Evaluation of the toxicity of the pesticide acephate and its by-product methamidophos over the behaviour of zebrafish Danio rerio (Cypriniformes, Cyprinidae)

Some Teleosts use geomagnetic field (GMF) for orientation (see review Krylov et al., 2013). However, there are very few experimental studies of the orientation with GMF in Cyprinids from natural populations. Recently, there have been studies on the influence of GMF on behavior in Cyprinids from laboratory strains (Hart et al., 2012; Ward et al., 2014). It was reported that zebrafish (Danio rerio) are able to perceive a static magnetic field of 100 µT (Shcherbakov et al., 2005). Takebe and the coauthors (2012) showed that zebrafish prefer the two opposite directions of the GMF after being released in the centre of a circular arena. Comparative studies of Cyprinids from laboratory strains and natural populations will expand knowledge of the magnetoreception used for orientation in GMF by these Teleosts. The aim was to study the influence of GMF and its modifications on the preferred directions in laboratory strains of D. rerio and Rutilus rutilus from the Rybinsk Reservoir under observation in a circular arena. Wild-type zebrafish were obtained from a commercial distributer. Roach underyearlings were caught at the channel joining the landing stage of IBIW RAS with the Rybinsk reservoir. Changes in the GMF were generated using three pairs of mutually orthogonal Helmholtz coils. These coils were connected to three constant current sources using an AKIP-1103 DC switching power supply. Fish were placed into an opaque tank without a bottom at the centre of the circular arena. The circular arena was placed inside the Helmholtz coils. After one minute, the observation tank was raised and the fish chose their initial direction of travel. Four artificial GMF modifications were tried: 1. 180 degrees reversal of both vertical and horizontal GMF components 2. 180 degrees reversal of the vertical GMF component 3. 180 degrees reversal of the horizontal GMF component 4. 90 degrees clockwise turn of the horizontal GMF component It is known that the behavioral responses of zebrafish to different influences are stable and they may persist through experiments on the assumption of a recovery period. All zebrafish individuals were tested in each of the four modifications and parallel controls. In the experiments with R. rutilus we only studied the influence of the 90 degrees clockwise turn of the horizontal GMF component on preferred direction. The fishes’ movements in the arena were recorded by a Panasonic-HC-X900M video camera. We recorded the angle of preferred direction as the fish crossed the 10 cm radius from the centre of the arena. A Northward direction corresponds to 0/360 degrees. Rayleigh’s z-test for unimodal and axial distribution was used to evaluate the significance of the preferred direction. The significance of the differences between preferred directions in the control and experimental groups was estimated using Watson’s U2-test. D. rerio. Significant preference of a single direction was not observed in any of the experiments. However, control groups (GMF) displayed a significant preference for the two opposite directions gravitating North and South (Figs. 1e, 1f, 1h). Among the experimental groups, bidirectional orientation was observed only by rotation of the horizontal component by 90 degrees clockwise (Fig. 1d). In this case, fish preferred Westward and Eastward directions. R. rutilus. Significant preference of the East-northeast direction was found. This direction matched the direction from the location where individuals were caught to the deep-water part of Rybinsk Reservoir (Fig. 2). On rotation of the horizontal component by 90 degrees clockwise, fish tended to move to the South-southeast. The angle between preferred directions in the experimental and control groups was 79.87 degrees. Differences in preferred directions between experimental and control groups were statistically significant (U2 = 0.38, p < 0.001). Many Teleosts are known to possess special cells which accumulate magnetite during ontogenesis and are used for magnetoreception (Walker, 2011). Magnetite was also found in tissues of zebrafish (Dixson, 2012). The results of our study confirm the bimodal distribution of D. rerio preferred directions in GMF observed by Takebe. Among the various modifications of GMF, only the rotation of the horizontal component by 90 degrees clockwise significantly changed the preferred direction of the zebrafish. The preference for two opposite directions that was observed in the GMF is associated with the use of the axial horizontal component of GMF for orientation, but with no reference to its direction. Similar preferences for two opposite directions were observed in Oncorhynchus nerka juveniles, as well as in Salmo trutta and Oncorhynchus mykiss embryos, under different magnetic conditions (Quinn and Brannon, 1982; Formicki et al., 1997). Adult fish from natural habitats usually choose only the direction of the GMF. It is possible that the importance of magnetosensitivity is currently declining in D. rerio due to both the human-induced changes of natural habitats and a long-term period of zebrafish strains being kept in aquaculture. Such reduction of magnetosensitivity may result in the inability to distinguish the direction and inclination of GMF vector and, as a consequence, bimodal distribution of preferred directions. This is the first study on the use of GMF for orientation in R. rutilus from a natural population. Our results confirm the presence of magnetosensitivity in roach. At the same time, the preferred direction in GMF matched the direction to the mouth of the channel where the fish were caught. It is possible that fish stressed by experimental manipulations have tried to “leave” the experimental arena in the usual direction of escape to the deep-water part of reservoir. Figure 1. Bimodal distribution of preferred directions in zebrafish by the reversal of vertical (a), horizontal (b), both vertical and horizontal (c) components of GMF, and by the rotation of the horizontal component by 90 degrees clockwise (d). Distributions of preferred directions in control conditions (GMF) for each experiment are given under corresponding diagrams (e, f, g, h). Figure 2. Distribution of preferred directions of roach in a GMF (a) and the rotation of the horizontal component of the GMF by 90 degrees clockwise (b). Sample area with designation of the direction of the channel to the Rybinsk Reservoir (c). Asterisk shows the point of sampling.

Zebrafish: A Model System to Study Heritable Skin Diseases

The primary pathological hallmark of Parkinson disease (PD) is the profound loss of dopaminergic neurons in the substantia nigra pars compacta. To facilitate the understanding of the underling mechanism of PD, several zebrafish PD models have been generated to recapitulate the characteristics of dopaminergic (DA) neuron loss. In zebrafish studies, tyrosine hydroxylase 1 (th1) has been frequently used as a molecular marker of DA neurons. However, th1 also labels norepinephrine and epinephrine neurons. Recently, a homologue of th1, named tyrosine hydroxylase 2 (th2), was identified based on the sequence homology and subsequently used as a novel marker of DA neurons. In this study, we present evidence that th2 co-localizes with serotonin in the ventral diencephalon and caudal hypothalamus in zebrafish embryos. In addition, knockdown of th2 reduces the level of serotonin in the corresponding th2-positive neurons. This phenotype can be rescued by both zebrafish th2 and mouse tryptophan hydroxylase 1 (Tph1) mRNA as well as by 5-hydroxytryptophan, the product of tryptophan hydroxylase. Moreover, the purified Th2 protein has tryptophan hydroxylase activity comparable with that of the mouse TPH1 protein in vitro. Based on these in vivo and in vitro results, we conclude that th2 is a gene encoding for tryptophan hydroxylase and should be used as a marker gene of serotonergic neurons.

ZebrafishVol. 13, No. S1 Survey & SynopsisHusbandry and Health Program Survey SynopsisChristian Lawrence, Judith S. Eisen, and Zoltán M. VargaChristian LawrenceAquatic Resources Program, Boston Children's Hospital, Boston, Massachusetts.Search for more papers by this author, Judith S. EisenInstitute of Neuroscience, University of Oregon, Eugene, Oregon.Search for more papers by this author, and Zoltán M. VargaZebrafish International Resource Center, Institute of Neuroscience, University of Oregon, Eugene, Oregon.Search for more papers by this authorPublished Online:28 Jun 2016https://doi.org/10.1089/zeb.2016.1309AboutSectionsView articleView Full TextPDF/EPUB Permissions & CitationsPermissionsDownload CitationsTrack CitationsAdd to favorites Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail View articleFiguresReferencesRelatedDetailsCited byA FELASA Working Group Survey on Fish Species Used for Research, Methods of Euthanasia, Health Monitoring, and Biosecurity in Europe, North America, and Oceania24 August 2022 | Biology, Vol. 11, No. 9A Multi-Site Assessment of Anesthetic Overdose, Hypothermic Shock, and Electrical Stunning as Methods of Euthanasia for Zebrafish (Danio rerio) Embryos and Larvae1 April 2022 | Biology, Vol. 11, No. 4Enrichment for Laboratory Zebrafish—A Review of the Evidence and the Challenges5 March 2021 | Animals, Vol. 11, No. 3Zebrafish: Housing and husbandry recommendations11 September 2019 | Laboratory Animals, Vol. 54, No. 3The Impact of Pseudoloma neurophilia Infection on Body Condition of Zebrafish Justin L. Sanders, Joana F. Monteiro, Sandra Martins, Ana Catarina Certal, and Michael L. Kent27 March 2020 | Zebrafish, Vol. 17, No. 2Health Surveillance ProgramsEvidence of Centrocestus formosanus (Nishigori, 1924) in Zebrafish (Danio rerio) Carmelo Iaria, Sergio Migliore, Daniele Macri, Maurizio Bivona, Fabiano Capparucci, Gabriella Gaglio, and Fabio Marino2 December 2019 | Zebrafish, Vol. 16, No. 6Tools for studying the metabolism of new psychoactive substances for toxicological screening purposes – A comparative study using pooled human liver S9, HepaRG cells, and zebrafish larvaeToxicology Letters, Vol. 305Transmission of Pseudoloma neurophilia in Laboratory Zebrafish (Danio rerio) When Using Mass Spawning Chambers and Recommendations for Chamber Disinfection Samantha M. Peneyra, Jose Cardona-Costa, Julie White, Christopher M. Whipps, Elyn R. Riedel, Neil S. Lipman, and Christine Lieggi1 February 2018 | Zebrafish, Vol. 15, No. 1International survey on the use and welfare of zebrafish Danio rerio in research20 February 2017 | Journal of Fish Biology, Vol. 90, No. 5Systems pharmacology of hepatic metabolism in zebrafish larvaeDrug Discovery Today: Disease Models, Vol. 22 Volume 13Issue S1Jul 2016 InformationCopyright 2016, Mary Ann Liebert, Inc.To cite this article:Christian Lawrence, Judith S. Eisen, and Zoltán M. Varga.Husbandry and Health Program Survey Synopsis.Zebrafish.Jul 2016.S-5-S-7.http://doi.org/10.1089/zeb.2016.1309Published in Volume: 13 Issue S1: June 28, 2016Online Ahead of Print:June 1, 2016PDF download

Pulutan (Urena lobata) is one of medicinal plant used to treat some diseases traditionally and pre-clinical studies have showed its efficacy. However, the study about its safety has not been evaluated completely. An acute toxicity test has to be performed in order to screen for its safety. The objective of study to determine the acute toxicity level of Urena lobata (U. lobata) leaf extract on embryo phase, juvenile and adult of zebrafish (Danio rerio) and the role of its active constituents through in silico methods. This was an experimental laboratory study using embryo, juvenile and adult of zebrafish (Danio rerio). The leaf of U. lobata was extracted by decoction methods and the extract was diluted from 12000 mg/L to 500 mg/L. The animals were exposed to the extracts for 96 hours. Toxicity level of herbs was defined using lethal concentration-50 (LC-50) obtained through linear regression. In silico study was performed using a web-based software application (iLAB ACD). The LC-50 values of U. lobata leaf extract for embryo, juvenile and adult of zebrafish (Danio rerio) were 2548 mg/L, 8748 mg/L and 8088 mg/L, respectively. Acute toxicity level of U. lobata on embryo is higher compared to juvenile and adult of zebrafish. After identification of active compound and in silico study was performed, Stigmasterol and β-sitosterol in U. lobata showed high toxicity level based on LD-50 value. Level toxicity of U. lobata on zebrafish embryo was moderate (0.5-5.0 g/L) and it shows teratogenic effect, meanwhile, its effects on juvenile and adult fish were considered mild (5.0-15.0 g/L).

The acute toxic effects of imidazolium-based ionic liquids with different alkyl-chain lengths and anions on zebrafish (Danio rerio)

Dietary and xenobiotic compounds may alter endocrine signaling and lipid homeostasis, thus inducing obesity. We describe a short-term assay method, the zebrafish obesogenic (ZO) test, for examining the effects of diet, drugs, and environmental contaminants, singly or in combination, on white adipose tissue (WAT) dynamics in live larvae. The ZO test is an intermediate step in obesity research, between in vitro and rodent assays, and may be also used to study the effect of environmental toxicants on the adiposity of aquatic species. The procedure, using Nile Red (NR) fluorescent probe to reveal adipocyte lipid droplets, is suitable for pharmaceutical or toxicological screening. Larvae treated at an environmentally-relevant concentration of tributyltin chloride (TBT), an environmental obesogen, exhibited a remarkable increase in adiposity, irrespective of the lipid composition of the background diet. Exogenous compounds, e.g., rosiglitazone or TBT, known to increase adiposity in the fasting state, were classified as obesogenic. Anti-obesogenic compounds favored a decrease in adiposity in the fasting state. The ZO test, using adipocyte lipid droplet size and adiposity as its endpoints, is a whole-organism alternative testing assay for obesogenic and anti-obesogenic compounds and mixtures and provides relevant information for environmental and human risk assessments.

The adult central nervous cholinergic system of a neurogenetic model animal, the zebrafish Danio rerio

All organisms respond to environmental, chemical and physiological stresses by enhanced synthesis of an evolutionarily conserved family of proteins known as heat shock proteins (HSPs) or stress proteins. Certain HSPs are also expressed constitutively during cell growth and development, and they function as molecular chaperones. The transcriptional regulation of hsp genes is mediated by the heat shock transcription factor (HSF). The stress response has been studied mostly in mammalian cell lines or organisms normally maintained under constant laboratory conditions. There is much less information on the regulation of the stress response of animals, such as fish, that have to tolerate large fluctuations in environmental and internal conditions. To characterize the regulation of the heat shock response in fish, we have cloned the first heat shock transcription factor from fish, zebrafish Danio rerio. Phylogenetic analysis confirms that the isolated zebrafish HSF belongs to the HSF1 family and is therefore designated zHSF1. Analysis by reverse transcriptase polymerase chain reaction (RT-PCR) shows the presence of two zHSF1 mRNA forms that are expressed in a tissue-specific fashion upon exposure to heat stress. Both forms are expressed in gonads under all conditions; in liver and to a lesser extent in the gills, the longer splice form of zHSF1 disappears upon heat shock. We present evidence for a unique tissue-specific regulation of HSF1 upon exposure to elevated temperature.

The value of the zebrafish (Danio rerio) as a model organism continues to expand. In developing the model, current feeding practice in zebrafish laboratories includes the use of commercially available diets. In this study, we compared outcomes in growth, body composition, and reproduction among zebrafish fed five highly utilized commercial diets and one formulated chemically defined reference diet. Wild-type zebrafish larvae were raised on live feed until 21 days postfertilization and then fed diets for 16 weeks. All fish received a daily ration of >5% of body weight (adjusted biweekly). Growth varied among diets throughout the feeding trial, and at study termination (week 16), significant differences among diets were observed for terminal weight gain, body condition index, body fat deposition, and reproductive outcomes. In addition, the proportion of viable embryos produced from females fed the formulated reference diet was high relative to the commercial diets. These data suggest that metabolic profiles, most likely reflecting nutrient/energy availability, utilization, and allocation, vary relative to diet in zebrafish. Undefined differences in metabolic profiles could result in erroneous predictions of health outcomes and make comparisons among laboratories more challenging. We recommend that dietary standards should be defined for zebrafish to support their common utility in biomedical research.

Thiamine (vitamin B1) metabolism is an important driver of human and animal health and ecological functioning. Some organisms, including species of ferns, mollusks, and fish, contain thiamine-degrading enzymes known as thiaminases, and consumption of these organisms can lead to thiamine deficiency in the consumer. Consumption of fish containing thiaminase has led to elevated mortality and recruitment failure in farmed animals and wild salmonine populations around the world. In the North American Great Lakes, consumption of the non-native prey fish alewife (Alosa pseudoharengus) by native lake trout (Salvelinus namaycush) led to thiamine deficiency in the trout, contributed to elevated fry mortality, and impeded natural population recruitment. Several thiaminases have been genetically characterized in bacteria and unicellular eukaryotes, and the source of thiaminase in multicellular organisms has been hypothesized to be gut microflora. In an unexpected discovery, we identified thiaminase I genes in zebrafish (Danio rerio) with homology to bacterial tenA thiaminase II. The biochemical activity of zebrafish thiaminase I (GenBank NP_001314821.1) was confirmed in a recombinant system. Genes homologous to the zebrafish tenA-like thiaminase I were identified in many animals, including common carp (Cyprinus carpio), zebra mussel (Dreissena polymorpha) and alewife. Thus, the source of thiaminase I in alewife impacting lake trout populations is likely to be de novo synthesis.

Uranium-induced sensory alterations in the zebrafish Danio rerio

Data variability complicates reproducibility and the interpretation of experimental results. Different animal models have been employed to decrease variability to enhance experimental power. However, variation frequently persists among and within strains/lines. In zebrafish (Danio rerio), inbred lines (e.g., NHGRI-1) derived from wild-type lines have been produced to greatly decrease genetic variation, with the goal of providing better understanding of genetic backgrounds that may influence the experimental outcome of studies employing such lines. We hypothesized that variations in morphological phenotypes shaped by environmental stressors early in development are correlated with the intrinsic degree of genetic variability of zebrafish lines. We compared morphological variability (yolk–chorion ratio, body mass, embryo mass, total length, condition factor, and specific growth rate) in wild-type AB and NHGRI-1 zebrafish lines as a function of their responses to altered temperature and oxygen availability during the first 7 days post-fertilization. Overall, both lines showed similar developmental trajectories for yolk–chorion ratio, embryo mass, and total length. Additionally, condition factor and specific growth rate showed similar responses within each line, regardless of temperature and hypoxia. Importantly, the coefficient of variation for each variable was significantly lower in NHGRI-1 than AB larvae for 151 of 187 assessed morphological endpoints. Thus, the low-heterozygosity NHGRI-1 zebrafish line can be useful for decreasing inter-individual variation in morphological responses to environmental stressors, thereby aiding in the interpretation of results and enhancing experimental reproducibility.

Pre-spermiogenic initiation of flagellar growth and correlative ultrastructural observations on nuage, nuclear and mitochondrial developmental morphology in the zebrafish Danio rerio

Simple SummaryThe maintenance and manipulation of AB strain zebrafish oocytes at 26 °C was found to be possible for 2 h without incurring a marked reduction in fertilization potential. However, the post-ovulatory ageing of oocytes for 6 h resulted in an almost complete loss of egg viability. All larvae derived from the 4- and 6-h aged oocytes were characterized by physical abnormalities. Ageing oocytes for 4 h resulted in the incidence of ploidy anomalies having a four-fold increase. These results make a valuable contribution with respect to the control of experimental reproduction in zebrafish, which is currently accepted as an excellent model animal.Fish egg quality can be markedly influenced by the oocyte age after ovulation. In this study, we examined the duration of oocyte ageing in the zebrafish (Danio rerio) and whether prolonged ageing is associated with the incidence of ploidy anomalies in the resulting embryos. Oocytes were incubated in vitro for 6 h post-stripping (HPS) at 26 °C and fertilized at 2-h intervals. Meanwhile, for eggs fertilized immediately after stripping, the fertilization, embryo survival, and hatching rates started at ~80%; these rates decreased to 39%, 24%, and 16%, respectively, for oocytes that had been stored for 4 h (p ˂ 0.05), and there was an almost complete loss of egg viability at 6 HPS. Furthermore, almost 90% of the embryos derived from 6-h aged oocytes died prior to hatching, and all larvae originating from 4- and 6-h aged oocytes showed malformations. The proportion of ploidy abnormal embryos was significantly greater at 4 HPS (18.5%) than at either 0 or 2 HPS (4.7% and 8.8%, respectively). The results revealed that zebrafish oocytes retained their fertilization potential for up to 2 h after stripping at 26 °C and indicated the contribution of post-ovulatory oocyte ageing in the occurrence of ploidy anomalies in the resulting embryos.