promote ovulation and maintain egg shape. This work reveals an important mechanism for JH-regulated insect reproduction.

Influences of lead exposure on its accumulation in organs, meat, eggs and bone during laying period of hens

Elevating levels of environmental lead (Pb) results in serious hazards to health of animals and human beings. In this study, daily diet with three different levels of Pb (Pb nitrate at doses of 1, 10, and 100 mg/kg body weight) were fed to ISA Brown layers. It showed that the kidney and liver have the relatively high Pb concentration (2.34 and 0.51 ppm) after culture, while the meat has the Pb concentration as low as 0.07 ppm (lower than the standard of Codex Alimentarius). It was also confirmed that egg laying worked as a potential pathway for hens to excrete Pb as Pb concentrations in eggshell and yolk increased from 0.10 to 3.11 ppm. However, the Pb concentration in egg white remains at a safe level (<0.10 ppm). Furthermore, even the intake of low dose Pb can cause a decline of bone mineral density and bone strength. Raman spot and mapping analysis indicated that carotenoids content in humerus from the hens of high dose group increased significantly, which hence can be applied as an indicator for resist stress. The degradation of bone quality will further damage the health of laying hens. Therefore, Pb exposure not only toxifies organs and reduces physiological features (e.g., body weight and laying rate) instantly, but also hurts poultry via degrading bone quality in long term. Additionally, the probability of excessive Pb in poultry meat is less than those of viscera and eggs, indicating its low risk to food safety.

Polybrominated diphenyl ethers (PBDEs) concentrations in soil and plants around municipal dumpsites in Abuja, Nigeria.

Polybrominated diphenyl ethers (PBDEs) are listed as persistent organic pollutants (POPs) in the Stockholm Convention. It has been established that PBDEs may be released into the environment during improper handling and disposal of e-waste and other products containing PBDEs that is prevalent in developing countries. This research work assessed the status of PBDE contamination at dumpsites in Nigeria. Soil and edible plant samples were collected from the dumpsites and control sites for analysis. The concentrations of ∑7PBDE in the topsoils around the dumpsites at 0-15cm depth ranged from 112 to 366ng/g dry weight (dw) while that of the topsoil of the control site 500m from the dumpsite ranged from 26.8 to 39.7ng/g dw. These high concentrations stem likely from open burning of waste including electronic waste on the landfills. Plant samples (bentgrass, spinach, tomatoes, pumpkin and sweet potatoes) around the dumpsites were found to be contaminated by PBDEs with levels ranging from 25.0 to 60.5ng/g dw in plant roots and from 8.45 to 32.2ng/g dw in plant shoots for ∑7PBDE. This suggests that consumption of vegetables by humans and ingestion of contaminated soils and feed by chickens and cows can transfer PBDEs into the human food chain around the dumpsites. The comparison of PBDE levels in soils and the PBDE levels in chicken eggs from the former study indicate that PBDE levels in the soils are sufficient to explain the levels in the chicken eggs with a reasonable carry-over rate for PBDEs of 0.28 on average. The PBDE contamination in the soil was sufficient to result in a relevant exposure of humans via accumulation in eggs. The study shows that a better management of end-of-life products containing PBDEs is needed to reduce PBDE exposure risk in Africa.

Interleukin (IL)-33 is dispensable for Schistosoma mansoni worm maturation and the maintenance of egg-induced pathology in intestines of infected mice

BackgroundSchistosomes are trematode worms that dwell in their definitive host’s blood vessels, where females lay eggs that need to be discharged into the environment with host excreta to maintain their life-cycle. Both worms and eggs require type 2 immunity for their maturation and excretion, respectively. However, the immune molecules that orchestrate such immunity remain unclear. Interleukin (IL)-33 is one of the epithelium-derived cytokines that induce type 2 immunity in tissues. The aim of this study was to determine the role of IL-33 in the maturation, reproduction and excretion of Schistosoma mansoni eggs, and in the maintenance of egg-induced pathology in the intestines of mice.MethodsThe morphology of S. mansoni worms and the number of eggs in intestinal tissues were studied at different time points post-infection in S. mansoni-infected IL-33-deficient (IL-33−/−) and wild-type (WT) mice. IL-5 and IL-13 production in the spleens and mesenteric lymph nodes were measured. Tissue histology was performed on the terminal ilea of both infected and non-infected mice.ResultsWorms from IL-33−/− and WT mice did not differ morphologically at 4 and 6 weeks post-infection (wpi). The number of eggs in intestinal tissues of IL-33−/− and WT mice differed only slightly. At 6 wpi, IL-33−/− mice presented impaired type 2 immunity in the intestines, characterized by a decreased production of IL-5 and IL-13 in mesenteric lymph nodes and fewer inflammatory infiltrates with fewer eosinophils in the ilea. There was no difference between IL-33−/− and WT mice in the levels of IL-25 and thymic stromal lymphopoietin (TSLP) in intestinal tissues.ConclusionsDespite its ability to initiate type 2 immunity in tissues, IL-33 alone seems dispensable for S. mansoni maturation and its absence may not affect much the accumulation of eggs in intestinal tissues. The transient impairment of type 2 immunity observed in the intestines, but not spleens, highlights the importance of IL-33 over IL-25 and TSLP in initiating, but not maintaining, locally-induced type 2 immunity in intestinal tissues during schistosome infection. Further studies are needed to decipher the role of each of these molecules in schistosomiasis and clarify the possible interactions that might exist between them.Graphical

New anthelmintic preparation Unifascide and its efficacy in treatment of fascioliasis in sheep

Sheep fascioliasis occurs with an extent of invasion in the range of 23-38% with an intensity of invasion of 1-48 specimens per animal in the regions of the North Caucasus. The most infested places with trematodes were pastures (84.0% of contaminated soil samples), and small pastures near natural water bodies (73.5% of contaminated soil samples), forest-shrub forb pastures located along the continuation of wind-sheltered forest belts (60.0% of soil samples). Researchers have found that the least contaminated with Fasciola hepatica eggs are herb meadow pastures (35.0% of soil samples) and cultivated pastures made from a mixture of Sudanese grass and clover (12.0% of contaminated soil samples). In samples per 1 g of soil, eggs of trematodes were found on average 113.2±6.0 specimens, that is, 2.4 times more than in feces (on average, 47.3±3.4 specimens per 1 g feces), which indicates the accumulation of viable eggs in biotopes. In this regard, the development of new complex anthelmintic preparation for the treatment and prevention of fascioliasis in sheep remains an urgent task. The authors' research consisted in testing a new complex anthelmintic drug Unifascide for sheep fascioliasis. Experimental tests of the Unifascide preparation for fascioliasis of sheep were carried out on 30 heads using the group method. Experimental and control animals (n = 30) weighing 32-36 kg were divided into 3 groups according to the principle of analogs, 10 animals per a group. Due to the results the degree of extension efficiency was 90.0 and intensity efficiency was 92.5%. The preparation is recommended for implementation in the practice of therapeutic and prophylactic deworming for chronic fascioliasis of sheep.

Consumption of monogenean eggs by crustaceans and fish

The use of biological agents to control parasitic diseases in aquaculture is becoming increasingly popular as it is considered safe, effective and economically beneficial strategy for sustainable aquaculture practices. Monogeneans are among the most problematic parasites in fish farms. Their local outbreaks are largely attributed to the accumulation of eggs on farming structures, and the removal of these eggs by biological agents can be a novel solution to control monogenean diseases. We assessed the consumption of monogenean eggs by two amphipod species (a gammarid and a caprellid), the grass shrimp Palaemon pacificus and three fish (two monacanthids and Girella punctata). The ingestion of Neobenedenia girellae and/or Heteraxine heterocerca eggs was directly or indirectly confirmed in all of the tested organisms. The eggs ingested by the crustaceans lost viability, while those eaten by fish hatched after excretion. Monacanthid filefish consumed N. girellae eggs at the highest rate, up to more than 23,000 eggs individual-1 24 hr-1. A cohabitation of Seriola dumerili with a monacanthid, Rudarius ercodes, showed a lower acquisition of N. girellae than those kept without R. ercodes. The results indicated that these crustaceans and fish can be useful biological agents for removing monogenean eggs from culturing facilities.

Two Late Cretaceous sauropods reveal titanosaurian dispersal across South America

South American titanosaurians have been central to the study of the evolution of Cretaceous sauropod dinosaurs. Despite their remarkable diversity, the fragmentary condition of several taxa and the scarcity of records outside Patagonia and southwestern Brazil have hindered the study of continental-scale paleobiogeographic relationships. We describe two new Late Cretaceous titanosaurians from Quebrada de Santo Domingo (La Rioja, Argentina), which help to fill a gap between these main areas of the continent. Our phylogenetic analysis recovers both new species, and several Brazilian taxa, within Rinconsauria. The data suggest that, towards the end of the Cretaceous, this clade spread throughout southern South America. At the same locality, we discovered numerous accumulations of titanosaurian eggs, likely related to the new taxa. With eggs distributed in three levels along three kilometres, the new site is one of the largest ever found and provides further evidence of nesting site philopatry among Titanosauria.

Toxicities of microplastic fibers and granules on the development of zebrafish embryos and their combined effects with cadmium

Toxicity of microplastics (MPs) in granular form to aquatic animals has been frequently tested, whereas the effects of fibrous MPs remain further explored. In this study, the effects of polyethylene terephthalate granular particles (p-PET, approximately 150 μm in diameter) and fibers (f-PET, approximately 3–5 mm in length and 20 μm in diameter) on the development of zebrafish embryos and their joint effects with cadmium (Cd) were compared. p-PET and f-PET accelerated the velocities of blood flow and heart rate and inhibited hatching in zebrafish embryos because of their barrier effects on the channels in the embryonic chorion and enhanced the mechanical strength of the chorion. The Cd content in the chorion increased by p-PET due to the adsorption of p-PET on the chorion. By contrast, more f-PET dissociated in culture medium and resulted in low Cd content in the chorion. Given that chorion can effectively block p-PET and f-PET, the Cd accumulation in eggs significantly decreased (p < 0.05) under p-PET/f-PET and Cd combined treatment because of the reduction in the bioavailability of Cd. Therefore, p-PET and f-PET decreased the toxicities of Cd on all the target endpoints in this study, and the detoxification effect of f-PET at 72 hpf was more significant than that of p-PET. These results suggest that the toxicity induced by MPs might be form-related.