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Modulation of nociceptive-like behavior in zebrafish (Danio rerio) by environmental stressors
Maximino, Caio;
Psychology & Neuroscience , 2011, DOI: 10.3922/j.psns.2011.1.017
Abstract: zebrafish have been demonstrated to react consistently to noxious chemical stimuli and present reliable phenotypes of stress, fear, and anxiety. in this article, we describe the modulation of nociceptive-like responses of zebrafish to fear-, stress-, and anxiety-eliciting situations. animals were exposed to an alarm substance, confinement stress, or a novel environment before being injected with 1% acetic acid in the tail. the alarm substance and confinement stress reduced the display of erratic movements and tail-beating behavior elicited by acetic acid. the novelty of the environment, in contrast, increased the frequency of tail-beating behavior. the results suggest that descending modulatory control of nociception exists in zebrafish, with apparent fear- and stress-induced analgesia and anxiety-induced hyperalgesia.
Identifcation of Novel Retroid Agents in Danio rerio, Oryzias latipes, Gasterosteus aculeatus and Tetraodon nigroviridis
Holly A. Basta,Alex J. Buzak,Marcella A. McClure
Evolutionary Bioinformatics , 2007,
Abstract: Retroid agents are genomes that encode a reverse transcriptase (RT) and replicate or transpose by way of an RNA intermediate. The Genome Parsing Suite (GPS) is software created to identify and characterize Retroid agents in any genome database (McClure et al. 2005). The detailed analysis of all Retroid agents found by the GPS in Danio rerio (zebrafsh), Oryzias latipes (medaka), Gasterosteus aculeatus (stickleback) and Tetraodon nigroviridis (spotted green pufferfish) reveals extensive Retroid agent diversity in the compact genomes of all four fish. Novel Retroid agents were identified by the GPS software: the telomerase reverse transcriptase (TERT) in O. latipes, G. aculeatus and T. nigroviridis and a potential TERT in D. rerio, a retrotransposon in D. rerio, and multiple lineages of endogenous retroviruses (ERVs) in D. rerio, O. latipes and G. aculeatus.
Daily variation in the shoaling behavior of zebrafish Danio rerio  [cached]
Current Zoology , 2012,
Abstract: Shoaling behavior provides numerous fitness benefits for fish, including enhanced access to mates, increased success in foraging and protection from predators. We were interested in determining whether shoaling intensity differed throughout the day. To do this we kept adult zebrafish Danio rerio in different lighting conditions for 10 days: “Normal” (12:12LD, lights on at 0800 hrs), “Reverse” (12:12LD, lights on at 2000 hrs), DD, or LL, and then observed the shoaling behavior at different times during the day. Our findings suggest that daily variations exist in shoaling behavior, with mean shoaling times for fish from the ‘normal’ group being the lowest at the mid–point of the dark phase in the fish’s subjective day (00:00 hrs), then rising significantly throughout the day, reaching their highest intensity at 20:00 hrs (lights out). Fish from the “reverse” LD cycle (lights on at 20:00 hrs) showed differences in the mean shoaling times at different times of day, but did not show a gradual increase in shoaling throughout their subjective day. Fish from the DD and LL groups did not show significant differences in the mean shoaling values at different times of day, suggesting that the differences observed in LD fish may not represent circadian rhythms. Therefore, these results demonstrate the existence of daily variations in the shoaling behavior of fish and suggest that environmental cues in the form of light/dark cycles play an important role in regulating these variations [Current Zoology 58 (1): 129–137, 2012].
Thyroidal angiogenesis in zebrafish (Danio rerio) exposed to high perchlorate concentration
Iü Sema, Karayazi, A Isisag
African Journal of Biotechnology , 2009,
Abstract: As a well known environmental contaminant, perchlorate inhibits thyroidal iodide uptake and reduces thyroid hormone levels. In zebrafish (Danio rerio) exposed to high concentrations of sodium perchlorate (200, 350 and 500 mg/L) for 10 days, remarkable angiogenesis was identified, not only histopathologically but also statistically by counting of the small, medium and large sized (grades 1 to 3) vessels per unit area. Angiogenic response is concluded as the most sensitive parameter for rating of high concentrations of perchlorate exposure.
The effect of fipronil on some reproduction parameters of zebrafish (Danio rerio)  [PDF]
Anca Boaru,Cristina Iuliana El Mahdy,Bogdan Georgescu
Aquaculture, Aquarium, Conservation & Legislation , 2013,
Abstract: Our research investigated the effects of fipronil on the reproduction dynamics and parametersof the zebrafish (Danio rerio). The experiment consisted in exposing ready to spawn fish and the spawnitself to three different concentrations of the test substance. The survival rate over the 21 days ofexposure was 100% in both the three experimental groups and control group. However, the effects onreproductive parameters were evident even at the lowest concentration of fipronil applied while exposureto the highest dose of fipronil decreased the spawn obtained considerably and as well the fecundationand hatching percentages, compared to the control group.
Effects of Trimethyltin Chloride on Physiological and Biochemistrical Characteristics of (Danio rerio)
三甲基氯化锡对斑马鱼(Danio rerio)生理生化特性的影响

Li Zhifei,Gong Wangbao,Xie Jun,Wang Guangjun,Yu Deguang,Yu Ermeng,Wang Haiying,Tang Xiaojiang,

生态毒理学报 , 2011,
Abstract: To explore the toxicity of trimethyltin chloride (TMT) on fish, effects of TMT on physiological and biochemistrical characteristics of Danio rerio were measured using the acute toxicity test. According to the 96 h-LC50 value of TMT, three different concentration groups (0.39, 0.78, 1.17 mg·L-1) were set. The activity changes of Na+,K+-ATPase in the gills, AchE in the head and SOD in the muscle were detected in 72 hours. The results showed that 96 h-LC50 value of TMT on Danio rerio was 2.35 mg·L-1 and the safe concentration was 0.23 mg·L-1. There was a significant inhibition to Na+,K+-ATPase in the gills. When TMT concentration was more than 0.78 mg·L-1, the enzyme activity was virtually inhibited (the inhibition ratio>32%). Na+,K+-ATPase activity was inhibited in the low concentration (0.39 mg·L-1) and had a trend of recovery to the level of control group after 24 h. TMT showed an inhibitor to AchE in the head of Danio rerio, which would increased with the increasing of the time and medicine density. Because of the high motion of AchE in the head, only Danio rerio in the most concentration group (1.17 mg·L-1) was significantly inhibited (p<0.05). SOD activity in muscle of Danio rerio showed that the trend of increasing first, and then decreased. The higher TMT concentration was, the faster the enzyme activity activated and declined. Among all groups, the groups of 0.39, 0.78 and 1.17 mg·L-1 would get to the most inhibition effect which were 153%, 145% and 153% times of control group at 48, 24 and 12 h, respectively. All results indicated that TMT was high toxicity to Danio rerio. Na+,K+-ATPase in the gills was the important target of TMT.
Reconstruction of Danio rerio Metabolic Model Accounting for Subcellular Compartmentalisation  [PDF]
Micha?l Bekaert
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0049903
Abstract: Plant and microbial metabolic engineering is commonly used in the production of functional foods and quality trait improvement. Computational model-based approaches have been used in this important endeavour. However, to date, fish metabolic models have only been scarcely and partially developed, in marked contrast to their prominent success in metabolic engineering. In this study we present the reconstruction of fully compartmentalised models of the Danio rerio (zebrafish) on a global scale. This reconstruction involves extraction of known biochemical reactions in D. rerio for both primary and secondary metabolism and the implementation of methods for determining subcellular localisation and assignment of enzymes. The reconstructed model (ZebraGEM) is amenable for constraint-based modelling analysis, and accounts for 4,988 genes coding for 2,406 gene-associated reactions and only 418 non-gene-associated reactions. A set of computational validations (i.e., simulations of known metabolic functionalities and experimental data) strongly testifies to the predictive ability of the model. Overall, the reconstructed model is expected to lay down the foundations for computational-based rational design of fish metabolic engineering in aquaculture.
From Schooling to Shoaling: Patterns of Collective Motion in Zebrafish (Danio rerio)  [PDF]
Noam Miller, Robert Gerlai
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0048865
Abstract: Animal groups on the move can take different configurations. For example, groups of fish can either be ‘shoals’ or ‘schools’: shoals are simply aggregations of individuals; schools are shoals exhibiting polarized, synchronized motion. Here we demonstrate that polarization distributions of groups of zebrafish (Danio rerio) are bimodal, showing two distinct modes of collective motion corresponding to the definitions of shoaling and schooling. Other features of the group's motion also vary consistently between the two modes: zebrafish schools are faster and less dense than zebrafish shoals. Habituation to an environment can also alter the proportion of time zebrafish groups spend schooling or shoaling. Models of collective motion suggest that the degree and stability of group polarization increases with the group's density. Examining zebrafish groups of different sizes from 5 to 50, we show that larger groups are less polarized than smaller groups. Decreased fearfulness in larger groups may function similarly to habituation, causing them to spend more time shoaling than schooling, contrary to most models' predictions.
Bioconcentration and Antioxidant Status Responses in Zebrafish (Danio Rerio) Under Atrazine Exposure
Abeer Ghazie A. Al-Sawafi,Yunjun Yan
International Journal of Chemical Engineering and Applications , 2013, DOI: 10.7763/ijcea.2013.v4.295
Abstract: The present study was planned designed to investigate the chronic impacts of herbicide atrazine exposure on stress biomarkers acetylcholinesterase activity (AChE) and oxidative stress responses in brain of zebrafish (Danio rerio), and determine the bioconcentration of atrazine in whole body of fish. Chronic exposure to atrazine unveiled a markedly discourage in the activity of AChE. However, significant increase in the activities of catalase (CAT) and superoxide dismutase (SOD) and both influenced by atraizine, and CAT was over sensitivity to atrazine compared with SOD. The highest bioconcentration factor (BCF) of atrazine in the fish treated was (12.8543×104 and 13.5891×104) after 24h exposure to (0.957 and 1.913 mg L-1) and 13.238×104, after 25 d exposure to 0.638 mg L 1 of atrazine respectively. This study showed that the zebrafish have ability to bioaccumulate of the herbicide atrazine rapidly. atrazine accumulation in zebrafish has a private importance due to the implication of atrazine in chronically health problems, as well as the information contained in our study is useful for understand the mechanism of atrazine induced oxidative stress in fish.
Probiotic Supplementation Promotes Calcification in Danio rerio Larvae: A Molecular Study  [PDF]
Francesca Maradonna, Giorgia Gioacchini, Silvia Falcinelli, Daniela Bertotto, Giuseppe Radaelli, Ike Olivotto, Oliana Carnevali
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0083155
Abstract: A growing number of studies have been showing that dietary probiotics can exert beneficial health effects in both humans and animals. We previously demonstrated that dietary supplementation with Lactobacillus rhamnosus - a component of the human gut microflora - enhances reproduction, larval development, and the biomineralization process in Danio rerio (zebrafish). The aim of this study was to identify the pathways affected by L. rhamnosus during zebrafish larval development. Our morphological and histochemical findings show that L. rhamnosus accelerates bone deposition through stimulation of the expression of key genes involved in ossification, e.g. runt-related transcription factor 2 (runx2), Sp7 transcription factor (sp7), matrix Gla protein (mgp), and bone gamma-carboxyglutamate (gla) protein (bglap) as well as through inhibition of sclerostin (sost), a bone formation inhibitor. Western blot analysis of mitogen-activated protein kinase 1 and 3-(Mapk1 and Mapk3), which are involved in osteoblast and osteocyte differentiation, documented an increase in Mapk1 16 days post fertilization (dpf) and of Mapk3 23 dpf in individuals receiving L. rhamnosus supplementation. Interestingly, a reduction of sost detected in the same individuals suggests that the probiotic may help treat bone disorders.
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