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1.
The mechanosensory lateral line system of fish is responsible for several functions such as balance, hearing, and orientation in water flow and is formed by neuromast receptor organs distributed on head, trunk and tail. Superficial and canal neuromasts can be distinguished for localization and morphological differences. Several information is present regarding the superficial neuromasts of zebrafish and other teleosts especially during larval and juvenile stages, while not as numerous data are so far available about the ultrastructural characteristics of the canal neuromasts in adult zebrafish. Therefore, the aim of this study was to investigate by transmission electron microscopy the ultrastructural aspects of cells present in the canal neuromasts. Besides the typical cellular aspects of the neuromast, different cellular types of hair cells were observed that could be identified as developing hair cells during the physiological turnover. The knowledge of the observed cellular types of the canal neuromasts and their origin could give a contribution to studies carried out on adult zebrafish used as model in neurological and non‐neurological damages, such as deafness and vestibular disorders.  相似文献   
2.
We reported the involvement of oxidative stress and prostaglandins including thromboxane and prostacyclin in pre-cardiac edema (early edema) caused by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). While the involvement of oxidative stress in TCDD-induced toxicity has been frequently reported, the mechanism of its action is still unclear. In the present study, oxidative stress inducers including paraquat, hydrogen peroxide (H2O2) and rotenone augmented early edema (edema) induced by a low concentration of TCDD (0.1 ppb) at 55 hr post fertilization (hpf), while each of them alone did not cause edema. Edema caused by TCDD plus oxidative stress inducers was almost abolished by antioxidants, an antagonist for thromboxane receptor (ICI-192,605) and an agonist for prostacyclin receptor (beraprost), suggesting that the site of action of these inducers was in the regular signaling pathway after activation of aryl hydrocarbon receptor type 2 (AHR2) by TCDD. Oxidative stress inducers also enhanced edema caused by an agonist for the thromboxane receptor (U46619), and the enhancement was also inhibited by antioxidants. Sulforaphane and auranofin, activators of Nrf2 that is a master regulator of anti-oxidative response, did not affect U46619-evoked edema but almost abolished TCDD-induced edema and potentiation by paraquat in both TCDD- and U46619-induced edema. Taken together, the results suggest that oxidative stress augments pre-cardiac edema caused by TCDD via activation of thromboxane receptor-mediated signaling in developing zebrafish. As paraquat and other oxidative stress inducers used also are environmental pollutants, interaction between dioxin-like compounds and exogenous source of oxidative stress should also be considered.  相似文献   
3.
A major challenge to the widespread production of transgenic, knockout and knockdown zebrafish has been the absence of a simple and effective procedure for introducing macromolecules into the fertilized egg. None of the existing techniques for gene transfer in fish embryos has proven to be a major advance over cytoplasm microinjection, which is a technically demanding and time‐consuming procedure. This report addresses this need, considering that the development of protocols for lipid‐based transfection with fish embryos would considerably simplify gene transfer in this complex biological model. In this study, lipid‐based transfection with two different reporter vectors was carried out in zebrafish embryos at different developmental stages. The parameters tested included different plasmid/transfection reagent ratios as well as the influence of an added transfection enhancer reagent. When embryos were transfected in the blastula stage with a pEGFP‐N1 vector, more than 35% successfully incorporated the plasmid and expressed the fluorescent protein 24 h after transfection. The transfection enhancer did not show any significant effect in our experiments. This work presents an approach to implement this technique as a faster, cheaper and more practical alternative than microinjection.  相似文献   
4.
Two new guaiazulene-based analogues, ochracenoids A (1) and B (2), along with four known analogues (3–6), were isolated from the gorgonian Anthogorgia ochracea collected from the South China Sea. The planar structures of the new compounds were elucidated by comprehensive spectroscopic data. The absolute configuration of 1 was determined as 3R by the comparison of TDDFT calculated electronic circular dichroism with its experimental spectrum. Compound 1 is a rare guaiazulene-based analogue possessing a unique C16 skeleton. The possible generation process of 1 through an intermolecular one-carbon-transfer reaction was also discussed. Compound 2 was previously described as a presumed intermediate involved in the biogenesis of anthogorgienes A and I. Compound 3 exhibited antiproliferative effects on the embryo development of zebrafish Danio rerio.  相似文献   
5.
Angiogenesis is the formation of blood vessels from pre-existing vasculature. Excessive or uncontrolled angiogenesis is a major contributor to many pathological conditions whereas inhibition of aberrant angiogenesis is beneficial to patients with pathological angiogenesis. Catunaregin is a core of novel marine compound isolated from mangrove associate. The potential anti-angiogenesis of catunaregin was investigated in human umbilical vein endothelial cells (HUVECs) and zebrafish. HUVECs were treated with different concentrations of catunaregin in the presence or absence of VEGF. The angiogenic phenotypes including cell invasion cell migration and tube formation were evaluated following catunaregin treatment in HUVECs. The possible involvement of AKT, eNOS and ERK1/2 in catunaregin-induced anti-angiogenesis was explored using Western blotting. The anti-angiogenesis of catunaregin was further tested in the zebrafish embryo neovascularization and caudal fin regeneration assays. We found that catunaregin dose-dependently inhibited angiogenesis in both HUVECs and zebrafish embryo neovascularization and zebrafish caudal fin regeneration assays. In addition, catunaregin significantly decreased the phosphorylation of Akt and eNOS, but not the phosphorylation of ERK1/2. The present work demonstrates that catunaregin exerts the anti-angiogenic activity at least in part through the regulation of the Akt and eNOS signaling pathways.  相似文献   
6.
兽药添加剂喹乙醇的生态毒理学效应研究   总被引:6,自引:0,他引:6  
采用水生生物斑马鱼(Daniorerio)、鲤鱼(Cyprinuscarpio)和土壤生物赤子爱胜蚓(Eiseniafoetida)作为生物材料,通过斑马鱼急性毒性试验、斑马鱼胚胎发育试验、鲤鱼肾细胞单细胞凝胶电泳试验、蚯蚓急性毒性试验、蚯蚓生化毒性试验以及蚯蚓体腔细胞单细胞凝胶电泳试验,对兽药添加剂喹乙醇分别从生物个体、细胞和分子水平进行了生态毒理学效应研究。急性毒性试验结果表明,喹乙醇实验浓度范围内对斑马鱼和蚯蚓的急性毒性均不大。胚胎发育试验结果表明,喹乙醇对斑马鱼胚胎的72hEC50为221.20mg·L-1,具有明显致畸效应。蚯蚓生化毒性试验表明,喹乙醇能促进蚯蚓体内SOD酶活性,并呈现一定剂量-效应关系,但对纤维素酶影响不明显,单细胞凝胶电泳试验结果表明,喹乙醇具有一定遗传毒性,能引起鲤鱼肾脏细胞和蚯蚓体腔细胞DNA损伤,与空白对照相比有显著差异,并呈现出一定剂量-效应关系。  相似文献   
7.
Inflammation is a complicated host-protective response to stimuli and toxic conditions, and is considered as a double-edged sword. A sulfated Saccharina japonica polysaccharide (LJPS) with a sulfate content of 9.07% showed significant inhibitory effects against lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 macrophage cells and zebrafish. Its chemical and structural properties were investigated via HPLC, GC, FTIR, and NMR spectroscopy. In vitro experiments demonstrated that LJPS significantly inhibited the generation of nitric oxide (NO) and prostaglandin E2 (PGE2) via the downregulation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression and suppressed pro-inflammatory cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-1β production via the nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signal pathways in LPS-induced RAW 264.7 cells. Moreover, LJPS showed strong protective effects against LPS-induced inflammatory responses in zebrafish, increasing the survival rate, reducing the heart rate and yolk sac edema size, and inhibiting cell death and the production of intracellular reactive oxygen species (ROS) and NO. Its convenience for large-scale production and significant anti-inflammatory activity indicated the potential application of LJPS in functional foods, cosmetics, and pharmaceutical industries.  相似文献   
8.
猪链球菌2型分离株对野生斑马鱼的致病性   总被引:1,自引:1,他引:0  
以野生斑马鱼为模式动物,对6株mrp+epf+sly+猪链球菌2型(SS2)分离株进行致病性比较。斑马鱼经腹腔接种不同稀释度的SS2分离株,连续观察5d,Kaplan-Meier生存曲线分析并统计半数致死量(LD50)。结果显示,6个分离株对斑马鱼的LD50在10^5cfu-10^6cfu之间,临床株与非临床株的毒力差异不显著(P〉0.05)。从攻毒后死亡的鱼腹腔和脑可分离到SS2,并伴有腹腔出血及肝、肠、脑部炎性病变。表明SS2可感染斑马鱼,为进一步研究SS2的体内感染机制及毒力因子功能等奠定了基础。  相似文献   
9.
Ambient temperature during early stages of life has a substantial effect on physiological processes, eliciting phenotypic plasticity during zebrafish developmental stages. Zebrafish are known to possess a noteworthy ability to modify their phenotype in dependence of environmental factors. However, there is a poor understanding of the effects of temperature during embryogenesis, which influences the biological functions such as survival ability and masculinization in later developmental stages. Since the middle embryonic phase (pharyngula period) is genetically the most conserved stage in embryogenesis, it is very susceptible to embryonic lethality in developmental processes of vertebrates. Here, we tested the effect of transient perturbations (heat shock) during early development (5–24 hr post‐fertilization; hpf) at 35°C compared to control group at 28°C, on survival ability of zebrafish to study the embryonic and post‐embryonic mortality. We studied the variation of heat‐induced masculinization among and across the families in response to high temperature. Furthermore, morphometric traits of adult zebrafish at different developmental time points were measured in order to estimate the temperature × sex interaction effect. We found the highest embryonic mortality around the gastrula and segmentation periods in both experimental groups, with significantly lower survival ability in the temperature‐treated group (73.30% ± 0.58% vs. 70.19% ± 0.57%, respectively). A higher hatching success was observed in the control group (71.08% ± 0.61%) compared to the heat‐induced group (67.95% ± 0.60%). A distinct reduction in survival ability was also observed in both experimental groups during the first two weeks after hatching, followed by a reduced level of changes thereafter. We found sex ratio imbalances across all families, with 25.2% more males under temperature treatment. Our study on growth performance has shown a positive effect of increased temperature on growth plasticity, with a greater impact on female fish in response to high ambient temperature.  相似文献   
10.
omd基因编码骨调蛋白,可以调控人类骨骼的矿化。目前关于omd基因对鱼类骨骼矿化的作用尚不清楚。为了探究omd基因对鱼类骨骼的影响,调查了omd基因在斑马鱼不同发育阶段和不同组织的表达,并利用CRISPR/Cas9基因编辑技术,成功构建斑马鱼omd基因突变体(omd-/-)。结果表明:omd基因在斑马鱼体内随着发育表达量逐渐增加,在脊柱和肌肉中表达较高;相比野生型斑马鱼,omd-/-品系斑马鱼的骨骼形态和尾部肌肉结构未发现明显变化,脊柱的钙含量下调59.81%;与野生型相比,omd-/-纯合敲除品系斑马鱼平均游泳距离下降33.93%,平均游泳速度下降39.44%,相对静止的时间增加88.26%,游泳能力下降。这些结果表明,omd基因缺失影响斑马鱼脊柱的矿化,并在一定程度上影响了斑马鱼的活动能力。  相似文献   
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