• Toxicological Research
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• v.32 no.2
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• pp.123-132
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• 2016

The impact of mobile phone (MP) radiation on the brain is of specific interest to the scientific community and warrants investigations, as MP is held close to the head. Studies on humans and rodents revealed hazards MP radiation associated such as brain tumors, impairment in cognition, hearing etc. Melatonin (MT) is an important modulator of CNS functioning and is a neural antioxidant hormone. Zebrafish has emerged as a popular model organism for CNS studies. Herein, we evaluated the impact of GSM900MP (GSM900MP) radiation exposure daily for 1 hr for 14 days with the SAR of 1.34W/Kg on neurobehavioral and oxidative stress parameters in zebrafish. Our study revealed that, GSM900MP radiation exposure, significantly decreased time spent near social stimulus zone and increased total distance travelled, in social interaction test. In the novel tank dive test, the GSM900MP radiation exposure elicited anxiety as revealed by significantly increased time spent in bottom half; freezing bouts and duration and decreased distance travelled, average velocity, and number of entries to upper half of the tank. Exposed zebrafish spent less time in the novel arm of the Y-Maze, corroborating significant impairment in learning as compared to the control group. Exposure decreased superoxide dismutase (SOD), catalase (CAT) activities whereas, increased levels of reduced glutathione (GSH) and lipid peroxidation (LPO) was encountered showing compromised antioxidant defense. Treatment with MT significantly reversed the above neurobehavioral and oxidative derangements induced by GSM900MP radiation exposure. This study traced GSM900MP radiation exposure induced neurobehavioral aberrations and alterations in brain oxidative status. Furthermore, MT proved to be a promising therapeutic candidate in ameliorating such outcomes in zebrafish.

• Journal of Microbiology and Biotechnology
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• v.20 no.8
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• pp.1243-1250
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• 2010

A cDNA encoding a cysteine protease inhibitor (CPI) was isolated from the cDNA library of clamworm Perinereis aibuhitensis Grube. The deduced amino acid sequence analysis showed that the protein had 51%, 48%, and 48% identity with Zgc:153129 from Danio rerio, cystatin B from Theromyzon tessulatum, and the ChainA, stefin B tetramer from Homo sapiens, respectively. The gene was cloned into the intracellular expression vector pET-15b and expressed in Escherichia coli. The recombinant CPI (PA-CPI) was purified by affinity chromatography on Ni-charged resin and ion-exchange chromatography on DEAE-Sepharose FF. The relative molecular mass of PA-CPI was 16 kDa as deduced by SDS-PAGE. Activity analysis showed that the recombinant protein could inhibit the proteolytic activity of papain. A constitutive and secretive expression vector was also constructed, and the cDNA encoding CPI was subcloned into the vector for extracellular expression. Western blotting analysis results showed that the PA-CPI was secreted into the medium. Bioassay demonstrated that E. coli DH5${\alpha}$ harboring pUC18ompAcat-CPI showed a significant difference in mortality to the Asian longhorned beetle Anoplophora glabripennis compared with untransformed E. coli DH5${\alpha}$ and control.

• Development and Reproduction
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• v.7 no.2
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• pp.69-80
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• 2003

The zebrafish(Danio rerio) is a pre-eminent vertebrate model system for clarification of the roles of specific genes and signaling pathways in development. We show examples of positional cloning in two developmental mutants in zebrafish. headless: The severe head defects in headless(hdl) mutants are due to a mutation in T-cell factor-3(Tcf3). Loss of Tcf3 function in the hdl mutant reveals that Hdl represses Wnt target genes. The results provide genetic evidence that a component of the Wnt signaling pathway is essential in vertebrate head formation and patterning. mind bomb: Reduced lateral inhibition in mind bomb(mib) mutants permits too many neural precursors to differentiate as neurons. Positional cloning of mib revealed that it is a gene in the Notch pathway that encodes a ubiquitin E3 ligase. Mib interacts with the intracellular domain of Delta to promote its internalization. The results suggest a model for Notch activation where the Delta-Notch interaction is followed by endocytosis of Delta and transendocytosis of the Notch extracellular domain by the signaling cell.

• Development and Reproduction
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• v.13 no.3
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• pp.199-205
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• 2009

HSP70 has widely been induced in in vivo hyperthermia conditions in various organisms to study gene regulation and recently neuroprotectve roles of the induced gene expression under varying conditions. We investigated different responses among various tissues in zebrafish under heat shock to evaluate whether spatial and temporal expression pattern of zebrafish (z) hsp70 in transcriptional and translational level under heat shock stress in different brain regions. Heat shock groups were given for 1 h at $37^{\circ}C$ after recovery by transferring the treated animals back to $28^{\circ}C$ for 1, 2 and 24 h for recovery, respectively. Control (CTRL) group was kept at $28^{\circ}C$. At the end of treatments, five animals were collected and used for isolation of total RNAs and peptides from the corresponding tissues. Expression of zhsp70 mRNA showed different patterns in recovery periods in the tissues including the brain, eye, intestines, muscles, heart and testis by RT-PCR. Unlike the RT-PCR analysis, Northern blot analysis demonstrated nearly 30-fold increase in zhsp70 at 1 h heat shock, suggesting that RT-PCR may not be appropriate in unmasking regulation of the time-dependent zhsp70 expression. In the experiment involving different brain regions, the cerebellum showed gradual activation at 1 h to R1h and decreases in R2h and R24h, while the medulla oblongata and optic tectum showed gradual increase at R1h and decrease at R24h, indicating that different brain tissues respond specifically to heat shock in inducing zhsp70 and recovering from the heat shock status. Western blot analysis also demonstrated that the intracellular levels of zHSP70 in three different brain regions including the cerebellum, medulla oblongata and optic tectum are differently induced and recovered to normal state. These results clearly demonstrate that different regions of the body and the brain tissues are responding differently to heat shock in the aspects of its level of expression and speed of recovery.

• Animal cells and systems
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• v.16 no.3
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• pp.198-206
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• 2012

Anxiety in zebrafish can be determined by examining their bottom-dwelling and light-avoidance behavior. This study determines the effects of physostigmine and scopolamine on anxiety in zebrafish by measuring swimming frequency for three horizontal layers and three vertical columns of a water test tank illuminated by a light source located above the central surface of the tank. In the 1 h session, zebrafish in the control group preferred the bottom layer the most and the center column the least. Zebrafish treated with 2-20 ${\mu}M$ physostigmine were more likely to prefer the to layer than controls, and there were significant pairwise differences between physostigmine-treated zebrafish and controls, indicating the anxiolytic effect of physostigmine. Further, 10 and $20{\mu}M$ physostigmine-treated zebrafish no longer avoided the center column. Scopolamine had no anxiolytic effect on bottom-dwelling and light-avoidance behaviors but suppressed the anxiolytic effect of physostigmine. In terms of their preference for various zones formed by layers and columns, zebrafish in the control group preferred the bottom left and right zones the most. Physostigmine had a positive effect on the preference for the top center zone, which was suppressed by scopolamine pretreatment. The results suggest that the level of anxiety in zebrafish can be reduced by activating acetylcholinergic neurotransmitter systems, which is mediated in part by muscarinic receptors.

• Journal of Microbiology and Biotechnology
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• v.33 no.2
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• pp.167-179
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• 2023

The rifampicin-resistant strain E9-302 of Edwardsiella ictaluri strain 669 (WT) was generated by continuous passage on BHI agar plates containing increasing concentrations of rifampicin. E9-302 was attenuated significantly by 119 times to zebrafish Danio rerio compared to WT in terms of the 50% lethal dose (LD₅₀). Zebrafish vaccinated with E9-302 via intraperitoneal (IP) injection at a dose of 1 × 10³ CFU/fish had relative percentage survival (RPS) rates of 85.7% when challenged with wild-type E. ictaluri via IP 14 days post-vaccination (dpv). After 14 days of primary vaccination with E9-302 via immersion (IM) at a dose of 4 × 10⁷ CFU/ml, a booster IM vaccination with E9-302 at a dose of 2 × 10⁷ CFU/ml exhibited 65.2% RPS against challenge with wild-type E. ictaluri via IP 7 days later. These results indicated that the rifampicin-resistant attenuated strain E9-302 had potential as a live vaccine against E. ictaluri infection. A previously unreported amino acid site change at position 142 of the RNA polymerase (RNAP) β subunit encoded by the gene rpoB associated with rifampicin resistance was identified. Analysis of the whole-genome sequencing results revealed multiple missense mutations in the virulence-related genes esrB and sspH2 in E9-302 compared with WT, and a 189 bp mismatch in one gene, whose coding product was highly homologous to glycosyltransferase family 39 protein. This study preliminarily explored the molecular mechanism underlying the virulence attenuation of rifampicin-resistant strain E9-302 and provided a new target for the subsequent study of the pathogenic mechanism of E. ictaluri.

• Korean Journal of Biological Psychiatry
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• v.30 no.1
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• pp.17-23
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• 2023

Objectives This study aims to develop valid experimental models for depression through chronic reserpine exposure to zebrafish (Danio rerio). Methods The effect of chronic reserpine on zebrafish behavior in the novel tank was examined. Changes of gene expression on telencephalon were also investigated. Results Chronic reserpine (40 mg/L, 7 days) induced overt behavioral effects, but markedly reduced activity, resembling motor retardation in depression. In telencephalon of zebrafish, gene expression associated with monoamine oxidase and norepinephrine transporter was decreased. Expression of serotonin transporter gene was increased. Conclusions Our results show that the pharmacological model of depression in zebrafish can induce not only behavioral changes, but also monoamine changes in the homology of human mood regulation centers.

• Korean Journal of Ichthyology
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• v.26 no.3
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• pp.171-178
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• 2014

Myogenesis is the formation process of multinucleated myofiber with a contractile capacity from muscle satellite cell (MSCs) during life. This process is tightly controlled by several transcription factors such as Pax3 and Pax7 (paired box protein 3 and 7), MEF2C (myocyte enhancer factor 2) and MRFs (myogenic regulatory factors) etc. On the contrary, myostatin (MSTN) is a transforming growth factor-${\beta}$ superfamily, which functions as a negative regulator of skeletal muscle development and growth. Carnosic acid (CA) is a major phenolic component in rosemary (Rosmarinus officinalis) and have been reported various biological activities such as anticancer, antioxidant, antimicrobial and therapeutic agents for amnesia, dementia, alzheimer's disease. This study was confirmed to effects of CA on muscle cell line and muscle tissue alteration of zebrafish by intramuscular injection or feeding methods. $10{\mu}M$ CA showed a non-cytotoxic on myoblast and a complete inhibition effect against myostatin activity on luciferase assay. In intramuscular injection experiment, the total protein and triglyceride amount of $10{\mu}M/kg$ of CA injected group increased by 11% and decreased by 13% compared to these of the no injected group. In histology analysis of muscle tissues by hematoxylin/eosin staining, the number of muscle fiber of $10{\mu}M/kg$ of CA injected group decreased by 29% and fiber area increased 40% compared to these of no injected group. In feeding experiment, the total protein and triglyceride amount no significance difference compared to these of the normal feeding group. In histology analysis, the number of muscle fiber of 1% CA fed group decreased by 35% and fiber area increased 56% compared to these of normal fed group. We identified that CA have an effect on hypertrophy of muscle fiber in adult zebrafish and the results of this study are considered as the basic data that can reveal the mechanisms of muscle formation via gene and protein level analysis.

• Journal of Pharmacopuncture
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• v.19 no.4
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• pp.319-328
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• 2016

Objectives: Advancements in nanotechnology have led to nanoparticle (NP) use in various fields of medicine. Although the potential of NPs is promising, the lack of documented evidence on the toxicological effects of NPs is concerning. A few studies have documented that homeopathy uses NPs. Unfortunately, very few sound scientific studies have explored the toxic effects of homeopathic drugs. Citing this lack of high-quality scientific evidence, regulatory agencies have been reluctant to endorse homeopathic treatment as an alternative or adjunct treatment. This study aimed to enhance our insight into the impact of commercially-available homeopathic drugs, to study the presence of NPs in those drugs and any deleterious effects they might have, and to determine the distribution pattern of NPs in zebrafish embryos (Danio rerio). Methods: Homeopathic dilutions were studied using high-resolution transmission electron microscopy with selected area electron diffraction (SAED). For the toxicity assessment on Zebrafish, embryos were exposed to a test solution from 4 - 6 hours post-fertilization, and embryos/larvae were assessed up to 5 days post-fertilization (dpf ) for viability and morphology. Toxicity was recorded in terms of mortality, hatching delay, phenotypic defects and metal accumulation. Around 5 dpf was found to be the optimum developmental stage for evaluation. Results: The present study aimed to conclusively prove the presence of NPs in all high dilutions of homeopathic drugs. Embryonic zebrafish were exposed to three homeopathic drugs with two potencies (30CH, 200CH) during early embryogenesis. The resulting morphological and cellular responses were observed. Exposure to these potencies produced no visibly significant malformations, pericardial edema, and mortality and no necrotic and apoptotic cellular death. Conclusion: Our findings clearly demonstrate that no toxic effects were observed for these three homeopathic drugs at the potencies and exposure times used in this study. The embryonic zebrafish model is recommended as a well-established method for rapidly assessing the toxicity of homeopathic drugs.

• Journal of Life Science
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• v.25 no.2
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• pp.151-157
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• 2015

Zebrafish (Danio rerio) has been more widely used to study pharmacology. Oxytectracycline (OTC) is a broad-spectrum antibiotic and works by interfering with the ability to produce essential proteins of bacteria. The aim of this study was to identify the effects of exposure to OTC on behavioral changes or endocrine response in zebrafish. The behavioral effects of exposure to OTC (50, 100 or 200 mg/l) were characterized in several novelty-based paradigms such as the novel tank or open field test in zebrafish. Moreover, to investigate effects of exposure to OTC on endocrine response, we measured whole-body cortisol level using cortisol ELISA kit. As results of novel tank test, duration in top and immobile duration were significantly increased by the exposure to OTC in a concentration-dependent manner (p<0.05). In addition, moving distance, highly mobile, velocity and zone transition were significantly decreased by the exposure to OTC in a concentration-dependent manner (p<0.05). As results of open field test, the exposure to OTC increased immobile duration significantly (p<0.05). However, moving distance, mobile duration and velocity were significantly decreased by the exposure to OTC in a concentration-dependent manner (p<0.05). Besides, the exposure to OTC elevated whole-body cortisol levels in zebrafish. These results suggest that the exposure to OTC may induce chemical stress in zebrafish.