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Sample records for zebra fish embryos

  1. Self-association of Gata1 enhances transcriptional activity in vivo in zebra fish embryos.

    PubMed

    Nishikawa, Keizo; Kobayashi, Makoto; Masumi, Atsuko; Lyons, Susan E; Weinstein, Brant M; Liu, P Paul; Yamamoto, Masayuki

    2003-11-01

    Gata1 is a prototype transcription factor that regulates hematopoiesis, yet the molecular mechanisms by which Gata1 transactivates its target genes in vivo remain unclear. We previously showed, in transgenic zebra fish, that Gata1 autoregulates its own expression. In this study, we characterized the molecular mechanisms for this autoregulation by using mutations in the Gata1 protein which impair autoregulation. Of the tested mutations, replacement of six lysine residues with alanine (Gata1KA6), which inhibited self-association activity of Gata1, reduced the Gata1-dependent induction of reporter gene expression driven by the zebra fish gata1 hematopoietic regulatory domain (gata1 HRD). Furthermore, overexpression of wild-type Gata1 but not Gata1KA6 rescued the expression of Gata1 downstream genes in vlad tepes, a germ line gata1 mutant fish. Interestingly, both GATA sites in the double GATA motif in gata1 HRD were critical for the promoter activity and for binding of the self-associated Gata1 complex, whereas only the 3'-GATA site was required for Gata1 monomer binding. These results thus provide the first in vivo evidence that the ability of Gata1 to self-associate critically contributes to the autoregulation of the gata1 gene.

  2. Comparison of cholin- and carboxylesterase enzyme inhibition and visible effects in the zebra fish embryo bioassay under short-term paraoxon-methyl exposure.

    PubMed

    Küster, E; Altenburger, R

    2006-01-01

    The acute zebra fish embryo test (Danio rerio Hamilton-Buchanan, 1822) is an accepted bioassay to assess the toxicity of waste water that may be used for the replacement of testing with adult fish. It is also suggested for chemical hazard characterization and assessment, although only a few groups of substances have yet been studied. Specifically acting substances such as neurotoxic insecticides pose a potentially hazard for non-target fish. To establish whether the proposed zebra fish embryo test protocol and the inhibition of cholinesterases (acetylcholinesterase EC 3.1.1.7, propionylcholinesterase EC 3.1.1.8) and carboxylesterase (EC 3.1.1.1) enzymes can be used in a similar fashion for hazard characterization and risk assessment of chemicals and environmental samples, two types of experiments were conducted. Visual effects of exposure to the organophosphate metabolite paraoxon-methyl after 24 and 48 h in the zebra fish embryo test system were analysed with the use of an inverse microscope (rate of mortality, developmental disturbances, heart rate and others). The inhibition to cholinesterases and carboxylesterase was also measured. Enzyme inhibition as a biomarker of exposure was about 70 times more sensitive than the effects in the zebra fish embryo test with an IC50 below 1.2 micromol compared with an EC50 of 91 micromol. The dose-response relationships showed different curve characteristics with a linear increase of enzyme inhibition compared with a sigmoidal curve for the overt effects. Significant overt effects could only be seen at concentrations at which already 80% of the activities of the different esterases were inhibited.

  3. Investigation of a Brazilian tannery effluent by means of zebra fish (Danio rerio) embryo acute toxicity (FET) test.

    PubMed

    Rocha, Otávio Pelegrino; De Oliveira, Danielle Palma

    2017-01-01

    Tannery effluents consist of a complex chemical composition not only limited to primary pollutants, which also require biological detection as these compounds may produce adverse effects. The fish embryo toxicity (FET) test with Danio rerio is an alternative method in hazard and risk assessment for determination of chemical-mediated effects. The aim of this investigation was to use the FET test to detect compounds and consequent effects in Brazilian tannery effluents. Samples were collected from the inlet and outlet of the effluent treatment plant at a tannery located in Restinga, São Paulo, Brazil. The toxicological effects were assessed using FET assay for a period of 144 hr using indices such as (1) coagulation of fertilized eggs, (2) lack of detachment of tail-bud from yolk sac, (3) absence of spontaneous movement, (4) yolk sack edema, (5) malformation of the tail, (6) scoliosis, and (7) deformation of swim bladder in the embryos. Data showed that effluent treatment plant exposure produced acute toxicity in D. rerio embryos as evidenced by coagulation of fertilized eggs in up to 5% of all diluted samples 24 hr post fertilization for inlet effluent samples compared to 100% coagulation for outlet samples. Results demonstrated that these effects may not be attributed to metals, but to other non-detected components, such as dyes, pigments, biocides, carriers, surfactants, or other organic compounds that might be present in these complex mixtures. The use of D. rerio embryos was found to be useful as an additional tool for ecotoxicity testing to assess the potential environmental acute toxicity influence of tannery effluents.

  4. Transcription-dependent induction of G1 phase during the zebra fish midblastula transition.

    PubMed

    Zamir, E; Kam, Z; Yarden, A

    1997-02-01

    The early development of the zebra fish (Danio rerio) embryo is characterized by a series of rapid and synchronous cell cycles with no detectable transcription. This period is followed by the midblastula transition (MBT), during which the cell cycle gradually lengthens, cell synchrony is lost, and zygotic transcription is initially detected. In this work, we examined the changes in the pattern of the cell cycle during MBT in zebra fish and whether these changes are dependent on the initiation of zygotic transcription. To characterize the pattern of the early zebra fish cell cycles, the embryonic DNA content was determined by flow cytometric analysis. We found that G1 phase is below detection levels during the first 10 cleavages and can be initially detected at the onset of MBT. Inhibition of zygotic transcription, by microinjection of actinomycin D, abolished the appearance of G1 phase at MBT. Premature activation of zygotic transcription, by microinjection of nonspecific DNA, induced G1 phase before the onset of MBT, while coinjection of actinomycin D and nonspecific DNA abolished this early appearance of G1 phase. We therefore suggest that during the early development of the zebra fish embryo, G1 phase appears at the onset of MBT and that the activation of transcription at MBT is essential and sufficient for the G1-phase induction.

  5. Transcriptional repressor foxl1 regulates central nervous system development by suppressing shh expression in zebra fish.

    PubMed

    Nakada, Chisako; Satoh, Shinya; Tabata, Yoko; Arai, Ken-ichi; Watanabe, Sumiko

    2006-10-01

    We identified zebra fish forkhead transcription factor l1 (zfoxl1) as a gene strongly expressed in neural tissues such as midbrain, hindbrain, and the otic vesicle at the early embryonic stage. Loss of the function of zfoxl1 effected by morpholino antisense oligonucleotide resulted in defects in midbrain and eye development, and in that of formation of the pectoral fins. Interestingly, ectopic expression of shh in the midbrain and elevated pax2a expression in the optic stalk were observed in foxl1 MO-injected embryos. In contrast, expression of pax6a, which is negatively regulated by shh, was suppressed in the thalamus and pretectum regions, supporting the idea of augmentation of the shh signaling pathway by suppression of foxl1. Expression of zfoxl1-EnR (repressing) rather than zfoxl1-VP16 (activating) resulted in a phenotype similar to that induced by foxl1-mRNA, suggesting that foxl1 may act as a transcriptional repressor of shh in zebra fish embryos. Supporting this notion, foxl1 suppressed isolated 2.7-kb shh promoter activity in PC12 cells, and the minimal region of foxl1 required for its transcriptional repressor activity showed strong homology with the groucho binding motif, which is found in genes encoding various homeodomain proteins. In view of all of our data taken together, we propose zfoxl1 to be a novel regulator of neural development that acts by suppressing shh expression.

  6. Dissection and Downstream Analysis of Zebra Finch Embryos at Early Stages of Development

    PubMed Central

    Murray, Jessica R.; Stanciauskas, Monika E.; Aralere, Tejas S.; Saha, Margaret S.

    2014-01-01

    The zebra finch (Taeniopygiaguttata) has become an increasingly important model organism in many areas of research including toxicology1,2, behavior3, and memory and learning4,5,6. As the only songbird with a sequenced genome, the zebra finch has great potential for use in developmental studies; however, the early stages of zebra finch development have not been well studied. Lack of research in zebra finch development can be attributed to the difficulty of dissecting the small egg and embryo. The following dissection method minimizes embryonic tissue damage, which allows for investigation of morphology and gene expression at all stages of embryonic development. This permits both bright field and fluorescence quality imaging of embryos, use in molecular procedures such as in situ hybridization (ISH), cell proliferation assays, and RNA extraction for quantitative assays such as quantitative real-time PCR (qtRT-PCR). This technique allows investigators to study early stages of development that were previously difficult to access. PMID:24999108

  7. Predation on exotic zebra mussels by native fishes: Effects on predator and prey

    USGS Publications Warehouse

    Magoulick, D.D.; Lewis, L.C.

    2002-01-01

    1. Exotic zebra mussels, Dreissena polymorpha, occur in southern U.S. waterways in high densities, but little is known about the interaction between native fish predators and zebra mussels. Previous studies have suggested that exotic zebra mussels are low profitability prey items and native vertebrate predators are unlikely to reduce zebra mussel densities. We tested these hypotheses by observing prey use of fishes, determining energy content of primary prey species of fishes, and conducting predator exclusion experiments in Lake Dardanelle, Arkansas. 2. Zebra mussels were the primary prey eaten by 52.9% of blue catfish, Ictalurus furcatus; 48.2% of freshwater drum, Aplodinotus grunniens; and 100% of adult redear sunfish, Lepomis microlophus. Blue catfish showed distinct seasonal prey shifts, feeding on zebra mussels in summer and shad, Dorosoma spp., during winter. Energy content (joules g-1) of blue catfish prey (threadfin shad, Dorosoma petenense; gizzard shad, D. cepedianum; zebra mussels; and asiatic clams, Corbicula fluminea) showed a significant species by season interaction, but shad were always significantly greater in energy content than bivalves examined as either ash-free dry mass or whole organism dry mass. Fish predators significantly reduced densities of large zebra mussels (>5 mm length) colonising clay tiles in the summers of 1997 and 1998, but predation effects on small zebra mussels (???5 mm length) were less clear. 3. Freshwater drum and redear sunfish process bivalve prey by crushing shells and obtain low amounts of higher-energy food (only the flesh), whereas blue catfish lack a shell-crushing apparatus and ingest large amounts of low-energy food per unit time (bivalves with their shells). Blue catfish appeared to select the abundant zebra mussel over the more energetically rich shad during summer, then shifted to shad during winter when shad experienced temperature-dependent stress and mortality. Native fish predators can suppress adult zebra

  8. How well can fishes prey on zebra mussels in eastern North America?

    USGS Publications Warehouse

    French, John R. P.

    1993-01-01

    Literature on mollusk-eating fishes was reviewed to determine the potential for different species of fish to control zebra mussels in eastern North America. At least six species are potential predators of zebra mussels because they possess (1) both upper and lower pharyngeal teeth or (2) lower pharyngeal teeth and chewing pads located on the dorsal roof for crushing mollusk shells. Freshwater drum (Aplodinotus grunniens) and two centrarchids, redear sunfish (Lepomis microlophus) and pumpkinseed (L. gibbosus), possess both upper and lower pharyngeal teeth and are likely to consume more zebra mussels than fishes with only lower pharyngeal teeth. Only two catostomid species, copper and river redhorses (Moxostoma hubbsi and M. carinatum), have chewing pads that enable them to crush mollusks. The exotic omnivorous common carp (Cyprinus carpio), possessing lower teeth and a chewing pad, may prey on zebra mussels when aquatic insect larvae, its preferred food, become rare. Managing populations of drum, sunfishes and redhorses to reduce exploitation of large individuals and improve their habitats are suggested as means to intensify biological control of zebra mussels in eastern North America. Other Eurasian molluscivores, the roach (Rutilus rutilus) and the black carp (Mylopharyngodon piceus) should not be introduced into North America because research has shown repeatedly that an introduced biological controller usually does not forage for unwanted pests or reside only in preferred habitats of pests. Drum, sunfishes and redhorses should be preferred over these exotics as biological controllers of zebra mussels in North America because these native fishes will likely occupy newly established habitats of zebra mussels.

  9. Assessing the potential for fish predation to impact zebra mussels (Dreissena polymorpha): Insight from bioenergetics models

    USGS Publications Warehouse

    Eggleton, M.A.; Miranda, L.E.; Kirk, J.P.

    2004-01-01

    Rates of annual food consumption and biomass were modeled for several fish species across representative rivers and lakes in eastern North America. Results were combined to assess the relative potential of fish predation to impact zebra mussels (Dreissena polymorpha). Predicted annual food consumption by fishes in southern waters was over 100% greater than that in northern systems because of warmer annual water temperatures and presumed increases in metabolic demand. Although generally increasing with latitude, biomasses of several key zebra mussel fish predators did not change significantly across latitudes. Biomasses of some less abundant fish predators did increase significantly with latitude, but increases were not of the magnitude to offset predicted decreases in food consumption. Our results generally support the premise that fishes in rivers and lakes of the southern United States (U.S.) have inherently greater potential to impact zebra mussels by predation. Our simulations may provide a partial explanation of why zebra mussel invasions have not been as rapid and widespread in southern U.S. waters compared to the Great Lakes region. ?? Blackwell Munksgaard, 2004.

  10. Modulation of antioxidant defense and immune response in zebra fish (Danio rerio) using dietary sodium propionate.

    PubMed

    Safari, Roghieh; Hoseinifar, Seyed Hossein; Kavandi, Morteza

    2016-12-01

    The present study explores the effect of dietary sodium propionate on mucosal immune response and expression of antioxidant enzyme genes in zebra fish (Danio rerio). Six hundred healthy zebra fish (0.42 ± 0.06 g) supplied, randomly stocked in 12 aquariums and fed on basal diets supplemented with different levels of sodium propionate [0 (control), 5, 10 and 20 g kg -1 ] for 8 weeks. At the end of the feeding trial, mucosal immune parameters (TNF-α, IL-1β, Lyz), antioxidant enzyme (SOD, CAT) as well as heat shock protein 70 (HSP70) gene expression were measured. The results revealed feeding on sodium propionate significantly up-regulated inflammatory response genes (TNF-α, IL-1β, Lyz) in a dose-dependent manner (P < 0.05). However, antioxidant enzyme genes significantly down-regulated in the treated group compared with control (P < 0.05). Also, HSP70 gene expression was higher in the liver of fish fed the basal diet and deceased with elevation of sodium propionate levels in the diet. These results showed beneficial effects of dietary sodium propionate on mucosal immune response as well as the antioxidant defense of zebra fish.

  11. Cognition Enhancing Activity of Sulforaphane Against Scopolamine Induced Cognitive Impairment in Zebra Fish (Danio rerio).

    PubMed

    Rajesh, Venugopalan; Ilanthalir, Sakthivel

    2016-10-01

    Several epidemiological studies have shown that consumption of large quantities of vegetables especially cruciferous vegetables (Broccoli and Brussels sprouts) can protect against chronic diseases. Sulforaphane, an isothiocynate found in cruciferous vegetables has been demonstrated to have neuroprotective effects in several experimental paradigms. This study was undertaken to examine the effect of sulforaphane on cognitive impairment in zebra fish model using a novel method of fear conditioning. Initially, the normal behaviour of zebra fishes was studied in light-dark tank for 10 min daily for 10 days. Fishes were then divided into seven groups of twelve in each. Group I served as normal, group II served as fear conditioned control, group III and group IV were sulforaphane (25 µM/L) and piracetam (200 mg/L) treated respectively. Group V served as scopolamine (400 µM/L) induced memory impairment fishes. Group VI and VII were sulforaphane (25 µM/L) and piracetam (200 mg/L) treated scopolamine induced memory impairment groups respectively. In normal behavioural analysis, fishes preferred to stay in dark compartment. The average number of entries into the dark and time spent in dark were significantly more. Fishes in group II to VII were individually subjected to fear conditioning passive avoidance task and evaluated for learned task memory. It was observed that the average number of entries into dark and time spent in dark were significantly decreased. After exposure to respective treatment fishes in group III to VII were subjected to cognitive evaluation. There was no significant difference in cognition of group III and IV fishes exposed to sulforaphane and piracetam alone respectively. Fishes exposed to scopolamine showed a significant cognitive impairment. Sulforaphane exposure prior to scopolamine significantly retained the memory of learned task. These findings suggest that sulforaphane might be a promising therapeutic agent for cognitive enhancement in

  12. Fish as bioreactors: transgene expression of human coagulation factor VII in fish embryos.

    PubMed

    Hwang, Gyulin; Müller, Ferenc; Rahman, M Aziz; Williams, Darren W; Murdock, Paul J; Pasi, K John; Goldspink, Geoffrey; Farahmand, Hamid; Maclean, Norman

    2004-01-01

    A plasmid containing human coagulation factor VII (hFVII) complementary DNA regulated by a cytomegalovirus promoter was microinjected into fertilized eggs of zebrafish, African catfish, and tilapia. The active form of hFVll was detected in the fish embryos by various assays. This positive expression of human therapeutic protein in fish embryos demonstrates the possibility of exploitation of transgenic fish as bioreactors.

  13. Crystal structure and potential physiological role of zebra fish thioesterase superfamily member 2 (fTHEM2)

    SciTech Connect

    Yu, Shanshan; Li, Han; Gao, Feng

    2015-08-07

    Thioesterase superfamily member 2 (THEM2) is an essential protein for mammalian cell proliferation. It belongs to the hotdog-fold thioesterase superfamily and catalyzes hydrolysis of thioester bonds of acyl-CoA in vitro, while its in vivo function remains unrevealed. In this study, Zebra fish was selected as a model organism to facilitate the investigations on THEM2. First, we solved the crystal structure of recombinant fTHEM2 at the resolution of 1.80 Å, which displayed a similar scaffolding as hTHEM2. Second, functional studies demonstrated that fTHEM2 is capable of hydrolyzing palmitoyl-CoA in vitro. In addition, injection of morpholino against fTHEM2 at one-cell stage resulted in distorted early embryomore » development, including delayed cell division, retarded development and increased death rate. The above findings validated our hypothesis that fTHEM2 could serve as an ideal surrogate for studying the physiological functions of THEM2. - Highlights: • The crystal structure of recombinant fTHEM2 is presented. • fTHEM2 is capable of hydrolyzing palmitoyl-CoA. • The influence of fTHEM2 on early embryo development is demonstrated.« less

  14. Zebra mussels (Dreissena polymorpha) limit food for larval fish (Pimephales promelas) in turbulent systems: A bioenergetics analysis

    USGS Publications Warehouse

    Bartsch, L.A.; Richardson, W.B.; Sandheinrich, M.B.

    2003-01-01

    We conducted a factorial experiment, in outdoor mesocosms, on the effects of zebra mussels and water column mixing (i.e., turbulence) on the diet, growth, and survival of larval fathead minnows (Pimephales promelas). Significant (P < 0.05) larval mortality occurred by the end of the experiment with the highest mortality (90%) occurring in the presence of both turbulence and zebra mussels, whereas mortality was 37% in treatment with turbulence and 17% and 18% in the zebra mussels treatment, and the control, respectively. The size of individual fish was significantly different among treatments at the end of the experiment and was inversely related to survival. Levels of trophic resources (i.e., phyto and zooplankton) varied among treatments and were treatment specific. Turbulent mixing facilitated removal of phytoplankton by zebra mussels by making the entire water column of the tanks available to these benthic filter feeders. Early in the experiment (Day = 0 to 14) the physical process of turbulent mixing likely caused a reduction in standing stocks of zooplankton. The interactive effect of turbulence and mussels reduced copepod and rotifer stocks, through physical processes and through filtration by zebra mussels, relative to the turbulence treatment. The reductions in the number of total zooplankton in the turbulent mixing mesocosms and the further reduction of rotifer and copepod in the turbulence and mussels treatment coincided with a period of increased reliance of larval fathead minnows on these prey. Estimates of consumption from bioenergetics modeling and measured prey standing stocks indicated caloric resources of suitable prey in turbulence treatments during the early weeks of the experiment were insufficient to prevent starvation. Early mortality in the turbulence and mussels treatment likely released surviving fish from intense intraspecific competition and resulted in higher individual growth rates. A combination of high abundance of zebra mussels in an

  15. Zebra mussels (Dreissena polymorpha) limit food for larval fish (Pimephales promelas) in turbulent systems: a bioenergetics analysis

    USGS Publications Warehouse

    Bartsch, L.A.; Richardson, W.B.; Sandheinrich, M.B.

    2003-01-01

    We conducted a factorial experiment, in outdoor mesocosms, on the effects of zebra mussels and water column mixing (i.e., turbulence) on the diet, growth, and survival of larval fathead minnows (Pimephales promelas). Significant (P < 0.05) larval mortality occurred by the end of the experiment with the highest mortality (90%) occurring in the presence of both turbulence and zebra mussels, whereas mortality was 37% in treatment with turbulence and 17% and 18% in the zebra mussels treatment, and the control, respectively. The size of individual fish was significantly different among treatments at the end of the experiment and was inversely related to survival. Levels of trophic resources (i.e., phyto and zooplankton) varied among treatments and were treatment specific. Turbulent mixing facilitated removal of phytoplankton by zebra mussels by making the entire water column of the tanks available to these benthic filter feeders. Early in the experiment (Day = 0 to 14) the physical process of turbulent mixing likely caused a reduction in standing stocks of zooplankton. The interactive effect of turbulence and mussels reduced copepod and rotifer stocks, through physical processes and through filtration by zebra mussels, relative to the turbulence treatment. The reductions in the number of total zooplankton in the turbulent mixing mesocosms and the further reduction of rotifer and copepod in the turbulence and mussels treatment coincided with a period of increased reliance of larval fathead minnows on these prey. Estimates of consumption from bioenergetics modeling and measured prey standing stocks indicated caloric resources of suitable prey in turbulence treatments during the early weeks of the experiment were insufficient to prevent starvation. Early mortality in the turbulence and mussels treatment likely released surviving fish from intense intraspecific competition and resulted in higher individual growth rates. A combination of high abundance of zebra mussels in an

  16. Impact of motorboats on fish embryos depends on engine type

    PubMed Central

    Jain-Schlaepfer, Sofia; Fakan, Eric; Rummer, Jodie L; Simpson, Stephen D; McCormick, Mark I

    2018-01-01

    Abstract Human generated noise is changing the natural underwater soundscapes worldwide. The most pervasive sources of underwater anthropogenic noise are motorboats, which have been found to negatively affect several aspects of fish biology. However, few studies have examined the effects of noise on early life stages, especially the embryonic stage, despite embryo health being critical to larval survival and recruitment. Here, we used a novel setup to monitor heart rates of embryos from the staghorn damselfish (Amblyglyphidodon curacao) in shallow reef conditions, allowing us to examine the effects of in situ boat noise in context with real-world exposure. We found that the heart rate of embryos increased in the presence of boat noise, which can be associated with the stress response. Additionally, we found 2-stroke outboard-powered boats had more than twice the effect on embryo heart rates than did 4-stroke powered boats, showing an increase in mean individual heart rate of 1.9% and 4.6%, respectively. To our knowledge this is the first evidence suggesting boat noise elicits a stress response in fish embryo and highlights the need to explore the ecological ramifications of boat noise stress during the embryo stage. Also, knowing the response of marine organisms caused by the sound emissions of particular engine types provides an important tool for reef managers to mitigate noise pollution. PMID:29593871

  17. Impact of motorboats on fish embryos depends on engine type.

    PubMed

    Jain-Schlaepfer, Sofia; Fakan, Eric; Rummer, Jodie L; Simpson, Stephen D; McCormick, Mark I

    2018-01-01

    Human generated noise is changing the natural underwater soundscapes worldwide. The most pervasive sources of underwater anthropogenic noise are motorboats, which have been found to negatively affect several aspects of fish biology. However, few studies have examined the effects of noise on early life stages, especially the embryonic stage, despite embryo health being critical to larval survival and recruitment. Here, we used a novel setup to monitor heart rates of embryos from the staghorn damselfish ( Amblyglyphidodon curacao ) in shallow reef conditions, allowing us to examine the effects of in situ boat noise in context with real-world exposure. We found that the heart rate of embryos increased in the presence of boat noise, which can be associated with the stress response. Additionally, we found 2-stroke outboard-powered boats had more than twice the effect on embryo heart rates than did 4-stroke powered boats, showing an increase in mean individual heart rate of 1.9% and 4.6%, respectively. To our knowledge this is the first evidence suggesting boat noise elicits a stress response in fish embryo and highlights the need to explore the ecological ramifications of boat noise stress during the embryo stage. Also, knowing the response of marine organisms caused by the sound emissions of particular engine types provides an important tool for reef managers to mitigate noise pollution.

  18. Comparison of the acute toxicity for gamma-cyhalothrin and lambda-cyhalothrin to zebra fish and shrimp.

    PubMed

    Wang, Wei; Cai, D J; Shan, Z J; Chen, W L; Poletika, Nick; Gao, X W

    2007-03-01

    Gamma-cyhalothrin 15CS (GCH) contains only the active stereoisomer of the two isomers found in lambda-cyhalothrin 25EW (LCH). GCH (0.5 x rate) provides equivalent overall insect control as LCH (1 x rate). Both formulations showed high acute toxicity to zebra fish (Brachydanio rerio H.B.) and shrimp (Macrobrachium nippoensis de Haan). The 96-h LC(50(zebra fish,GCH)) is 1.93 microg a.i/L and LC(50(zebra fish,LCH)) is 1.94 microg a.i/L. LC(50(shrimp,GCH)) is 0.28 microg a.i./L and LC(50(shrimp,LCH)) 0.04 microg a.i./L. This indicates that the toxicity to shrimp is likely stereochemistry-dependent. The fates of GCH and LCH are similar in laboratory simulated rice paddy water and their concentrations decrease rapidly, with no GCH or LCH detected after 3 or 4 days. Both are toxic to shrimp in a simulated paddy irrigation reservoir even though treated return water is diluted 5 times. No shrimp fatality is shown in the GCH-treated paddy water after a 4-day holding period, and longer than 5 days is necessary to reach a zero fatality rate for LCH. This is compatible with the 7-day water holding period considered reasonable in agricultural practice.

  19. ZebraBeat: a flexible platform for the analysis of the cardiac rate in zebrafish embryos

    NASA Astrophysics Data System (ADS)

    de Luca, Elisa; Zaccaria, Gian Maria; Hadhoud, Marwa; Rizzo, Giovanna; Ponzini, Raffaele; Morbiducci, Umberto; Santoro, Massimo Mattia

    2014-05-01

    Heartbeat measurement is important in assesssing cardiac function because variations in heart rhythm can be the cause as well as an effect of hidden pathological heart conditions. Zebrafish (Danio rerio) has emerged as one of the most useful model organisms for cardiac research. Indeed, the zebrafish heart is easily accessible for optical analyses without conducting invasive procedures and shows anatomical similarity to the human heart. In this study, we present a non-invasive, simple, cost-effective process to quantify the heartbeat in embryonic zebrafish. To achieve reproducibility, high throughput and flexibility (i.e., adaptability to any existing confocal microscope system and with a user-friendly interface that can be easily used by researchers), we implemented this method within a software program. We show here that this platform, called ZebraBeat, can successfully detect heart rate variations in embryonic zebrafish at various developmental stages, and it can record cardiac rate fluctuations induced by factors such as temperature and genetic- and chemical-induced alterations. Applications of this methodology may include the screening of chemical libraries affecting heart rhythm and the identification of heart rhythm variations in mutants from large-scale forward genetic screens.

  20. Fish embryo toxicity of carbamazepine, diclofenac and metoprolol.

    PubMed

    van den Brandhof, Evert-Jan; Montforts, Mark

    2010-11-01

    Frequently measured pharmaceuticals in environmental samples were tested in fish embryo toxicity (FET) tests with Danio rerio, based on the draft OECD test protocol. In this FET test 2-h-old zebrafish embryos were exposed for 72 h to carbamazepine, diclofenac and metoprolol to observe effects on embryo mortality, gastrulation, somite formation, tail movement and detachment, pigmentation, heartbeat, malformation of head, otoliths and heart, scoliosis, deformity of yolk, and hatching success at 24, 48 and 72 h. We found specific effects on growth retardation above 30.6 mg/l for carbamazepine, on hatching, yolk sac and tail deformation above 1.5mg/l for diclofenac, and on scoliosis and growth retardation above 12.6 mg/l for metoprolol. Scoring all effect parameters, the 72-h-EC(50) values were: for carbamazepine 86.5mg/l, for diclofenac 5.3mg/l and for metoprolol 31.0mg/l (mean measured concentrations). In conclusion, our results for carbamazepine and metoprolol are in agreement with other findings for aquatic toxicity, and also fish embryos responded in much the same way as rat embryos did. For diclofenac, the FET test performs comparably to Early Life Stage testing. Copyright © 2010 Elsevier Inc. All rights reserved.

  1. The fish embryo test (FET): origin, applications, and future.

    PubMed

    Braunbeck, Thomas; Kais, Britta; Lammer, Eva; Otte, Jens; Schneider, Katharina; Stengel, Daniel; Strecker, Ruben

    2015-11-01

    Originally designed as an alternative for the acute fish toxicity test according to, e.g., OECD TG 203, the fish embryo test (FET) with the zebrafish (Danio rerio) has been optimized, standardized, and validated during an OECD validation study and adopted as OECD TG 236 as a test to assess toxicity of embryonic forms of fish. Given its excellent correlation with the acute fish toxicity test and the fact that non-feeding developmental stages of fish are not categorized as protected stages according to the new European Directive 2010/63/EU on the protection of animals used for scientific purposes, the FET is ready for use not only for range-finding but also as a true alternative for the acute fish toxicity test, as required for a multitude of national and international regulations. If-for ethical reasons-not accepted as a full alternative, the FET represents at least a refinement in the sense of the 3Rs principle. Objections to the use of the FET have mainly been based on the putative lack of biotransformation capacity and the assumption that highly lipophilic and/or high molecular weight substances might not have access to the embryo due to the protective role of the chorion. With respect to bioactivation, the only substance identified so far as not being activated in the zebrafish embryo is allyl alcohol; all other biotransformation processes that have been studied in more detail so far were found to be present, albeit, in some cases, at lower levels than in adult fish. With respect to larger molecules, the extension of the test duration to 96 h (i.e., beyond hatch) has-at least for the substances tested so far-compensated for the reduced access to the embryo; however, more research is necessary to fully explore the applicability of the FET to substances with a molecular weight >3 kDa as well as substances with a neurotoxic mode of action. An extension of the endpoints to also cover sublethal endpoints makes the FET a powerful tool for the detection of

  2. Extracellular acidification activates ovarian cancer G-protein-coupled receptor 1 and GPR4 homologs of zebra fish

    SciTech Connect

    Mochimaru, Yuta; Azuma, Morio; Oshima, Natsuki

    2015-02-20

    Mammalian ovarian G-protein-coupled receptor 1 (OGR1) and GPR4 are identified as a proton-sensing G-protein-coupled receptor coupling to multiple intracellular signaling pathways. In the present study, we examined whether zebra fish OGR1 and GPR4 homologs (zOGR1 and zGPR4) could sense protons and activate the multiple intracellular signaling pathways and, if so, whether the similar positions of histidine residue, which is critical for sensing protons in mammalian OGR and GPR4, also play a role to sense protons and activate the multiple signaling pathways in the zebra fish receptors. We found that extracellular acidic pH stimulated CRE-, SRE-, and NFAT-promoter activities in zOGR1more » overexpressed cells and stimulated CRE- and SRE- but not NFAT-promoter activities in zGPR4 overexpressed cells. The substitution of histidine residues at the 12th, 15th, 162th, and 264th positions from the N-terminal of zOGR1 with phenylalanine attenuated the proton-induced SRE-promoter activities. The mutation of the histidine residue at the 78th but not the 84th position from the N-terminal of zGPR4 to phenylalanine attenuated the proton-induced SRE-promoter activities. These results suggest that zOGR1 and zGPR4 are also proton-sensing G-protein-coupled receptors, and the receptor activation mechanisms may be similar to those of the mammalian receptors. - Highlights: • Zebra fish OGR1 and GPR4 homologs (zOGR1, zGPR4) are proton-sensing receptors. • The signaling pathways activated by zOGR1 and zGPR4 are different. • Histidine residues critical for sensing protons are conserved.« less

  3. Investigation of calcium-dependent activity and conformational dynamics of zebra fish 12-lipoxygenase.

    PubMed

    Mittal, Monica; Hasan, Mahmudul; Balagunaseelan, Navisraj; Fauland, Alexander; Wheelock, Craig; Rådmark, Olof; Haeggström, Jesper Z; Rinaldo-Matthis, Agnes

    2017-08-01

    A 12-lipoxygenase in zebra fish (zf12-LOX) was found to be required for normal embryonic development and LOXs are of great interest for targeted drug designing. In this study, we investigate the structural-functional aspects of zf12-LOX in response to calcium. A soluble version of zf12-LOX was created by mutagenesis. Based on multiple sequence alignment, we mutated the putative calcium-responsive amino acids in N-PLAT domain of soluble zf12-LOX. Using a series of biophysical methods, we ascertained the oligomeric state, stability, structural integrity and conformational changes of zf12-LOX in response to calcium. We also compared the biophysical properties of soluble zf12-LOX with the mutant in the absence and presence of calcium. Here we provide a detailed characterization of soluble zf12-LOX and the mutant. Both proteins exist as compact monomers in solution, however the enzyme activity of soluble zf12-LOX is significantly increased in presence of calcium. We find that the stimulatory effect of calcium on zf12-LOX is related to a change in protein structure as observed by SAXS, adopting an open-state. In contrast, enzyme with a mutated calcium regulatory site has reduced activity-response to calcium and restricted large re-modeling, suggesting that it retains a closed-state in response to calcium. Taken together, our study suggests that Ca 2+ -dependent regulation is associated with different domain conformation(s) that might change the accessibility to substrate-binding site in response to calcium. The study can be broadly implicated in better understanding the mode(s) of action of LOXs, and the enzymes regulated by calcium in general. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Locomotor behavior of fish hatched from embryos exposed to flight conditions

    NASA Technical Reports Server (NTRS)

    Kleerekoper, H.

    1978-01-01

    Embryos of Fundulus heteroclitus in various stages of development were exposed to space flight conditions aboard Apollo spacecraft and Cosmos satellites. The objective of the study was to ascertain whether fish hatched from these embryos displayed locomotor behavior different from that of control fish of the same age. An electronic monitoring technique was used to record behavior. Results indicate no change in locomotor behavior in fish on Apollo Spacecraft, but inexplicable significant changes were noted in fish aboard Cosmos Satellites.

  5. Zebra Fish Lacking Adaptive Immunity Acquire an Antiviral Alert State Characterized by Upregulated Gene Expression of Apoptosis, Multigene Families, and Interferon-Related Genes

    PubMed Central

    García-Valtanen, Pablo; Martínez-López, Alicia; López-Muñoz, Azucena; Bello-Perez, Melissa; Medina-Gali, Regla M.; Ortega-Villaizán, María del Mar; Varela, Monica; Figueras, Antonio; Mulero, Víctoriano; Novoa, Beatriz; Estepa, Amparo; Coll, Julio

    2017-01-01

    To investigate fish innate immunity, we have conducted organ and cell immune-related transcriptomic as well as immunohistologic analysis in mutant zebra fish (Danio rerio) lacking adaptive immunity (rag1−/−) at different developmental stages (egg, larvae, and adult), before and after infection with spring viremia carp virus (SVCV). The results revealed that, compared to immunocompetent zebra fish (rag1+/+), rag1−/− acquired increased resistance to SVCV with age, correlating with elevated transcript levels of immune genes in skin/fins and lymphoid organs (head kidney and spleen). Gene sets corresponding to apoptotic functions, immune-related multigene families, and interferon-related genes were constitutively upregulated in uninfected adult rag1−/− zebra fish. Overexpression of activated CASPASE-3 in different tissues before and after infection with SVCV further confirmed increased apoptotic function in rag1−/− zebra fish. Concurrently, staining of different tissue samples with a pan-leukocyte antibody marker showed abundant leukocyte infiltrations in SVCV-infected rag1−/− fish, coinciding with increased transcript expression of genes related to NK-cells and macrophages, suggesting that these genes played a key role in the enhanced immune response of rag1−/− zebra fish to SVCV lethal infection. Overall, we present evidence that indicates that rag1−/− zebra fish acquire an antiviral alert state while they reach adulthood in the absence of adaptive immunity. This antiviral state was characterized by (i) a more rapid response to viral infection, which resulted in increased survival, (ii) the involvement of NK-cell- and macrophage-mediated transcript responses rather than B- and/or T-cell dependent cells, and (iii) enhanced apoptosis, described here for the first time, as well as the similar modulation of multigene family/interferon-related genes previously associated to fish that survived lethal viral infections. From this and other studies

  6. Invasive zebra mussels (Driessena polymorpha) and Asian clams (Corbicula fluminea) survive gut passage of migratory fish species: implications for dispersal

    USGS Publications Warehouse

    Gatlin, Michael R.; Shoup, Daniel E.; Long, James M.

    2013-01-01

    The introduction and spread of invasive species is of great concern to natural resource managers in the United States. To effectively control the spread of these species, managers must be aware of the multitude of dispersal methods used by the organisms. We investigated the potential for survival through the gut of a migrating fish (blue catfish, Ictalurus furcatus) as a dispersal mechanism for two invasive bivalves: zebra mussel (Driessena polymorpha) and Asian clam (Corbicula fluminea). Blue catfish (N = 62) were sampled over several months from Sooner Lake, Oklahoma, transported to a laboratory and held in individual tanks for 48 h. All fecal material was collected and inspected for live mussels. Survival was significantly related to water temperature in the lake at the time of collection, with no mussels surviving above 21.1 C°, whereas 12 % of zebra mussels (N = 939) and 39 % of Asian clams (N = 408) consumed in cooler water survived gut passage. This research demonstrates the potential for blue catfish to serve as a dispersal vector for invasive bivalves at low water temperatures.

  7. Dependence between LD50 for Rodents and LC50 for Adult Fish and Fish Embryos.

    PubMed

    Zolotarev, K V; Belyaeva, N F; Mikhailov, A N; Mikhailova, M V

    2017-02-01

    We revealed empirical dependences between common logarithm of a ratio of rat oral LD 50 to LC a 50 for adult fish and lgP for 50 different chemicals; and common logarithm of a ratio of the oral LD 50 in rodents to LC e 50 for fish embryos and lgP for 30 different chemicals. The dependences were obtained by constructing a trend line between experimental points and calculation of Pearson's R correlation coefficient as a measure of regression significance. These dependences can show the influence of substance lipophilicity on its toxicity for aquatic organisms comparing to mammals.

  8. Function of identified motoneurones and co-ordination of primary and secondary motor systems during zebra fish swimming.

    PubMed Central

    Liu, D W; Westerfield, M

    1988-01-01

    1. The activity of the two classes of motoneurones, primary and secondary, which innervate myotomal muscle fibres in the zebra fish, was monitored with electromyographic and intracellular techniques. 2. Simultaneous EMG and intracellular recordings from muscle fibres showed that the activity of the two motor systems and of individual primary motoneurones can be distinguished by recording EMG spikes during swimming. 3. Measurements of EMG spikes demonstrated that primary and secondary motoneurones are co-ordinately activated over a wide range of conditions during normal swimming. 4. During swimming the primary motoneurones within a given segment are usually co-activated although they sometimes fire independently. 5. When different primary motoneurones within a given segment are co-activated, they fire nearly synchronously. 6. We conclude that the primary motoneurones are used principally, although not exclusively, during fast swimming, struggling and the startle response, whereas secondary motoneurones function primarily during slower swimming. PMID:3253426

  9. Cadmium stress assessment based on the electrocardiogram characteristics of zebra fish (Danio rerio): QRS complex could play an important role.

    PubMed

    Xing, Na; Ji, Lizhen; Song, Jie; Ma, Jingchun; Li, Shangge; Ren, Zongming; Xu, Fei; Zhu, Jianping

    2017-10-01

    The electrocardiogram (ECG) of zebra fish (Danio rerio) expresses cardiac features that are similar to humans. Here we use sharp microelectrode measurements to obtain ECG characteristics in adult zebra fish and analyze the effects of cadmium chloride (CdCl 2 ) on the heart. We observe the overall changes of ECG parameters in different treatments (0.1 TU, 0.5 TU and 1.0 TU CdCl 2 ), including P wave, Q wave, R wave, S wave, T wave, PR interval (atrial contraction), QRS complex (ventricular depolarization), ST segment, and QT interval (ventricular repolarization). The trends of the ECG parameters showed some responses to the concentration and exposure time of CdCl 2 , but it was difficult to obtain more information about the useful indicators in water quality assessment depending on tendency analysis alone. A self-organizing map (SOM) showed that P values, R values, and T values were similar; R wave and T wave amplitude were similar; and most important, QRS value was similar to the CdCl 2 stress according to the classified data patterns including CdCl 2 stress (E) and ECG components based on the Ward linkage. It suggested that the duration of QRS complex was related to environmental stress E directly. The specification and evaluation of ECG parameters in Cd 2+ pollution suggested that there is a markedly significant correlation between QRS complex and CdCl 2 stress with the highest r (0.729) and the smallest p (0.002) among all ECG characteristics. In this case, it is concluded that QRS complex can be used as an indicator in the CdCl 2 stress assessment due to the lowest AIC data abased on the linear regression model between the CdCl 2 stress and ECG parameters. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Several synthetic progestins disrupt the glial cell specific-brain aromatase expression in developing zebra fish

    SciTech Connect

    Cano-Nicolau, Joel

    The effects of some progestins on fish reproduction have been recently reported revealing the hazard of this class of steroidal pharmaceuticals. However, their effects at the central nervous system level have been poorly studied until now. Notwithstanding, progesterone, although still widely considered primarily a sex hormone, is an important agent affecting many central nervous system functions. Herein, we investigated the effects of a large set of synthetic ligands of the nuclear progesterone receptor on the glial-specific expression of the zebrafish brain aromatase (cyp19a1b) using zebrafish mechanism-based assays. Progesterone and 24 progestins were first screened on transgenic cyp19a1b-GFP zebrafish embryos. Wemore » showed that progesterone, dydrogesterone, drospirenone and all the progesterone-derived progestins had no effect on GFP expression. Conversely, all progestins derived from 19-nortesterone induced GFP in a concentration-dependent manner with EC{sub 50} ranging from the low nM range to hundreds nM. The 19-nortestosterone derived progestins levonorgestrel (LNG) and norethindrone (NET) were further tested in a radial glial cell context using U251-MG cells co-transfected with zebrafish ER subtypes (zfERα, zfERβ1 or zfERβ2) and cyp19a1b promoter linked to luciferase. Progesterone had no effect on luciferase activity while NET and LNG induced luciferase activity that was blocked by ICI 182,780. Zebrafish-ERs competition assays showed that NET and LNG were unable to bind to ERs, suggesting that the effects of these compounds on cyp19a1b require metabolic activation prior to elicit estrogenic activity. Overall, we demonstrate that 19-nortestosterone derived progestins elicit estrogenic activity by inducing cyp19a1b expression in radial glial cells. Given the crucial role of radial glial cells and neuro-estrogens in early development of brain, the consequences of exposure of fish to these compounds require further investigation. - Highlights: • P4

  11. Higher growth rate and gene expression in male zebra finch embryos are independent of manipulation of maternal steroids in the eggs.

    PubMed

    Lutyk, Dorota; Tagirov, Makhsud; Drobniak, Szymon; Rutkowska, Joanna

    2017-12-01

    Sexual dimorphism in prenatal development is widespread among vertebrates, including birds. Its mechanism remains unclear, although it has been attributed to the effect of maternal steroid hormones. The aim of this study was to investigate how increased levels of steroid hormones in the eggs influence early embryonic development of male and female offspring. We also asked whether maternal hormones take part in the control of sex-specific expression of the genes involved in prenatal development. We experimentally manipulated hormones' concentrations in the egg yolk by injecting zebra finch females prior to ovulation with testosterone or corticosterone. We assessed growth rate and expression levels of CDK7, FBP1 and GHR genes in 37h-old embryos. We found faster growth and higher expression of two studied genes in male compared to female embryos. Hormonal treatment, despite clearly differentiating egg steroid levels, had no effect on the sex-specific pattern of the embryonic gene expression, even though we confirmed expression of receptors of androgens and glucocorticoids at such an early stage of development. Thus, our study shows high stability of the early sex differences in the embryonic development before the onset of sexual differentiation and indicates their independence of maternal hormones in the egg. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Extensive review of fish embryo acute toxicities for the prediction of GHS acute systemic toxicity categories.

    PubMed

    Scholz, Stefan; Ortmann, Julia; Klüver, Nils; Léonard, Marc

    2014-08-01

    Distribution and marketing of chemicals require appropriate labelling of health, physical and environmental hazards according to the United Nations global harmonisation system (GHS). Labelling for (human) acute toxicity categories is based on experimental findings usually obtained by oral, dermal or inhalative exposure of rodents. There is a strong societal demand for replacing animal experiments conducted for safety assessment of chemicals. Fish embryos are considered as alternative to animal testing and are proposed as predictive model both for environmental and human health effects. Therefore, we tested whether LC50s of the fish embryo acute toxicity test would allow effectively predicting of acute mammalian toxicity categories. A database of published fish embryo LC50 containing 641 compounds was established. For these compounds corresponding rat oral LD50 were identified resulting in 364 compounds for which both fish embryo LC50 and rat LD50 was available. Only a weak correlation of fish embryo LC50 and rat oral LD50 was obtained. Fish embryos were also not able to effectively predict GHS oral acute toxicity categories. We concluded that due to fundamental exposure protocol differences (single oral dose versus water-borne exposure) a reverse dosimetry approach is needed to explore the predictive capacity of fish embryos. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. A novel approach to assessing environmental disturbance based on habitat selection by zebra fish as a model organism.

    PubMed

    Araújo, Cristiano V M; Griffith, Daniel M; Vera-Vera, Victoria; Jentzsch, Paul Vargas; Cervera, Laura; Nieto-Ariza, Beatriz; Salvatierra, David; Erazo, Santiago; Jaramillo, Rusbel; Ramos, Luis A; Moreira-Santos, Matilde; Ribeiro, Rui

    2018-04-01

    Aquatic ecotoxicity assays used to assess ecological risk assume that organisms living in a contaminated habitat are forcedly exposed to the contamination. This assumption neglects the ability of organisms to detect and avoid contamination by moving towards less disturbed habitats, as long as connectivity exists. In fluvial systems, many environmental parameters vary spatially and thus condition organisms' habitat selection. We assessed the preference of zebra fish (Danio rerio) when exposed to water samples from two western Ecuadorian rivers with apparently distinct disturbance levels: Pescadillo River (highly disturbed) and Oro River (moderately disturbed). Using a non-forced exposure system in which water samples from each river were arranged according to their spatial sequence in the field and connected to allow individuals to move freely among samples, we assayed habitat selection by D. rerio to assess environmental disturbance in the two rivers. Fish exposed to Pescadillo River samples preferred downstream samples near the confluence zone with the Oro River. Fish exposed to Oro River samples preferred upstream waters. When exposed to samples from both rivers simultaneously, fish exhibited the same pattern of habitat selection by preferring the Oro River samples. Given that the rivers are connected, preference for the Oro River enabled us to predict a depression in fish populations in the Pescadillo River. Although these findings indicate higher disturbance levels in the Pescadillo River, none of the physical-chemical variables measured was significantly correlated with the preference pattern towards the Oro River. Non-linear spatial patterns of habitat preference suggest that other environmental parameters like urban or agricultural contaminants play an important role in the model organism's habitat selection in these rivers. The non-forced exposure system represents a habitat selection-based approach that can serve as a valuable tool to unravel the factors

  14. Biophotonic patterns of optical interactions between fish eggs and embryos.

    PubMed

    Beloussov, L V; Burlakov, A B; Louchinskaia, N N

    2003-05-01

    The optical (non-substantial) interactions between various biological samples have been evident in a number of cases mainly by the effects on their functional activity and developmental patterns. However, the mechanisms of these interactions have remained obscure. Effect of optical interaction has been observed on the intensity and Fourier patterns of biophoton emission of fish embryos. We demonstrate that: (1) the short-term optical interactions are accompanied by a gradual decrease of a total emission intensity of the interacting batches; (2) this effect is spread laterally to that part of a batch which does not have any direct optical contacts with its partner; and (3) the long-term optical contacts lead to a mutual exchange of spectral characteristics of interacting batches in which the total spectral density values are reversed (often with an overshoot). The reversal rate depends upon the developmental distance between the optical partners and the initial differences of their spectral characteristics. The results are discussed in terms of a sub-radiance and Le Chatelier principle.

  15. Use of fish embryo toxicity tests for the prediction of acute fish toxicity to chemicals.

    PubMed

    Belanger, Scott E; Rawlings, Jane M; Carr, Gregory J

    2013-08-01

    The fish embryo test (FET) is a potential animal alternative for the acute fish toxicity (AFT) test. A comprehensive validation program assessed 20 different chemicals to understand intra- and interlaboratory variability for the FET. The FET had sufficient reproducibility across a range of potencies and modes of action. In the present study, the suitability of the FET as an alternative model is reviewed by relating FET and AFT. In total, 985 FET studies and 1531 AFT studies were summarized. The authors performed FET-AFT regressions to understand potential relationships based on physical-chemical properties, species choices, duration of exposure, chemical classes, chemical functional uses, and modes of action. The FET-AFT relationships are very robust (slopes near 1.0, intercepts near 0) across 9 orders of magnitude in potency. A recommendation for the predictive regression relationship is based on 96-h FET and AFT data: log FET median lethal concentration (LC50) = (0.989 × log fish LC50) - 0.195; n = 72 chemicals, r = 0.95, p < 0.001, LC50 in mg/L. A similar, not statistically different regression was developed for the entire data set (n = 144 chemicals, unreliable studies deleted). The FET-AFT regressions were robust for major chemical classes with suitably large data sets. Furthermore, regressions were similar to those for large groups of functional chemical categories such as pesticides, surfactants, and industrial organics. Pharmaceutical regressions (n = 8 studies only) were directionally correct. The FET-AFT relationships were not quantitatively different from acute fish-acute fish toxicity relationships with the following species: fathead minnow, rainbow trout, bluegill sunfish, Japanese medaka, and zebrafish. The FET is scientifically supportable as a rational animal alternative model for ecotoxicological testing of acute toxicity of chemicals to fish. Copyright © 2013 SETAC.

  16. Fish embryos on land: terrestrial embryo deposition lowers oxygen uptake without altering growth or survival in the amphibious fish Kryptolebias marmoratus.

    PubMed

    Wells, Michael W; Turko, Andy J; Wright, Patricia A

    2015-10-01

    Few teleost fishes incubate embryos out of water, but the oxygen-rich terrestrial environment could provide advantages for early growth and development. We tested the hypothesis that embryonic oxygen uptake is limited in aquatic environments relative to air using the self-fertilizing amphibious mangrove rivulus, Kryptolebias marmoratus, which typically inhabits hypoxic, water-filled crab burrows. We found that adult mangrove rivulus released twice as many embryos in terrestrial versus aquatic environments and that air-reared embryos had accelerated developmental rates. Surprisingly, air-reared embryos consumed 44% less oxygen and possessed larger yolk reserves, but attained the same mass, length and chorion thickness. Water-reared embryos moved their opercula ∼2.5 more times per minute compared with air-reared embryos at 7 days post-release, which probably contributed to the higher rates of oxygen uptake and yolk utilization we observed. Genetically identical air- and water-reared embryos from the same parent were raised to maturity, but the embryonic environment did not affect growth, reproduction or emersion ability in adults. Therefore, although aspects of early development were plastic, these early differences were not sustained into adulthood. Kryptolebias marmoratus embryos hatched out of water when exposed to aerial hypoxia. We conclude that exposure to a terrestrial environment reduces the energetic costs of development partly by reducing the necessity of embryonic movements to dispel stagnant boundary layers. Terrestrial incubation of young would be especially beneficial to amphibious fishes that occupy aquatic habitats of poor water quality, assuming low terrestrial predation and desiccation risks. © 2015. Published by The Company of Biologists Ltd.

  17. Switch from sexual to parthenogenetic reproduction in a zebra shark

    PubMed Central

    Dudgeon, Christine L.; Coulton, Laura; Bone, Ren; Ovenden, Jennifer R.; Thomas, Severine

    2017-01-01

    Parthenogenesis is a natural form of asexual reproduction in which embryos develop in the absence of fertilisation. Most commonly found in plants and invertebrate organisms, an increasing number of vertebrate species have recently been reported employing this reproductive strategy. Here we use DNA genotyping to report the first demonstration of an intra-individual switch from sexual to parthenogenetic reproduction in a shark species, the zebra shark Stegostoma fasciatum. A co-housed, sexually produced daughter zebra shark also commenced parthenogenetic reproduction at the onset of maturity without any prior mating. The demonstration of parthenogenesis in these two conspecific individuals with different sexual histories provides further support that elasmobranch fishes may flexibly adapt their reproductive strategy to environmental circumstances. PMID:28091617

  18. Switch from sexual to parthenogenetic reproduction in a zebra shark.

    PubMed

    Dudgeon, Christine L; Coulton, Laura; Bone, Ren; Ovenden, Jennifer R; Thomas, Severine

    2017-01-16

    Parthenogenesis is a natural form of asexual reproduction in which embryos develop in the absence of fertilisation. Most commonly found in plants and invertebrate organisms, an increasing number of vertebrate species have recently been reported employing this reproductive strategy. Here we use DNA genotyping to report the first demonstration of an intra-individual switch from sexual to parthenogenetic reproduction in a shark species, the zebra shark Stegostoma fasciatum. A co-housed, sexually produced daughter zebra shark also commenced parthenogenetic reproduction at the onset of maturity without any prior mating. The demonstration of parthenogenesis in these two conspecific individuals with different sexual histories provides further support that elasmobranch fishes may flexibly adapt their reproductive strategy to environmental circumstances.

  19. Annually recurring parthenogenesis in a zebra shark Stegostoma fasciatum.

    PubMed

    Robinson, D P; Baverstock, W; Al-Jaru, A; Hyland, K; Khazanehdari, K A

    2011-11-01

    A zebra shark, Stegostoma fasciatum, held in captivity at the Burj Al Arab aquarium, produced embryos and pups in the absence of a male. A total of 15 pups were produced from eggs laid within the aquarium over a period of four consecutive years commencing 2007. Parthenogenesis was confirmed through DNA analysis for three pups sampled during the first two consecutive egg cycles and is presumed to be the method of reproduction responsible thereafter. © 2011 The Authors. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles.

  20. Enhancing the fathead minnow fish embryo toxicity test: Optimizing embryo production and assessing the utility of additional test endpoints.

    PubMed

    Roush, Kyle S; Krzykwa, Julie C; Malmquist, Jacob A; Stephens, Dane A; Sellin Jeffries, Marlo K

    2018-05-30

    The fathead minnow fish embryo toxicity (FET) test has been identified as a potential alternative to toxicity test methods that utilize older fish. However, several challenges have been identified with the fathead minnow FET test, including: 1) difficulties in obtaining appropriately-staged embryos for FET test initiation, 2) a paucity of data comparing fathead minnow FET test performance to the fathead minnow larval growth and survival (LGS) test and 3) a lack of sublethal endpoints that could be used to estimate chronic toxicity and/or predict adverse effects. These challenges were addressed through three study objectives. The first objective was to optimize embryo production by assessing the effect of breeding group composition (number of males and females) on egg production. Results showed that groups containing one male and four females produced the largest clutches, enhancing the likelihood of procuring sufficient numbers of embryos for FET test initiation. The second study objective was to compare the performance of the FET test to that of the fathead minnow LGS test using three reference toxicants. The FET and LGS tests were similar in their ability to predict the acute toxicity of sodium chloride and ethanol, but the FET test was found to be more sensitive than the LGS test for sodium dodecyl sulfate. The last objective of the study was to evaluate the utility and practicality of several sublethal metrics (i.e., growth, developmental abnormalities and growth- and stress-related gene expression) as FET test endpoints. Developmental abnormalities, including pericardial edema and hatch success, were found to offer the most promise as additional FET test endpoints, given their responsiveness, potential for predicting adverse effects, ease of assessment and low cost of measurement. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Is the fish embryo toxicity test (FET) with the zebrafish (Danio rerio) a potential alternative for the fish acute toxicity test?

    PubMed

    Lammer, E; Carr, G J; Wendler, K; Rawlings, J M; Belanger, S E; Braunbeck, Th

    2009-03-01

    The fish acute toxicity test is a mandatory component in the base set of data requirements for ecotoxicity testing. The fish acute toxicity test is not compatible with most current animal welfare legislation because mortality is the primary endpoint and it is often hypothesized that fish suffer distress and perhaps pain. Animal alternative considerations have also been incorporated into new European REACH regulations through strong advocacy for the reduction of testing with live animals. One of the most promising alternative approaches to classical acute fish toxicity testing with live fish is the fish embryo toxicity (FET) test. The FET has been a mandatory component in routine whole effluent testing in Germany since 2005 and has already been standardized at the international level. In order to analyze the applicability of the FET also in chemical testing, a comparative re-evaluation of both fish and fish embryo toxicity data was carried out for a total of 143 substances, and statistical approaches were developed to evaluate the correlation between fish and fish embryo toxicity data. Results confirm that fish embryo tests are neither better nor worse than acute fish toxicity tests and provide strong scientific support for the FET as a surrogate for the acute fish toxicity test.

  2. Regulatory aspects on the use of fish embryos in environmental toxicology.

    PubMed

    Halder, Marlies; Léonard, Marc; Iguchi, Taisen; Oris, James T; Ryder, Kathy; Belanger, Scott E; Braunbeck, Thomas A; Embry, Michelle R; Whale, Graham; Norberg-King, Teresa; Lillicrap, Adam

    2010-07-01

    Animal alternative tests are gaining serious consideration in an array of environmental sciences, particularly as they relate to sound management of chemicals and wastewater discharges. The ILSI Health and Environmental Sciences Institute and the European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC) held an International Workshop on the Application of the Fish Embryo Test in March, 2008. This relatively young discipline is following advances in animal alternatives for human safety sciences, and it is advisable to develop a broad comparison of how animal alternative tests involving fish are viewed in a regulatory context over a wide array of authorities or advising bodies. These include OECD, Western Europe, North America, and Japan. This paper summarizes representative practices from these regions. Presently, the global regulatory environment has varying stances regarding the protection of fish for use as an experimental animal. Such differences have a long-term potential to lead to a lack of harmony in approaches to fish toxicity testing, especially for chemicals in commerce across multiple geographic regions. Implementation of alternative methods and approaches will be most successful if accepted globally, including methods of fish toxicity testing. An important area for harmonization would be in the interpretation of protected and nonprotected life stages of fish. Use of fish embryos represent a promising alternative and allow bridging to more technically challenging alternatives with longer prospective timelines, including cell-based assays, ecotoxicogenomics, and QSARs. (c) 2010 SETAC.

  3. Development of a general baseline toxicity QSAR model for the fish embryo acute toxicity test.

    PubMed

    Klüver, Nils; Vogs, Carolina; Altenburger, Rolf; Escher, Beate I; Scholz, Stefan

    2016-12-01

    Fish embryos have become a popular model in ecotoxicology and toxicology. The fish embryo acute toxicity test (FET) with the zebrafish embryo was recently adopted by the OECD as technical guideline TG 236 and a large database of concentrations causing 50% lethality (LC 50 ) is available in the literature. Quantitative Structure-Activity Relationships (QSARs) of baseline toxicity (also called narcosis) are helpful to estimate the minimum toxicity of chemicals to be tested and to identify excess toxicity in existing data sets. Here, we analyzed an existing fish embryo toxicity database and established a QSAR for fish embryo LC 50 using chemicals that were independently classified to act according to the non-specific mode of action of baseline toxicity. The octanol-water partition coefficient K ow is commonly applied to discriminate between non-polar and polar narcotics. Replacing the K ow by the liposome-water partition coefficient K lipw yielded a common QSAR for polar and non-polar baseline toxicants. This developed baseline toxicity QSAR was applied to compare the final mode of action (MOA) assignment of 132 chemicals. Further, we included the analysis of internal lethal concentration (ILC 50 ) and chemical activity (La 50 ) as complementary approaches to evaluate the robustness of the FET baseline toxicity. The analysis of the FET dataset revealed that specifically acting and reactive chemicals converged towards the baseline toxicity QSAR with increasing hydrophobicity. The developed FET baseline toxicity QSAR can be used to identify specifically acting or reactive compounds by determination of the toxic ratio and in combination with appropriate endpoints to infer the MOA for chemicals. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Interaction of carboxylated CdSe/ZnS quantum dots with fish embryos: Towards understanding of nanoparticles toxicity.

    PubMed

    Rotomskis, Ričardas; Jurgelėnė, Živilė; Stankevičius, Mantas; Stankevičiūtė, Milda; Kazlauskienė, Nijolė; Jokšas, Kęstutis; Montvydienė, Danguolė; Kulvietis, Vytautas; Karabanovas, Vitalijus

    2018-09-01

    Due to colloidal instability even with protective coatings, nanoparticles tend to aggregate in complex environments and possibly interact with biota. In this study, visualization of quantum dots (QDs) interaction with rainbow trout (Oncorhynchus mykiss) embryos was performed. Studies on zebrafish (Danio rerio) and pearl gourami (Trichogaster leerii) embryos have shown that QDs interact with embryos in a general manner and their affects are independent on the type of the embryo. It was demonstrated that carboxylated CdSe/ZnS QDs (4 nM) were aggregating in accumulation media and formed agglomerates on the surface of fish embryos under 1-12 days incubation in deep-well water. Detailed analysis of QDs distribution on fish embryos surface and investigation of the penetration of QDs through embryo's membrane showed that the chorion protects embryos from the penetration through the chorion and the accumulation of nanoparticles inside the embryos. Confocal microscopy and spectroscopy studies on rainbow trout embryos demonstrated that QDs cause chorion damage, due to QDs aggregation on the surface of chorion, even the formation of the agglomerates at the outer part of the embryos and/or with the mucus were detected. Aggregation of QDs and formation of agglomerates on the outer part of the embryo's membrane caused the intervention of the aggregates to the chorion and even partially destroyed the embryo's chorion. The incorporation of QDs in chorion was confirmed by two methods: in living embryos from a 3D reconstruction view, and in slices of embryos from a histology view. The damage of chorion integrity might have adverse effects on embryonic development. Moreover, for the first time the toxic effect of QDs was separated from the heavy metal toxicity, which is most commonly discussed in the literature to the toxicity of the QDs. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Towards an alternative for the acute fish LC(50) test in chemical assessment: the fish embryo toxicity test goes multi-species -- an update.

    PubMed

    Braunbeck, Thomas; Boettcher, Melanie; Hollert, Henner; Kosmehl, Thomas; Lammer, Eva; Leist, Erik; Rudolf, Mark; Seitz, Nadja

    2005-01-01

    After its standardisation at the national level in Germany (DIN 38415-6, 2001, 2001), the 48 h sewage testing assay with zebrafish (Danio rerio) embryos has been submitted for standardisation to ISO. As an alternative to the conventional acute (96 h) fish test, a modified fish embryo test will be submitted to the OECD for chemical testing in late 2005. For this, a protocol originally designed for zebrafish was adapted to fit also the requirements of other OECD species, namely medaka (Oryzias latipes) and fathead minnow (Pimephales promelas). Results document that the transfer of the protocol is possible with only minor modifications. Data obtained from embryo tests with the three species are comparable. Statistical analysis of existing zebrafish embryo toxicity data resulted in the conclusions (1) that there is a reliable correlation between the fish embryo test and the acute fish test, (2) that the confidence belt of the regression line was relatively small, but that the prediction range was relatively wide. The regression thus seems appropriate to describe the relationship between acute fish and embryo LC(50) with good confidence, but is less appropriate as a prediction model. Investigations into oxygen requirements of zebrafish embryos reveal that they adapt to a broad range of oxygen levels and survive at concentrations of 2 mg/l without malformations. Zebrafish embryos can thus be exposed in very small toxicant volumes (100 microl), which is of particular interest for the testing of metabolites. Dechorionation studies with 48 h old zebrafish embryos indicate that the barrier function of the chorion increases with the lipophilicity of the test compound. Finally, examples are given as to how additional endpoints can be incorporated into the fish embryo test protocol to extend its scope, e.g. to sediment toxicity assessment or genotoxicity and mutagenicity testing.

  6. Changes in the dielectric properties of medaka fish embryos during development, studied by electrorotation

    SciTech Connect

    Shirakashi, Ryo, E-mail: aa21150@iis.u-tokyo.ac.jp; Mischke, Miriam; Fischer, Peter

    2012-11-09

    Highlights: Black-Right-Pointing-Pointer Electrorotation offers a non-invasive tool for dielectric analysis of fish embryos. Black-Right-Pointing-Pointer The three-shell dielectric model matches the rotation spectra of medaka eggs. Black-Right-Pointing-Pointer The capacitance value suggests a double-membrane structure of yolk envelope. -- Abstract: The Japanese medaka fish, Oryzias latipes, has become a powerful vertebrate model organism in developmental biology and genetics. The present study explores the dielectric properties of medaka embryos during pre-hatching development by means of the electrorotation (ROT) technique. Due to their layered structure, medaka eggs exhibited up to three ROT peaks in the kHz-MHz frequency range. During development from blastula to earlymore » somite stage, ROT spectra varied only slightly. But as the embryo progressed to the late-somite stage, the ROT peaks underwent significant changes in frequency and amplitude. Using morphological data obtained by light and electron microscopy, we analyzed the ROT spectra with a three-shell dielectric model that accounted for the major embryonic compartments. The analysis yielded a very high value for the ionic conductivity of the egg shell (chorion), which was confirmed by independent osmotic experiments. A relatively low capacitance of the yolk envelope was consistent with its double-membrane structure revealed by transmission electron microscopy. Yolk-free dead eggs exhibited only one co-field ROT peak, shifted markedly to lower frequencies with respect to the corresponding peak of live embryos. The dielectric data may be useful for monitoring the development and changes in fish embryos' viability/conditions in basic research and industrial aquaculture.« less

  7. Characterization of the multixenobiotic resistance (MXR) mechanism in embryos and larvae of the zebra mussel (Dreissena polymorpha) and studies on its role in tolerance to single and mixture combinations of toxicants.

    PubMed

    Faria, Melissa; Navarro, Ana; Luckenbach, Till; Piña, Benjamin; Barata, Carlos

    2011-01-17

    The study of the cellular mechanisms of tolerance of organisms to pollution is a key issue in aquatic environmental risk assessment. Recent evidence indicates that multixenobiotic resistance (MXR) mechanisms represent a general biological defense of many marine and freshwater organisms against environmental toxicants. In this work, toxicologically relevant xenobiotic efflux transporters were studied in early life stages of zebra mussels (Dreissena polymorpha). Expression of a P-gp1 (ABCB1) transporter gene and its associated efflux activities during development were studied, using qRT-PCR and the fluorescent transporter substrates rhodamine B and calcein-AM combined with specific transporter inhibitors (chemosensitizers). Toxicity bioassays with the model P-gp1 chemotherapeutic drug vinblastine applied singly and in combination with different chemosensitizers were performed to elucidate the tolerance role of the P-gp1 efflux transporter. Results evidenced that the gene expression and associated efflux activities of ABC transporters were low or absent in eggs and increased significantly in 1-3d old trochophora and veliger larvae. Specific inhibitors of Pgp1 and/or MRP transport activities including cyclosporine A, MK571, verapamil and reversin 205 and the musk celestolide resulted in a concentration dependent inhibition of related transport activities in zebra mussel veliger larvae, with IC50 values in the lower micromolar range and similar to those reported for mammals, fish and mussels. Binary mixtures of the tested transporter inhibitors except celestolide with the anticancer drug and P-gp1 substrate vinblastine increased the toxicity of the former compound more than additively. These results indicate that MXR transporter activity is high in early life-stages of the zebra mussel and that may play an important role in the tolerance to environmental contaminants. Copyright © 2010 Elsevier B.V. All rights reserved.

  8. Progress Towards the Development of a Fathead Minnow Embryo Test and Comparison to the Zebrafish Embryo Test for Assessing Acute Fish Toxicity

    EPA Science Inventory

    The Zebrafish Embryo Test (ZFET) for acute fish toxicity is a well developed method nearing adoption as an OECD Test Guideline. Early drafts of the test guideline (TG) envisioned a suite of potential test species to be covered including zebrafish, fathead minnow, Japanese Medaka...

  9. Oil and oil dispersant do not cause synergistic toxicity to fish embryos.

    PubMed

    Adams, Julie; Sweezey, Michael; Hodson, Peter V

    2014-01-01

    Atlantic herring (Clupea harengus) embryos were exposed to water accommodated fractions (WAFs; oil dissolved in water) and chemically enhanced water accommodated fractions (CEWAFs; oil dispersed in water with Corexit 9500A) of Medium South American (MESA) crude oil. The CEWAF was approximately 100-fold more toxic than WAF based on nominal loadings of test solutions (% v/v). In contrast, the ratio of WAF and CEWAF toxicity expressed as measured oil concentrations approximated 1.0, indicating that the higher toxicity of CEWAFs was caused by an increase in exposure to hydrocarbons with chemical dispersion. In a second experiment, the chronic toxicity of Corexit 9500A and chemically dispersed heavy fuel oil 7102 (HFO 7102) to rainbow trout (Oncorhynchus mykiss) embryos was compared to chemically dispersed Nujol, a nontoxic mineral oil. Dispersant alone was toxic, but caused different signs of toxicity than HFO 7102. Nujol at a dispersant-to-oil ratio of 1:20 was nontoxic, suggesting that dispersant was sequestered by oil and not present at toxic concentrations. In contrast, the same nominal loadings of dispersed HFO 7102 caused concentration-dependent increases in toxicity. Both experiments suggest that chemically dispersed oil was more toxic to fish embryos than solutions created by mechanical mixing due to the increased exposure of fish to petroleum hydrocarbons and not to changes in hydrocarbon toxicity. The Nujol control discriminated between the toxicity of oil and chemical dispersant and would be a practical addition to programs of dispersant testing.

  10. Dechorionation as a tool to improve the fish embryo toxicity test (FET) with the zebrafish (Danio rerio).

    PubMed

    Henn, Kirsten; Braunbeck, Thomas

    2011-01-01

    Prior to hatching, the zebrafish embryo is surrounded by an acellular envelope, the chorion. Despite repeated speculations, it could not be clarified unequivocally whether the chorion represents an effective barrier and, thus, protects the embryo from exposure to distinct chemicals. Potentially, there is a risk of generating false negative results in developmental toxicity studies due to limited permeability of the chorion for some compounds. The simplest way to exclude this is to remove the chorion and expose the "naked" embryo. In the context of ecotoxicity testing, standardized protocols do not exist for fish embryo dechorionation, and survival rates of dechorionated embryos have usually not been subjected to statistical analysis. Since reproducibly high survival rates are of fundamental importance for chemical toxicity assessment, the present study was designed to develop and optimize a dechorionation procedure. With appropriate modifications of the fish embryo test protocol, embryos can be dechorionated at 24h post-fertilization (hpf) with survival rates of ≥90%. However, for fish embryo tests with dechorionated embryos, the standard positive control test substance, 3,4-dichloroaniline, should be replaced by another compound, e.g., acetone, since 3,4-dichloroaniline exerts its effects during the first 24h of development. Dechorionation of younger stages (<24 hpf) is generally possible, however with lower survival rates. The effect of dechorionation was demonstrated with the cationic polymer Luviquat HM 552, which is blocked by the chorion non-dechorionated embryos due to its molecular weight of ~400,000 Dalton, but becomes strongly toxic after dechorionation. Copyright © 2010 Elsevier Inc. All rights reserved.

  11. PAH toxicity at aqueous solubility in the fish embryo test with Danio rerio using passive dosing.

    PubMed

    Seiler, Thomas-Benjamin; Best, Nina; Fernqvist, Margit Møller; Hercht, Hendrik; Smith, Kilian E C; Braunbeck, Thomas; Mayer, Philipp; Hollert, Henner

    2014-10-01

    As part of the risk assessment process within REACh, prior to manufacturing and distribution of chemical substances their (eco)toxicological impacts have to be investigated. The fish embryo toxicity test (FET) with the zebrafish Danio rerio has gained a high significance as an in vitro alternative to animal testing in (eco)toxicology. However, for hydrophobic organic chemicals it remains a technical challenge to ensure constant freely dissolved concentration at the maximum exposure level during such biotests. Passive dosing with PDMS silicone was thus applied to control the freely dissolved concentration of ten PAHs at their saturation level in the FET. The experiments gave repeatable results, with the toxicity of the PAHs generally increasing with the maximum chemical activities of the PAHs. HPLC analysis confirmed constant exposure at the saturation level. In additional experiments, fish embryos without direct contact to the silicone surface showed similar mortalities as those exposed with direct contact to the silicone. Silicone oil overlaying the water phase as a novel passive dosing phase had no observable effects on the development of the fish embryos until hatching. This study provides further data to support the close relationship between the chemical activity and the toxicity of hydrophobic organic compounds. Passive dosing from PDMS silicone enabled reliable toxicity testing of (highly) hydrophobic substances at aqueous solubility, providing a practical way to control toxicity exactly at the maximum exposure level. This approach is therefore expected to be useful as a cost-effective initial screening of hydrophobic chemicals for potential adverse effects to freshwater vertebrates. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. 6-Gingerol Suppresses Adipocyte-Derived Mediators of Inflammation In Vitro and in High-Fat Diet-Induced Obese Zebra Fish.

    PubMed

    Choi, Jia; Kim, Kui-Jin; Kim, Byung-Hak; Koh, Eun-Jeong; Seo, Min-Jung; Lee, Boo-Yong

    2017-02-01

    The present study was performed to investigate the molecular mechanism of 6-gingerol on adipocyte-mediated systemic inflammation in vitro and in high-fat diet-induced obese zebra fish. 6-Gingerol decreased adipogenesis due to the suppression of adipocyte differentiation markers, including peroxisome proliferator-activated receptor gamma, CCAATT enhancer binding protein α , and adipocyte protein 2, and triglyceride synthesis enzymes, including sterol regulatory element-binding protein-1, fatty acid synthase, lysophosphatidic acid acyltransferase, and acyl-coA : diacylglycerol acyltransferase 1, in 3T3-L1. A coculture insert system using 3T3-L1 with RAW 264.7 (coculture insert system using fully differentiated 3T3-L1 cells with RAW 264.7 macrophages) revealed that 6-gingerol increased anti-inflammatory cytokine interleukin-10. The expression of TNF α , monocyte chemotactic protein-1, interleukin-1 β , and interleukin-6 were decreased in the coculture insert system using fully differentiated 3T3-L1 cells with RAW 264.7 macrophages treated with 6-gingerol. Moreover, the coculture insert system using fully differentiated 3T3-L1 cells with RAW 264.7 macrophages treated with 6-gingerol inhibited the protein expression of TNF α and monocyte chemotactic protein-1 in RAW 264.7. 6-Gingerol decreased c-JUN N-terminal kinase and I kappa B kinase beta and its downstream target AP-1 expression in the coculture insert system using fully differentiated 3T3-L1 cells with RAW 264.7 macrophages. Furthermore, 6-gingerol decreased the expression of inducible nitric oxide synthase stimulated by the coculture insert system using fully differentiated 3T3-L1 cells with RAW 264.7 macrophages in RAW 264.7 and attenuated nitric oxide production in diet-induced obese zebra fish. Our results suggest that 6-gingerol suppresses inflammation through the regulation of the c-JUN N-terminal kinase-I kappa B kinase beta and its downstream targets. Georg Thieme Verlag KG Stuttgart · New York.

  13. Fish embryo toxicity test: identification of compounds with weak toxicity and analysis of behavioral effects to improve prediction of acute toxicity for neurotoxic compounds.

    PubMed

    Klüver, Nils; König, Maria; Ortmann, Julia; Massei, Riccardo; Paschke, Albrecht; Kühne, Ralph; Scholz, Stefan

    2015-06-02

    The fish embryo toxicity test has been proposed as an alternative for the acute fish toxicity test, but concerns have been raised for its predictivity given that a few compounds have been shown to exhibit a weak acute toxicity in the fish embryo. In order to better define the applicability domain and improve the predictive capacity of the fish embryo test, we performed a systematic analysis of existing fish embryo and acute fish toxicity data. A correlation analysis of a total of 153 compounds identified 28 compounds with a weaker or no toxicity in the fish embryo test. Eleven of these compounds exhibited a neurotoxic mode of action. We selected a subset of eight compounds with weaker or no embryo toxicity (cyanazine, picloram, aldicarb, azinphos-methyl, dieldrin, diquat dibromide, endosulfan, and esfenvalerate) to study toxicokinetics and a neurotoxic mode of action as potential reasons for the deviating fish embryo toxicity. Published fish embryo LC50 values were confirmed by experimental analysis of zebrafish embryo LC50 according to OECD guideline 236. Except for diquat dibromide, internal concentration analysis did not indicate a potential relation of the low sensitivity of fish embryos to a limited uptake of the compounds. Analysis of locomotor activity of diquat dibromide and the neurotoxic compounds in 98 hpf embryos (exposed for 96 h) indicated a specific effect on behavior (embryonic movement) for the neurotoxic compounds. The EC50s of behavior for neurotoxic compounds were close to the acute fish toxicity LC50. Our data provided the first evidence that the applicability domain of the fish embryo test (LC50s determination) may exclude neurotoxic compounds. However, neurotoxic compounds could be identified by changes in embryonic locomotion. Although a quantitative prediction of acute fish toxicity LC50 using behavioral assays in fish embryos may not yet be possible, the identification of neurotoxicity could trigger the conduction of a conventional fish

  14. Prevention of zebra mussel infestation and dispersal during aquaculture operations

    USGS Publications Warehouse

    Waller, D.L.; Fisher, S.W.; Dabrowska, H.

    1996-01-01

    The zebra mussel Dreissena polymorpha, an exotic invasive species, poses a major threat to North American fish management programs and the aquaculture industry. Fish hatcheries may become infected with zebra mussels from a variety of sources, including the water supply, fish shipments, boats, and equipment. The hatcheries could then serve as agents for the overland dispersal of zebra mussels into stocked waters and to other fish hatcheries. We evaluated the effectiveness and safety of aquaculture chemicals for use in controlling zebra mussels in fish hatcheries and preventing dispersal of veligers during fish transport. Chemicals were evaluated for use in fish transport and as disinfectants for ponds and equipment. Standardized static toxicity tests were conducted with representative species of warmwater, coolwater, and coldwater fishes and with larval (3-d-old veligers), early juvenile (settling larvae), and adult zebra mussels. Chemical concentrations and exposure durations were based on recommended treatment levels for fish, eggs, and ponds. Recommended treatment levels were also exceeded, if necessary, to establish lethal levels for zebra mussels of different developmental stages. Our results indicate that some chemicals currently in use in hatcheries may be effective for controlling zebra mussels in various operations. Chloride salts were the safest and most effective therapeutants tested for use in fish transport. The toxicity of chloride salts to fish varied among species and with temperature; only one treatment regime (sodium chloride at 10,000 mg/L) was safe to all fish species that we tested, but it was only effective on veliger and settler stages of the zebra mussel. Effective disinfectants were benzalkonium chloride for use on equipment and rotenone for use in ponds after fish are harvested. The regulatory status of the identified chemicals is discussed as well as several nonchemical control alternatives.

  15. Pore-water and epibenthic exposures in contaminated sediments using embryos of two estuarine fish species

    SciTech Connect

    Jelinski, J.A.; Anderson, S.L.

    1995-12-31

    The authors` objectives were to determine the feasibility of using embryos of two fish species, Menidia beryllina and Atherinops affinis, in estuarine sediment toxicity tests at ambient temperatures and salinities, and to compare pore-water and sediment water interface corer (SWIC) exposure techniques using these same species. The ultimate goal is to determine whether these pore-water and SWIC methods can be used in in situ exposure studies. Sediment samples were collected at both a reference and contaminated site at the Mare Island Naval Shipyard in San Francisco Bay. Pore-water testes were conducted using methods developed in the laboratory, and SWIC testsmore » were conducted using a modification of B. Anderson et al. Salinity and temperature tolerance experiments revealed that M. beryllina embryos can tolerate temperatures between 160 C and 240 C and salinities of 10 ppt to 25 ppt, whereas A. affinis has a temperature range between 160 C and 200 C. Comparisons between pore-water and SWIC exposures at a reference site within MINSY showed no significant difference in hatching success. However, hatching success in SWIC exposures was significantly lower than pore-water exposures at a previously characterized contaminated site. In conclusion, both M. beryllina and A. affinis embryos may be useful for sediment and in situ toxicity testing in estuarine environments. Their wide temperature and salinity tolerances allow for minimal test manipulations, and M. beryllina showed excellent hatching success in reference sediments for both types of exposures.« less

  16. Fishing on chips: up-and-coming technological advances in analysis of zebrafish and Xenopus embryos.

    PubMed

    Zhu, Feng; Skommer, Joanna; Huang, Yushi; Akagi, Jin; Adams, Dany; Levin, Michael; Hall, Chris J; Crosier, Philip S; Wlodkowic, Donald

    2014-11-01

    Biotests performed on small vertebrate model organisms provide significant investigative advantages as compared with bioassays that employ cell lines, isolated primary cells, or tissue samples. The main advantage offered by whole-organism approaches is that the effects under study occur in the context of intact physiological milieu, with all its intercellular and multisystem interactions. The gap between the high-throughput cell-based in vitro assays and low-throughput, disproportionally expensive and ethically controversial mammal in vivo tests can be closed by small model organisms such as zebrafish or Xenopus. The optical transparency of their tissues, the ease of genetic manipulation and straightforward husbandry, explain the growing popularity of these model organisms. Nevertheless, despite the potential for miniaturization, automation and subsequent increase in throughput of experimental setups, the manipulation, dispensing and analysis of living fish and frog embryos remain labor-intensive. Recently, a new generation of miniaturized chip-based devices have been developed for zebrafish and Xenopus embryo on-chip culture and experimentation. In this work, we review the critical developments in the field of Lab-on-a-Chip devices designed to alleviate the limits of traditional platforms for studies on zebrafish and clawed frog embryo and larvae. © 2014 International Society for Advancement of Cytometry. © 2014 International Society for Advancement of Cytometry.

  17. Studying the effects of genistein on gene expression of fish embryos as an alternative testing approach for endocrine disruption.

    PubMed

    Schiller, Viktoria; Wichmann, Arne; Kriehuber, Ralf; Muth-Köhne, Elke; Giesy, John P; Hecker, Markus; Fenske, Martina

    2013-01-01

    Assessment of endocrine disruption currently relies on testing strategies involving adult vertebrates. In order to minimize the use of animal tests according to the 3Rs principle of replacement, reduction and refinement, we propose a transcriptomics and fish embryo based approach as an alternative to identify and analyze an estrogenic activity of environmental chemicals. For this purpose, the suitability of 48 h and 7 days post-fertilization zebrafish and medaka embryos to test for estrogenic disruption was evaluated. The embryos were exposed to the phytoestrogen genistein and subsequently analyzed by microarrays and quantitative real-time PCR. The functional analysis showed that the genes affected related to multiple metabolic and signaling pathways in the early fish embryo, which reflect the known components of genistein's mode of actions, like apoptosis, estrogenic response, hox gene expression and steroid hormone synthesis. Moreover, the transcriptomic data also suggested a thyroidal mode of action and disruption of the nervous system development. The parallel testing of two fish species provided complementary data on the effects of genistein at gene expression level and facilitated the separation of common from species-dependent effects. Overall, the study demonstrated that combining fish embryo testing with transcriptomics can deliver abundant information about the mechanistic effects of endocrine disrupting chemicals, rendering this strategy a promising alternative approach to test for endocrine disruption in a whole organism in-vitro scale system. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. The fish embryo toxicity test as an animal alternative method in hazard and risk assessment and scientific research.

    PubMed

    Embry, Michelle R; Belanger, Scott E; Braunbeck, Thomas A; Galay-Burgos, Malyka; Halder, Marlies; Hinton, David E; Léonard, Marc A; Lillicrap, Adam; Norberg-King, Teresa; Whale, Graham

    2010-04-15

    Animal alternatives research has historically focused on human safety assessments and has only recently been extended to environmental testing. This is particularly for those assays that involve the use of fish. A number of alternatives are being pursued by the scientific community including the fish embryo toxicity (FET) test, a proposed replacement alternative to the acute fish test. Discussion of the FET methodology and its application in environmental assessments on a global level was needed. With this emerging issue in mind, the ILSI Health and Environmental Sciences Institute (HESI) and the European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC) held an International Workshop on the Application of the Fish Embryo Test as an Animal Alternative Method in Hazard and Risk Assessment and Scientific Research in March, 2008. The workshop included approximately 40 scientists and regulators representing government, industry, academia, and non-governmental organizations from North America, Europe, and Asia. The goal was to review the state of the science regarding the investigation of fish embryonic tests, pain and distress in fish, emerging approaches utilizing fish embryos, and the use of fish embryo toxicity test data in various types of environmental assessments (e.g., hazard, risk, effluent, and classification and labeling of chemicals). Some specific key outcomes included agreement that risk assessors need fish data for decision-making, that extending the FET to include eluethereombryos was desirable, that relevant endpoints are being used, and that additional endpoints could facilitate additional uses beyond acute toxicity testing. The FET was, however, not yet considered validated sensu OECD. An important action step will be to provide guidance on how all fish tests can be used to assess chemical hazard and to harmonize the diverse terminology used in test guidelines adopted over the past decades. Use of the FET in context of effluent assessments

  19. Predicting adult fish acute lethality with the zebrafish embryo: relevance of test duration, endpoints, compound properties, and exposure concentration analysis.

    PubMed

    Knöbel, Melanie; Busser, Frans J M; Rico-Rico, Angeles; Kramer, Nynke I; Hermens, Joop L M; Hafner, Christoph; Tanneberger, Katrin; Schirmer, Kristin; Scholz, Stefan

    2012-09-04

    The zebrafish embryo toxicity test has been proposed as an alternative for the acute fish toxicity test, which is required by various regulations for environmental risk assessment of chemicals. We investigated the reliability of the embryo test by probing organic industrial chemicals with a wide range of physicochemical properties, toxicities, and modes of toxic action. Moreover, the relevance of using measured versus nominal (intended) exposure concentrations, inclusion of sublethal endpoints, and different exposure durations for the comparability with reported fish acute toxicity was explored. Our results confirm a very strong correlation of zebrafish embryo to fish acute toxicity. When toxicity values were calculated based on measured exposure concentrations, the slope of the type II regression line was 1 and nearly passed through the origin (1 to 1 correlation). Measured concentrations also explained several apparent outliers. Neither prolonged exposure (up to 120 h) nor consideration of sublethal effects led to a reduced number of outliers. Yet, two types of compounds were less lethal to embryos than to adult fish: a neurotoxic compound acting via sodium channels (permethrin) and a compound requiring metabolic activation (allyl alcohol).

  20. Incubation media affect the survival, pathway and time of embryo development in Neotropical annual fish Austrolebias nigrofasciatus (Rivulidae).

    PubMed

    da Fonseca, A P; Volcan, M V; Robaldo, R B

    2018-01-01

    To analyse the survival, pathway and time of embryo development in the annual fish Austrolebias nigrofasciatus eggs were monitored in four liquid media and two damp media under experimental conditions for 130 days until their development was complete. Eggs kept in the same breeding water from oviposition remained in diapause I (DI) during all experiments. In constrast, up to the stage prior to entering diapause II (DII), the other media had no influence on development. Embryos at this stage (DII), however, show longer development time when treated in medium with water and powdered coconut shell so that about 80% of embryos remained in DII at 100 days. In contrast, all other treatments had a significantly lower proportion of embryos remaining in DII. When treated with Yamamoto's solution in humid media, embryos showed the fastest development. The first fully developed embryos (DIII) were seen at 27 days after oviposition. It took an average of 46-58 days for 50% of eggs in each treatment to reach DIII. Compared with other studies, survival in all incubation media was high at between 70 and 98%. Taken together, it can be concluded that all incubation media were found to be viable for maintaining embryos. Altering developmental trajectories through the manipulation of diapauses in different media makes this species a potential model organism for laboratory studies. © 2017 The Fisheries Society of the British Isles.

  1. Transcriptional Repressor foxl1 Regulates Central Nervous System Development by Suppressing shh Expression in Zebra Fish†

    PubMed Central

    Nakada, Chisako; Satoh, Shinya; Tabata, Yoko; Arai, Ken-ichi; Watanabe, Sumiko

    2006-01-01

    We identified zebra fish forkhead transcription factor l1 (zfoxl1) as a gene strongly expressed in neural tissues such as midbrain, hindbrain, and the otic vesicle at the early embryonic stage. Loss of the function of zfoxl1 effected by morpholino antisense oligonucleotide resulted in defects in midbrain and eye development, and in that of formation of the pectoral fins. Interestingly, ectopic expression of shh in the midbrain and elevated pax2a expression in the optic stalk were observed in foxl1 MO-injected embryos. In contrast, expression of pax6a, which is negatively regulated by shh, was suppressed in the thalamus and pretectum regions, supporting the idea of augmentation of the shh signaling pathway by suppression of foxl1. Expression of zfoxl1-EnR (repressing) rather than zfoxl1-VP16 (activating) resulted in a phenotype similar to that induced by foxl1-mRNA, suggesting that foxl1 may act as a transcriptional repressor of shh in zebra fish embryos. Supporting this notion, foxl1 suppressed isolated 2.7-kb shh promoter activity in PC12 cells, and the minimal region of foxl1 required for its transcriptional repressor activity showed strong homology with the groucho binding motif, which is found in genes encoding various homeodomain proteins. In view of all of our data taken together, we propose zfoxl1 to be a novel regulator of neural development that acts by suppressing shh expression. PMID:16980626

  2. Medaka Fish Embryo Developed for STS-78 Life and Microgravity Spacelab (LMS)

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Launched on June 20, 1996, the STS-78 mission's primary payload was the Life and Microgravity Spacelab (LMS), which was managed by the Marshall Space Flight Center (MSFC). During the 17 day space flight, the crew conducted a diverse slate of experiments divided into a mix of life science and microgravity investigations. In a manner very similar to future International Space Station operations, LMS researchers from the United States and their European counterparts shared resources such as crew time and equipment. Five space agencies (NASA/USA, European Space Agency/Europe (ESA), French Space Agency/France, Canadian Space Agency /Canada, and Italian Space Agency/Italy) along with research scientists from 10 countries worked together on the design, development and construction of the LMS. This photo represents the development of Medaka Fish Embryos, one of the many studies of the LMS mission.

  3. An automated assay for the assessment of cardiac arrest in fish embryo.

    PubMed

    Puybareau, Elodie; Genest, Diane; Barbeau, Emilie; Léonard, Marc; Talbot, Hugues

    2017-02-01

    Studies on fish embryo models are widely developed in research. They are used in several research fields including drug discovery or environmental toxicology. In this article, we propose an entirely automated assay to detect cardiac arrest in Medaka (Oryzias latipes) based on image analysis. We propose a multi-scale pipeline based on mathematical morphology. Starting from video sequences of entire wells in 24-well plates, we focus on the embryo, detect its heart, and ascertain whether or not the heart is beating based on intensity variation analysis. Our image analysis pipeline only uses commonly available operators. It has a low computational cost, allowing analysis at the same rate as acquisition. From an initial dataset of 3192 videos, 660 were discarded as unusable (20.7%), 655 of them correctly so (99.25%) and only 5 incorrectly so (0.75%). The 2532 remaining videos were used for our test. On these, 45 errors were made, leading to a success rate of 98.23%. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Dichlorvos Exposure Results in Large Scale Disruption of Energy Metabolism in the Liver of the Zebra Fish, Danio Rerio

    DTIC Science & Technology

    2015-10-24

    zebrafish reference genome sequence and its relationship to the human genome . Nature. 2013;496(7446):498–503. 21. Linney E, Upchurch L, Donerly S. Zebrafish...To obtain a broader understanding of the effects of dichlorvos on liver metabolism, we per- formed a genome -wide analysis of gene expression in the ...condition) for whole genome transcript ana- lysis, and fixed another set of fish for histological evaluation (n = 5/condition). We determined the target

  5. Automated Lab-on-a-Chip Technology for Fish Embryo Toxicity Tests Performed under Continuous Microperfusion (μFET).

    PubMed

    Zhu, Feng; Wigh, Adriana; Friedrich, Timo; Devaux, Alain; Bony, Sylvie; Nugegoda, Dayanthi; Kaslin, Jan; Wlodkowic, Donald

    2015-12-15

    The fish embryo toxicity (FET) biotest has gained popularity as one of the alternative approaches to acute fish toxicity tests in chemical hazard and risk assessment. Despite the importance and common acceptance of FET, it is still performed in multiwell plates and requires laborious and time-consuming manual manipulation of specimens and solutions. This work describes the design and validation of a microfluidic Lab-on-a-Chip technology for automation of the zebrafish embryo toxicity test common in aquatic ecotoxicology. The innovative device supports rapid loading and immobilization of large numbers of zebrafish embryos suspended in a continuous microfluidic perfusion as a means of toxicant delivery. Furthermore, we also present development of a customized mechatronic automation interface that includes a high-resolution USB microscope, LED cold light illumination, and miniaturized 3D printed pumping manifolds that were integrated to enable time-resolved in situ analysis of developing fish embryos. To investigate the applicability of the microfluidic FET (μFET) in toxicity testing, copper sulfate, phenol, ethanol, caffeine, nicotine, and dimethyl sulfoxide were tested as model chemical stressors. Results obtained on a chip-based system were compared with static protocols performed in microtiter plates. This work provides evidence that FET analysis performed under microperfusion opens a brand new alternative for inexpensive automation in aquatic ecotoxicology.

  6. DMSO modifies the permeability of the zebrafish (Danio rerio) chorion-implications for the fish embryo test (FET).

    PubMed

    Kais, B; Schneider, K E; Keiter, S; Henn, K; Ackermann, C; Braunbeck, T

    2013-09-15

    Since 2007, when REACH came into force, the fish embryo test has received increasing attention as a potential alternative for the acute fish test. Due to its low toxicity and the ability to permeate biological membranes without significant damage to their structural integrity, dimethyl sulfoxide (DMSO) is a commonly used solvent in the fish embryo test. Little is known, however, about the membrane penetration properties of DMSO, the impact of different concentrations of DMSO on the potential barrier function of the zebrafish chorion and on changes in the uptake of chemicals into the embryo. Therefore, in the present study, the fluorescent dyes fluorescein (mol wt 332; Pow 3.4) and 2,7-dichlorofluorescein (mol wt 401; Pow 4.7), both substances with limited water solubility, were used to visualize the uptake into the egg as well as the accumulation in the embryo of the zebrafish depending on different concentrations of DMSO. The distribution of fluorescein within the egg compartments varied with DMSO concentration: When dissolved in 0.01% DMSO, fluorescein did not pass the chorion. In contrast, concentrations ≥ 0.1% DMSO increasingly facilitated the uptake into the perivitelline space. In contrast, the uptake of 2,7-dichlorofluorescein was not substantially increased with rising DMSO concentrations, indicating the importance of factors other than the solvent (e.g. mol wt). With respect to the fish embryo test, results indicate that DMSO may be used without complications as a solvent, however, only at a maximum concentration of 0.01% (0.1 mL/L) as already indicated in the OECD difficult substances paper (OECD, 2000). Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Fitness consequences of polymorphic inversions in the zebra finch genome.

    PubMed

    Knief, Ulrich; Hemmrich-Stanisak, Georg; Wittig, Michael; Franke, Andre; Griffith, Simon C; Kempenaers, Bart; Forstmeier, Wolfgang

    2016-09-29

    Inversion polymorphisms constitute an evolutionary puzzle: they should increase embryo mortality in heterokaryotypic individuals but still they are widespread in some taxa. Some insect species have evolved mechanisms to reduce the cost of embryo mortality but humans have not. In birds, a detailed analysis is missing although intraspecific inversion polymorphisms are regarded as common. In Australian zebra finches (Taeniopygia guttata), two polymorphic inversions are known cytogenetically and we set out to detect these two and potentially additional inversions using genomic tools and study their effects on embryo mortality and other fitness-related and morphological traits. Using whole-genome SNP data, we screened 948 wild zebra finches for polymorphic inversions and describe four large (12-63 Mb) intraspecific inversion polymorphisms with allele frequencies close to 50 %. Using additional data from 5229 birds and 9764 eggs from wild and three captive zebra finch populations, we show that only the largest inversions increase embryo mortality in heterokaryotypic males, with surprisingly small effect sizes. We test for a heterozygote advantage on other fitness components but find no evidence for heterosis for any of the inversions. Yet, we find strong additive effects on several morphological traits. The mechanism that has carried the derived inversion haplotypes to such high allele frequencies remains elusive. It appears that selection has effectively minimized the costs associated with inversions in zebra finches. The highly skewed distribution of recombination events towards the chromosome ends in zebra finches and other estrildid species may function to minimize crossovers in the inverted regions.

  8. A high throughput passive dosing format for the Fish Embryo Acute Toxicity test.

    PubMed

    Vergauwen, Lucia; Schmidt, Stine N; Stinckens, Evelyn; Maho, Walid; Blust, Ronny; Mayer, Philipp; Covaci, Adrian; Knapen, Dries

    2015-11-01

    High throughput testing according to the Fish Embryo Acute Toxicity (FET) test (OECD Testing Guideline 236) is usually conducted in well plates. In the case of hydrophobic test substances, sorptive and evaporative losses often result in declining and poorly controlled exposure conditions. Therefore, our objective was to improve exposure conditions in FET tests by evaluating a passive dosing format using silicone O-rings in standard 24-well polystyrene plates. We exposed zebrafish embryos to a series of phenanthrene concentrations until 120h post fertilization (hpf), and obtained a linear dilution series. We report effect values for both mortality and sublethal morphological effects based on (1) measured exposure concentrations, (2) (lipid normalized) body residues and (3) chemical activity. The LC50 for 120hpf was 310μg/L, CBR50 (critical body residue) was 2.72mmol/kg fresh wt and La50 (lethal chemical activity) was 0.047. All values were within ranges expected for baseline toxicity. Impaired swim bladder inflation was the most pronounced morphological effect and swimming activity was reduced in all exposure concentrations. Further analysis showed that the effect on swimming activity was not attributed to impaired swim bladder inflation, but rather to baseline toxicity. We conclude that silicone O-rings (1) produce a linear dilution series of phenanthrene in the 120hpf FET test, (2) generate and maintain aqueous concentrations for reliable determination of effect concentrations, and allow for obtaining mechanistic toxicity information, and (3) cause no toxicity, demonstrating its potential as an extension of the FET test when testing hydrophobic chemicals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Diel and distributional abundance patterns of fish embryos and larvae in the lower Columbia and Deschutes rivers

    USGS Publications Warehouse

    Gadomski, D.M.; Barfoot, C.A.

    1998-01-01

    Diel and distributional abundance patterns of free embryos and larvae of fishes in the lower Columbia River Basin were investigated. Ichthyoplankton samples were collected in 1993 during day and night in the main-channel and a backwater of the lower Columbia River, and in a tributary, the Deschutes River. Fish embryos and larvae collected in the main-channel Columbia River were primarily (85.6%) of native taxa (peamouth Mylocheilus caurinus, northern squawfish Ptychocheilus oregonensis, suckers Catostomus spp., and sculpins Cottus spp.), with two introduced species (American shad Alosa sapidissima and common carp Cyprinus carpio) comprising a smaller percentage of the catch (13.3%). Similarly, in the Deschutes River native taxa [lampreys (Petromyzontidae), minnows (Cyprinidae), and suckers Catostomus spp.] dominated collections (99.5% of the catch). In contrast, 83.5% of embryos and larvae in the Columbia River backwater were of introduced taxa [American shad, common carp, and sunfishes (Centrarchidae)]. In all locations, all dominant taxa except sculpins were collected in significantly greater proportions at night. Taxon-specific differences in proportions of embryos and larvae collected at night can in some instances be related to life history styles. In the main-channel Columbia River, northern squawfish and peamouth were strongly nocturnal and high proportions still had yolksacs, suggesting that they had recently hatched and were drifting downriver to rearing areas. In contrast, sculpin abundances were similar during day and night, and sculpins mostly had depleted yolksacs, indicating sculpins were feeding and rearing in offshore limnetic habitats. Taxon-specific diel abundance patterns and their causes must be considered when designing effective sampling programs for fish embryos and larvae.

  10. Development of a flow-through system for the fish embryo toxicity test (FET) with the zebrafish (Danio rerio).

    PubMed

    Lammer, E; Kamp, H G; Hisgen, V; Koch, M; Reinhard, D; Salinas, E R; Wendler, K; Zok, S; Braunbeck, Th

    2009-10-01

    The acute fish test is still a mandatory component in chemical hazard and risk assessment. However, one of the objectives of the new European chemicals policy (REACH - Registration, Evaluation, Authorization and Restriction of Chemicals) is to promote non-animal testing. For whole effluent testing in Germany, the fish embryo toxicity test (FET) with the zebrafish (Danio rerio) has been an accepted and mandatory replacement of the fish test since January 2005. For chemical testing, however, further optimization of the FET is required to improve the correlation between the acute fish test and the alternative FET. Since adsorption of the test chemical to surfaces may reduce available exposure concentrations, a flow-through system for the FET using modified commercially available polystyrene 24-well microtiter plates was developed, thus combining the advantages of the standard FET with those of continuous delivery of test substances. The advantages of the design presented include: small test footprint, availability of adequate volumes of test solution for subsequent chemical analysis, and sufficient flow to compensate for effects of non-specific adsorption within 24h. The flow-through test system can also be utilized to conduct longer-term embryo larval fish tests, thus offering the possibility for teratogenicity testing.

  11. EVALUATING THE EFFECTS OF FLY ASH EXPOSURE ON FISH EARLY LIFE STAGES: FATHEAD MINNOW EMBRYO-LARVAL TESTS

    SciTech Connect

    Greeley Jr, Mark Stephen; Elmore, Logan R; McCracken, Kitty

    2012-05-01

    On December 22, 2008, a dike containing fly ash and bottom ash in an 84-acre complex of the Tennessee Valley Authority's (TVA) Kingston Steam Plant in East Tennessee failed and released a large quantity of ash into the adjacent Emory River. Ash deposits extended as far as 4 miles upstream (Emory River mile 6) of the Plant, and some ash was carried as far downstream as Tennessee River mile 564 ({approx}4 miles downstream of the Tennessee River confluence with the Clinch River). A byproduct of coal burning power plants, fly ash contains a variety of metals and other elements which,more » at sufficient concentrations and in specific forms, can be toxic to biological systems. The effects of fly ash contamination on exposed fish populations depend on the magnitude and duration of exposure, with the most significant risk considered to be the effects of specific ash constituents, especially selenium, on fish early life stages. Uptake by adult female fish of fly ash constituents through the food chain and subsequent maternal transfer of contaminants to the developing eggs is thought to be the primary route of selenium exposure to larval fish (Woock and others 1987, Coyle and others 1993, Lemly 1999, Moscatello and others 2006), but direct contact of the fertilized eggs and developing embryos to ash constituents in river water and sediments is also a potential risk factor (Woock and others 1987, Coyle and others 1993, Jezierska and others 2009). To address the risk of fly ash from the Kingston spill to the reproductive health of downstream fish populations, ORNL has undertaken a series of studies in collaboration with TVA including: (1) a field study of the bioaccumulation of fly ash constituents in fish ovaries and the reproductive condition of sentinel fish species in reaches of the Emory and Clinch Rivers affected by the fly ash spill; (2) laboratory tests of the potential toxicity of fly ash from the spill area on fish embryonic and larval development (reported in the

  12. Mixture toxicity of wood preservative products in the fish embryo toxicity test.

    PubMed

    Coors, Anja; Dobrick, Jan; Möder, Monika; Kehrer, Anja

    2012-06-01

    Wood preservative products are used globally to protect wood from fungal decay and insects. We investigated the aquatic toxicity of five commercial wood preservative products, the biocidal active substances and some formulation additives contained therein, as well as six generic binary mixtures of the active substances in the fish embryo toxicity test (FET). Median lethal concentrations (LC50) of the single substances, the mixtures, and the products were estimated from concentration-response curves and corrected for concentrations measured in the test medium. The comparison of the experimentally observed mixture toxicity with the toxicity predicted by the concept of concentration addition (CA) showed less than twofold deviation for all binary mixtures of the active substances and for three of the biocidal products. A more than 60-fold underestimation of the toxicity of the fourth product by the CA prediction was detected and could be explained fully by the toxicity of one formulation additive, which had been labeled as a hazardous substance. The reason for the 4.6-fold underestimation of toxicity of the fifth product could not be explained unambiguously. Overall, the FET was found to be a suitable screening tool to verify whether the toxicity of formulated wood preservatives can reliably be predicted by CA. Applied as a quick and simple nonanimal screening test, the FET may support approaches of applying component-based mixture toxicity predictions within the environmental risk assessment of biocidal products, which is required according to European regulations. Copyright © 2012 SETAC.

  13. Development of Cardiovascular and Neurodevelopmental Metrics as Sublethal Endpoints for the Fish Embryo Toxicity Test.

    PubMed

    Krzykwa, Julie C; Olivas, Alexis; Jeffries, Marlo K Sellin

    2018-06-19

    The fathead minnow fish embryo toxicity (FET) test has been proposed as a more humane alternative to current toxicity testing methods, as younger organisms are thought to experience less distress during toxicant exposure. However, the FET test protocol does not include endpoints that allow for the prediction of sublethal adverse outcomes, limiting its utility relative to other test types. Researchers have proposed the development of sublethal endpoints for the FET test to increase its utility. The present study 1) developed methods for previously unmeasured sublethal metrics in fathead minnows (i.e., spontaneous contraction frequency and heart rate) and 2) investigated the responsiveness of several sublethal endpoints related to growth (wet weight, length, and growth-related gene expression), neurodevelopment (spontaneous contraction frequency, and neurodevelopmental gene expression), and cardiovascular function and development (pericardial area, eye size and cardiovascular related gene expression) as additional FET test metrics using the model toxicant 3,4-dichloroaniline. Of the growth, neurological and cardiovascular endpoints measured, length, eye size and pericardial area were found to more responsive than the other endpoints, respectively. Future studies linking alterations in these endpoints to longer-term adverse impacts are needed to fully evaluate the predictive power of these metrics in chemical and whole effluent toxicity testing. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  14. A novel system for embryo-larval toxicity testing of pelagic fish: Applications for impact assessment of Deepwater Horizon crude oil.

    PubMed

    Stieglitz, John D; Mager, Edward M; Hoenig, Ronald H; Alloy, Matthew; Esbaugh, Andrew J; Bodinier, Charlotte; Benetti, Daniel D; Roberts, Aaron P; Grosell, Martin

    2016-11-01

    Key differences in the developmental process of pelagic fish embryos, in comparison to embryos of standard test fish species, present challenges to obtaining sufficient control survival needed to successfully perform traditional toxicity testing bioassays. Many of these challenges relate to the change in buoyancy, from positive to negative, of pelagic fish embryos that occurs just prior to hatch. A novel exposure system, the pelagic embryo-larval exposure chamber (PELEC), has been developed to conduct successful bioassays on the early life stages (ELSs; embryos/larvae) of pelagic fish. Using this unique recirculating upwelling system, it was possible to significantly improve control survival in pelagic fish ELS bioassays compared to commonly used static exposure methods. Results demonstrate that control performance of mahi-mahi (Coryphaena hippurus) embryos in the PELEC system, measured as percent survival after 96-hrs, significantly outperformed agitated static exposure and static exposure systems. Similar significant improvements in 72-hr control survival were obtained with yellowfin tuna (Thunnus albacares). The PELEC system was subsequently used to test the effects of photo-induced toxicity of crude oil to mahi-mahi ELSs over the course of 96-hrs. Results indicate a greater than 9-fold increase in toxicity of Deepwater Horizon (DWH) crude oil during co-exposure to ambient sunlight compared to filtered ambient sunlight, revealing the importance of including natural sunlight in 96-hr DWH crude oil bioassays as well as the PELEC system's potential application in ecotoxicological assessments. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Species-specific considerations in using the fish embryo test as an alternative to identify endocrine disruption.

    PubMed

    Schiller, Viktoria; Zhang, Xiaowei; Hecker, Markus; Schäfers, Christoph; Fischer, Rainer; Fenske, Martina

    2014-10-01

    A number of regulations have been implemented that aim to control the release of potentially adverse endocrine disrupters into the aquatic environment based on evidence from laboratory studies. Currently, such studies rely on testing approaches with adult fish because reliable alternatives have not been validated so far. Fish embryo tests have been proposed as such an alternative, and here we compared two species (medaka and zebrafish) to determine their suitability for the assessment of substances with estrogenic and anti-androgenic activity. Changes in gene expression (in here the phrase gene expression is used synonymously to gene transcription, although it is acknowledged that gene expression is additionally regulated, e.g., by translation and protein stability) patterns between the two species were compared in short term embryo exposure tests (medaka: 7-day post fertilization [dpf]; zebrafish: 48 and 96h post fertilization [hpf]) by using relative quantitative real-time RT-PCR. The tested genes were related to the hypothalamic-gonadal-axis and early steroidogenesis. Test chemicals included 17α-ethinylestradiol and flutamide as estrogenic and anti-androgenic reference compounds, respectively, as well as five additional substances with endocrine activities, namely bisphenol A, genistein, prochloraz, linuron and propanil. Estrogenic responses were comparable in 7-dpf medaka and 48/96-hpf zebrafish embryos and included transcriptional upregulation of aromatase b, vitellogenin 1 as well as steroidogenic genes, suggesting that both species reliably detected exposure to estrogenic compounds. However, anti-androgenic responses differed between the two species, with each species providing specific information concerning the mechanism of anti-androgenic disruption in fish embryos. Although small but significant changes in the expression of selected genes was observed in 48-hpf zebrafish embryos, exposure prolonged to 96hpf was necessary to obtain a response indicative

  16. The weaker points of fish acute toxicity tests and how tests on embryos can solve some issues.

    PubMed

    Wedekind, Claus; von Siebenthal, Beat; Gingold, Ruth

    2007-07-01

    Fish acute toxicity tests play an important role in environmental risk assessment and hazard classification because they allow for first estimates of the relative toxicity of various chemicals in various species. However, such tests need to be carefully interpreted. Here we shortly summarize the main issues which are linked to the genetics and the condition of the test animals, the standardized test situations, the uncertainty about whether a given test species can be seen as representative to a given fish fauna, the often missing knowledge about possible interaction effects, especially with micropathogens, and statistical problems like small sample sizes and, in some cases, pseudoreplication. We suggest that multi-factorial embryo tests on ecologically relevant species solve many of these issues, and we shortly explain how such tests could be done to avoid the weaker points of fish acute toxicity tests.

  17. Poly(N-isopropylacrylamide)-coated thermo-responsive nanoparticles for controlled delivery of sulfonated Zn-phthalocyanine in Chinese hamster ovary cells in vitro and zebra fish in vivo

    NASA Astrophysics Data System (ADS)

    He, Jia; Chen, Ji-Yao; Wang, Pu; Wang, Pei-Nan; Guo, Jia; Yang, Wu-Li; Wang, Chang-Chun; Peng, Qian

    2007-10-01

    Poly(N-isopropylacrylamide) (PNIPAM)-coated Fe3O4@SiO2@CdTe multifunctional nanoparticles with photoluminescent (PL), thermosensitive and magnetic properties, were investigated as carriers to deliver water-soluble, fluorescent sulfonated Zn-phthalocyanine (ZnPcS), a photosensitizing drug for photodynamic therapy of cancer, in Chinese hamster ovary (CHO) cells in vitro and zebra fish in vivo. PNIPAM is a well-known thermo-responsive polymer with a volume phase transition temperature. This property allows it to be swollen in water at temperatures lower than 32-34 °C to take up ZnPcS and shrunken to expel the drug at higher temperatures. Since the PL band of CdTe quantum dots (QDs) as indicators for the nanoparticles is at 585 nm and the emission band of ZnPcS is at 680 nm, it is possible to study the temperature-dependent release of ZnPcS from the nanoparticles by fluorescence measurements. ZnPcS was embedded in the PNIPAM of the nanoparticles at 25 °C in phosphate buffered saline (PBS) solution and released at 37 °C, measured with a spectrophotometer. When CHO cells had been incubated with the ZnPcS-loaded nanoparticles at 27 °C, a similar intracellular localization pattern of CdTe QDs and ZnPcS was seen by multichannel measurements in confocal laser scanning microscopy (CLSM), but a diffuse pattern of only ZnPcS fluorescence was detected in the cytoplasm of the cells at 37 °C, indicating a release of ZnPcS from the nanoparticles. Similar results were also found in the intestinal tract of zebra fish in vivo after intake of the nanoparticles. Since the nanoparticles contain magnetic (Fe3O4) material, the nanoparticles could also be manipulated to change their location in the intestinal tract of the zebra fish with an external magnetic field gradient of 300 G mm-1. The results presented suggest that such multifunctional nanoparticles may have combined potential for temperature-dependent drug delivery, QD photodetection and magnetic manipulation in diagnosis and

  18. The effect of zebra mussel consumption on growth of freshwater drum in Lake Erie

    USGS Publications Warehouse

    French, John R. P.; Bur, Michael T.

    1996-01-01

    We examined food habits and scale annuli of freshwater drum (Aplodinotus grunniens) from western Lake Erie to determine whether increasing predation on zebra mussels (Dreissena polymorpha) had affected growth of freshwater drum. The volume of zebra mussels in drum guts was greater in older fish. Growth of age classes 3–4, which consumed few zebra mussels, was greater in the most productive year for zebra mussels, July 1990–August 1991, than in three prior years. The total lengths of 5-year-old drum changed little. The mean total length of 6-year-old females has declined since the zebra mussel invaded Lake Erie, even through mussels comprised more than two-thirds of gut samples in these fish. These studies suggest that zebra mussels may not benefit freshwater drum when serving as a staple in the diet. PDF

  19. Development of space-fertilized eggs and formation of primordial germ cells in the embryos of medaka fish

    NASA Astrophysics Data System (ADS)

    Ijiri, K.

    In the second International Microgravity Laboratory (IML-2) mission in 1994, four small Japanese killifish (Medaka, Oryzias latipes) made a space travel of 15 days aboard a space shuttle. These four adult Medaka fish successfully mated in space for the first time among vertebrate animals. Moreover, the eggs they laid developed normally, at least in their external appearance, hatching as fry (baby fish) in space. Fish mated and laid eggs every day during the first week. Near the end of the mission most of the eggs had a well-developed body with two pigmented eyes. In total, 43 eggs were laid (detected), out of which 8 fry hatched in space, as truly `space-originated' babies. A further 30 fry hatched within 3 days after landing. This is the normal hatching rate, compared with the ground-based data. Among the 8 space-originated fry, four were killed for histological sections, and germ cells at the gonadal region were counted for each fry. Their numbers were in the range of the germ cells of the normal control fry (ground-kept samples). Thus, as embryos developed normally in their external appearance, inside the embryos the formation of primordial germ cells took place normally in space, and their migration to the genital ridges was not hindered by microgravity. The two of the remaining space-originated fry have grown up and been creating their offspring in the laboratory. This proved that the primordial germ cells formed in space were also normal from a functional point of view. The four space-travelled adult fish re-started mating and laying eggs on the 7th day after landing and continued to do so every day afterward. Fertilization rate and hatchability of these eggs were as high as the eggs laid by the laboratory-kept fish. This fact implies that in gametogenesis of adult fish, there are no specific stages of germ cells extremely susceptible to microgravity.

  20. High-throughput assessment of oxidative respiration in fish embryos: Advancing adverse outcome pathways for mitochondrial dysfunction.

    PubMed

    Souders, Christopher L; Liang, Xuefang; Wang, Xiaohong; Ector, Naomi; Zhao, Yuan H; Martyniuk, Christopher J

    2018-06-01

    Mitochondrial dysfunction is a prevalent molecular event that can result in multiple adverse outcomes. Recently, a novel high throughput method to assess metabolic capacity in fish embryos following exposure to chemicals has been adapted for environmental toxicology. Assessments of oxygen consumption rates using the Seahorse XF(e) 24/96 Extracellular Flux Analyzer (Agilent Technologies) can be used to garner insight into toxicant effects at early stages of development. Here we synthesize the current state of the science using high throughput metabolic profiling in zebrafish embryos, and present considerations for those wishing to adopt high throughput methods for mitochondrial bioenergetics into their research. Chemicals that have been investigated in zebrafish using this metabolic platform include herbicides (e.g. paraquat, diquat), industrial compounds (e.g. benzo-[a]-pyrene, tributyltin), natural products (e.g. quercetin), and anti-bacterial chemicals (i.e. triclosan). Some of these chemicals inhibit mitochondrial endpoints in the μM-mM range, and reduce basal respiration, maximum respiration, and spare capacity. We present a theoretical framework for how one can use mitochondrial performance data in zebrafish to categorize chemicals of concern and prioritize mitochondrial toxicants. Noteworthy is that our studies demonstrate that there can be considerable variation in basal respiration of untreated zebrafish embryos due to clutch-specific effects as well as individual variability, and basal oxygen consumption rates (OCR) can vary on average between 100 and 300 pmol/min/embryo. We also compare OCR between chorionated and dechorionated embryos, as both models are employed to test chemicals. After 24 h, dechorionated embryos remain responsive to mitochondrial toxicants, although they show a blunted response to the uncoupling agent carbonylcyanide-4-trifluoromethoxyphenylhydrazone (FCCP); dechorionated embryos are therefore a viable option for investigations

  1. Gene expression analysis in zebrafish embryos: a potential approach to predict effect concentrations in the fish early life stage test.

    PubMed

    Weil, Mirco; Scholz, Stefan; Zimmer, Michaela; Sacher, Frank; Duis, Karen

    2009-09-01

    Based on the hypothesis that analysis of gene expression could be used to predict chronic fish toxicity, the zebrafish (Danio rerio) embryo test (DarT), developed as a replacement method for the acute fish test, was expanded to a gene expression D. rerio embryo test (Gene-DarT). The effects of 14 substances on lethal and sublethal endpoints of the DarT and on expression of potential marker genes were investigated: the aryl hydrocarbon receptor 2, cytochrome P450 1A (cypla), heat shock protein 70, fizzy-related protein 1, the transcription factors v-maf musculoaponeurotic fibrosarcoma oncogene family protein g (avian) 1 and NF-E2-p45-related factor, and heme oxygenase 1 (hmox1). After exposure of zebrafish embryos for 48 h, differential gene expression was evaluated using reverse transcriptase-polymerase chain reaction, gel electrophoresis, and densitometric analysis of the gels. All tested compounds significantly affected the expression of at least one potential marker gene, with cyp1a and hmox1 being most sensitive. Lowest-observed-effect concentrations (LOECs) for gene expression were below concentrations resulting in 10% lethal effects in the DarT. For 10 (3,4- and 3,5-dichloroaniline, 1,4-dichlorobenzene, 2,4-dinitrophenol, atrazine, parathion-ethyl, chlorotoluron, genistein, 4-nitroquinoline-1-oxide, and cadmium) out of the 14 tested substances, LOEC values derived with the Gene-DarT differ by a factor of less than 10 from LOEC values of fish early life stage tests with zebrafish. For pentachloroaniline and pentachlorobenzene, the Gene-DarT showed a 23- and 153-fold higher sensitivity, respectively, while for lindane, it showed a 13-fold lower sensitivity. For ivermectin, the Gene-DarT was by a factor of more than 1,000 less sensitive than the acute fish test. The results of the present study indicate that gene expression analysis in zebrafish embryos could principally be used to predict effect concentrations in the fish early life stage test.

  2. Inhibitory Effects of Red Wine on Lipid Oxidation in Fish Oil Emulsion and Angiogenesis in Zebrafish Embryo.

    PubMed

    Sun, Haiyan; Zhang, Yulin; Shen, Yixiao; Zhu, Yongchao; Wang, Hua; Xu, Zhimin

    2017-03-01

    The capabilities of red wine against lipid oxidation and angiogenesis were evaluated by using a fish oil emulsion system and an in vivo zebrafish embryos model, respectively. The red wine contained 12 different antioxidant phenolics which levels were led by anthocyanins (140.46 mg/L), catechin (55.08 mg/L), and gallic acid (46.76 mg/L). The diversity of the phenolics in red wine was greater than the tea, coffee, or white wine selected as a peer control in this study. The total phenolics concentration of red wine was 305.53 mg/L, although the levels of tea, coffee, and white wine were 85.59, 76.85, and 26.57 mg/L, respectively. The activity of red wine in scavenging DPPH (2,2-diphenyl-1-picrylhydrazyl) free radicals was approximately 4 times higher than the tea and 8 times than the coffee or white wine. The red wine showed the highest capability in preventing long chain PUFA oxidation in the fish oil emulsion. Because of the outstanding antioxidant activity of red wine, the red wine dried extract was used to monitor its inhibitory effect against angiogenesis by using transgenic zebrafish embryos (Tg[fli1:egfp] y1 ) with fluorescent blood vessels. After incubated in 100 μg/mL of the extract solution for 26 h pf, each of the embryos had a lower number of intersegmental vessel than the control embryo. The inhibition rate of red wine extract against growing of angiogenic blood vessel reached 100%. © 2017 Institute of Food Technologists®.

  3. Prolonging hypothermic storage (4 C) of bovine embryos with fish antifreeze protein.

    PubMed

    Ideta, Atsushi; Aoyagi, Yoshito; Tsuchiya, Kanami; Nakamura, Yuuki; Hayama, Kou; Shirasawa, Atsushi; Sakaguchi, Kenichiro; Tominaga, Naomi; Nishimiya, Yoshiyuki; Tsuda, Sakae

    2015-01-01

    Embryos obtained via superovulation are necessary for mammalian artificial reproduction, and viability is a key determinant of success. Nonfreezing storage at 4 C is possible, but currently used storage solutions can maintain embryo viability for only 24-48 h. Here we found that 10 mg/ml antifreeze protein (AFP) dissolved in culture medium 199 with 20% (v/v) fetal bovine serum and 25 mM HEPES could keep bovine embryos alive for 10 days at 4 C. We used a recombinant AFP isolated from the notched-fin eelpout (Zoarces elongatus Kner). Photomicroscopy indicated that the AFP-embryo interaction was enhanced at 37 C. Embryos pre-warmed with the AFP solution at 37 C for 60 min maintained high viability, whereas those that were not pre-warmed could live no longer than 7 days. Thus, short-term storage of bovine embryos was achieved by a combination of AFP-containing medium and controlled pre-warming.

  4. Towards more ecological relevance in sediment toxicity testing with fish: Evaluation of multiple bioassays with embryos of the benthic weatherfish (Misgurnus fossilis).

    PubMed

    Schreiber, Benjamin; Fischer, Jonas; Schiwy, Sabrina; Hollert, Henner; Schulz, Ralf

    2018-04-01

    The effects of sediment contamination on fish are of high significance for the protection of ecosystems, human health and economy. However, standardized sediment bioassays with benthic fish species, that mimic bioavailability of potentially toxic compounds and comply with the requirements of alternative test methods, are still scarce. In order to address this issue, embryos of the benthic European weatherfish (Misgurnus fossilis) were exposed to freeze-dried sediment (via sediment contact assays (SCA)) and sediment extracts (via acute fish embryo toxicity tests) varying in contamination level. The extracts were gained by accelerated solvent extraction with (i) acetone and (ii) pressurized hot water (PHWE) and subsequently analyzed for polycyclic aromatic hydrocarbons, polychlorinated biphenyls and polychlorinated dibenzodioxins and dibenzofurans. Furthermore, embryos of the predominately used zebrafish (Danio rerio) were exposed to extracts from the two most contaminated sediments. Results indicated sufficient robustness of weatherfish embryos towards varying test conditions and sensitivity towards relevant sediment-bound compounds. Furthermore, a compliance of effect concentrations derived from weatherfish embryos exposed to sediment extracts (96h-LC 50 ) with both measured gradient of sediment contamination and previously published results was observed. In comparison to zebrafish, weatherfish embryos showed higher sensitivity to the bioavailability-mimicking extracts from PHWE but lower sensitivity to extracts gained with acetone. SCAs conducted with weatherfish embryos revealed practical difficulties that prevented an implementation with three of four sediments tested. In summary, an application of weatherfish embryos, using bioassays with sediment extracts from PHWE might increase the ecological relevance of sediment toxicity testing: it allows investigations using benthic and temperate fish species considering both bioavailable contaminants and animal welfare

  5. Microencapsulated fluorescent pH probe as implantable sensor for monitoring the physiological state of fish embryos.

    PubMed

    Gurkov, Anton; Sadovoy, Anton; Shchapova, Ekaterina; Teh, Cathleen; Meglinski, Igor; Timofeyev, Maxim

    2017-01-01

    In vivo physiological measurement is a major challenge in modern science and technology, as is environment conservation at the global scale. Proper toxicological testing of widely produced mixtures of chemicals is a necessary step in the development of new products, allowing us to minimize the human impact on aquatic ecosystems. However, currently available bioassay-based techniques utilizing small aquatic organisms such as fish embryos for toxicity testing do not allow assessing in time the changes in physiological parameters in the same individual. In this study, we introduce microencapsulated fluorescent probes as a promising tool for in vivo monitoring of internal pH variation in zebrafish embryos. The pH alteration identified under stress conditions demonstrates the applicability of the microencapsulated fluorescent probes for the repeated analysis of the embryo's physiological state. The proposed approach has strong potential to simultaneously measure a range of physiological characteristics using a set of specific fluorescent probes and to finally bring toxicological bioassays and related research fields to a new level of effectiveness and sensitivity.

  6. Integrated chip-based physiometer for automated fish embryo toxicity biotests in pharmaceutical screening and ecotoxicology.

    PubMed

    Akagi, Jin; Zhu, Feng; Hall, Chris J; Crosier, Kathryn E; Crosier, Philip S; Wlodkowic, Donald

    2014-06-01

    Transgenic zebrafish (Danio rerio) models of human diseases have recently emerged as innovative experimental systems in drug discovery and molecular pathology. None of the currently available technologies, however, allow for automated immobilization and treatment of large numbers of spatially encoded transgenic embryos during real-time developmental analysis. This work describes the proof-of-concept design and validation of an integrated 3D microfluidic chip-based system fabricated directly in the poly(methyl methacrylate) transparent thermoplastic using infrared laser micromachining. At its core, the device utilizes an array of 3D micromechanical traps to actively capture and immobilize single embryos using a low-pressure suction. It also features built-in piezoelectric microdiaphragm pumps, embryo-trapping suction manifold, drug delivery manifold, and optically transparent indium tin oxide heating element to provide optimal temperature during embryo development. Furthermore, we present design of the proof-of-concept off-chip electronic interface equipped with robotic servo actuator driven stage, innovative servomotor-actuated pinch valves, and embedded miniaturized fluorescent USB microscope. Our results showed that the innovative device has 100% embryo-trapping efficiency while supporting normal embryo development for up to 72 hr in a confined microfluidic environment. We also showed data that this microfluidic system can be readily applied to kinetic analysis of a panel of investigational antiangiogenic agents in transgenic zebrafish lines. The optical transparency and embryo immobilization allow for convenient visualization of developing vasculature patterns in response to drug treatment without the need for specimen re-positioning. The integrated electronic interfaces bring the lab-on-a-chip systems a step closer to realization of complete analytical automation. © 2014 International Society for Advancement of Cytometry.

  7. Predation of the zebra mussel (Dreissena polymorpha) by freshwater drum in western Lake Erie

    USGS Publications Warehouse

    French, John R. P.; Bur, Michael T.; Nalepa, Thomas F.; Schloesser, Donald W.

    1992-01-01

    Environmental and economic problems associated with the colonization of zebra mussels (Dreissena polymorpha) in western Lake Erie created a need to investigate control mechanisms. Predation by fishes is one potential means of control, but predation on zebra mussels by native fishes in Lake Erie is unknown. The freshwater drum (Aplodinotus grunniens) is the most likely fish predator since it is the only fish with pharyngeal teeth capable of crushing mollusk shells. In 1990, freshwater drum were collected in western Lake Erie from 9 sites near rocky reefs and 13 sites with silt or sand bottoms, and gut contents were examined. Predation on zebra mussels increased as drum size increased. Small drum (200-249 mm in length) fed mainly on dipterans, amphipods, and small fish; small zebra mussels (375 mm in length) fed almost exclusively on zebra mussels (seasons and locations combined). The smallest drum capable of crushing zebra mussel shells was 265 mm. Since freshwater drum over 375 mm feed heavily on zebra mussels, they may become a possible biological control mechanism for mussels in portions of North America.

  8. The use of the zebrafish (Danio rerio) embryo for the acute toxicity testing of surfactants, as a possible alternative to the acute fish test.

    PubMed

    Vaughan, Martin; van Egmond, Roger

    2010-06-01

    At present, the acute toxicity of chemicals to fish is most commonly estimated by means of a short-term test on juvenile or adult animals (OECD TG 203). Although, over the last few years, the numbers used have been reduced due to the implementation of the Three Rs (Reduction, Refinement and Replacement), significant numbers of fish are still used in acute toxicity tests. With the introduction of the new European Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) system, this number is likely to increase dramatically. The aim of this work was to test the acute toxicity of a number of anionic, cationic and non-ionic surfactants to embryos of the zebrafish (Danio rerio), over 48 hours, as a possible alternative to the standard 96-hour fish acute test. We measured the toxicities of 15 surfactants, and compared the results to previously generated adult D. rerio LC50 data (or other fish species, if these data were not available). Comparison of the LC50 data showed that embryos appear to be as sensitive to cationic and non-ionic surfactants as the adult fish, but possibly are more sensitive to anionic surfactants. Toxicity testing with the embryo test can be carried out more quickly than with the adult test, uses much less space and media, requires less effort, and therefore can be performed at a reduced cost. The embryo test may also uncover additional sub-lethal effects, although these were not observed for surfactants. The data presented here show that the 48-hour embryo test can be considered as a suitable alternative to the adult acute fish test for surfactants.

  9. Fish embryo toxicity test, threshold approach, and moribund as approaches to implement 3R principles to the acute fish toxicity test.

    PubMed

    Dang, ZhiChao; van der Ven, Leo T M; Kienhuis, Anne S

    2017-11-01

    The acute fish toxicity test (AFT) is requested by EU legal frameworks for hazard classification and risk assessment. AFT is one of the few regulatory required tests using death as an endpoint. This paper reviews efforts made to reduce, refine and replace (3Rs) AFT. We make an inventory of information requirements for AFT, summarize studies on 3Rs of AFT and give recommendations. The fish embryo toxicity test (FET) is proposed as a replacement of AFT and analyses have focused on two aspects: assessing the capacity of FET in predicting AFT and defining the applicability domain of FET. Six comparison studies have consistently shown a strong correlation of FET and AFT. In contrast, the applicability domain of FET has not yet been fully defined. FET has not yet been accepted as a replacement of AFT by any EU legal frameworks to fulfill information requirements because FET is insensitive to some chemicals. It is recommended that the outlier chemicals that do not correlate between FET and AFT should be further investigated. When necessary, additional FET data should be generated. Another effort to reduce and refine AFT is incorporation of FET into the threshold approach. Furthermore, moribund as an endpoint of fish death has been introduced in revising AFT guideline to reduce the duration of suffering for refinement. This endpoint, however, needs further work on the link of moribund and death. Global regulatory acceptance of the moribund endpoint would be critical for this development. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Effects of Nanosilver Exposure on Cholinesterase Activities, CD41, and CDF/LIF-Like Expression in ZebraFish (Danio rerio) Larvae

    PubMed Central

    Myrzakhanova, Marzhan; Gambardella, Chiara; Falugi, Carla; Gatti, Antonietta M.; Tagliafierro, Grazia; Diaspro, Alberto

    2013-01-01

    Metal nanosolicoparticles are suspected to cause diseases in a number of organisms, including man. In this paper, we report the effects of nanosilver (Ag, 1–20 nm particles) on the early development of the zebrafish, a well-established vertebrate model. Embryos at the midgastrula stage were exposed to concentrations ranging from 100 to 0.001 mg/L to verify the effects on different endpoints: lethality, morphology, expression of cholinergic molecules, and development of the immune system. (1) Relative risk of mortality was exponential in the range between 0.001 and 10 mg/L. Exposure to 100 mg/L caused 100% death of embryos before reaching the tail-bud stage. (2) Developmental anomalies were present in the 72 h larvae obtained from embryos exposed to nanosilver: whole body length, decreased eye dimension, and slow response to solicitation by gentle touch with a needle tip, with a significant threshold at 0.1 mg/L. (3) Dose-dependent inhibition of acetylcholinesterase activity was significant among the exposures, except between 1 mg/L and 10 mg/L. (4) The distribution of CD41+ cells and of CDF/LIF-like immunoreactivity was altered according to the Ag concentration. The possible effect of nanosilver in impairing immune system differentiation through the inhibition of molecules related to the cholinergic system is discussed. PMID:23991412

  11. RETINOID METABOLISM IN FISH EMBRYOS FROM SENSITIVE AND RESISTANT POPULATIONS EXPOSED TO DIOXIN-LIKE COMPOUNDS

    EPA Science Inventory

    Early developmental stages of fish are extremely sensitive to a class of toxic and persistent environmental contaminants known as dioxin-like compounds (DLCs). Most of the toxicological actions of DLCs are mediated via the Aryl hydrocarbon Receptor (AhR) that regulates transcript...

  12. The zebrafish embryo model in toxicology and teratology, September 2–3, 2010, Karlsruhe, Germany.

    PubMed

    Busch, Wibke; Duis, Karen; Fenske, Martina; Maack, Gerd; Legler, Juliette; Padilla, Stephanie; Strähle, Uwe; Witters, Hilda; Scholz, Stefan

    2011-05-01

    The use of fish embryos is gaining popularity for research in the area of toxicology and teratology. Particularly embryos of the zebrafish offer an array of different applications ranging from regulatory testing to mechanistic research. For this reason a consortium of two research centres and a company with the support of the COST Action EuFishBiomed has organised the Workshop “The zebrafish embryo model in toxicology and teratology”, in Karlsruhe, Germany, 2nd–3rd September 2010. The workshop aimed at bringing together experts from different areas of toxicology using the (zebra)fish embryo and stimulating networking between scientists and representatives from regulatory bodies, research institutions and industry. Recent findings, presented in various platform presentations in the area of regulatory toxicity, high throughput screening, toxicogenomics, as well as environmental and human risk assessment are highlighted in this meeting report. Furthermore, the constraints and possibilities of the model as discussed at the workshop are described. A follow up-meeting was appreciated by the about 120 participants and is planned for 2012.

  13. Effects of preincubation of eggs and activation medium on the percentage of eyed embryos in ide (Leuciscus idus), an externally fertilizing fish.

    PubMed

    Siddique, Mohammad Abdul Momin; Linhart, Otomar; Krejszeff, Sławomir; Żarski, Daniel; Król, Jarosław; Butts, Ian Anthony Ernest

    2016-03-15

    Standardization of fertilization protocols is crucial for improving reproductive techniques for externally fertilizing fish in captive breeding. Therefore, the objectives of this study were to determine the effects of preincubation of eggs and activation medium on the percentage of eyed embryos for ide (Leuciscus idus). Pooled eggs from five females were preincubated in three different activating media for 0, 30, 60, 90, and 120 seconds and then fertilized by pooled sperm from five males. At the eyed-egg stage, the percentage of viable embryos was later calculated. Results showed that preincubation time was significant for the freshwater activation medium (P < 0.001), such that the percentage of eyed embryos declined across the preincubation time gradient. Additionally, there was an effect on the percentage of eyed embryos when eggs were incubated with Woynarovich solution (P < 0.001), such that a decline was detected at 90 seconds, whereas no effect was detected for the saline water medium. Activating medium had a significant effect on the percentage of eyed embryos for each preincubation time (P < 0.05). More precisely, freshwater produced the lowest percentage of eyed embryos at all preincubation times (ranged from 1.9% at 120 seconds to 43.6% at 0 seconds), whereas saline water and Woynarovich solution produced the highest percentage of eyed embryos at 0 seconds and 30 seconds before incubation. Woynarovich solution produced the highest percentage of eyed embryos at 60 seconds (65.26%), whereas saline water produced the highest percentage at 90 seconds (68.37%). No difference was detected between saline water and Woynarovich solution at 120 seconds. Examination of sperm traits showed no impact of activating medium on computer assisted sperm analysis parameters. Together, these results suggest that saline water or Woynarovich solution improve fertilization rate in ide during IVF; thus, these media are useful for standardizing fertilization protocols and

  14. Effects of cadmium-enriched sediment on fish and amphibian embryo-larval stages

    SciTech Connect

    Francis, P.C.; Birge, W.J.; Black, J.A.

    1984-08-01

    Aquatic toxicity tests were conducted to evaluate the effects of cadmium-enriched sediment on embryo-larval stages of the goldfish (Carassius auratus), leopard frog (Rana pipiens), and largemouth bass (Micropterus salmoides). Natural stream sediment was collected and enriched with cadmium to nominal concentrations of 1.0, 10.0, 100, and 1000 mg/kg. Enriched sediments were placed in Pyrex dishes and covered with 350 ml of reconstituted water. Fertilized eggs were placed in the dishes and maintained through 4 days posthatching, giving a total exposure time of 6 to 7 days. For all tests the cadmium concentrations ranged from 1.1 to 76.5 micrograms/liter in watermore » above sediments containing 1 to 1000 mg Cd/kg, respectively. Although low frequencies of mortality were observed in all tests, goldfish, leopard frog, and bass exposed to sediments enriched to 1000 mg Cd/kg accumulated 4.61, 12.55, and 60.0 micrograms Cd/g, respectively. No significant correlations were found between mortality of the goldfish and leopard frog and the cadmium concentrations in either water or sediment. However, all three species showed strong correlations between cadmium concentrations in water and tissue, sediment and tissue, and water and sediment. Tissue cadmium concentrations were related to the length of time test organisms were in direct contact with cadmium-enriched sediment.« less

  15. Alternative methods for toxicity assessments in fish: comparison of the fish embryo toxicity and the larval growth and survival tests in zebrafish and fathead minnows.

    PubMed

    Jeffries, Marlo K Sellin; Stultz, Amy E; Smith, Austin W; Rawlings, Jane M; Belanger, Scott E; Oris, James T

    2014-11-01

    An increased demand for chemical toxicity evaluations has resulted in the need for alternative testing strategies that address animal welfare concerns. The fish embryo toxicity (FET) test developed for zebrafish (Danio rerio) is one such alternative, and the application of the FET test to other species such as the fathead minnow (Pimephales promelas) has been proposed. In the present study, the performances of the FET test and the larval growth and survival (LGS; a standard toxicity testing method) test in zebrafish and fathead minnows were evaluated. This required that testing methods for the fathead minnow FET and zebrafish LGS tests be harmonized with existing test methods and that the performance of these testing strategies be evaluated by comparing the median lethal concentrations of 2 reference toxicants, 3,4-dicholoraniline and ammonia, obtained via each of the test types. The results showed that procedures for the zebrafish FET test can be adapted and applied to the fathead minnow. Differences in test sensitivity were observed for 3,4-dicholoraniline but not ammonia; therefore, conclusions regarding which test types offer the least or most sensitivity could not be made. Overall, these results show that the fathead minnow FET test has potential as an alternative toxicity testing strategy and that further analysis with other toxicants is warranted in an effort to better characterize the sensitivity and feasibility of this testing strategy. © 2014 SETAC.

  16. Evaluation of water quality during successive severe drought years within Microcystis blooms using fish embryo toxicity tests for the San Francisco Estuary, California.

    PubMed

    Kurobe, Tomofumi; Lehman, Peggy W; Haque, M E; Sedda, Tiziana; Lesmeister, Sarah; Teh, Swee

    2018-01-01

    In the San Francisco Estuary, California, the largest estuary on the Pacific Coast of North America, the frequency and intensity of drought and associated cyanobacteria blooms are predicted to increase with climate change. To assess the impact of water quality conditions on estuarine fish health during successive severe drought years with Microcystis blooms, we performed fish embryo toxicity testing with Delta Smelt and Medaka. Fish embryos were exposed to filtered ambient water collected from the San Francisco Estuary during the Microcystis bloom season in 2014 and 2015, the third and fourth most severe recorded drought years in California. Medaka embryos incubated in filtered ambient waters exhibited high mortality rates (>77%), which was mainly due to bacterial growth. Medaka mortality data was negatively correlated with chloride, and positively correlated with water temperature, total and dissolved organic carbon, and ambient and net chlorophyll a concentration. Delta Smelt embryo mortality rates were lower (<42%) and no prominent seasonal or geographic trend was observed. There was no significant correlation between the Delta Smelt mortality data and water quality parameters. Aeromonas was the dominant bacteria that adversely affected Medaka. The growth of Aeromonas was suppressed when salinity was greater than or equal to 1psu and resulted in a significant reduction in mortality rate. Bacterial growth test demonstrated that the lysate of Microcystis cells enhanced the growth of Aeromonas. Toxin production by Microcystis is a major environmental concern, however, we conclude that dissolved substances released from Microcystis blooms could result in water quality deterioration by promoting growth of bacteria. Furthermore, a distinctive developmental deformity was observed in Medaka during the toxicity tests; somite formation was inhibited at the same time that cardiogenesis occurred and the functional heart was observed to be beating. The exact cause of the

  17. Sediment-contact fish embryo toxicity assay with Danio rerio to assess particle-bound pollutants in the Tietê River Basin (São Paulo, Brazil).

    PubMed

    Rocha, Paula Suares; Bernecker, Conny; Strecker, Ruben; Mariani, Carolina Fiorillo; Pompêo, Marcelo Luiz Martins; Storch, Volker; Hollert, Henner; Braunbeck, Thomas

    2011-10-01

    The Tietê River and its tributary Pinheiros River receive a highly complex organic and inorganic pollutants load from sanitary sewage and industrial sources, as well as agricultural and agroindustrial activities. The aim of the present study was to evaluate the embryotoxic and teratogenic effects of sediments from selected locations in the Tietê River Basin by means of the sediment contact embryo toxicity assay with Danio rerio, in order to provide a comprehensive and realistic insight into the bioavailable hazard potential of these sediment samples. Lethal and sub-lethal effects were recorded, and high embryo toxicity could be found in the samples not only in the vicinity of the megacity São Paulo (Billings reservoir and Pinheiros River samples), but also downstream (in the reservoirs Barra Bonita, Promissão and Três Irmãos). Results confirm that most toxicity is due to the discharges of the metropolitan area of São Paulo. However, they also indicate additional sources of pollutants along the river course, probably from industrial, agricultural and agroindustrial residues, which contribute to the degradation of each area. The sediment contact fish embryo test showed to be powerful tool to detect embryo toxicity in sediments, not only by being a sensitive method, but also for taking into account bioavailability. This test provides an ecological highly realistic and relevant exposure scenario, and should therefore be added in ecotoxicological sediment quality assessments. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Influence of metal(loid) bioaccumulation and maternal transfer on embryo-larval development in fish exposed to a major coal ash spill

    DOE PAGES

    Greeley, Jr., Mark Stephen; Adams, S. Marshall; Elmore, Logan R.; ...

    2016-01-03

    In December 2008, an earthen retaining wall at the Tennessee Valley Authority (TVA) Kingston Fossil Fuel Plant failed and released 4.1 million m 3 of coal ash to rivers flowing into Watts Bar Reservoir in east Tennessee, United States (U.S.). As part of a comprehensive effort to evaluate the risks to aquatic resources from this spill – the largest in U.S. history – we compared bioaccumulation and maternal transfer of selenium (Se), arsenic (As), and mercury (Hg) in adult redear sunfish ( Lepomis macrolophus), collected two years after the spill from both coal-ash exposed and non-exposed areas of the Emorymore » and Clinch Rivers, with the success of embryo-larval development in their offspring. Whole body and ovary concentrations of Se in female sunfish at three study sites downstream of the spill were significantly elevated (site means = 4.9–5.3 and 6.7–9.0 mg/kg d.w. whole body and ovary concentrations, respectively) compared with concentrations in fish from reference sites upstream of the spill site (2.2–3.2 mg/kg d.w. for whole bodies and 3.6–4.8 mg/kg d.w. for ovaries). However, Se concentrations in coal ash-exposed areas remain below proposed U.S. Environmental Protection Agency (USEPA) criteria for the protection of aquatic life. Site-to-site variation in fish concentrations of As and Hg were not well-correlated with ash-exposure, reflecting the multiple sources of these metal(loid)s in the affected watersheds. In 7-day laboratory tests of embryos and larvae derived from in vitro crosses of eggs and sperm from these field-collected sunfish, fertilization success, hatching success, embryo-larval survival, and incidences of developmental abnormalities did not differ significantly between ash-exposed and non-exposed fish. Furthermore, these developmental endpoints were not correlated with whole body or ovary concentrations of Se, As, or Hg in the maternal fish, or with fish size, ovary weight, or gonadal-somatic indices. Furthermore, results from

  19. Influence of metal(loid) bioaccumulation and maternal transfer on embryo-larval development in fish exposed to a major coal ash spill

    SciTech Connect

    Greeley, Jr., Mark Stephen; Adams, S. Marshall; Elmore, Logan R.

    In December 2008, an earthen retaining wall at the Tennessee Valley Authority (TVA) Kingston Fossil Fuel Plant failed and released 4.1 million m 3 of coal ash to rivers flowing into Watts Bar Reservoir in east Tennessee, United States (U.S.). As part of a comprehensive effort to evaluate the risks to aquatic resources from this spill – the largest in U.S. history – we compared bioaccumulation and maternal transfer of selenium (Se), arsenic (As), and mercury (Hg) in adult redear sunfish ( Lepomis macrolophus), collected two years after the spill from both coal-ash exposed and non-exposed areas of the Emorymore » and Clinch Rivers, with the success of embryo-larval development in their offspring. Whole body and ovary concentrations of Se in female sunfish at three study sites downstream of the spill were significantly elevated (site means = 4.9–5.3 and 6.7–9.0 mg/kg d.w. whole body and ovary concentrations, respectively) compared with concentrations in fish from reference sites upstream of the spill site (2.2–3.2 mg/kg d.w. for whole bodies and 3.6–4.8 mg/kg d.w. for ovaries). However, Se concentrations in coal ash-exposed areas remain below proposed U.S. Environmental Protection Agency (USEPA) criteria for the protection of aquatic life. Site-to-site variation in fish concentrations of As and Hg were not well-correlated with ash-exposure, reflecting the multiple sources of these metal(loid)s in the affected watersheds. In 7-day laboratory tests of embryos and larvae derived from in vitro crosses of eggs and sperm from these field-collected sunfish, fertilization success, hatching success, embryo-larval survival, and incidences of developmental abnormalities did not differ significantly between ash-exposed and non-exposed fish. Furthermore, these developmental endpoints were not correlated with whole body or ovary concentrations of Se, As, or Hg in the maternal fish, or with fish size, ovary weight, or gonadal-somatic indices. Furthermore, results from

  20. Applicability of the fish embryo acute toxicity (FET) test (OECD 236) in the regulatory context of Registration, Evaluation, Authorisation, and Restriction of Chemicals (REACH).

    PubMed

    Sobanska, Marta; Scholz, Stefan; Nyman, Anna-Maija; Cesnaitis, Romanas; Gutierrez Alonso, Simon; Klüver, Nils; Kühne, Ralph; Tyle, Henrik; de Knecht, Joop; Dang, Zhichao; Lundbergh, Ivar; Carlon, Claudio; De Coen, Wim

    2018-03-01

    In 2013 the Organisation for Economic Co-operation and Development (OECD) test guideline (236) for fish embryo acute toxicity (FET) was adopted. It determines the acute toxicity of chemicals to embryonic fish. Previous studies show a good correlation of FET with the standard acute fish toxicity (AFT) test; however, the potential of the FET test to predict AFT, which is required by the Registration, Evaluation, Authorisation, and Restriction of Chemicals (REACH) regulation (EC 1907/2006) and the Classification, Labelling and Packaging (CLP) Regulation (EC 1272/2008), has not yet been fully clarified. In 2015 the European Chemicals Agency (ECHA) requested that a consultant perform a scientific analysis of the applicability of FET to predict AFT. The purpose was to compare the toxicity of substances to fish embryos and to adult fish, and to investigate whether certain factors (e.g., physicochemical properties, modes of action, or chemical structures) could be used to define the applicability boundaries of the FET test. Given the limited data availability, the analysis focused on organic substances. The present critical review summarizes the main findings and discusses regulatory application of the FET test under REACH. Given some limitations (e.g., neurotoxic mode of action) and/or remaining uncertainties (e.g., deviation of some narcotic substances), it has been found that the FET test alone is currently not sufficient to meet the essential information on AFT as required by the REACH regulation. However, the test may be used within weight-of-evidence approaches together with other independent, relevant, and reliable sources of information. The present review also discusses further research needs that may overcome the remaining uncertainties and help to increase acceptance of FET as a replacement for AFT in the future. For example, an increase in the availability of data generated according to OECD test guideline 236 may provide evidence of a higher predictive power

  1. Fish embryo tests with Danio rerio as a tool to evaluate surface water and sediment quality in rivers influenced by wastewater treatment plants using different treatment technologies.

    PubMed

    Thellmann, Paul; Köhler, Heinz-R; Rößler, Annette; Scheurer, Marco; Schwarz, Simon; Vogel, Hans-Joachim; Triebskorn, Rita

    2015-11-01

    In order to evaluate surface water and the sediment quality of rivers connected to wastewater treatment plants (WWTPs) with different treatment technologies, fish embryo tests (FET) with Danio rerio were conducted using native water and sediment samples collected upstream and downstream of four WWTPs in Southern Germany. Two of these WWTPs are connected to the Schussen River, a tributary of Lake Constance, and use a sand filter with final water purification by flocculation. The two others are located on the rivers Schmiecha and Eyach in the area of the Swabian Alb and were equipped with a powdered activated carbon stage 20 years ago, which was originally aimed at reducing the release of stains from the textile industry. Several endpoints of embryo toxicity including mortality, malformations, reduced hatching rate, and heart rate were investigated at defined time points of embryonic development. Higher embryotoxic potentials were found in water and sediments collected downstream of the WWTPs equipped with sand filtration than in the sample obtained downstream of both WWTPs upgraded with a powdered activated carbon stage.

  2. Review of techniques to prevent introduction of zebra mussels (Dreissena polymorpha) during native mussel (Unionoidea) conservation activities

    USGS Publications Warehouse

    Cope, W.G.; Newton, T.J.; Gatenby, C.M.

    2003-01-01

    Because of the declines in diversity and abundance of native freshwater mussels (superfamily Unionoidea), and the potential decimation of populations of native mussels resulting from the rapid spread of the exotic zebra mussel Dreissena polymorpha, management options to eliminate or reduce the threat of the zebra mussel are needed. Relocating native mussels to refugia (artificial and natural) has been proposed to mitigate the threat of zebra mussels to native species. Relocation of native mussels to refugia such as fish hatchery facilities or natural habitats within their historic range. Which are unlikely to be infested by zebra mussels, necessitates that protocols be developed to prevent the inadvertent introduction of zebra mussels. Several recent studies have developed Such protocols, and have assessed their effectiveness on the health and survival of native mussels during subsequent relocation to various refugia. The purpose of this project is to synthesize and evaluate the current protocols and to develop a set of procedures that resource managers and researchers should consider before conducting conservation activities in zebra mussel infested waters. We found that the existing protocols have many common points of concern, such as facility modification and suitability, zebra mussel risk assessment and management procedures, and health and disease management procedures. These conservation protocols may have broad applicability to other situations and locations. A summary and evaluation of the information in these main areas, along with recommended guidelines, are presented in this article.

  3. Pharyngeal teeth of the freshwater drum (Aplodinotus grunniens) a predator of the zebra mussel (Dreissena polymorpha)

    USGS Publications Warehouse

    French, John R. P.

    1997-01-01

    The morphology of pharyngeal teeth of freshwater drum (Aplodinotus grunniens) was studied to determine changes that occur during growth of drum that may relate to consumption of zebra mussel (Dreissena polymorpha) by larger fish. Pharyngeal teeth were of three types. Cardiform teeth were replaced by villiform teeth, which were replaced by molariform teeth as the size class of drum increased. Molariform teeth comprised over 85% of total surface area of dentition in fish 265 mm long.

  4. New Concerns Emerge as Zebra Mussel Spreads.

    ERIC Educational Resources Information Center

    Walter, Martha L., Ed.

    1992-01-01

    Reports on the Zebra Mussel invasion of North American inland waterways. Discusses United States Army Corps of Engineers operations that may facilitate or be affected by the spread of Zebra Mussels, the threat to native clams, chemical and mechanical control methods, natural solutions, and ongoing research. (MCO)

  5. Surgical manipulation of mammalian embryos in vitro.

    PubMed

    Naruse, I; Keino, H; Taniguchi, M

    1997-04-01

    Whole-embryo culture systems are useful in the fields of not only embryology but also teratology, toxicology, pharmacology, and physiology. Of the many advantages of whole-embryo culture, we focus here on the surgical manipulation of mammalian embryos. Whole-embryo culture allows us to manipulate mammalian embryos, similarly to fish, amphibian and avian embryos. Many surgical experiments have been performed in mammalian embryos in vitro. Such surgical manipulation alters the destiny of morphogenesis of the embryos and can answer many questions concerning developmental issues. As an example of surgical manipulation using whole-embryo culture systems, one of our experiments is described. Microsurgical electrocauterization of the deep preaxial mesodermal programmed cell death zone (fpp) in the footplate prevented the manifestation of polydactyly in genetic polydactyly mouse embryos (Pdn/Pdn), in which fpp was abolished.

  6. Zebra Stripes through the Eyes of Their Predators, Zebras, and Humans.

    PubMed

    Melin, Amanda D; Kline, Donald W; Hiramatsu, Chihiro; Caro, Tim

    2016-01-01

    The century-old idea that stripes make zebras cryptic to large carnivores has never been examined systematically. We evaluated this hypothesis by passing digital images of zebras through species-specific spatial and colour filters to simulate their appearance for the visual systems of zebras' primary predators and zebras themselves. We also measured stripe widths and luminance contrast to estimate the maximum distances from which lions, spotted hyaenas, and zebras can resolve stripes. We found that beyond ca. 50 m (daylight) and 30 m (twilight) zebra stripes are difficult for the estimated visual systems of large carnivores to resolve, but not humans. On moonless nights, stripes are difficult for all species to resolve beyond ca. 9 m. In open treeless habitats where zebras spend most time, zebras are as clearly identified by the lion visual system as are similar-sized ungulates, suggesting that stripes cannot confer crypsis by disrupting the zebra's outline. Stripes confer a minor advantage over solid pelage in masking body shape in woodlands, but the effect is stronger for humans than for predators. Zebras appear to be less able than humans to resolve stripes although they are better than their chief predators. In conclusion, compared to the uniform pelage of other sympatric herbivores it appears highly unlikely that stripes are a form of anti-predator camouflage.

  7. Fishing

    SciTech Connect

    Walker, G.

    1984-09-01

    Two classifications of fishing jobs are discussed: open hole and cased hole. When there is no casing in the area of the fish, it is called open hole fishing. When the fish is inside the casing, it is called cased hole fishing. The article lists various things that can become a fish-stuck drill pipe, including: broken drill pipe, drill collars, bit, bit cones, hand tools dropped in the well, sanded up or mud stuck tubing, packers become stuck, and much more. It is suggested that on a fishing job, all parties involved should cooperate with each other, and that fishingmore » tool people obtain all the information concerning the well. That way they can select the right tools and methods to clean out the well as quickly as possible.« less

  8. ZEBRA battery meets USABC goals

    NASA Astrophysics Data System (ADS)

    Dustmann, Cord-H.

    In 1990, the California Air Resources Board has established a mandate to introduce electric vehicles in order to improve air quality in Los Angeles and other capitals. The United States Advanced Battery Consortium has been formed by the big car companies, Electric Power Research Institute (EPRI) and the Department of Energy in order to establish the requirements on EV-batteries and to support battery development. The ZEBRA battery system is a candidate to power future electric vehicles. Not only because its energy density is three-fold that of lead acid batteries (50% more than NiMH) but also because of all the other EV requirements such as power density, no maintenance, summer and winter operation, safety, failure tolerance and low cost potential are fulfilled. The electrode material is plain salt and nickel in combination with a ceramic electrolyte. The cell voltage is 2.58 V and the capacity of a standard cell is 32 Ah. Some hundred cells are connected in series and parallel to form a battery with about 300 V OCV. The battery system including battery controller, main circuit-breaker and cooling system is engineered for vehicle integration and ready to be mounted in a vehicle [J. Gaub, A. van Zyl, Mercedes-Benz Electric Vehicles with ZEBRA Batteries, EVS-14, Orlando, FL, Dec. 1997]. The background of these features are described.

  9. Zebra mussels invade Lake Erie muds

    USGS Publications Warehouse

    Berkman, Paul Arthur; Haltuch, Melissa A.; Tichich, Emily; Garton, David W.; Kennedy, Gregory W.; Gannon, John E.; Mackey, Scudder D.; Fuller, Jonathan A.; Liebenthal, Dale L.

    1998-01-01

    Zebra mussels (Dreissena polymorpha) originated in western Russia but have now become widespread in Europe and North America. They are widely known for their conspicuous invasion of rocks and other hard substrates in North American and European watersheds. We have found beds of zebra mussels directly colonizing sand and mud sediments each year across hundreds of square kilometres of North America's Lake Erie. This transformation of sedimentary habitats into mussel beds represents an unforeseen change in the invasive capacity of this species.

  10. Zebra Stripes through the Eyes of Their Predators, Zebras, and Humans

    PubMed Central

    Melin, Amanda D.; Kline, Donald W.; Hiramatsu, Chihiro; Caro, Tim

    2016-01-01

    The century-old idea that stripes make zebras cryptic to large carnivores has never been examined systematically. We evaluated this hypothesis by passing digital images of zebras through species-specific spatial and colour filters to simulate their appearance for the visual systems of zebras’ primary predators and zebras themselves. We also measured stripe widths and luminance contrast to estimate the maximum distances from which lions, spotted hyaenas, and zebras can resolve stripes. We found that beyond ca. 50 m (daylight) and 30 m (twilight) zebra stripes are difficult for the estimated visual systems of large carnivores to resolve, but not humans. On moonless nights, stripes are difficult for all species to resolve beyond ca. 9 m. In open treeless habitats where zebras spend most time, zebras are as clearly identified by the lion visual system as are similar-sized ungulates, suggesting that stripes cannot confer crypsis by disrupting the zebra’s outline. Stripes confer a minor advantage over solid pelage in masking body shape in woodlands, but the effect is stronger for humans than for predators. Zebras appear to be less able than humans to resolve stripes although they are better than their chief predators. In conclusion, compared to the uniform pelage of other sympatric herbivores it appears highly unlikely that stripes are a form of anti-predator camouflage. PMID:26799935

  11. Uranium mining wastes: The use of the Fish Embryo Acute Toxicity Test (FET) test to evaluate toxicity and risk of environmental discharge.

    PubMed

    Lourenço, J; Marques, S; Carvalho, F P; Oliveira, J; Malta, M; Santos, M; Gonçalves, F; Pereira, R; Mendo, S

    2017-12-15

    Active and abandoned uranium mining sites often create environmentally problematic situations, since they cause the contamination of all environmental matrices (air, soil and water) with stable metals and radionuclides. Due to their cytotoxic, genotoxic and teratogenic properties, the exposure to these contaminants may cause several harmful effects in living organisms. The Fish Embryo Acute Toxicity Test (FET) test was employed to evaluate the genotoxic and teratogenic potential of mine liquid effluents and sludge elutriates from a deactivated uranium mine. The aims were: a) to determine the risk of discharge of such wastes in the environment; b) the effectiveness of the chemical treatment applied to the uranium mine water, which is a standard procedure generally applied to liquid effluents from uranium mines and mills, to reduce its toxicological potential; c) the suitability of the FET test for the evaluation the toxicity of such wastes and the added value of including the evaluation of genotoxicity. Results showed that through the FET test it was possible to determine that both elutriates and effluents are genotoxic and also that the mine effluent is teratogenic at low concentrations. Additionally, liquid effluents and sludge elutriates affect other parameters namely, growth and hatching and that water pH alone played an important role in the hatching process. The inclusion of genotoxicity evaluation in the FET test was crucial to prevent the underestimation of the risks posed by some of the tested effluents/elutriates. Finally, it was possible to conclude that care should be taken when using benchmark values calculated for specific stressors to evaluate the risk posed by uranium mining wastes to freshwater ecosystems, due to their chemical complexity. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Zebra: A striped network file system

    NASA Technical Reports Server (NTRS)

    Hartman, John H.; Ousterhout, John K.

    1992-01-01

    The design of Zebra, a striped network file system, is presented. Zebra applies ideas from log-structured file system (LFS) and RAID research to network file systems, resulting in a network file system that has scalable performance, uses its servers efficiently even when its applications are using small files, and provides high availability. Zebra stripes file data across multiple servers, so that the file transfer rate is not limited by the performance of a single server. High availability is achieved by maintaining parity information for the file system. If a server fails its contents can be reconstructed using the contents of the remaining servers and the parity information. Zebra differs from existing striped file systems in the way it stripes file data: Zebra does not stripe on a per-file basis; instead it stripes the stream of bytes written by each client. Clients write to the servers in units called stripe fragments, which are analogous to segments in an LFS. Stripe fragments contain file blocks that were written recently, without regard to which file they belong. This method of striping has numerous advantages over per-file striping, including increased server efficiency, efficient parity computation, and elimination of parity update.

  13. Bioassessment of mercury, cadmium, polychlorinated biphenyls, and pesticides in the upper Mississippi river with Zebra mussels (Dreissena polymorpha)

    USGS Publications Warehouse

    Cope, W. Gregory; Bartsch, Michelle; Rada, Ronald G.; Balogh, Steven J.; Rupprecht, John E.; Young, R. David; Johnson, D. Kent

    1999-01-01

    Zebra mussels (Dreissena polymorpha) were sampled from artificial substrates deployed from May 30 to October 19, 1995, at 19 locks and dams from Minneapolis, MN, to Muscatine, IA. Analyses of composite tissue samples of zebra mussels (10−20-mm length) revealed accumulation of mercury (Hg), cadmium (Cd), and polychlorinated biphenyls (PCBs) during a 143-d exposure period. Concentrations of total Hg ranged from 2.6 to 6.1 ng/g wet weight and methylmercury (CH3Hg) from 1.0 to 3.3 ng/g wet weight. About 50% (range 30−70%) of the mean total Hg in zebra mussels was CH3Hg. Cadmium ranged from 76 to 213 ng/g wet weight. Concentrations of total PCBs (Aroclor 1254) in zebra mussels varied longitudinally (range 1000−7330 ng/g lipid weight), but the composition of PCB congeners (total of 21 measured) was similar throughout the river. Chlordane and dieldrin were the only two pesticides detected of the 15 analyzed. Zebra mussels are sentinels of contaminant bioavailability in the Upper Mississippi River and may be an important link in the trophic transfer of contaminants in the river because of their increasing importance in the diets of certain fish and waterfowl.

  14. Gene duplication and fragmentation in the zebra finch major histocompatibility complex.

    PubMed

    Balakrishnan, Christopher N; Ekblom, Robert; Völker, Martin; Westerdahl, Helena; Godinez, Ricardo; Kotkiewicz, Holly; Burt, David W; Graves, Tina; Griffin, Darren K; Warren, Wesley C; Edwards, Scott V

    2010-04-01

    Due to its high polymorphism and importance for disease resistance, the major histocompatibility complex (MHC) has been an important focus of many vertebrate genome projects. Avian MHC organization is of particular interest because the chicken Gallus gallus, the avian species with the best characterized MHC, possesses a highly streamlined minimal essential MHC, which is linked to resistance against specific pathogens. It remains unclear the extent to which this organization describes the situation in other birds and whether it represents a derived or ancestral condition. The sequencing of the zebra finch Taeniopygia guttata genome, in combination with targeted bacterial artificial chromosome (BAC) sequencing, has allowed us to characterize an MHC from a highly divergent and diverse avian lineage, the passerines. The zebra finch MHC exhibits a complex structure and history involving gene duplication and fragmentation. The zebra finch MHC includes multiple Class I and Class II genes, some of which appear to be pseudogenes, and spans a much more extensive genomic region than the chicken MHC, as evidenced by the presence of MHC genes on each of seven BACs spanning 739 kb. Cytogenetic (FISH) evidence and the genome assembly itself place core MHC genes on as many as four chromosomes with TAP and Class I genes mapping to different chromosomes. MHC Class II regions are further characterized by high endogenous retroviral content. Lastly, we find strong evidence of selection acting on sites within passerine MHC Class I and Class II genes. The zebra finch MHC differs markedly from that of the chicken, the only other bird species with a complete genome sequence. The apparent lack of synteny between TAP and the expressed MHC Class I locus is in fact reminiscent of a pattern seen in some mammalian lineages and may represent convergent evolution. Our analyses of the zebra finch MHC suggest a complex history involving chromosomal fission, gene duplication and translocation in the

  15. The Effects of Zebra Mussels (Dreissena polymorpha) on the Foraging Success of Eurasian Perch (Perca fluviatilis) and Ruffe (Gymnocephalus cernuus)

    NASA Astrophysics Data System (ADS)

    Dieterich, Axel; Mörtl, Martin; Eckmann, Reiner

    2004-07-01

    Complex habitat structures can influence the foraging success of fish. Competition for food between fish species can therefore depend on the competitors' abilities to cope with structural complexity. In laboratory experiments, we comparatively assessed effects of zebra mussels (Dreissena polymorpha Pall.) on the foraging success of Eurasian perch (Perca fluviatilis L.) and ruffe (Gymnocephalus cernuus (L.)). In single-species and mixed-species experiments, the fish were fed caddisfly larvae (Tinodes waeneri (L.)) over complex (mussel-covered stones) and less-complex (bare stones) substrates. With intraspecific competition, food consumption by perch and ruffe decreased significantly when the complex substrate was used. With interspecific competition, food consumption by perch and ruffe did not change with substrate complexity, but perch clearly out-competed ruffe on both substrates. Zebra mussel beds provide a refuge for macrozoobenthos against predation by ruffe and probably also by perch. (

  16. Experimental evidence that stripes do not cool zebras.

    PubMed

    Horváth, Gábor; Pereszlényi, Ádám; Száz, Dénes; Barta, András; Jánosi, Imre M; Gerics, Balázs; Åkesson, Susanne

    2018-06-19

    There are as many as 18 theories for the possible functions of the stripes of zebras, one of which is to cool the animal. We performed field experiments and thermographic measurements to investigate whether thermoregulation might work for zebra-striped bodies. A zebra body was modelled by water-filled metal barrels covered with horse, cattle and zebra hides and with various black, white, grey and striped patterns. The barrels were installed in the open air for four months while their core temperature was measured continuously. Using thermography, the temperature distributions of the barrel surfaces were compared to those of living zebras. The sunlit zebra-striped barrels reproduced well the surface temperature characteristics of sunlit zebras. We found that there were no significant core temperature differences between the striped and grey barrels, even on many hot days, independent of the air temperature and wind speed. The average core temperature of the barrels increased as follows: white cattle, grey cattle, real zebra, artificial zebra, grey horse, black cattle. Consequently, we demonstrate that zebra-striped coats do not keep the body cooler than grey coats challenging the hypothesis of a thermoregulatory role of zebra stripes.

  17. Dynamics of zebra finch and mockingbird vocalizations

    NASA Astrophysics Data System (ADS)

    Cimenser, Aylin

    Along with humans, whales, and bats, three groups of birds which include songbirds (oscines) such as the Zebra Finch (Taeniopygia guttata) and Mockingbird (Mimus polyglottos) are the only creatures known to learn sounds by imitation. Numerous similarities between human and songbird vocalizations exist and, recently, it has been shown that Zebra Finch in particular possesses a gene, FoxP2, known to be involved in human language. This thesis investigates song development in Zebra Finches, as well as the temporal dynamics of song in Mockingbirds. Zebra Finches have long been the system of choice for studying vocal development, ontogeny, and complexity in birdsong. Physicists find them intriguing because the spectrally complex vocalizations of the Zebra Finch can exhibit sudden transitions to chaotic dynamics, period doubling & mode-locking phenomena. Mockingbirds, by contrast, provide an ideal system to examine the richness of an avian repertoire, since these musically versatile songbirds typically know upwards of 200 songs. To analyse birdsong data, we have developed a novel clustering algorithm that can be applied to the bird's syllables, tracing their dynamics back to the earliest stages of vocal development. To characterize birdsong we have used Fourier techniques, based upon multitaper spectral analysis, to optimally work around the constraints imposed by (Heisenberg's) time-frequency uncertainty principle. Furthermore, estimates that provide optimal compromise between frequency and temporal resolution have beautiful connections with solutions to the Helmholtz wave equation in prolate spheroidal coordinates. We have used this connection to provide firm foundation for certain heuristics used in the literature to compute associated spectral derivatives and supply a pedagogical account here in this thesis. They are of interest because spectral derivatives emphasize sudden changes in the dynamics of the underlying phenomenon, and often provide a nice way to visualize

  18. Evaluating the Zebrafish Embryo Toxicity Test for Pesticide ...

    EPA Pesticide Factsheets

    Given the numerous chemicals used in society, it is critical to develop tools for accurate and efficient evaluation of potential risks to human and ecological receptors. Fish embryo acute toxicity tests are 1 tool that has been shown to be highly predictive of standard, more resource-intensive, juvenile fish acute toxicity tests. However, there is also evidence that fish embryos are less sensitive than juvenile fish for certain types of chemicals, including neurotoxicants. The utility of fish embryos for pesticide hazard assessment was investigated by comparing published zebrafish embryo toxicity data from pesticides with median lethal concentration 50% (LC50) data for juveniles of 3 commonly tested fish species: rainbow trout, bluegill sunfish, and sheepshead minnow. A poor, albeit significant, relationship (r2 = 0.28; p < 0.05) was found between zebrafish embryo and juvenile fish toxicity when pesticides were considered as a single group, but a much better relationship (r2 = 0.64; p < 0.05) when pesticide mode of action was factored into an analysis of covariance. This discrepancy is partly explained by the large number of neurotoxic pesticides in the dataset, supporting previous findings that commonly used fish embryo toxicity test endpoints are particularly insensitive to neurotoxicants. These results indicate that it is still premature to replace juvenile fish toxicity tests with embryo-based tests such as the Organisation for Economic Co-op

  19. Appraisal of unimodal cues during agonistic interactions in Maylandia zebra

    PubMed Central

    Ben Ammar, Imen; Fernandez, Marie S.A.; Boyer, Nicolas; Attia, Joël; Fonseca, Paulo J.; Amorim, M. Clara P.; Beauchaud, Marilyn

    2017-01-01

    Communication is essential during social interactions including animal conflicts and it is often a complex process involving multiple sensory channels or modalities. To better understand how different modalities interact during communication, it is fundamental to study the behavioural responses to both the composite multimodal signal and each unimodal component with adequate experimental protocols. Here we test how an African cichlid, which communicates with multiple senses, responds to different sensory stimuli in a social relevant scenario. We tested Maylandia zebra males with isolated chemical (urine or holding water coming both from dominant males), visual (real opponent or video playback) and acoustic (agonistic sounds) cues during agonistic interactions. We showed that (1) these fish relied mostly on the visual modality, showing increased aggressiveness in response to the sight of a real contestant but no responses to urine or agonistic sounds presented separately, (2) video playback in our study did not appear appropriate to test the visual modality and needs more technical prospecting, (3) holding water provoked territorial behaviours and seems to be promising for the investigation into the role of the chemical channel in this species. Our findings suggest that unimodal signals are non-redundant but how different sensory modalities interplay during communication remains largely unknown in fish. PMID:28785523

  20. Zebras and Biting Flies: Quantitative Analysis of Reflected Light from Zebra Coats in Their Natural Habitat

    PubMed Central

    Britten, Kenneth H.; Thatcher, Timothy D.; Caro, Tim

    2016-01-01

    Experimental and comparative evidence suggests that the striped coats of zebras deter biting fly attack, but the mechanisms by which flies fail to target black-and-white mammals are still opaque. Two hypotheses have been proposed: stripes might serve either to defeat polarotaxis or to obscure the form of the animal. To test these hypotheses, we systematically photographed free-living plains zebras in Africa. We found that black and white stripes both have moderate polarization signatures with a similar angle, though the degree (magnitude) of polarization in white stripes is lower. When we modeled the visibility of these signals from different distances, we found that polarization differences between stripes are invisible to flies more than 10 m away because they are averaged out by the flies’ low visual resolution. At any distance, however, a positively polarotactic insect would have a distinct signal to guide its visual approach to a zebra because we found that polarization of light reflecting from zebras is higher than from surrounding dry grasses. We also found that the stripes themselves are visible to flies at somewhat greater distances (up to 20 m) than the polarization contrast between stripes. Together, these observations support hypotheses in which zebra stripes defeat visually guided orienting behavior in flies by a mechanism independent of polarotaxis. PMID:27223616

  1. Zebra Mussel Chemical Control Guide.

    DTIC Science & Technology

    2000-01-01

    References 80 Aromatic Hydrocarbons 82 BULAB6009 82 Chemical Name and Formulations 82 Mode of Action 82 Application Strategies 82 Timing of Application...organisms once they are bound to anionic substances (Dobbs et al. 1995). b. Aromatic hydrocarbons . Compounds such as BULAB® 6009 and MEXEL 432™ also...Pallas): A new mollusc in the Great Lakes," Can. J. FishAquat. Sei. 46, 1587-1591. Heitanen, E. (1997). "Toxicity testing of Endod, a natural

  2. Locally extensive meningoencephalitis caused by Miamiensis avidus (syn. Philasterides dicentrarchi) in a zebra shark.

    PubMed

    Li, Wen-Ta; Lo, Chieh; Su, Chen-Yi; Kuo, Hsuan; Lin, Susanne Je-Han; Chang, Hui-Wei; Pang, Victor Fei; Jeng, Chian-Ren

    2017-10-18

    Scuticociliatosis, caused by ciliated protozoa in the subclass Scuticociliatia of the phylum Ciliophora, can cause fatal disease in teleost fish species. However, information on scuticociliatosis in elasmobranchs is still scarce. In this report, we describe a case of locally extensive meningoencephalitis caused by Miamiensis avidus (syn. Philasterides dicentrarchi) in a 2 yr old captive zebra shark Stegostoma fasciatum. Granulocytic meningoencephalitis was observed through histological assessment. Inflammation was confined to the ventral aspect of the brain with a large number of ciliated protozoa, transforming into non-suppurative meningitis in the lateral aspect, and gradually vanished in the dorsal aspect. No histopathological and polymerase chain reaction (PCR) evidence of systemic dissemination of M. avidus was found. PCR targeting the gene coding the small-subunit ribosomal RNA (SSUrRNA) of M. avidus was performed on the brain, liver, and gill tissues, and only brain tissue yielded a positive result. The DNA sequences from amplicons of the protozoal SSUrRNA gene were completely matched to that of M. avidus. The distribution of protozoa in the current case was mainly located in the brain and suggests the possibility of a direct neural invasive pathway of M. avidus through the nasal cavity/ampullary system and/or a unique tissue tropism of M. avidus specific to the brain in zebra sharks. Further investigations on the pathogenesis of M. avidus in elasmobranchs, especially zebra sharks, are needed.

  3. Comparative Cytogenetics between Two Important Songbird, Models: The Zebra Finch and the Canary

    PubMed Central

    dos Santos, Michelly da Silva; Kretschmer, Rafael; Frankl-Vilches, Carolina; Bakker, Antje; Gahr, Manfred; O´Brien, Patricia C. M.; Ferguson-Smith, Malcolm A.

    2017-01-01

    Songbird species (order Passeriformes, suborder Oscines) are important models in various experimental fields spanning behavioural genomics to neurobiology. Although the genomes of some songbird species were sequenced recently, the chromosomal organization of these species is mostly unknown. Here we focused on the two most studied songbird species in neuroscience, the zebra finch (Taeniopygia guttata) and the canary (Serinus canaria). In order to clarify these issues and also to integrate chromosome data with their assembled genomes, we used classical and molecular cytogenetics in both zebra finch and canary to define their chromosomal homology, localization of heterochromatic blocks and distribution of rDNA clusters. We confirmed the same diploid number (2n = 80) in both species, as previously reported. FISH experiments confirmed the occurrence of multiple paracentric and pericentric inversions previously found in other species of Passeriformes, providing a cytogenetic signature for this order, and corroborating data from in silico analyses. Additionally, compared to other Passeriformes, we detected differences in the zebra finch karyotype concerning the morphology of some chromosomes, in the distribution of 5S rDNA clusters, and an inversion in chromosome 1. PMID:28129381

  4. Strong effects of predation by fishes on an invasive macroinvertebrate in a large floodplain river

    USGS Publications Warehouse

    Bartsch, M.R.; Bartsch, L.A.; Gutreuter, S.

    2005-01-01

    We assessed the effects of fish predation on zebra mussels (Dreissena polymorpha) in Navigation Pool 8 of the Upper Mississippi River from 13 May to 5 October, 1998. Concrete-block samplers were deployed at 18 randomly chosen sites in the main-channel border, with 6 sites in the upper, middle, and lower segments of the pool. Two blocks, 1 of which was enclosed in a cage to exclude large predatory fishes, were deployed at each site. After 145 d, blocks were retrieved from 12 of the 18 sites, and zebra mussels were found on all blocks. Densities of zebra mussels were higher on caged blocks than uncaged blocks, and the magnitudes of the differences varied spatially. Mean mussel densities on uncaged blocks were reduced by 66%, 86%, and 20% compared to caged blocks in the upper, middle, and lower pool segments, respectively, over the 145-d interval. Mean daily instantaneous zebra mussel mortality rates from large predators ranged from 0.0016 to 0.0138. Similarly, biomass of zebra mussels was higher on caged than uncaged blocks. Mean mussel biomass on uncaged blocks was reduced by 64% pool-wide, relative to biomass on caged blocks. Zebra mussels were consumed by at least 6 fish taxa including redhorse stickers (Moxostoma spp.), common carp (Cyprinus carpio), bluegill (Lepomis macrochirus), quillback carpsucker (Carpiodes cyprinus), flathead catfish (Pylodictis olivaris), and freshwater drum (Aplodinotus grunniens). Fish predation had an important moderating effect on zebra mussel demography in Pool 8.

  5. Evaluating the zebrafish embryo toxicity test for pesticide hazard screening.

    PubMed

    Glaberman, Scott; Padilla, Stephanie; Barron, Mace G

    2017-05-01

    Given the numerous chemicals used in society, it is critical to develop tools for accurate and efficient evaluation of potential risks to human and ecological receptors. Fish embryo acute toxicity tests are 1 tool that has been shown to be highly predictive of standard, more resource-intensive, juvenile fish acute toxicity tests. However, there is also evidence that fish embryos are less sensitive than juvenile fish for certain types of chemicals, including neurotoxicants. The utility of fish embryos for pesticide hazard assessment was investigated by comparing published zebrafish embryo toxicity data from pesticides with median lethal concentration 50% (LC50) data for juveniles of 3 commonly tested fish species: rainbow trout, bluegill sunfish, and sheepshead minnow. A poor, albeit significant, relationship (r 2  = 0.28; p < 0.05) was found between zebrafish embryo and juvenile fish toxicity when pesticides were considered as a single group, but a much better relationship (r 2  = 0.64; p < 0.05) when pesticide mode of action was factored into an analysis of covariance. This discrepancy is partly explained by the large number of neurotoxic pesticides in the dataset, supporting previous findings that commonly used fish embryo toxicity test endpoints are particularly insensitive to neurotoxicants. These results indicate that it is still premature to replace juvenile fish toxicity tests with embryo-based tests such as the Organisation for Economic Co-operation and Development Fish Embryo Acute Toxicity Test for routine pesticide hazard assessment, although embryo testing could be used with other screening tools for testing prioritization. Environ Toxicol Chem 2017;36:1221-1226. © 2016 SETAC. © 2016 SETAC.

  6. Invasion of the Zebra Mussels: A Mock Trial Activity

    ERIC Educational Resources Information Center

    Beck, Judy A.; Czerniak, Charlene M.

    2005-01-01

    In this activity, students learn about the important topic of invasive species, specifically Zebra Mussels. Students role-play different characters in a real-life situation: the trial of the Zebra Mussel for unlawful disruption of the Great Lakes ecosystem. Students will also learn about jurisprudential inquiry by examining the trial process. This…

  7. Gene duplication and fragmentation in the zebra finch major histocompatibility complex

    PubMed Central

    2010-01-01

    Background Due to its high polymorphism and importance for disease resistance, the major histocompatibility complex (MHC) has been an important focus of many vertebrate genome projects. Avian MHC organization is of particular interest because the chicken Gallus gallus, the avian species with the best characterized MHC, possesses a highly streamlined minimal essential MHC, which is linked to resistance against specific pathogens. It remains unclear the extent to which this organization describes the situation in other birds and whether it represents a derived or ancestral condition. The sequencing of the zebra finch Taeniopygia guttata genome, in combination with targeted bacterial artificial chromosome (BAC) sequencing, has allowed us to characterize an MHC from a highly divergent and diverse avian lineage, the passerines. Results The zebra finch MHC exhibits a complex structure and history involving gene duplication and fragmentation. The zebra finch MHC includes multiple Class I and Class II genes, some of which appear to be pseudogenes, and spans a much more extensive genomic region than the chicken MHC, as evidenced by the presence of MHC genes on each of seven BACs spanning 739 kb. Cytogenetic (FISH) evidence and the genome assembly itself place core MHC genes on as many as four chromosomes with TAP and Class I genes mapping to different chromosomes. MHC Class II regions are further characterized by high endogenous retroviral content. Lastly, we find strong evidence of selection acting on sites within passerine MHC Class I and Class II genes. Conclusion The zebra finch MHC differs markedly from that of the chicken, the only other bird species with a complete genome sequence. The apparent lack of synteny between TAP and the expressed MHC Class I locus is in fact reminiscent of a pattern seen in some mammalian lineages and may represent convergent evolution. Our analyses of the zebra finch MHC suggest a complex history involving chromosomal fission, gene

  8. Molecular ecology of zebra mussel invasions.

    PubMed

    May, Gemma E; Gelembiuk, Gregory W; Panov, Vadim E; Orlova, Marina I; Lee, Carol Eunmi

    2006-04-01

    The invasion of the zebra mussel, Dreissena polymorpha, into North American waters has resulted in profound ecological disturbances and large monetary losses. This study examined the invasion history and patterns of genetic diversity among endemic and invading populations of zebra mussels using DNA sequences from the mitochondrial cytochrome oxidase I (COI) gene. Patterns of haplotype frequency indicate that all invasive populations of zebra mussels from North America and Europe originated from the Ponto-Caspian Sea region. The distribution of haplotypes was consistent with invasive populations arising from the Black Sea drainage, but could not exclude the possibility of an origin from the Caspian Sea drainage. Similar haplotype frequencies among North American populations of D. polymorpha suggest colonization by a single founding population. There was no evidence of invasive populations arising from tectonic lakes in Turkey, while lakes in Greece and Macedonia contained only Dreissena stankovici. Populations in Turkey might be members of a sibling species complex of D. polymorpha. Ponto-Caspian derived populations of D. polymorpha (theta = 0.0011) and Dreissena bugensis (one haplotype) exhibited low levels of genetic diversity at the COI gene, perhaps as a result of repeated population bottlenecks. In contrast, geographically isolated tectonic lake populations exhibited relatively high levels of genetic diversity (theta = 0.0032 to 0.0134). It is possible that the fluctuating environment of the Ponto-Caspian basin facilitated the colonizing habit of invasive populations of D. polymorpha and D. bugensis. Our findings were concordant with the general trend of destructive freshwater invaders in the Great Lakes arising from the Ponto-Caspian Sea basin.

  9. Environmentally Safe Control of Zebra Mussel Fouling

    SciTech Connect

    Daniel Molloy

    2008-02-29

    The two primary objectives of this USDOE-NETL contract were successfully achieved during the project: (1) to accelerate research on the development of the bacterium Pseudomonas fluorescens strain CL145A (Pf-CL145A) as a biocontrol agent for zebra mussels (Dreissena polymorpha) and quagga mussels (Dreissena rostriformis bugensis)--two invasive freshwater bivalve species that are infesting water pipes in power plants; and (2) to identify a private-sector company that would move forward to commercialize Pf-CL145A as a substitute for the current polluting use of biocide chemicals for control of these dreissenid mussels in power plant pipes.

  10. Identification of larvae: The zebra mussel (Dreissena polymorpha), quagga mussel (Dreissena rosteriformis bugensis), and Asian clam (Corbicula fluminea)

    USGS Publications Warehouse

    Nichols, S. Jerrine; Black, M.G.

    1994-01-01

    There are presently four freshwater bivalves in the United States that produce larvae or veligers commonly found in the water column: two forms of Asian clams and two species of dreissenids. Portions of the geographic range of three of these bivalves, one species of Asian clam (Corbicula fluminea), zebra mussels (Dreissena polymorpha), and quagga mussels (Dreissena rosteriformis bugensis), overlap, causing problems with larval identification. To determine which characteristics can be used to separate larval forms, adult Asian clams, quaggas, and zebra mussels were brought into the laboratory and induced to spawn, and the resulting larvae were reared. Hybrids between quaggas and zebra mussels were also produced, but not reared to maturity. Characteristics allowing for the most rapid and accurate separation of larvae were hinge length, shell length/height, shell shape, shell size, and the presence or absence of a foot and velum. These characteristics were observed in laboratory-reared larvae of known parentage and field-caught larvae of unknown parentage. In most cases, larvae of the Asian clam can be readily separated from those produced by either type of dreissenid on the basis of shell size and presence of a foot. Separating the gametes and embryos of the two types of dreissenids is not possible, but after shell formation, most of the larval stages can be distinguished. Hinge length, shell length/height, and the similarity in size of the shell valves can be used to separate straight-hinged, umbonal, pediveliger, and plantigrade larvae. Quagga × zebra mussel hybrids show characteristics of both parents and are difficult to identify.

  11. Zebra mussel infestation of unionid bivalves (Unionidae) in North America

    USGS Publications Warehouse

    Schloesser, Don W.; Nalepa, Thomas F.; Mackie, Gerald L.

    1996-01-01

    In 1989, zebra mussels received national attention in North America when they reached densities exceeding 750,000/m2 in a water withdrawal facility along the shore of western Lake Erie of the Laurentian Great Lakes. Although water withdrawal problems caused by zebra mussels have been of immediate concern, ecological impacts attributed to mussels are likely to be the more important long-term issue for surface waters in North America. To date, the epizoic colonization (i.e., infestation) of unionid bivalve mollusks by zebra mussels has caused the most direct and severe ecological impact. Infestation of and resulting impacts caused by zebra mussels on unionids in the Great Lakes began in 1988. By 1990, mortality of unionids was occurring at some locations; by 1991, extant populations of unionids in western Lake Erie were nearly extirpated; by 1992, unionid populations in the southern half of Lake St. Clair were extirpated; by 1993, unionids in widely separated geographic areas of the Great Lakes and the Mississippi River showed high mortality due to mussel infestation. All infested unionid species in the Great Lakes (23) have become infested and exhibited mortality within two to four years after heavy infestation began. Data indicate that mean zebra mussel densities >5,000–6,000/m2 and infestation intensities >100-200/unionid in the presence of heavy zebra mussel recruitment results in near total mortality of unionids. At present, all unionid species in rivers, streams, and akes that sympatrically occur with zebra mussels have been infested and, in many locations, negatively impacted by zebra mussels. We do not know the potential consequences of infestation on the 297 unionid species found in North America, but believe zebra mussels pose an immediate threat to the abundance and diversity of unionids.

  12. Crayfish (Orconectes virilis) predation on zebra mussels (Dreissena polymorpha)

    USGS Publications Warehouse

    Love, Joy; Savino, Jacqueline F.

    1993-01-01

    In laboratory studies, we quantified predation rates and handling time of crayfish (Orconectes virilis) on zebra mussels (Dreissena polymorpha) and rainbow trout (Oncorhhynchus mykiss) eggs. In single prey species tests, crayfish ate zebra mussels at similar rates as they ate rainbow trout eggs. When both prey were present, crayfish preferred rainbow trout eggs. Handling time of mussels was about twice that of rainbow trout eggs, and energetic content of mussels was lower. Therefore, net benefit for foraging on rainbow trout eggs was about three times that of foraging on zebra mussels.

  13. A food web modeling analysis of a Midwestern, USA eutrophic lake dominated by non-native Common Carp and Zebra Mussels

    USGS Publications Warehouse

    Colvin, Michael E.; Pierce, Clay; Stewart, Timothy W.

    2015-01-01

    Food web modeling is recognized as fundamental to understanding the complexities of aquatic systems. Ecopath is the most common mass-balance model used to represent food webs and quantify trophic interactions among groups. We constructed annual Ecopath models for four consecutive years during the first half-decade of a zebra mussel invasion in shallow, eutrophic Clear Lake, Iowa, USA, to evaluate changes in relative biomass and total system consumption among food web groups, evaluate food web impacts of non-native common carp and zebra mussels on food web groups, and to interpret food web impacts in light of on-going lake restoration. Total living biomass increased each year of the study; the majority of the increase due to a doubling in planktonic blue green algae, but several other taxa also increased including a more than two-order of magnitude increase in zebra mussels. Common carp accounted for the largest percentage of total fish biomass throughout the study even with on-going harvest. Chironomids, common carp, and zebra mussels were the top-three ranking consumer groups. Non-native common carp and zebra mussels accounted for an average of 42% of the total system consumption. Despite the relatively high biomass densities of common carp and zebra mussel, food web impacts was minimal due to excessive benthic and primary production in this eutrophic system. Consumption occurring via benthic pathways dominated system consumption in Clear Lake throughout our study, supporting the argument that benthic food webs are significant in shallow, eutrophic lake ecosystems and must be considered if ecosystem-level understanding is to be obtained.

  14. Miniaturized Embryo Array for Automated Trapping, Immobilization and Microperfusion of Zebrafish Embryos

    PubMed Central

    Akagi, Jin; Khoshmanesh, Khashayar; Evans, Barbara; Hall, Chris J.; Crosier, Kathryn E.; Cooper, Jonathan M.; Crosier, Philip S.; Wlodkowic, Donald

    2012-01-01

    Zebrafish (Danio rerio) has recently emerged as a powerful experimental model in drug discovery and environmental toxicology. Drug discovery screens performed on zebrafish embryos mirror with a high level of accuracy the tests usually performed on mammalian animal models, and fish embryo toxicity assay (FET) is one of the most promising alternative approaches to acute ecotoxicity testing with adult fish. Notwithstanding this, automated in-situ analysis of zebrafish embryos is still deeply in its infancy. This is mostly due to the inherent limitations of conventional techniques and the fact that metazoan organisms are not easily susceptible to laboratory automation. In this work, we describe the development of an innovative miniaturized chip-based device for the in-situ analysis of zebrafish embryos. We present evidence that automatic, hydrodynamic positioning, trapping and long-term immobilization of single embryos inside the microfluidic chips can be combined with time-lapse imaging to provide real-time developmental analysis. Our platform, fabricated using biocompatible polymer molding technology, enables rapid trapping of embryos in low shear stress zones, uniform drug microperfusion and high-resolution imaging without the need of manual embryo handling at various developmental stages. The device provides a highly controllable fluidic microenvironment and post-analysis eleuthero-embryo stage recovery. Throughout the incubation, the position of individual embryos is registered. Importantly, we also for first time show that microfluidic embryo array technology can be effectively used for the analysis of anti-angiogenic compounds using transgenic zebrafish line (fli1a:EGFP). The work provides a new rationale for rapid and automated manipulation and analysis of developing zebrafish embryos at a large scale. PMID:22606275

  15. Zebra mussel beds: an effective feeding ground for Ponto-Caspian gobies or suitable shelter for their prey?

    PubMed

    Kobak, Jarosław; Poznańska, Małgorzata; Jermacz, Łukasz; Kakareko, Tomasz; Prądzynski, Daniel; Łodygowska, Małgorzata; Montowska, Karolina; Bącela-Spychalska, Karolina

    2016-01-01

    Aggregations of the Ponto-Caspian invasive zebra mussel ( Dreissena polymorpha ) constitute a suitable habitat for macroinvertebrates, considerably increasing their abundance and providing effective antipredator protection. Thus, the overall effect of a mussel bed on particular predator species may vary from positive to negative, depending on both prey density increase and predator ability to prey in a structurally complex habitat. Alien Ponto-Caspian goby fish are likely to be facilitated when introduced into new areas by zebra mussels, provided that they are capable of utilizing mussel beds as habitat and feeding grounds. We ran laboratory experiments to find which prey (chironomid larvae) densities (from ca. 500 to 2,000 individuals m -2 ) in a mussel bed make it a more beneficial feeding ground for the racer goby Babka gymnotrachelus (RG) and western tubenose goby Proterorhinus semilunaris (WTG) compared to sandy and stone substrata (containing the basic prey density of 500 ind. m -2 ). Moreover, we checked how food availability affects habitat selection by fish. Mussel beds became more suitable for fish than alternative mineral substrata when food abundance was at least two times higher (1,000 vs. 500 ind. m -2 ), regardless of fish size and species. WTG was associated with mussel beds regardless of its size and prey density, whereas RG switched to this habitat when it became a better feeding ground than alternative substrata. Larger RG exhibited a stronger affinity for mussels than small individuals. WTG fed more efficiently from a mussel bed at high food abundances than RG. A literature review has shown that increasing chironomid density, which in our study was sufficient to make a mussel habitat an attractive feeding ground for the gobies, is commonly observed in mussel beds in the field. Therefore, we conclude that zebra mussels may positively affect the alien goby species and are likely to facilitate their establishment in novel areas, contributing to an

  16. Chromosome analysis in embryos from young patients with previous parity.

    PubMed

    Kilani, Z; Magli, Mc; Qaddomi, E; Ferraretti, Ap; Shaban, M; Crippa, A; Haj Hassan, L; Shenfield, F; Gianaroli, L

    2014-09-01

    This study included 173 young couples of proven fertility who had previously undergone preimplantation genetic screening for chromosomes X and Y for family balancing. Several months later, when the outcome of the pregnancies was already known, the blastomeres from the corresponding embryos transferred were reanalysed by fluorescence in-situ hybridization (FISH) for chromosomes 13, 16, 18, 21, 22 with the aim of investigating correlation with embryo viability and the level of FISH sensitivity (embryos confirmed to be euploid). According to the results, informative in 152 couples, the proportion of euploid embryos was significantly lower in 53 nonpregnant women when compared with 99 women with term pregnancy (49% versus 75% respectively, P < 0.001). In addition, in 21 nonpregnant patients, all embryos transferred were found to be chromosomally abnormal. The level of FISH sensitivity was calculated in the group of term pregnancies where the number of euploid embryos was expected to exceed or match with the number of babies born. The resulting false-negative rate was 4.0% per patient and 1.9% per embryo. These findings confirmed the limited prediction power of embryo morphology on implantation but also the relevance of chromosomal abnormalities in causing embryo demise. Copyright © 2014 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  17. The fish embryo toxicity test as a replacement for the larval growth and survival test: A comparison of test sensitivity and identification of alternative endpoints in zebrafish and fathead minnows.

    PubMed

    Jeffries, Marlo K Sellin; Stultz, Amy E; Smith, Austin W; Stephens, Dane A; Rawlings, Jane M; Belanger, Scott E; Oris, James T

    2015-06-01

    The fish embryo toxicity (FET) test has been proposed as an alternative to the larval growth and survival (LGS) test. The objectives of the present study were to evaluate the sensitivity of the FET and LGS tests in fathead minnows (Pimephales promelas) and zebrafish (Danio rerio) and to determine if the inclusion of sublethal metrics as test endpoints could enhance test utility. In both species, LGS and FET tests were conducted using 2 simulated effluents. A comparison of median lethal concentrations determined via each test revealed significant differences between test types; however, it could not be determined which test was the least and/or most sensitive. At the conclusion of each test, developmental abnormalities and the expression of genes related to growth and toxicity were evaluated. Fathead minnows and zebrafish exposed to mock municipal wastewater-treatment plant effluent in a FET test experienced an increased incidence of pericardial edema and significant alterations in the expression of genes including insulin-like growth factors 1 and 2, heat shock protein 70, and cytochrome P4501A, suggesting that the inclusion of these endpoints could enhance test utility. The results not only show the utility of the fathead minnow FET test as a replacement for the LGS test but also provide evidence that inclusion of additional endpoints could improve the predictive power of the FET test. © 2015 SETAC.

  18. Control Strategies for Zebra Mussel Infestations at Public Facilities

    DTIC Science & Technology

    1992-07-01

    detailed examina- tion of hard -to-reach surfaces or specific components (such as fire protection systems or intake pipes for sensor devices) should...trash racks. Trash racks could become partially clogged with zebra mussels, shells , and other debris. Flow through the openings would be reduced, and... shells to the top of the lock wall. These are now used by Ontario Hydro for removing zebra mussels. At most facilities, the culvert is totally dewatered

  19. Evaluation of cytotoxicity, genotoxicity and teratogenicity of marine sediments from Qingdao coastal areas using in vitro fish cell assay, comet assay and zebrafish embryo test.

    PubMed

    Yang, Fan; Zhang, Qianqian; Guo, Huarong; Zhang, Shicui

    2010-10-01

    Marine sediments are often a final sink for numerous anthropogenic contaminants and may impose serious effects on benthic organisms and ecosystem. An in vitro cell assay using a cell line derived from flounder gill (FG) cells, an in vitro comet assay in FG cells, and an in vitro zebrafish embryo assay were used to evaluate the in vitro cytotoxicity (measured by MTT reduction), genotoxicity and teratogenicity of crude sediment extracts of Li Cang (LC), Zhan Qiao (ZQ) and Olympic Sailing Center (OSC) from Qingdao coastal area. Sediments from the three sites displayed different cytotoxicity, genotoxicity and teratogenicity potencies; however, all three assays yielded similar LOECs (lowest observed effect concentration) for each site, suggesting that the assays were equally sensitive to and suitable for initial screening of the LOECs of marine sediments. The cytotoxicity, genotoxicity and teratogenicity for these three sampling sites were in the same order of LC>ZQ>OSC, indicating different degrees of contamination. Interestingly, trials with the three sediment extracts at the doses inducing a similar cytotoxicity as evaluated with MTT reduction did not produce similar genotoxicity and teratogenicity, with the genotoxic and teratogenic activities of LC and ZQ extracts being markedly higher than those of OSC sediments. These findings indicate that cytotoxicity does not form a fully equivalent toxicity index with that of genotoxicity and teratogenicity. Therefore, in order to assess the true toxic potential of marine sediments, all three assays should be performed. Analysis of 16 EPA (US Environmental Protection Agency) priority PAHs in these three sediment samples showed a clear correlation between PAH concentrations and sediment toxicities, with a higher PAH content corresponding to higher toxicity although PAHs are surely not the only cause. Copyright © 2010 Elsevier Ltd. All rights reserved.

  20. Long-depth imaging of specific gene expressions in whole-mount mouse embryos with single-photon excitation confocal fluorescence microscopy and FISH.

    PubMed

    Palmes-Saloma, C; Saloma, C

    2000-07-01

    Long-depth imaging of specific gene expression in the midgestation whole-mount mouse embryo (WME) is demonstrated with single-photon excitation (1PE) confocal fluorescence microscopy and fluorescence in situ hybridization. Expression domains of Pax-6 mRNA transcripts were labeled with an in situ hybridization probe that is a RNA sequence complementary to the cloned gene fragment and were rendered visible using two fluorochrome-conjugated antibodies that fluoresce at peak wavelengths of lambda(F) = 0.525 microm and lambda(F) = 0. 580 microm, respectively. Distributions of Pax-6 mRNA domains as deep as 1000 microm in the day 9.5 WME were imaged with a long-working-distance (13.6 mm) objective lens (magnification 5x). The scattering problem posed by the optically thick WME sample is alleviated by careful control of the detector pinhole size and the application of simple but fast postdetection image enhancement techniques, such as space and wavelength averaging to produce high-quality fluorescence images. A three-dimensional reconstruction that clearly shows the Pax-6 mRNA expression domains in the forebrain, diencephalon, optic cup, and spinal cord of the day 9.5 WME is obtained. The advantages of 1PE confocal fluorescence imaging over two-photon excitation fluorescence imaging are discussed for the case of long-depth imaging in highly scattering media. Imaging in midgestation WMEs at optical depths of more than 350 microm has not yet been realized with two-photon fluorescence excitation. Copyright 2000 Academic Press.

  1. Full genome sequences of zebra-borne equine herpesvirus type 1 isolated from zebra, onager and Thomson's gazelle.

    PubMed

    Guo, Xiaoqin; Izume, Satoko; Okada, Ayaka; Ohya, Kenji; Kimura, Takashi; Fukushi, Hideto

    2014-09-01

    A strain of equine herpesvirus type 1 (EHV-1) was isolated from zebra. This strain, called "zebra-borne EHV-1", was also isolated from an onager and a gazelle in zoological gardens in U.S.A. The full genome sequences of the 3 strains were determined. They shared 99% identities with each other, while they shared 98% and 95% identities with the horse derived EHV-1 and equine herpesvirus type 9, respectively. Sequence data indicated that the EHV-1 isolated from a polar bear in Germany is one of the zebra-borne EHV-1 and not a recombinant virus. These results indicated that zebra-borne EHV-1 is a subtype of EHV-1.

  2. Zebra: An advanced PWR lattice code

    SciTech Connect

    Cao, L.; Wu, H.; Zheng, Y.

    2012-07-01

    This paper presents an overview of an advanced PWR lattice code ZEBRA developed at NECP laboratory in Xi'an Jiaotong Univ.. The multi-group cross-section library is generated from the ENDF/B-VII library by NJOY and the 361-group SHEM structure is employed. The resonance calculation module is developed based on sub-group method. The transport solver is Auto-MOC code, which is a self-developed code based on the Method of Characteristic and the customization of AutoCAD software. The whole code is well organized in a modular software structure. Some numerical results during the validation of the code demonstrate that this code has a good precisionmore » and a high efficiency. (authors)« less

  3. USGS Zebra Mussel Monitoring Program for north Texas

    USGS Publications Warehouse

    Churchill, Christopher J.; Baldys, Stanley

    2012-01-01

    The U.S. Geological Survey (USGS) Zebra Mussel Monitoring Program for north Texas provides early detection and monitoring of zebra mussels (Dreissena polymorpha) by using a holistic suite of detection methods. The program is designed to assess zebra mussel occurrence, distribution, and densities in north Texas waters by using four approaches: (1) SCUBA diving, (2) water-sample collection with plankton tow nets (followed by laboratory analyses), (3) artificial substrates, and (4) water-quality sampling. Data collected during this type of monitoring can assist rapid response efforts and can be used to quantify the economic and ecological effects of zebra mussels in the north Texas area. Monitoring under this program began in April 2010. The presence of large zebra mussel populations often causes undesirable economic and ecological effects, including damage to water-processing infrastructure and hydroelectric powerplants (with an estimated 10-year cost of $3.1 billion), displacement of native mussels, increases in concentrations of certain species of cyanobacteria, and increases in concentrations of geosmin (an organic compound that results in taste and odor issues in water). Since no large-scale, environmentally safe eradication method has been developed for zebra mussels, it is difficult to remove established populations. Broad physicochemical adaptability, prolific reproductive capacity, and rapid dispersal methods have enabled zebra mussels, within a period of about 20 years, to establish populations under differing environmental conditions across much of the eastern part of the United States. In Texas, the presence of zebra mussels was first confirmed in April 2009 in Lake Texoma in the Red River Basin along the Texas-Oklahoma border. They were most likely introduced into Lake Texoma through overland transport from an infested water body. Since then, the presence of zebra mussels has been reported in both the Red River and Washita River arms of Lake Texoma, in

  4. Stimulatory and inhibitory mechanisms of slow muscle-specific myosin heavy chain gene expression in fish: Transient and transgenic analysis of torafugu MYH{sub M86-2} promoter in zebrafish embryos

    SciTech Connect

    Asaduzzaman, Md.; Kinoshita, Shigeharu, E-mail: akino@mail.ecc.u-tokyo.ac.jp; Bhuiyan, Sharmin Siddique

    The myosin heavy chain gene, MYH{sub M86-2}, exhibited restricted expression in slow muscle fibers of torafugu embryos and larvae, suggesting its functional roles for embryonic and larval muscle development. However, the transcriptional mechanisms involved in its expression are still ambiguous. The present study is the first extensive analysis of slow muscle-specific MYH{sub M86-2} promoter in fish for identifying the cis-elements that are crucial for its expression. Combining both transient transfection and transgenic approaches, we demonstrated that the 2614 bp 5′-flanking sequences of MYH{sub M86-2} contain a sufficient promoter activity to drive gene expression specific to superficial slow muscle fibers. Bymore » cyclopamine treatment, we also demonstrated that the differentiation of such superficial slow muscle fibers depends on hedgehog signaling activity. The deletion analyses defined an upstream fragment necessary for repressing ectopic MYH{sub M86-2} expression in the fast muscle fibers. The transcriptional mechanism that prevents MYH{sub M86-2} expression in the fast muscle fibers is mediated through Sox6 binding elements. We also demonstrated that Sox6 may function as a transcriptional repressor of MYH{sub M86-2} expression. We further discovered that nuclear factor of activated T cells (NFAT) binding elements plays a key role and myocyte enhancer factor-2 (MEF2) binding elements participate in the transcriptional regulation of MYH{sub M86-2} expression. - Highlights: ► MYH{sub M86-2} is highly expressed in slow muscle fibers of torafugu embryos and larvae. ► MYH{sub M86-2} promoter activity depends on the hedgehog signaling. ► Sox6 binding elements inhibits MYH{sub M86-2} expression in fast muscle fibers. ► Sox6 elements function as transcriptional repressor of MYH{sub M86-2} promoter activity. ► NFAT and MEF2 binding elements play a key role for directing MYH{sub M86-2} expression.« less

  5. The zebra mussel (Dreissena polymorpha), a new pest in North America: reproductive mechanisms as possible targets of control strategies

    USGS Publications Warehouse

    Ram, Jeffrey L.; Fong, Peter; Croll, Roger P.; Nichols, Susan J.; Wall, Darcie

    1992-01-01

    The zebra mussel (Dreissena polymorpha) has spread rapidly in temperate fresh waters of North America since its introduction into the Great Lakes in 1985 or 1986. It attaches to hard substrates, forming layers, occluding water intakes, encrusting and killing native mussels, filtering algae in competition with other planktivores, and possibly interfering with fish spawning. It reproduces prolifically, suggesting that an approach to its control may be by controlling its reproduction. Previous literature suggests that spawning in bivalves is regulated by both environmental and internal chemical cues. A suggested sequence is that phytoplankton chemicals initially trigger spawning; chemicals associated with gametes provide a species-specific pheromonal positive feedback for spawning; and the response to environmental chemicals is mediated internally by serotonin (5-HT). The role of 5-HT in zebra mussels is under investigation. Both males and females can be induced to spawn by either injection or external application of 5-HT. The response can also be activated by 8-hydroxy-2-(di-n-propylamino)-tetralin, an agonist at 5-HT1A receptors. HPLC analysis has detected 5-HT as the major biogenic amine in both male and female gonads. 5-HT immunocytochemistry demonstrates nerves containing serotonergic fibers innervating gonads of both males and females, with prominent varicosities surrounding the follicles in both sexes. A role of 5-HT in mediating spawning responses in zebra mussels is thus strongly supported. These studies have shown that reproductive behavior of zebra mussels can be modified by outside chemicals, a property that may be exploited for purposes of control.

  6. Species sensitivity distribution approach to primary risk analysis of the metal pyrithione photodegradation product, 2,2'-dipyridyldisulfide in the Inland Sea and induction of notochord undulation in fish embryos.

    PubMed

    Mochida, Kazuhiko; Amano, Haruna; Ito, Katsutoshi; Ito, Mana; Onduka, Toshimitsu; Ichihashi, Hideki; Kakuno, Akira; Harino, Hiroya; Fujii, Kazunori

    2012-08-15

    To carry out a primary risk assessment in the Inland Sea of Japan for 2,2'-dipyridyldisulfide [(PS)(2)], a metal pyrithione photodegradation product, we used a methodology based on the species sensitivity distribution (SSD) estimated with a Bayesian statistical model. We first conducted growth inhibition tests with three marine phytoplankton species, Tetraselmis tetrathele, Chaetoceros calcitrans, and Dunaliella tertiolecta. We also performed acute and early life stage toxicity (ELS) tests with a teleost fish, the mummichog (Fundulus heteroclitus). The algal growth inhibition tests revealed that the 72-h EC(50) ranged from 62 to 1100 μg/L. Acute toxicity tests with larval mummichogs revealed that the 96-h LC(50) was approximately 500 μg/L based on the actual toxicant concentrations. ELS testing of (PS)(2) under continuous flow-through conditions for 50 days revealed that growth was the most sensitive endpoint, and both total length and body weight were significantly lower in the groups exposed to 27 μg/L (PS)(2) compared to the solvent control group. We determined a lowest observed effect concentration of 17 μg/L and a NOEC of 5.9 μg/L based on the actual toxicant concentrations. By using the ecotoxicity data (LC(50) and EC(50)) from this study and previous work, we calculated a hazardous concentration that should protect 95% and 99% of species (HC(5) and HC(1)) based on the SSD derived with a Bayesian statistical model. The medians with 90% confidence intervals (parentheses) of the HC(5) and HC(1) were 31.0 (3.2, 101.8) μg/L and 10.1 (0.5, 44.2) μg/L, respectively. In the ELS test, about 80% of hatched larvae exposed to 243-μg/L (PS)(2) displayed a notochord undulation. To elucidate the cause of the notochord undulation, we carried out embryo toxicity tests by exposing embryos at various developmental stages to (PS)(2). Exposure to (PS)(2) through the entire gastrulae stage was important to induction of the morphological abnormality. Lysyl oxidase activity

  7. Song Recognition in Zebra Finches: Are There Sensitive Periods for Song Memorization?

    ERIC Educational Resources Information Center

    Braaten, Richard F.

    2010-01-01

    Male zebra finches learn to sing songs that they hear between 25 and 65 days of age, the sensitive period for song learning. In this experiment, male and female zebra finches were exposed to zebra finch songs either before (n = 9) or during (n = 4) the sensitive period. Following song exposure, recognition memory for the songs was assessed with an…

  8. Chemical regulation of spawning in the zebra mussel (Dreissena polymorpha)

    USGS Publications Warehouse

    Ram, Jeffrey L.; Nichols, S. Jerrine; Nalepa, Thomas F.; Schloesser, Donald W.

    1992-01-01

    Previous literature suggests that spawning in bivalves is chemically regulated, both by environmental chemical cues and by internal chemical mediators. In a model proposed for zebra mussels, chemicals from phytoplankton initially trigger spawning, and chemicals associated with gametes provide further stimulus for spawning. The response to environmental chemicals is internally mediated by a pathway utilizing serotonin (5-hydroxytryptamine, a neurotransmitter), which acts directly on both male and female gonads. The role of serotonin and most other aspects of the model have been tested only on bivalves other than zebra mussels. The effect of serotonin on zebra mussel spawning was tested. Serotonin (10-5 and 10-3 M) injected into ripe males induced spawning, but injection of serotonin into females did not. Gametes were not released by 10-6 serotonin; in most cases, serotonin injection did not release gametes from immature recipients. Serotonin injection provides a reliable means for identifying ripe male zebra mussels and for obtaining zebra mussel sperm without the need for dissection.

  9. Toxicity of chlorine to zebrafish embryos

    PubMed Central

    Kent, Michael L.; Buchner, Cari; Barton, Carrie; Tanguay, Robert L.

    2014-01-01

    Surface disinfection of fertilized fish eggs is widely used in aquaculture to reduce extraovum pathogens that may be released from brood fish during spawning, and this is routinely used in zebrafish (Danio rerio) research laboratories. Most laboratories use approximately 25 – 50 ppm unbuffered chlorine solution for 5 – 10 min. Treatment of embryos with chlorine has significant germicidal effects for many Gram-negative bacteria, viruses, and trophozoite stages of protozoa, it has reduced efficacy against cyst or spore stages of protozoa and certain Mycobacterium spp. Therefore, we evaluated the toxicity of unbufferred and buffered chlorine solution to embryos exposed at 6 or 24 hours post-fertilization (hpf) to determine if higher concentrations can be used for treating zebrafish embryos. Most of our experiments entailed using an outbred line (5D), with both mortality and malformations as endpoints. We found that 6 hpf embryos consistently were more resistant than 24 hpf embryos to the toxic effects of chlorine. Chlorine is more toxic and germicidal at lower pHs, and chlorine causes elevated pH. Consistent with this, we found that unbufferred chlorine solutions (pH ca 8–9) were less toxic at corresponding concentrations than solutions buffered to pH 7. Based on our findings here, we recommend treating 6 hpf embryos for 10 min and 24 hpf for 5 min with unbuffered chlorine solution at 100 ppm. One trial indicated that AB fish, a popular outbred line, are more susceptible to toxicity than 5Ds. This suggests that variability between zebrafish lines occurs, and researchers should evaluate each line or strain under their particular laboratory conditions for selection of the optimum chlorine treatment procedure. PMID:24429474

  10. Retinal histogenesis in an altricial avian species, the zebra finch (Taeniopygia guttata, Vieillot 1817).

    PubMed

    Álvarez-Hernán, Guadalupe; Sánchez-Resino, Elena; Hernández-Núñez, Ismael; Marzal, Alfonso; Rodríguez-León, Joaquín; Martín-Partido, Gervasio; Francisco-Morcillo, Javier

    2018-07-01

    Comparative developmental studies have shown that the retina of altricial fish and mammals is incompletely developed at birth, and that, during the first days of life, maturation proceeds rapidly. In contrast, precocial fish and mammals are born with fully differentiated retinas. Concerning birds, knowledge about retinal development is generally restricted to a single order of precocial birds, Galliformes, due to the fact that both the chicken and the Japanese quail are considered model systems. However, comparison of embryonic pre-hatchling retinal development between altricial and precocial birds has been poorly explored. The purpose of this study was to examine the morphogenesis and histogenesis of the retina in the altricial zebra finch (Taeniopygia guttata, Vieillot 1817) and compare the results with those from previous studies in the precocial chicken. Several maturational features (morphogenesis of the optic vesicle and optic cup, appearance of the first differentiated neurons, the period in which the non-apical cell divisions are observable, and the emergence of the plexiform layers) were found to occur at later stages in the zebra finch than in the chicken. At hatching, the retina of T. guttata showed the typical cytoarchitecture of the mature tissue, although features of immaturity were still observable, such as a ganglion cell layer containing many thick cells, very thin plexiform layers, and poorly developed photoreceptors. Moreover, abundant mitotic activity was detected in the entire retina, even in the regions where the layering was complete. The circumferential marginal zone was very prominent and showed abundant mitotic activity. The partially undifferentiated stage of maturation at hatching makes the T. guttata retina an appropriate model with which to study avian postnatal retinal neurogenesis. © 2018 Anatomical Society.

  11. Quagga and zebra mussels: biology, impacts, and control

    USGS Publications Warehouse

    Nalepa, Thomas F.; Schloesser, Don W.; Nalepa, Thomas F.; Schloesser, Don W.

    2013-01-01

    Quagga and Zebra Mussels: Biology, Impacts, and Control, Second Edition provides a broad view of the zebra/quagga mussel issue, offering a historic perspective and up-to-date information on mussel research. Comprising 48 chapters, this second edition includes reviews of mussel morphology, physiology, and behavior. It details mussel distribution and spread in Europe and across North America, and examines policy and regulatory responses, management strategies, and mitigation efforts. In addition, this book provides extensive coverage of the impact of invasive mussel species on freshwater ecosystems, including effects on water clarity, phytoplankton, water quality, food web changes, and consequences to other aquatic fauna. It also reviews and offers new insights on how zebra and quagga mussels respond and adapt to varying environmental conditions. This new edition includes seven video clips that complement chapter text and, through visual documentation, provide a greater understanding of mussel behavior and distribution.

  12. FindZebra: a search engine for rare diseases.

    PubMed

    Dragusin, Radu; Petcu, Paula; Lioma, Christina; Larsen, Birger; Jørgensen, Henrik L; Cox, Ingemar J; Hansen, Lars Kai; Ingwersen, Peter; Winther, Ole

    2013-06-01

    The web has become a primary information resource about illnesses and treatments for both medical and non-medical users. Standard web search is by far the most common interface to this information. It is therefore of interest to find out how well web search engines work for diagnostic queries and what factors contribute to successes and failures. Among diseases, rare (or orphan) diseases represent an especially challenging and thus interesting class to diagnose as each is rare, diverse in symptoms and usually has scattered resources associated with it. We design an evaluation approach for web search engines for rare disease diagnosis which includes 56 real life diagnostic cases, performance measures, information resources and guidelines for customising Google Search to this task. In addition, we introduce FindZebra, a specialized (vertical) rare disease search engine. FindZebra is powered by open source search technology and uses curated freely available online medical information. FindZebra outperforms Google Search in both default set-up and customised to the resources used by FindZebra. We extend FindZebra with specialized functionalities exploiting medical ontological information and UMLS medical concepts to demonstrate different ways of displaying the retrieved results to medical experts. Our results indicate that a specialized search engine can improve the diagnostic quality without compromising the ease of use of the currently widely popular standard web search. The proposed evaluation approach can be valuable for future development and benchmarking. The FindZebra search engine is available at http://www.findzebra.com/. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  13. Cooling strategies for brazilian flounder Paralichthys orbignyanus embryos.

    PubMed

    Varela, A S; Cardoso, T F; Fernandes E Silva, E; Goularte, K L; Okamoto, M H; Sampaio, L A; Jardim, R D; Corcini, C D

    Paralichthys orbignyanus is the species of the greatest potential for marine and estuarine fish farming in southern Brazil. Consequently, embryo cryopreservation becomes an important tool for increasing their production. To evaluate the effects of cooling protocols on the viability of embryos of P. orbignyanus at two stages of development (neurula and early differentiation of the tail). Control embryos were maintained at 23 degree C and treated embryos were cooled to 15 degree C, 10 degree C and 5 degree C at rapid, moderate and slow cooling rates. Then embryos were maintained at these different temperatures for 30, 60 and 90 min and the loss of viability assessed as hatching rates (HR) and morphologically normal larvae (MNL). The average HR for embryos following cooling was higher for those at the tail stage compared to the neurula stage (P<0.05). In both stages there was no statistical difference between the HR of control embryos and those exposed to rapid cooling. Also for tail stage embryos, there was no difference between MNL of control and rapidly cooled embryos. As first steps in the development of cryopreservation methods for P. orbignyanus embryos, the use of a rapid cooling and holding at 5 degree C for 30 min are recommended.

  14. Zebra Mussel Chemical Control Guide, Version 2.0

    DTIC Science & Technology

    2015-07-01

    delivery systems, including potable water treatment, agriculture, industry, power generation, and fire protection. Since this invasive organism’s...delivery systems, including potable water treatment, agriculture, industry, power generation, and fire protection (Mackie and Claudi 2010). Zebra mussels...generators, pipes, valves, sensing equipment (level, flow, and pressure) and fire protection (Mackie and Claudi 2010; Prescott et al. 2014). Other USACE

  15. Susceptibility of selected potato varieties to zebra chip potato disease

    USDA-ARS?s Scientific Manuscript database

    Zebra chip (ZC), an emerging and serious disease of potato has caused millions of dollars in losses to the potato industry in the United States, Mexico, Central America, and New Zealand. The disease has recently been associated with a previously undescribed species of liberibacter tentatively named ...

  16. Zebra chip development during storage: cause for concern?

    USDA-ARS?s Scientific Manuscript database

    Zebra chip disease is associated with infections by ‘Candidatus Liberibacter solanacearum’ (Lso), a bacterium spread by the potato psyllid Bactericera cockerelli. A major concern of the potato industry is the likelihood that Lso could cause asymptomatic infections prior to placement of tubers in col...

  17. Potato psyllid vector of zebra chip disease in Pacific Northwest

    USDA-ARS?s Scientific Manuscript database

    Zebra chip is a destructive disease of potatoes in the Pacific Northwest and other potato production regions of North America. The pathogen associated with this disease is transmitted by the potato psyllid. A team of researchers which included a scientist at the ARS in Wapato, WA updated an extens...

  18. Transfering vitamin C from fish to embryos

    USDA-ARS?s Scientific Manuscript database

    Beneficial effects of ascorbic acid supplementation to broodstock of a select aquaculture species is well documented. At the present levels of feeding, dietary means of vitamin C does not meet the requirements for maturation, reproduction and needs of early life stages of larvae. In addition, thi...

  19. Toxicity test of xanthone from mangosteen on zebrafish embryos

    NASA Astrophysics Data System (ADS)

    Noordin, Muhammad Akram Mohd; Noor, Mahanem Mat; Kamaruddin, Wan Mohd Aizat Wan; Lazim, Azwan Mat; Fazry, Shazrul

    2016-11-01

    Xanthone is a chemical compound identified in mangosteen pericarp. A previous study showed that xanthone has anti-proliferating effect on cancer cells. In this study we investigate the toxicity level of xanthone in zebrafish embryo to for future reference on other animal model. We employed Fish Embryo Toxicity (FET) assay to determine the toxicity level of different concentrations of xanthone. Embryos were observed at 24, 48 and 72 hours post fertilization (hpf) under microscope at 4× magnification. The extract showed toxicity effect on embryo at concentrations of 250, 125 and 62.5 µg/mL. Concentrations at 15.63, 7.81 and 3.91 µg / mL of xanthone did not harm the embryos and showed 100% of survival.

  20. Microfluidic EmbryoSort technology: towards in flow analysis, sorting and dispensing of individual vertebrate embryos

    NASA Astrophysics Data System (ADS)

    Fuad, Nurul M.; Wlodkowic, Donald

    2013-12-01

    The demand to reduce the numbers of laboratory animals has facilitated the emergence of surrogate models such as tests performed on zebrafish (Danio rerio) or African clawed frog's (Xenopus levis) eggs, embryos and larvae. Those two model organisms are becoming increasingly popular replacements to current adult animal testing in toxicology, ecotoxicology and also in drug discovery. Zebrafish eggs and embryos are particularly attractive for toxicological analysis due their size (diameter 1.6 mm), optical transparency, large numbers generated per fish and very straightforward husbandry. The current bottleneck in using zebrafish embryos for screening purposes is, however, a tedious manual evaluation to confirm the fertilization status and subsequent dispensing of single developing embryos to multitier plates to perform toxicity analysis. Manual procedures associated with sorting hundreds of embryos are very monotonous and as such prone to significant analytical errors due to operator's fatigue. In this work, we present a proofof- concept design of a continuous flow embryo sorter capable of analyzing, sorting and dispensing objects ranging in size from 1.5 - 2.5 mm. The prototypes were fabricated in polymethyl methacrylate (PMMA) transparent thermoplastic using infrared laser micromachining. The application of additive manufacturing processes to prototype Lab-on-a-Chip sorters using both fused deposition manufacturing (FDM) and stereolithography (SLA) were also explored. The operation of the device was based on a revolving receptacle capable of receiving, holding and positioning single fish embryos for both interrogation and subsequent sorting. The actuation of the revolving receptacle was performed using a DC motor and/or microservo motor. The system was designed to separate between fertilized (LIVE) and non-fertilized (DEAD) eggs, based on optical transparency using infrared (IR) emitters and receivers.

  1. Development of sexual partner preference in the zebra finch: a socially monogamous, pair-bonding animal.

    PubMed

    Adkins-Regan, Elizabeth

    2002-02-01

    Zebra finches are group living socially monogamous birds that pair for life. Partner preference is strongly sexually differentiated: males prefer to pair with females and females prefer to pair with males. Where do these preferences come from? What occurs during development that produces adult birds that pair with the opposite sex? There is surprisingly little animal research that addresses such questions, especially in species that form pair-bonds. Our research program focuses on two processes that may be involved in the development of adult sexual-partner preference: (1) early (possibly organizational) hormone actions and (2) social experience. Females treated with estradiol or fadrozole (an estrogen synthesis inhibitor) as nestlings or embryos showed masculinized sexual-partner preference as adults, preferring to pair with other females even when potential male partners were available. Removal of adult males from breeding cages, so that young birds were not exposed to males or to male-female pairs during development, eliminated sex-typical partner preferences; these birds were equally interested in both sexes and were more likely than controls to pair with a same-sex partner. These experiments provide insights into the development of sexual-partner preference that may be applicable to other group living pair-bonding animals with biparental care. They also contribute to the foundation of animal research that is necessary for a biological approach to understanding the pair-bonding component of human sexual orientation.

  2. Diffusion of small molecules into medaka embryos improved by electroporation

    PubMed Central

    2013-01-01

    Background Diffusion of small molecules into fish embryos is essential for many experimental procedures in developmental biology and toxicology. Since we observed a weak uptake of lithium into medaka eggs we started a detailed analysis of its diffusion properties using small fluorescent molecules. Results Contrary to our expectations, not the rigid outer chorion but instead membrane systems surrounding the embryo/yolk turned out to be the limiting factor for diffusion into medaka eggs. The consequence is a bi-phasic uptake of small molecules first reaching the pervitelline space with a diffusion half-time in the range of a few minutes. This is followed by a slow second phase (half-time in the range of several hours) during which accumulation in the embryo/yolk takes place. Treatment with detergents improved the uptake, but strongly affected the internal distribution of the molecules. Testing electroporation we could establish conditions to overcome the diffusion barrier. Applying this method to lithium chloride we observed anterior truncations in medaka embryos in agreement with its proposed activation of Wnt signalling. Conclusions The diffusion of small molecules into medaka embryos is slow, caused by membrane systems underneath the chorion. These results have important implications for pharmacologic/toxicologic techniques like the fish embryo test, which therefore require extended incubation times in order to reach sufficient concentrations in the embryos. PMID:23815821

  3. Do zebra mussels (Dreissena polymorpha) alter lake water chemistry in a way that favours Microcystis growth?

    PubMed

    Bykova, Olga; Laursen, Andrew; Bostan, Vadim; Bautista, Joseph; McCarthy, Lynda

    2006-12-01

    This study examined possible relationships between the presence of zebra mussels (Dreissena polymorpha) and Microcystis spp. abundance. Experiments were conducted in 12 microcosms designed to mimic shallow lake ecosystems. Fresh, aerated water with phytoplankton (pseudokirchneriella spp. and Microcystis spp.) was pumped into each microcosm daily to ensure zebra mussels were exposed to oxygen and food. Microcosms containing zebra mussels experienced significantly higher fluxes of nitrate (p=0.019) and lower fluxes of ortho-phosphate (p=0.047) into sediments. In a second experiment, water column nutrient concentrations were compared in microcosms with and without live zebra mussels. Consistent with results of the previous experiment, microcosms with zebra mussels had significantly less nitrate (p=0.023) and organic nitrogen (p=0.003) in the water column, while ammonium (p=0.074), phosphate (p=0.491), and dissolved organic carbon (p=0.820) in the water column were not different between microcosms with or without zebra mussels. Microcosms with zebra mussels also experienced a reduction in green algae (pseudokirchneriella) (p<0.001) and an increase in abundance of Microcystis (p<0.001) relative to microcosms without zebra mussels. In an experiment without zebra mussels, nutrient ratios (N/P) were manipulated to determine potential links between N/P and relative abundance of each phytoplankton. Manipulation of N/P was intended to mimic differences observed in microcosms with and without zebra mussels in the previous experiment. Low N/P (mimicking microcosms with zebra mussels) was related to an increase in Microcystis (p<0.001) and Microcystis/Pseudokirchneriella biovolume (p<0.001). It is this shift in N/P, and possibly some level of selective feeding, that is believed to have driven changes in the relative abundance of Microcystis. In lakes invaded by zebra mussels, alterations in the processing of nitrogen and phosphorus could contribute to the re-emergence of

  4. Lesser scaup forage on zebra mussels at Cook nuclear plant, Michigan

    USGS Publications Warehouse

    Mitchell, C.A.; Carlson, J.

    1993-01-01

    Nineteen of 21 Lesser Scaup (Aythya affinis) entrained while foraging at the water intake structures of Cook Nuclear Plant, Bridgman, Michigan had consumed zebra mussels (Dreissena polymorpha). The average number of zebra mussels in the upper gastrointestinal tract was 260; maximum number was 987. Migrating Lesser Scaup found this new food source during the first winter following settlement of zebra mussels on the water intake structures of the power plant.

  5. DNA barcoding and microsatellites help species delimitation and hybrid identification in endangered galaxiid fishes.

    PubMed

    Vanhaecke, Delphine; Garcia de Leaniz, Carlos; Gajardo, Gonzalo; Young, Kyle; Sanzana, Jose; Orellana, Gabriel; Fowler, Daniel; Howes, Paul; Monzon-Arguello, Catalina; Consuegra, Sofia

    2012-01-01

    The conservation of data deficient species is often hampered by inaccurate species delimitation. The galaxiid fishes Aplochiton zebra and Aplochiton taeniatus are endemic to Patagonia (and for A. zebra the Falkland Islands), where they are threatened by invasive salmonids. Conservation of Aplochiton is complicated because species identification is hampered by the presence of resident as well as migratory ecotypes that may confound morphological discrimination. We used DNA barcoding (COI, cytochrome b) and a new developed set of microsatellite markers to investigate the relationships between A. zebra and A. taeniatus and to assess their distributions and relative abundances in Chilean Patagonia and the Falkland Islands. Results from both DNA markers were 100% congruent and revealed that phenotypic misidentification was widespread, size-dependent, and highly asymmetric. While all the genetically classified A. zebra were correctly identified as such, 74% of A. taeniatus were incorrectly identified as A. zebra, the former species being more widespread than previously thought. Our results reveal, for the first time, the presence in sympatry of both species, not only in Chilean Patagonia, but also in the Falkland Islands, where A. taeniatus had not been previously described. We also found evidence of asymmetric hybridisation between female A. taeniatus and male A. zebra in areas where invasive salmonids have become widespread. Given the potential consequences that species misidentification and hybridisation can have for the conservation of these endangered species, we advocate the use of molecular markers in order to reduce epistemic uncertainty.

  6. IUCN classification zones concord with, but underestimate, the population genetic structure of the zebra shark Stegostoma fasciatum in the Indo-West Pacific.

    PubMed

    Dudgeon, C L; Broderick, D; Ovenden, J R

    2009-01-01

    The Indo-West Pacific (IWP), from South Africa in the western Indian Ocean to the western Pacific Ocean, contains some of the most biologically diverse marine habitats on earth, including the greatest biodiversity of chondrichthyan fishes. The region encompasses various densities of human habitation leading to contrasts in the levels of exploitation experienced by chondrichthyans, which are targeted for local consumption and export. The demersal chondrichthyan, the zebra shark, Stegostoma fasciatum, is endemic to the IWP and has two current regional International Union for the Conservation of Nature (IUCN) Red List classifications that reflect differing levels of exploitation: 'Least Concern' and 'Vulnerable'. In this study, we employed mitochondrial ND4 sequence data and 13 microsatellite loci to investigate the population genetic structure of 180 zebra sharks from 13 locations throughout the IWP to test the concordance of IUCN zones with demographic units that have conservation value. Mitochondrial and microsatellite data sets from samples collected throughout northern Australia and Southeast Asia concord with the regional IUCN classifications. However, we found evidence of genetic subdivision within these regions, including subdivision between locations connected by habitat suitable for migration. Furthermore, parametric F(ST) analyses and Bayesian clustering analyses indicated that the primary genetic break within the IWP is not represented by the IUCN classifications but rather is congruent with the Indonesian throughflow current. Our findings indicate that recruitment to areas of high exploitation from nearby healthy populations in zebra sharks is likely to be minimal, and that severe localized depletions are predicted to occur in zebra shark populations throughout the IWP region.

  7. IMPACT OF WATER PH ON ZEBRA MUSSEL MORTALITY

    SciTech Connect

    Daniel P. Molloy

    2002-10-15

    The experiments conducted this past quarter have suggested that the bacterium Pseudomonas fluorescens strain CL0145A is effective at killing zebra mussels throughout the entire range of pH values tested (7.2 to 8.6). Highest mortality was achieved at pH values characteristic of preferred zebra mussel waterbodies, i.e., hard waters with a range of 7.8 to 8.6. In all water types tested, however, ranging from very soft to very hard, considerable mussel kill was achieved (83 to 99% mean mortality), suggesting that regardless of the pH or hardness of the treated water, significant mussel kill can be achieved upon treatment with P.more » fluorescens strain CL0145A. These results further support the concept that this bacterium has significant potential for use as a zebra mussel control agent in power plant pipes receiving waters with a wide range of physical and chemical characteristics.« less

  8. Mortality of zebra mussel, Dreissena polymorpha, veligers during downstream transport

    USGS Publications Warehouse

    Horvath, T.G.; Lamberti, G.A.

    1999-01-01

    1. Streams flowing from lakes which contain zebra mussels, Dreissena polymorpha, provide apparently suitable habitats for mussel colonization and downstream range expansion, yet most such streams contain few adult mussels. We postulated that mussel veligers experience high mortality during dispersal via downstream transport. They tested this hypothesis in Christiana Creek, a lake-outlet stream in south-western Michigan, U.S.A., in which adult mussel density declined exponentially with distance downstream. 2. A staining technique using neutral red was developed and tested to distinguish quickly live and dead veligers. Live and dead veligers were distinguishable after an exposure of fresh samples to 13.3 mg L-1 of neutral red for 3 h. 3. Neutral red was used to determine the proportion of live veligers in samples taken longitudinally along Christiana Creek. The proportion of live veligers (mean ?? SE) declined from 90 ?? 3% at the lake outlet to 40 ?? 8% 18 km downstream. 4. Veligers appear to be highly susceptible to damage by physical forces (e.g. shear), and therefore, mortality in turbulent streams could be an important mechanism limiting zebra mussel dispersal to downstream reaches. Predictions of zebra mussel spread and population growth should consider lake-stream linkages and high mortality in running waters.

  9. Laterality of suckling behaviour in three zebra species.

    PubMed

    Pluháček, Jan; Olléová, Michaela; Bartošová, Jitka; Pluháčková, Jana; Bartoš, Luděk

    2013-01-01

    Although side preference while suckling is an easily characterised lateralised behaviour, few studies have been conducted. We observed laterality in suckling behaviour in three captive zebra species to test two hypotheses: laterality affected by the foal (motor laterality) and laterality affected by the mother. In total we observed 35 foals of Grevy's, plains, and mountain zebra in two zoos and recorded 5128 successful suckling bouts and 9095 unsuccessful suckling attempts. At the population level the only factor affecting side preference of suckling bouts and attempts was the identity of the individual foal. Ten foals showed individual preferences: seven foals preferred suckling from the left side of the mother, three preferred suckling from the right side of the mother. The individual preferences increased with increasing age of the foal. Only one foal was refused more often from the opposite side than the preferred side used for suckling whereas three other foals were refused from the preferred side. Foals that preferred suckling either from left or right side were refused by the mare more often than foals which showed non-preference. Thus lateral preferences in suckling behaviour of zebra foals seem to be in line with the motor laterality hypotheses.

  10. Heterospecific discrimination of Poecile vocalizations by zebra finches (Taeniopygia guttata).

    PubMed

    Guillette, Lauren M; Hoeschele, Marisa; Hahn, Allison H; Sturdy, Christopher B

    2013-08-01

    Previous perceptual research with black-capped and mountain chickadees has demonstrated that the D note of the namesake chick-a-dee call controlled species-based discrimination compared to other note types in this call. In the current experiment, we sought to determine whether discrimination performance of the chickadees was controlled by stimulus-specific properties or due to learning through experience. To accomplish this, we tested zebra finches, a songbird species that is distantly related to chickadees, and also unfamiliar with black-capped and mountain chickadee vocalizations, on the same species-based discrimination on which black-capped and mountain chickadees were previously trained. We found that zebra finches learned the discrimination in the fewest number of trials with the D note, compared to other note types (i.e., the A, B, and C notes). In addition, we compared the current results to earlier work and found that zebra finches learned the discrimination in fewer trials compared to black-capped chickadees, and, across all species, males learned the discrimination in fewer trials than females. We discuss the roles that acoustic complexity and learning play in classification of the three species of songbirds tested. More generally, these results point to the benefits derived from testing members of each sex in species that vary in their natural history, vocal output, and phylogenetic relatedness as a means to uncover the mechanisms underlying acoustic communication. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

  11. SURVIVAL OF STEELHEAD TROUT (SALMO GAIRDNERI) EGGS, EMBRYOS, AND FRY IN AIR-SUPERSATURATED WATER

    EPA Science Inventory

    Egg, embryo, fry, and swim-up stages of steelhead trout (Salmo gairdneri) were exposed to water at total gas saturation levels ranging from 130 to 115%. Eggs, embryos, and newly hatched fry were not affected at 126.7%, but at about day 16 posthatch when the fish began swimming up...

  12. [Progress in transgenic fish techniques and application].

    PubMed

    Ye, Xing; Tian, Yuan-Yuan; Gao, Feng-Ying

    2011-05-01

    Transgenic technique provides a new way for fish breeding. Stable lines of growth hormone gene transfer carps, salmon and tilapia, as well as fluorescence protein gene transfer zebra fish and white cloud mountain minnow have been produced. The fast growth characteristic of GH gene transgenic fish will be of great importance to promote aquaculture production and economic efficiency. This paper summarized the progress in transgenic fish research and ecological assessments. Microinjection is still the most common used method, but often resulted in multi-site and multi-copies integration. Co-injection of transposon or meganuclease will greatly improve the efficiency of gene transfer and integration. "All fish" gene or "auto gene" should be considered to produce transgenic fish in order to eliminate misgiving on food safety and to benefit expression of the transferred gene. Environmental risk is the biggest obstacle for transgenic fish to be commercially applied. Data indicates that transgenic fish have inferior fitness compared with the traditional domestic fish. However, be-cause of the genotype-by-environment effects, it is difficult to extrapolate simple phenotypes to the complex ecological interactions that occur in nature based on the ecological consequences of the transgenic fish determined in the laboratory. It is critical to establish highly naturalized environments for acquiring reliable data that can be used to evaluate the environ-mental risk. Efficacious physical and biological containment strategies remain to be crucial approaches to ensure the safe application of transgenic fish technology.

  13. Mitigation of unionid mortality caused by zebra mussel infestation: cleaning of unionids

    USGS Publications Warehouse

    Schloesser, Don W.

    1996-01-01

    Exotic zebra mussels Dreissena polymorpha have infested and caused mortality of native unionids in the Great Lakes since 1986; no other such parasitism of native unionids occurs in North America. Survival of unionids threatened by zebra mussel infestation was tested by suspending uncleaned and cleaned unionids in nearshore waters of western Lake Erie. Survival was determined, and newly settled zebra mussels were removed from clean unionids at eight intervals that ranged from 21 d to 77 d between 5 July 1990 and 3 July 1991. After 1 year, survival rates of uncleaned and cleaned unionids were 0% and 42%, respectively. Of the 10 species examined, only indivduals from 3 species (Amblema plicata plicata, Fusconaia flava, and Quadrula quadrula) survived 1 year. These species have relatively thick shells, which may have contributed to their survival. Removal of newly settled zebra mussels may be important to unionid survival because 98% of the zebra mussels removed after the initial cleaning were small mussels (<10 mm long) that could rapidly grow and cover unionids. At present, we do not know how zebra mussels cause mortality of unionids, but the removal of zebra mussels from unionids is the only method known that successfully reduces unionid mortality in waters colonized by zebra mussels.

  14. Are Horses Like Zebras, or Vice Versa? Children's Sensitivity to the Asymmetries of Directional Comparisons

    ERIC Educational Resources Information Center

    Chestnut, Eleanor K.; Markman, Ellen M.

    2016-01-01

    Adults exhibit strong preferences when framing symmetrical relations. Adults prefer, for example, "A zebra is like a horse" to "A horse is like a zebra," and "The bicycle is near the building" to "The building is near the bicycle." This is because directional syntax requires more typical or prominent items…

  15. Effects of shell morphology on mechanics of zebra and quagga mussel locomotion

    Treesearch

    S. M. Peyer; J. C. Hermanson; C. E. Lee

    2011-01-01

    Although zebra mussels (Dreissena polymorpha) initially colonized shallow habitats within the North American Great Lakes, quagga mussels (Dreissena bugensis) are becoming dominant in both shallow- and deep-water habitats. Shell morphology differs among zebra, shallow quagga and deep quagga mussels but functional consequences of...

  16. LC-MS Analysis of Phenolic Compounds in Tubers Showing Zebra Chip Symptoms

    USDA-ARS?s Scientific Manuscript database

    A new potato disorder called zebra chip (ZC) has been identified in the United States and has been especially problematic in Texas where substantial economic losses have been incurred. Upon frying, ZC tubers develop a dark “zebra chip” pattern of discoloration. LC-MS analysis of symptomatic tubers...

  17. Preference of redear sunfish on zebra mussels and rams-horn snails

    USGS Publications Warehouse

    French, John R. P.; Morgan, Michael N.

    1995-01-01

    We tested prey preferences of adult (200- to 222-mm long) redear sunfish (Lepomis microlophus) on two size classes of zebra mussels (Dreissena polymorpha) and two-ridge rams-horns (Helisoma anceps) in experimental aquaria. We also tested physical limitations on consuming these mollusks and determined prey bioenergetic profitability. Redear sunfish strongly preferred rams-horns over zebra mussels, but they displayed no size preference for either prey. Ingestion was not physically limited since both prey species up to 15-mm long fit within the pharyngeal gapes of redear sunfish. Rams-horns were more bioenergetically profitable than zebra mussels and ingestion of rams-horn shell fragments was about three times less than zebra mussels. Rams-horns were somewhat more resistant to shell-crushing, but all size ranges of both prey species tested were crushable by redear sunfish. These studies suggested that the redear sunfish should not be considered a panacea for biological control of zebra mussels.

  18. The use of positive reinforcement in training zebra sharks (Stegostoma fasciatum).

    PubMed

    Marranzino, Ashley

    2013-01-01

    Positive reinforcement training (PRT) was used on 4 adult zebra sharks, Stegostoma fasciatum, housed at the Downtown Aquarium, Denver, to determine the ability of zebra sharks to become desensitized to various stimuli associated with veterinary procedures. One male and 3 female sharks were trained for 12 weeks. As a result of PRT, all 4 zebra sharks were desensitized to staying within a closed holding tank off of the main exhibit, the presence of multiple trainers in the closed holding tank, and tactile stimulation. One of the 4 zebra sharks was also successfully desensitized to the presence of a stretcher being brought into the holding tank. All of these procedures are common in veterinary examinations, and it is hoped that desensitization to these stimuli will reduce the stress associated with examinations. The training accomplished has allowed for easier maintenance of the zebra sharks by the aquarium staff and an improvement in the care of the sharks.

  19. Bioaccumulation of pathogenic bacteria and amoeba by zebra mussels and their presence in watercourses.

    PubMed

    Mosteo, R; Goñi, P; Miguel, N; Abadías, J; Valero, P; Ormad, M P

    2016-01-01

    Dreissena polymorpha (the zebra mussel) has been invading freshwater bodies in Europe since the beginning of the nineteenth century. Filter-feeding organisms can accumulate and concentrate both chemical and biological contaminants in their tissues. Therefore, zebra mussels are recognized as indicators of freshwater quality. In this work, the capacity of the zebra mussel to accumulate human pathogenic bacteria and protozoa has been evaluated and the sanitary risk associated with their presence in surface water has also been assessed. The results show a good correlation between the pathogenic bacteria concentration in zebra mussels and in watercourses. Zebra mussels could therefore be used as an indicator of biological contamination. The bacteria (Escherichia coli, Enterococcus spp., Pseudomonas spp., and Salmonella spp.) and parasites (Cryptosporidium oocysts and free-living amoebae) detected in these mussels reflect a potential sanitary risk in water.

  20. Evaluating the Zebrafish Embryo Toxicity Test for Pesticide Hazard Screening

    EPA Science Inventory

    Given the numerous chemicals used in society, it is critical to develop tools for accurate and efficient evaluation of potential risks to human and ecological receptors. Fish embryo acute toxicity tests are 1 tool that has been shown to be highly predictive of standard, more reso...

  1. Shared and Unique Patterns of Embryo Development in Extremophile Poeciliids

    PubMed Central

    Riesch, Rüdiger; Schlupp, Ingo; Langerhans, R. Brian; Plath, Martin

    2011-01-01

    Background Closely related lineages of livebearing fishes have independently adapted to two extreme environmental factors: toxic hydrogen sulphide (H2S) and perpetual darkness. Previous work has demonstrated in adult specimens that fish from these extreme habitats convergently evolved drastically increased head and offspring size, while cave fish are further characterized by reduced pigmentation and eye size. Here, we traced the development of these (and other) divergent traits in embryos of Poecilia mexicana from benign surface habitats (“surface mollies”) and a sulphidic cave (“cave mollies”), as well as in embryos of the sister taxon, Poecilia sulphuraria from a sulphidic surface spring (“sulphur mollies”). We asked at which points during development changes in the timing of the involved processes (i.e., heterochrony) would be detectible. Methods and Results Data were extracted from digital photographs taken of representative embryos for each stage of development and each type of molly. Embryo mass decreased in convergent fashion, but we found patterns of embryonic fat content and ovum/embryo diameter to be divergent among all three types of mollies. The intensity of yellow colouration of the yolk (a proxy for carotenoid content) was significantly lower in cave mollies throughout development. Moreover, while relative head size decreased through development in surface mollies, it increased in both types of extremophile mollies, and eye growth was arrested in mid-stage embryos of cave mollies but not in surface or sulphur mollies. Conclusion Our results clearly demonstrate that even among sister taxa convergence in phenotypic traits is not always achieved by the same processes during embryo development. Furthermore, teleost development is crucially dependent on sufficient carotenoid stores in the yolk, and so we discuss how the apparent ability of cave mollies to overcome this carotenoid-dependency may represent another potential mechanism explaining

  2. The Importance of Non-Native Prey, the Zebra Mussel Dreissena polymorpha, for the Declining Greater Scaup Aythya marila: A Case Study at a Key European Staging and Wintering Site.

    PubMed

    Marchowski, Dominik; Neubauer, Grzegorz; Ławicki, Łukasz; Woźniczka, Adam; Wysocki, Dariusz; Guentzel, Sebastian; Jarzemski, Maciej

    2015-01-01

    The European population of Greater Scaup Aythya marila has experienced an alarming, ~60% decline in numbers over the last two decades. The brackish lagoons of the Odra River Estuary (ORE) in the south-western Baltic Sea, represent an important area for the species during the non-breeding season in Europe. The lagoons regularly support over 20 000 Scaup, with peaks exceeding 100 000 (38%-70% of the population wintering in NW Europe and the highest number recorded in April 2011-105 700). In the ORE, Scaup feed almost exclusively on the non-native Zebra Mussel Dreissena polymorpha. This mussel was present in the ORE already in the 19th century and continues to be superabundant. Using the results of 22 Scaup censuses (November to April 2002/2003 to 2013/2014) from the whole ORE (523 km2 of water), we show that Scaup flocks follow areas with the greatest area of occurrence and biomass of the Zebra Mussel, while areas with low mussel densities are ignored. The numbers of Scaup in the ORE are primarily related to the area of Zebra Mussel occurrence on the lagoon's bottom (km2) in a non-linear fashion. Zebra Mussels were absolutely prevalent (97% of biomass) in the digestive tracts of birds unintentionally by-caught in fishing nets (n = 32). We estimate that Scaup alone consume an average of 5 400 tons of Zebra Mussels annually, which represents 5.6% of the total resources of the mussel in the ORE. Our results provide a clear picture of the strong dependence of the declining, migratory duck species on the non-native mussel, its primary food in the ORE. Our findings are particularly important as they can form the basis for the conservation action plan aimed at saving the north-western European populations of Scaup.

  3. The Importance of Non-Native Prey, the Zebra Mussel Dreissena polymorpha, for the Declining Greater Scaup Aythya marila: A Case Study at a Key European Staging and Wintering Site

    PubMed Central

    Marchowski, Dominik; Neubauer, Grzegorz; Ławicki, Łukasz; Woźniczka, Adam; Wysocki, Dariusz; Guentzel, Sebastian; Jarzemski, Maciej

    2015-01-01

    The European population of Greater Scaup Aythya marila has experienced an alarming, ~60% decline in numbers over the last two decades. The brackish lagoons of the Odra River Estuary (ORE) in the south-western Baltic Sea, represent an important area for the species during the non-breeding season in Europe. The lagoons regularly support over 20 000 Scaup, with peaks exceeding 100 000 (38%–70% of the population wintering in NW Europe and the highest number recorded in April 2011–105 700). In the ORE, Scaup feed almost exclusively on the non-native Zebra Mussel Dreissena polymorpha. This mussel was present in the ORE already in the 19th century and continues to be superabundant. Using the results of 22 Scaup censuses (November to April 2002/2003 to 2013/2014) from the whole ORE (523 km2 of water), we show that Scaup flocks follow areas with the greatest area of occurrence and biomass of the Zebra Mussel, while areas with low mussel densities are ignored. The numbers of Scaup in the ORE are primarily related to the area of Zebra Mussel occurrence on the lagoon’s bottom (km2) in a non-linear fashion. Zebra Mussels were absolutely prevalent (97% of biomass) in the digestive tracts of birds unintentionally by-caught in fishing nets (n = 32). We estimate that Scaup alone consume an average of 5 400 tons of Zebra Mussels annually, which represents 5.6% of the total resources of the mussel in the ORE. Our results provide a clear picture of the strong dependence of the declining, migratory duck species on the non-native mussel, its primary food in the ORE. Our findings are particularly important as they can form the basis for the conservation action plan aimed at saving the north-western European populations of Scaup. PMID:26709707

  4. Mouse Embryo Compaction.

    PubMed

    White, M D; Bissiere, S; Alvarez, Y D; Plachta, N

    2016-01-01

    Compaction is a critical first morphological event in the preimplantation development of the mammalian embryo. Characterized by the transformation of the embryo from a loose cluster of spherical cells into a tightly packed mass, compaction is a key step in the establishment of the first tissue-like structures of the embryo. Although early investigation of the mechanisms driving compaction implicated changes in cell-cell adhesion, recent work has identified essential roles for cortical tension and a compaction-specific class of filopodia. During the transition from 8 to 16 cells, as the embryo is compacting, it must also make fundamental decisions regarding cell position, polarity, and fate. Understanding how these and other processes are integrated with compaction requires further investigation. Emerging imaging-based techniques that enable quantitative analysis from the level of cell-cell interactions down to the level of individual regulatory molecules will provide a greater understanding of how compaction shapes the early mammalian embryo. © 2016 Elsevier Inc. All rights reserved.

  5. Scanning electron microscopy of Strongylus spp. in zebra.

    PubMed

    Els, H J; Malan, F S; Scialdo-Krecek, R C

    1983-12-01

    The external ultrastructure of the anterior and posterior extremities of the nematodes, Strongylus asini , Strongylus vulgaris, Strongylus equinus and Strongylus edentatus, was studied with scanning electron microscopy (SEM). Fresh specimens of S. asini were collected from the caecum, ventral colon and vena portae of Equus burchelli and Equus zebra hartmannae ; S. vulgaris from the caecum, colon and arteria ileocolica of E. burchelli ; S. equinus from the ventral colon of E. z. hartmannae and S. edentatus from the caecum and ventral colon of both zebras , during surveys of parasites in zebras in the Etosha Game Reserve, South West Africa/Namibia, and the Kruger National Park, Republic of South Africa. The worms were cleaned, fixed and mounted by standard methods and photographed in a JEOL JSM - 35C scanning electron microscope (SEM) operating at 12kV . The SEM showed the following differences: the tips of the external leaf-crowns varied and were fine and delicate in S. asini , coarse and broad in S. vulgaris and, in S. equinus and S. edentatus, closely adherent, separating into single elements for half their length. The excretory pores showed only slight variation, and the morphology of the copulatory bursae did not differ from those seen with light microscopy. The genital cones differed markedly: S. asini had a ventral triangular projection and laterally 2 finger-like projections: in S. vulgaris there were numerous bosses on the lateral and ventral aspects of the cone; in S. equinus 2 finger-like processes projected laterocaudally ; and in S. edentatus 2 pairs of papilla-like processes projected laterally on the ventral aspects, and a pair of rounded projections and a pair of hair-like structures adorned the dorsal aspects.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Digital gene expression analysis of the zebra finch genome

    PubMed Central

    2010-01-01

    Background In order to understand patterns of adaptation and molecular evolution it is important to quantify both variation in gene expression and nucleotide sequence divergence. Gene expression profiling in non-model organisms has recently been facilitated by the advent of massively parallel sequencing technology. Here we investigate tissue specific gene expression patterns in the zebra finch (Taeniopygia guttata) with special emphasis on the genes of the major histocompatibility complex (MHC). Results Almost 2 million 454-sequencing reads from cDNA of six different tissues were assembled and analysed. A total of 11,793 zebra finch transcripts were represented in this EST data, indicating a transcriptome coverage of about 65%. There was a positive correlation between the tissue specificity of gene expression and non-synonymous to synonymous nucleotide substitution ratio of genes, suggesting that genes with a specialised function are evolving at a higher rate (or with less constraint) than genes with a more general function. In line with this, there was also a negative correlation between overall expression levels and expression specificity of contigs. We found evidence for expression of 10 different genes related to the MHC. MHC genes showed relatively tissue specific expression levels and were in general primarily expressed in spleen. Several MHC genes, including MHC class I also showed expression in brain. Furthermore, for all genes with highest levels of expression in spleen there was an overrepresentation of several gene ontology terms related to immune function. Conclusions Our study highlights the usefulness of next-generation sequence data for quantifying gene expression in the genome as a whole as well as in specific candidate genes. Overall, the data show predicted patterns of gene expression profiles and molecular evolution in the zebra finch genome. Expression of MHC genes in particular, corresponds well with expression patterns in other vertebrates

  7. "Bird Song Metronomics": Isochronous Organization of Zebra Finch Song Rhythm.

    PubMed

    Norton, Philipp; Scharff, Constance

    2016-01-01

    The human capacity for speech and vocal music depends on vocal imitation. Songbirds, in contrast to non-human primates, share this vocal production learning with humans. The process through which birds and humans learn many of their vocalizations as well as the underlying neural system exhibit a number of striking parallels and have been widely researched. In contrast, rhythm, a key feature of language, and music, has received surprisingly little attention in songbirds. Investigating temporal periodicity in bird song has the potential to inform the relationship between neural mechanisms and behavioral output and can also provide insight into the biology and evolution of musicality. Here we present a method to analyze birdsong for an underlying rhythmic regularity. Using the intervals from one note onset to the next as input, we found for each bird an isochronous sequence of time stamps, a "signal-derived pulse," or pulse(S), of which a subset aligned with all note onsets of the bird's song. Fourier analysis corroborated these results. To determine whether this finding was just a byproduct of the duration of notes and intervals typical for zebra finches but not dependent on the individual duration of elements and the sequence in which they are sung, we compared natural songs to models of artificial songs. Note onsets of natural song deviated from the pulse(S) significantly less than those of artificial songs with randomized note and gap durations. Thus, male zebra finch song has the regularity required for a listener to extract a perceived pulse (pulse(P)), as yet untested. Strikingly, in our study, pulses(S) that best fit note onsets often also coincided with the transitions between sub-note elements within complex notes, corresponding to neuromuscular gestures. Gesture durations often equaled one or more pulse(S) periods. This suggests that gesture duration constitutes the basic element of the temporal hierarchy of zebra finch song rhythm, an interesting parallel

  8. Mercury alters initiation and construction of nests by zebra finches, but not incubation or provisioning behaviors.

    PubMed

    Chin, Stephanie Y; Hopkins, William A; Cristol, Daniel A

    2017-11-01

    Mercury is an environmental contaminant that impairs avian reproduction, but the behavioral and physiological mechanisms underlying this effect are poorly understood. The objective of this study was to determine whether lifetime dietary exposure to mercury (1.2 µg/g wet weight in food) impacted avian parental behaviors, and how this might influence reproductive success. To distinguish between the direct effects of mercury on parents and offspring, we created four treatment groups of captive-bred zebra finches (Taeniopygia guttata), with control and mercury-exposed adults raising cross-fostered control or mercury-exposed eggs (from maternal transfer). Control parents were 23% more likely to fledge young than parents exposed to mercury, regardless of egg exposure. Mercury-exposed parents were less likely to initiate nests than controls and spent less time constructing them. Nests of mercury-exposed pairs were lighter, possibly due to an impaired ability to bring nest material into the nestbox. However, nest temperature, incubation behavior, and provisioning rate did not differ between parental treatments. Unexposed control eggs tended to have shorter incubation periods and higher hatching success than mercury-exposed eggs, but there was no effect of parental exposure on these parameters. We accidentally discovered that parent finches transfer some of their body burden of mercury to nestlings during feeding through secretion in the crop. These results suggest that, in mercury-exposed songbirds, pre-laying parental behaviors, combined with direct exposure of embryos to mercury, likely contribute to reduced reproductive success and should be considered in future studies. Further research is warranted in field settings, where parents are exposed to greater environmental challenges and subtle behavioral differences might have more serious consequences than were observed in captivity.

  9. Effect of Calcium Chloride on the Permeation of the Cryoprotectant Dimethyl Sulfoxide to Japanese Whiting Sillago japonica Embryos

    NASA Astrophysics Data System (ADS)

    Rahman, Sk. Mustafizur; Majhi, Sullip Kumar; Suzuki, Toru; Strussmann, Carlos Augusto; Watanabe, Manabu

    Cryopreservation of fish eggs and embryos is a highly desired tool to promote aquaculture production and fisheries resource management, but it is still not technically feasible. The failure to develop successful cryopreservation protocols for fish embryos is largely attributed to poor cryoprotectant permeability. The purpose of this study was to test the effectiveness of CaCl2 to enhance cryoprotectant uptake by fish embryos. In this study, embryos (somites and tail elongation stages) of Japanese whiting Sillago japonica were exposed to 10 and 15% dimethyl sulfoxide (DMSO) in artificial sea water (ASW) or a solution of 0.125M CaCl2 in distilled water for 20 min at 24°C. The toxicity of all solutions was estimated from the hatching rates of the embryos and High Performance Liquid Chromatography was used to determine the amount of DMSO taken up during impregnation. The results showed that DMSO incorporation into the embryos was greatly (›50%) enhanced in the presence of CaCl2 compared to ASW. CaCl2 itself was not toxic to the embryos but, probably as a result of the enhanced DMSO uptake, caused decreases in survival of about 14-44% relative to ASW. Somites stage embryos were more tolerant than tail elongation ones to DMSO both as ASW and CaCl2 solutions. The use of CaCl2 as a vehicle for DMSO impregnation could be a promising aid for the successful cryopreservation of fish embryos.

  10. Factors Affecting Zebra Mussel Kill by the Bacterium Pseudomonas fluorescens

    SciTech Connect

    Daniel P. Molloy

    2004-02-24

    The specific purpose of this research project was to identify factors that affect zebra mussel kill by the bacterium Pseudomonas fluorescens. Test results obtained during this three-year project identified the following key variables as affecting mussel kill: treatment concentration, treatment duration, mussel siphoning activity, dissolved oxygen concentration, water temperature, and naturally suspended particle load. Using this latter information, the project culminated in a series of pipe tests which achieved high mussel kill inside power plants under once-through conditions using service water in artificial pipes.

  11. The First Human Cloned Embryo.

    ERIC Educational Resources Information Center

    Cibelli, Jose B.; Lanza, Robert P.; West, Michael D.; Ezzell, Carol

    2002-01-01

    Describes a process known as parthenogenesis which produces cloned, early-stage embryos and human embryos generated only from eggs. Speculates that this technology puts therapeutic cloning within reach. (DDR)

  12. Occurrence of zebra mussels in near-shore areas of western Lake Erie

    USGS Publications Warehouse

    Custer, Christine M.; Custer, T.W.

    1997-01-01

    Zebra mussels (Dreissena polymorpha) invaded the Great Lakes in the mid-1980s and quickly reached high densities. The objective of this study was to determine current consumption of zebra mussels by waterfowl in the Great Lakes region. Feeding Lesser Scaups (Aythya affinis), Greater Scaups (A. marila), Canvasbacks (A. valisineria), Redheads (A. americana), Buffleheads (Bucephala albeola) and Common Goldeneyes (B. clangula) were collected in western Lake Erie and in Lake St. Clair between fall and spring, 1992-1993 to determine food habits. All 10 Redheads, 97% of Lesser Scaups, 83% of Goldeneyes, 60% of Buffleheads and 9% of Canvasbacks contained one or more zebra mussels in their upper gastrointestinal tracts. The aggregate percent of zebra mussels in the diet of Lesser Scaups was higher in Lake Erie (98.6%) than in Lake St. Clair (54.4%). Zebra mussels, (aggregate percent) dominated the diet of Common Goldeneyes (79.2%) but not in Buffleheads (23.5%), Redheads (21%) or Canvasbacks (9%). Lesser Scaups from Lake Erie fed on larger zebra mussels ( = 10.7 i?? 0.66 mm SE) than did Lesser Scaups from Lake St. Clair ( = 4.4 i?? 0.22 mm). Lesser Scaups, Buffleheads and Common Goldeneyes from Lake Erie consumed zebra mussels of similar size.

  13. Concentration-dependent toxicity effect of SDBS on swimming behavior of freshwater fishes.

    PubMed

    Zhang, Ying; Ma, Jing; Zhou, Siyun; Ma, Fang

    2015-07-01

    Sodium dodecyl benzene sulfonate (SDBS) is a kind of widely used anionic surfactant and its discharge may pose potential risk to the receiving aquatic ecosystem. The aim of our study is to investigate the toxic effect of SDBS on fish swimming behavior quantitatively, followed by examination whether there are significant differences of swimming behavior among applied fish species (i.e. zebra fish (Danio rerio), Japanese medaka (Oryzias latipes) and red carp (Cyprinus carpio)). The swimming speed and vertical position were analyzed after the fish exposed to SDBS aiming to reflect the toxicity of SDBS on fish. Our results showed that the swimming behavior of three fishes was significantly affected by SDBS, although there were slight differences of swimming pattern changes among three fish species when they exposed to the same concentration of SDBS. It could be seen that red carp, one of the native fish species in China, can be used as a model fish to reflect the water quality changes as well as zebra fish and Japanese medaka which are commonly used as model fishes. Our study also illustrated that the swimming behavior monitoring may have a good application prospect in pre-warning of water quality. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Transient Overexpression of adh8a Increases Allyl Alcohol Toxicity in Zebrafish Embryos

    PubMed Central

    Klüver, Nils; Ortmann, Julia; Paschke, Heidrun; Renner, Patrick; Ritter, Axel P.; Scholz, Stefan

    2014-01-01

    Fish embryos are widely used as an alternative model to study toxicity in vertebrates. Due to their complexity, embryos are believed to more resemble an adult organism than in vitro cellular models. However, concerns have been raised with respect to the embryo's metabolic capacity. We recently identified allyl alcohol, an industrial chemical, to be several orders of magnitude less toxic to zebrafish embryo than to adult zebrafish (embryo LC50 = 478 mg/L vs. fish LC50 = 0.28 mg/L). Reports on mammals have indicated that allyl alcohol requires activation by alcohol dehydrogenases (Adh) to form the highly reactive and toxic metabolite acrolein, which shows similar toxicity in zebrafish embryos and adults. To identify if a limited metabolic capacity of embryos indeed can explain the low allyl alcohol sensitivity of zebrafish embryos, we compared the mRNA expression levels of Adh isoenzymes (adh5, adh8a, adh8b and adhfe1) during embryo development to that in adult fish. The greatest difference between embryo and adult fish was found for adh8a and adh8b expression. Therefore, we hypothesized that these genes might be required for allyl alcohol activation. Microinjection of adh8a, but not adh8b mRNA led to a significant increase of allyl alcohol toxicity in embryos similar to levels reported for adults (LC50 = 0.42 mg/L in adh8a mRNA-injected embryos). Furthermore, GC/MS analysis of adh8a-injected embryos indicated a significant decline of internal allyl alcohol concentrations from 0.23-58 ng/embryo to levels below the limit of detection (< 4.6 µg/L). Injection of neither adh8b nor gfp mRNA had an impact on internal allyl alcohol levels supporting that the increased allyl alcohol toxicity was mediated by an increase in its metabolization. These results underline the necessity to critically consider metabolic activation in the zebrafish embryo. As demonstrated here, mRNA injection is one useful approach to study the role of candidate enzymes involved in

  15. Transgenesis in fish.

    PubMed

    Houdebine, L M; Chourrout, D

    1991-09-15

    Gene transfer into fish embryo is being performed in several species (trout, salmon, carps, tilapia, medaka, goldfish, zebrafish, loach, catfish, etc.). In most cases, pronuclei are not visible and microinjection must be done into the cytoplasm of early embryos. Several million copies of the gene are generally injected. In medaka, transgenesis was attempted by injection of the foreign gene into the nucleus of oocyte. Several reports indicate that the injected DNA was rapidly replicated in the early phase of embryo development, regardless of the origin and the sequence of the foreign DNA. The survival of the injected embryos was reasonably good and a large number reached maturity. The proportion of transgenic animals ranged from 1 to 50% or more, according to species and to experimentators. The reasons for this discrepancy have not been elucidated. In all species, the transgenic animals were mosaic. The copy number of the foreign DNA was different in the various tissues of an animal and a proportion lower than 50% of F1 offsprings received the gene from their parents. This suggests that the foreign DNA was integrated into the fish genome at the two cells stage or later. An examination of the integrated DNA in different cell types of an animal revealed that integration occurred mainly during early development. The transgene was found essentially unrearranged in the fish genome of the founders and offsprings. The transgenes were therefore stably transmitted to progeny in a Mendelian fashion. Southern blot analysis revealed the presence of possible junction fragments and also of minor bands which may result from a rearrangement of the injected DNA. In all species, the integrated DNA appeared mainly as random end-to-end concatemers. In adult trout blood cells, a small proportion of the foreign DNA was maintained in the form of non-integrated concatemers, as judged by the existence of end fragments. The transgenes were generally only poorly expressed. The majority of the

  16. Amygdala and socio-sexual behavior in male zebra finches.

    PubMed

    Ikebuchi, Maki; Hasegawa, Toshikazu; Bischof, Hans-Joachim

    2009-01-01

    Neuroanatomical studies including pathway tracing and cytochemical characterizations have suggested that the avian nucleus taeniae of the amygdala (TnA) might be homologous to a part of the mammalian medial amygdala. Recent behavioral observations in TnA-lesioned birds also reported deficits in the control of motivational aspects of behavior, advancing the concept of homology of the structure in the two classes of animals. To further examine the functional role of TnA, we used a highly social, monogamous song bird species, the zebra finch, for our experiments. Male birds received a focal lesion of TnA, and several aspects of socio-sexual behavior of these animals were compared with control bird behavior. We found that zebra finch males with TnA lesions were never chosen as sexual partners by a female in a triadic situation with another male because they showed less sexually motivated behavior. Because such sexually motivated behavior was shown in dyadic situations with a lesioned male and a female, however, and females in this situation also showed pair bonding behavior towards the lesioned males, TnA might be involved in other behaviors, not just sexual behavior towards females. Instead, it might play a role in the control of a variety of social encounters including male-female and male-male interactions. This research clearly indicates that TnA, by its involvement in the control of socio-sexual behavior, is functionally comparable with the mammalian medial amygdala. 2009 S. Karger AG, Basel.

  17. Zebra pattern in decametric radio emission of Jupiter

    NASA Astrophysics Data System (ADS)

    Panchenko, M.; Rošker, S.; Rucker, H. O.; Brazhenko, A.; Zarka, P.; Litvinenko, G.; Shaposhnikov, V. E.; Konovalenko, A. A.; Melnik, V.; Franzuzenko, A. V.; Schiemel, J.

    2018-03-01

    We report the systematic analysis of zebra-like fine spectral structures in decametric frequency range of Jovian radio emission. Observations were performed by the large ground-based radio telescope URAN-2 during three observation campaigns between, Sep., 2012, and May, 2015. In total, 51 zebra pattern (ZP) events were detected. These rare fine radio features are observed in frequency range from 12.5 to 29.7 MHz as quasi-harmonically related bands of enhanced brightness. ZPs are strongly polarized radio emission with a duration from 20 s to 290 s and flux densities 105-106 Jy (normalized to 1 AU), that is, 1-2 orders lower than for Io-decametric radio emission (DAM). Occurrence of the events does not depend on the position of Io satellite but is strongly controlled by the Jovian central meridian longitude (CML). ZPs are mainly detected in two active sectors of Jovian CMLs: 100∘ to 160∘ for Northern sources (right-handed polarized) and 300∘ and 60∘ (via 360∘) for the Southern sources (left-handed). The frequency interval between neighboring stripes is from 0.26 to 1.5 MHz and in most cases this interval increases with frequency. We discussed the double plasma resonance with electrons or ions as a possible source of the ZPs. The performed analysis of the observations allows us to conclude that the observed ZPs are a new type of narrow band spectral structures in the Jovian DAM.

  18. Amyloidosis in a Captive Zebra Finch (Taeniopygia guttata) Research Colony

    PubMed Central

    Shientag, Lisa J; Garlick, David S; Galati, Erin

    2016-01-01

    Five birds in a captive zebra finch research colony were diagnosed with systemic amyloidosis within a 7-mo period by means of postmortem Congo red staining and green birefringence under polarized light. The liver was the most frequently and usually the most seriously affected organ, followed by the spleen and then the kidney. All 5 birds had been clinically affected with various inflammatory, infectious, and neoplastic conditions associated with amyloid A (AA) amyloidosis in humans and animals. Immunohistochemistry using antisera against duck AA protein revealed that tissues from 2 of the 5 birds were positive for the presence of AA protein and systemic inflammation-associated amyloidosis. Although the development of AA amyloidosis has been associated with chronic inflammation, trauma, and various infectious and neoplastic diseases as well as possible genetic predispositions and stresses linked to overcrowding, the root causes for individual cases of AA amyloidosis are incompletely understood. As far as we know, this report is the first description of AA amyloidosis in captive, research zebra finches. PMID:27298248

  19. Evolutionary Analysis and Expression Profiling of Zebra Finch Immune Genes

    PubMed Central

    Ekblom, Robert; French, Lisa; Slate, Jon; Burke, Terry

    2010-01-01

    Genes of the immune system are generally considered to evolve rapidly due to host–parasite coevolution. They are therefore of great interest in evolutionary biology and molecular ecology. In this study, we manually annotated 144 avian immune genes from the zebra finch (Taeniopygia guttata) genome and conducted evolutionary analyses of these by comparing them with their orthologs in the chicken (Gallus gallus). Genes classified as immune receptors showed elevated dN/dS ratios compared with other classes of immune genes. Immune genes in general also appear to be evolving more rapidly than other genes, as inferred from a higher dN/dS ratio compared with the rest of the genome. Furthermore, ten genes (of 27) for which sequence data were available from at least three bird species showed evidence of positive selection acting on specific codons. From transcriptome data of eight different tissues, we found evidence for expression of 106 of the studied immune genes, with primary expression of most of these in bursa, blood, and spleen. These immune-related genes showed a more tissue-specific expression pattern than other genes in the zebra finch genome. Several of the avian immune genes investigated here provide strong candidates for in-depth studies of molecular adaptation in birds. PMID:20884724

  20. Zebra finches are able to learn affixation-like patterns.

    PubMed

    Chen, Jiani; Jansen, Naomi; ten Cate, Carel

    2016-01-01

    Adding an affix to transform a word is common across the world languages, with the edges of words more likely to carry out such a function. However, detecting affixation patterns is also observed in learning tasks outside the domain of language, suggesting that the underlying mechanism from which affixation patterns have arisen may not be language or even human specific. We addressed whether a songbird, the zebra finch, is able to discriminate between, and generalize, affixation-like patterns. Zebra finches were trained and tested in a Go/Nogo paradigm to discriminate artificial song element sequences resembling prefixed and suffixed 'words.' The 'stems' of the 'words,' consisted of different combinations of a triplet of song elements, to which a fourth element was added as either a 'prefix' or a 'suffix.' After training, the birds were tested with novel stems, consisting of either rearranged familiar element types or novel element types. The birds were able to generalize the affixation patterns to novel stems with both familiar and novel element types. Hence, the discrimination resulting from the training was not based on memorization of individual stimuli, but on a shared property among Go or Nogo stimuli, i.e., affixation patterns. Remarkably, birds trained with suffixation as Go pattern showed clear evidence of using both prefix and suffix, while those trained with the prefix as the Go stimulus used primarily the prefix. This finding illustrates that an asymmetry in attending to different affixations is not restricted to human languages.

  1. Staged Z-pinch Experiments on Cobra and Zebra

    NASA Astrophysics Data System (ADS)

    Wessel, Frank J.; Anderson, A.; Banasek, J. T.; Byvank, T.; Conti, F.; Darling, T. W.; Dutra, E.; Glebov, V.; Greenly, J.; Hammer, D. A.; Potter, W. M.; Rocco, S. V.; Ross, M. P.; Ruskov, E.; Valenzuela, J.; Beg, F.; Covington, A.; Narkis, J.; Rahman, H. U.

    2017-10-01

    A Staged Z-pinch (SZP), configured as a pre-magnetized, high-Z (Ar, or Kr) annular liner imploding onto a low-Z (H, or D) target, was tested on the Cornell University, Cobra Facility and the University of Nevada, Reno, Zebra Facility; each characterized similarly by a nominal 1-MA current and 100-ns risetime while possessing different diagnostic packages. XUV-fast imaging reveals that the SZP implosion dynamics is similar on both machines and that it is more stable with an axial (Bz) magnetic field, a target, or both, than without. On Zebra, where neutron production is possible, reproducible thermonuclear (DD) yields were recorded at levels in excess of 109/shot. Flux compression in the SZP is also expected to produce magnetic field intensities of the order of kilo-Tesla. Thus, the DD reaction produced tritions should also yield secondary DT neutrons. Indeed, secondaries are measured above the noise threshold at levels approaching 106/shot. Funded by the Advanced Research Projects Agency - Energy, under Grant Number DE-AR0000569.

  2. Colour preferences in nest-building zebra finches.

    PubMed

    Muth, Felicity; Steele, Matthew; Healy, Susan D

    2013-10-01

    Some bird species are selective in the materials they choose for nest building, preferring, for example, materials of one colour to others. However, in many cases the cause of these preferences is not clear. One of those species is the zebra finch, which exhibits strong preferences for particular colours of nest material. In an attempt to determine why these birds strongly prefer one colour of material over another, we compared the preferences of paired male zebra finches for nest material colour with their preferences for food of the same colours. We found that birds did indeed prefer particular colours of nest material (in most cases blue) but that they did not generally prefer food of one colour over the other colours. It appears, then, that a preference for one colour or another of nest material is specific to the nest-building context. This article is part of a Special Issue entitled: insert SI title. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. The Virtual Embryo Project

    EPA Science Inventory

    The v-Embryo™ is a far reaching new research program at the US EPA to develop a working computer model of a mammalian embryo that can be used to better understand the prenatal risks posed by environmental chemicals and to eventually predict a chemical’s potential developmental to...

  4. Longitudinal patterns in abundance of the zebra mussel (Dreissena polymorpha) in the upper Mississippi River

    USGS Publications Warehouse

    Cope, W.G.; Bartsch, M.R.; Hayden, R.R.

    1997-01-01

    We assessed the abundance of zebra mussels in the upper Mississippi River during 1995, four years after they were first found in the river. Samplers were deployed from May 30 to October 19, 1995, at 19 lock and dam facilities in the upper Mississippi River from Minneapolis, Minnesota, to Muscatine, Iowa. Zebra mussels were found at every lock and dam except the two sites farthest upstream (Minneapolis). Generally, densities of zebra mussels were greatest at sites 161 km and farther downstream of the Minneapolis area. The greatest mean mussel density was 11,432/m(2) at Fulton, Illinois.

  5. Embryo Aggregation in Pig Improves Cloning Efficiency and Embryo Quality.

    PubMed

    Buemo, Carla Paola; Gambini, Andrés; Moro, Lucia Natalia; Hiriart, María Inés; Fernández-Martín, Rafael; Collas, Philippe; Salamone, Daniel Felipe

    2016-01-01

    In this study, we analyzed the effects of the cloned embryo aggregation on in vitro embryo development and embryo quality by measuring blastocyst diameter and cell number, DNA fragmentation levels and the expression of genes associated with pluripotency, apoptosis, trophoblast and DNA methylation in the porcine. Zona-free reconstructed cloned embryos were cultured in the well of the well system, placing one (1x non aggregated group) or three (3x group) embryos per microwell. Our results showed that aggregation of three embryos increased blastocyst formation rate and blastocyst diameter of cloned pig embryos. DNA fragmentation levels in 3x aggregated cloned blastocysts were significantly decreased compared to 1x blastocysts. Levels of Oct4, Klf4, Igf2, Bax and Dnmt 1 transcripts were significantly higher in aggregated embryos, whereas Nanog levels were not affected. Transcripts of Cdx2 and Bcl-xl were essentially non-detectable. Our study suggests that embryo aggregation in the porcine may be beneficial for cloned embryo development and embryo quality, through a reduction in apoptotic levels and an improvement in cell reprogramming.

  6. Zebrafish embryo developmental toxicology assay.

    PubMed

    Panzica-Kelly, Julieta M; Zhang, Cindy X; Augustine-Rauch, Karen

    2012-01-01

    A promising in vitro zebrafish developmental toxicology assay was generated to test compounds for their teratogenic potential. The assay's predictivity is approximately 87% in AB strain fish (Brannen KC et al., Birth Defects Res B Dev Reprod Toxicol 89:66-77, 2010). The procedure entails exposing dechorionated gastrulation-stage embryos to a range of compound concentrations for 5 days throughout embryonic and larva development. The larvae are evaluated for viability in order to identify an LC25 (the compound concentration in which 25% lethality is observed) and morphological anomalies using a numerical score system to identify the NOAEL (no observed adverse effect level). These values are used to calculate the teratogenic index (LC25/NOAEL ratio) of each compound. If the teratogenic index is equal to or greater than 10 then the compound is classified as a teratogen, and if the ratio is less than 10 then the compound is classified as a nonteratogen (Brannen KC et al., Birth Defects Res B Dev Reprod Toxicol 89:66-77, 2010).

  7. Progressive hypoxia decouples activity and aerobic performance of skate embryos

    PubMed Central

    Di Santo, Valentina; Tran, Anna H.; Svendsen, Jon C.

    2016-01-01

    Although fish population size is strongly affected by survival during embryonic stages, our understanding of physiological responses to environmental stressors is based primarily on studies of post-hatch fishes. Embryonic responses to acute exposure to changes in abiotic conditions, including increase in hypoxia, could be particularly important in species exhibiting long developmental time, as embryos are unable to select a different environment behaviourally. Given that oxygen is key to metabolic processes in fishes and aquatic hypoxia is becoming more severe and frequent worldwide, organisms are expected to reduce their aerobic performance. Here, we examined the metabolic and behavioural responses of embryos of a benthic elasmobranch fish, the little skate (Leucoraja erinacea), to acute progressive hypoxia, by measuring oxygen consumption and movement (tail-beat) rates inside the egg case. Oxygen consumption rates were not significantly affected by ambient oxygen levels until reaching 45% air saturation (critical oxygen saturation, Scrit). Below Scrit, oxygen consumption rates declined rapidly, revealing an oxygen conformity response. Surprisingly, we observed a decoupling of aerobic performance and activity, as tail-beat rates increased, rather than matching the declining metabolic rates, at air saturation levels of 55% and below. These results suggest a significantly divergent response at the physiological and behavioural levels. While skate embryos depressed their metabolic rates in response to progressive hypoxia, they increased water circulation inside the egg case, presumably to restore normoxic conditions, until activity ceased abruptly around 9.8% air saturation. PMID:27293746

  8. Progressive hypoxia decouples activity and aerobic performance of skate embryos.

    PubMed

    Di Santo, Valentina; Tran, Anna H; Svendsen, Jon C

    2016-01-01

    Although fish population size is strongly affected by survival during embryonic stages, our understanding of physiological responses to environmental stressors is based primarily on studies of post-hatch fishes. Embryonic responses to acute exposure to changes in abiotic conditions, including increase in hypoxia, could be particularly important in species exhibiting long developmental time, as embryos are unable to select a different environment behaviourally. Given that oxygen is key to metabolic processes in fishes and aquatic hypoxia is becoming more severe and frequent worldwide, organisms are expected to reduce their aerobic performance. Here, we examined the metabolic and behavioural responses of embryos of a benthic elasmobranch fish, the little skate (Leucoraja erinacea), to acute progressive hypoxia, by measuring oxygen consumption and movement (tail-beat) rates inside the egg case. Oxygen consumption rates were not significantly affected by ambient oxygen levels until reaching 45% air saturation (critical oxygen saturation, S crit). Below S crit, oxygen consumption rates declined rapidly, revealing an oxygen conformity response. Surprisingly, we observed a decoupling of aerobic performance and activity, as tail-beat rates increased, rather than matching the declining metabolic rates, at air saturation levels of 55% and below. These results suggest a significantly divergent response at the physiological and behavioural levels. While skate embryos depressed their metabolic rates in response to progressive hypoxia, they increased water circulation inside the egg case, presumably to restore normoxic conditions, until activity ceased abruptly around 9.8% air saturation.

  9. OpenSource lab-on-a-chip physiometer for accelerated zebrafish embryo biotests.

    PubMed

    Akagi, Jin; Hall, Chris J; Crosier, Kathryn E; Cooper, Jonathan M; Crosier, Philip S; Wlodkowic, Donald

    2014-01-02

    Zebrafish (Danio rerio) embryo assays have recently come into the spotlight as convenient experimental models in both biomedicine and ecotoxicology. As a small aquatic model organism, zebrafish embryo assays allow for rapid physiological, embryo-, and genotoxic tests of drugs and environmental toxins that can be simply dissolved in water. This protocol describes prototyping and application of an innovative, miniaturized, and polymeric chip-based device capable of immobilizing a large number of living fish embryos for real-time and/or time-lapse microscopic examination. The device provides a physical address designation to each embryo during analysis, continuous perfusion of medium, and post-analysis specimen recovery. Miniaturized embryo array is a new concept of immobilization and real-time drug perfusion of multiple individual and developing zebrafish embryos inside the mesofluidic device. The OpenSource device presented in this protocol is particularly suitable to perform accelerated fish embryo biotests in ecotoxicology and phenotype-based pharmaceutical screening. Copyright © 2014 John Wiley & Sons, Inc.

  10. Predicting the spread of aquatic invaders: insight from 200 years of invasion by zebra mussels.

    PubMed

    Karatayev, Alexander Y; Burlakova, Lyubov E; Mastitsky, Sergey E; Padilla, Dianna K

    2015-03-01

    Understanding factors controlling the introduction and spread of species is crucial to improving the management of both natural populations and introduced species. The zebra mussel, Dreissena polymorpha, is considered the most aggressive freshwater invader in the Northern Hemisphere, and is a convenient model system for invasion biology, offering one of the best aquatic examples for examining the invasion process. We used data on 553 of the 1040 glacial lakes in the Republic of Belarus that were examined for the presence of zebra mussels. We used these data to build, test, and construct modified models to predict the spread of this invader, including selection of important parameters that could limit the spread of this invader. In spite of 200 years of continuous invasion, by 1996, zebra mussels were found in only 16.8% of all lakes studied. Of those lakes without zebra mussels in 1996, 66% were predicted to be susceptible to invasion by zebra mussels in the future, and 33% were predicted to be immune to successful invasion due to their water chemistry. Eighty lakes free of zebra mussels in 1996 were reexamined from 1997 to 2008. Of these, zebra mussels successfully invaded an additional 31 lakes, all of which were classified initially as suitable for zebra mussels; none of the lakes previously classified as unsuitable were invaded. We used the Random Forests classification algorithm with 16 environmental variables to determine the most important factors that differed between invaded lakes and those lakes suitable for invasion that have not yet been invaded. Distance to the nearest infested lakes was found to be the most important variable, followed by the lake area, color, average depth, and concentration of chloride, magnesium, and bicarbonate. This study provides a useful approach for predicting the spread of an invader across a landscape with variable habitat suitability that can be applied to a variety of species and systems.

  11. Immunoelectron microscopy in embryos.

    PubMed

    Sierralta, W D

    2001-05-01

    Immunogold labeling of proteins in sections of embryos embedded in acrylate media provides an important analytical tool when the resolving power of the electron microscope is required to define sites of protein function. The protocol presented here was established to analyze the role and dynamics of the activated protein kinase C/Rack1 regulatory system in the patterning and outgrowth of limb bud mesenchyme. With minor changes, especially in the composition of the fixative solution, the protocol should be easily adaptable for the postembedding immunogold labeling of any other antigen in tissues of embryos of diverse species. Quantification of the labeling can be achieved by using electron microscope systems capable of supporting digital image analysis. Copyright 2001 Academic Press.

  12. Ensoulment and IVF embryos.

    PubMed Central

    Shea, M C

    1987-01-01

    This paper examines the metaphysical question of 'ensoulment' in relation to the theory, put forward in an earlier paper, that human life begins when the newly formed body organs and systems of the embryo begin to function as an organised whole, at which stage there is evidence of a change of nature. Although Roman Catholic theology teaches that a human being is a union of physical body and spiritual soul, it is incorrect to interpret this in a dualistic sense. The meaning of 'soul' is considered and the conclusion reached that although both in the religious context and apart from it abortion is difficult to justify at any stage after conception, it does not follow that the use of 'spare' In Vitro Fertilisation (IVF) embryos should be rejected. If 'ensoulment' does not occur until the new organism functions as a whole then a decision not to make use of IVF embryos for medical purposes would be a heavy responsibility and not a 'safe' way out. PMID:3612702

  13. Kin recognition and adjustment of reproductive effort in zebra finches.

    PubMed

    Arct, Aneta; Rutkowska, Joanna; Martyka, Rafal; Drobniak, Szymon M; Cichon, Mariusz

    2010-12-23

    The differential allocation theory predicts that females should invest more in offspring produced with attractive partners, and a number of studies support this prediction in birds. Females have been shown to increase reproductive investment when mated to males showing elaborated sexual traits. However, mate attractiveness might also depend on the interaction between male and female genotypes. Accordingly, females should invest more in offspring sired by individuals that are genetically dissimilar or carry superior alleles. Here, we show in zebra finches (Taeniopygia guttata) that pairs of unfamiliar genetic brothers and sisters are less likely to reproduce in comparison with randomly mated pairs. Among the brother-sister pairs, those that attempted to breed laid smaller clutches and of lower total clutch mass. Our results provide the first experimental evidence that females adjust their reproductive effort in response to the genetic similarity of their partners. Importantly, these results imply a female ability to assess relatedness of a social mate without prior association.

  14. Kin recognition and adjustment of reproductive effort in zebra finches

    PubMed Central

    Arct, Aneta; Rutkowska, Joanna; Martyka, Rafał; Drobniak, Szymon M.; Cichoń, Mariusz

    2010-01-01

    The differential allocation theory predicts that females should invest more in offspring produced with attractive partners, and a number of studies support this prediction in birds. Females have been shown to increase reproductive investment when mated to males showing elaborated sexual traits. However, mate attractiveness might also depend on the interaction between male and female genotypes. Accordingly, females should invest more in offspring sired by individuals that are genetically dissimilar or carry superior alleles. Here, we show in zebra finches (Taeniopygia guttata) that pairs of unfamiliar genetic brothers and sisters are less likely to reproduce in comparison with randomly mated pairs. Among the brother–sister pairs, those that attempted to breed laid smaller clutches and of lower total clutch mass. Our results provide the first experimental evidence that females adjust their reproductive effort in response to the genetic similarity of their partners. Importantly, these results imply a female ability to assess relatedness of a social mate without prior association. PMID:20573618

  15. Transformation of temporal sequences in the zebra finch auditory system

    PubMed Central

    Lim, Yoonseob; Lagoy, Ryan; Shinn-Cunningham, Barbara G; Gardner, Timothy J

    2016-01-01

    This study examines how temporally patterned stimuli are transformed as they propagate from primary to secondary zones in the thalamorecipient auditory pallium in zebra finches. Using a new class of synthetic click stimuli, we find a robust mapping from temporal sequences in the primary zone to distinct population vectors in secondary auditory areas. We tested whether songbirds could discriminate synthetic click sequences in an operant setup and found that a robust behavioral discrimination is present for click sequences composed of intervals ranging from 11 ms to 40 ms, but breaks down for stimuli composed of longer inter-click intervals. This work suggests that the analog of the songbird auditory cortex transforms temporal patterns to sequence-selective population responses or ‘spatial codes', and that these distinct population responses contribute to behavioral discrimination of temporally complex sounds. DOI: http://dx.doi.org/10.7554/eLife.18205.001 PMID:27897971

  16. Gender determination of avian embryo

    DOEpatents

    Daum, Keith A.; Atkinson, David A.

    2002-01-01

    Disclosed is a method for gender determination of avian embryos. During the embryo incubation process, the outer hard shells of eggs are drilled and samples of allantoic fluid are removed. The allantoic fluids are directly introduced into an ion mobility spectrometer (IMS) for analysis. The resulting spectra contain the relevant marker peaks in the positive or negative mode which correlate with unique mobilities which are sex-specific. This way, the gender of the embryo can be determined.

  17. Elucidating the origin of chromosomal aberrations in IVF embryos by preimplantation genetic analysis.

    PubMed

    Frumkin, Tsvia; Malcov, Mira; Yaron, Yuval; Ben-Yosef, Dalit

    2008-01-30

    Preimplantation genetic screening (PGS) has been proposed as a method for improving success rates in patients with repeated IVF failures. This approach is based on the hypothesis that such failures are the result of aneuploid embryos. It has been suggested that FISH analysis of blastomeres removed from preimplantation embryos represent the chromosomal constitution of the entire embryo. However, it is not yet clear whether it also represents the chromosomal constitution of the implanted embryo. PGS reanalysis on day 5 of embryos designated as "aneuploid" on day 3 may demonstrate a high rate of mosaicism for chromosomal aberration. Some of these mosaic embryos are capable of developing into normal embryos by "self-correction". Others, however, may accumulate additional chromosomal anomalies. It is therefore concluded that the chromosomal constitution of a preimplantation embryo may evolve during early cleavages. Meiotic and post zygotic mitotic errors may account for these chromosomal aberrations. This review will focus on elucidating the origin of chromosomal changes during preimplantation embryo development by studying their chromosomal constitution at different stages.

  18. The antifreeze protein type I (AFP I) increases seabream (Sparus aurata) embryos tolerance to low temperatures.

    PubMed

    Robles, V; Barbosa, V; Herráez, M P; Martínez-Páramo, S; Cancela, M L

    2007-07-15

    To date, all attempts at fish embryo cryopreservation have failed. One of the main reasons for this to occur is the high chilling sensitivity reported in fish embryos thus emphasizing the need for further testing of different methods and alternative cryoprotective agents (CPAs) in order to improve our chances to succeed in this purpose. In this work we have used the antifreeze protein type I (AFP I) as a natural CPA. This protein is naturally expressed in sub-arctic fish species, and inhibits the growth of ice crystals as well as recrystallization during thawing. Embryos from Sparus aurata were microinjected with AFP I at different developmental stages, 2 cells and blastula, into the blastomere-yolk interface and into the yolk sac, respectively. Control, punctured and microinjected embryos were subjected to chilling at two different temperatures, 0 degrees C (1h) and -10 degrees C (15min) when embryos reached 5-somite stage. Embryos were subjected to -10 degrees C chilling in a 3M DMSO extender to avoid ice crystal formation in the external solution. Survival after chilling was established as the percentage of embryos that hatch. To study the AFP I distribution in the microinjected embryos, a confocal microscopy study was done. Results demonstrate that AFP I can significantly improve chilling resistance at 0 degrees C, particularly in 2-cell microinjected embryos, displaying nearly 100% hatching rates. This fact is in agreement with the confocal microscopy observations which confirmed the presence of the AFP protein in embryonic cells. These results support the hypothesis that AFP protect cellular structures by stabilizing cellular membranes.

  19. Human research cloning, embryos, and embryo-like artifacts.

    PubMed

    Hyun, Insoo; Jung, Kyu Won

    2006-01-01

    Research suggests that cloning is incapable of producing a viable embryo when it is used on primate eggs. In fact, the entity created may not qualify as an embryo at all. If the results stand, cloning avoids the moral objections typically lodged against it, and cloning is itself an "alternative source" of stem cells.

  20. Morphological embryo selection: an elective single embryo transfer proposal.

    PubMed

    Déniz, Francisco Parera; Encinas, Carlos; Fuente, Jorge La

    2018-03-01

    To describe a patient selection method for elective single embryo transfer (eSET), emphasizing inclusion criteria and results. This retrospective study included all cases seen in a private clinic between June 2011 and December 2016, in La Paz, Bolivia (3600 meters above sea level). Elective single embryo transfer was the method of choice in 34 IVF/ICSI cycles, all in the blastocyst stage. Gardner's blastocyst classification criteria were used. Between the two stages of the study (July 2015), each embryo grade implantation rate was recalculated, which led to the expansion of the inclusion criteria. The clinical pregnancy rate of the 34 cases in the first transfer group was 55.9% (19/34). Twin or multiple pregnancies did not occur. The cumulative pregnancy rate to date is 64% [(19+3)/34]. The first stage comprised 2.56% (12/468) of the patients offered elective single embryo transfers; the implantation rate was 58.3% (7/12). In the second stage, 14.29% (22/154) of the patients were eligible, and the implantation rate was 54.55% (12/22). The implementation of an eSET program based on in-depth morphological embryo assessment combined with the calculation of the implantation potential of each embryo grade led to acceptable clinical outcomes and fewer multiple pregnancies in patients transferred two embryos. Each clinic should be aware of the implantation rates of each embryo grade in its own setting.

  1. Morphological embryo selection: an elective single embryo transfer proposal

    PubMed Central

    Déniz, Francisco Parera; Encinas, Carlos; Fuente, Jorge La

    2018-01-01

    Objective To describe a patient selection method for elective single embryo transfer (eSET), emphasizing inclusion criteria and results. Methods This retrospective study included all cases seen in a private clinic between June 2011 and December 2016, in La Paz, Bolivia (3600 meters above sea level). Elective single embryo transfer was the method of choice in 34 IVF/ICSI cycles, all in the blastocyst stage. Gardner's blastocyst classification criteria were used. Between the two stages of the study (July 2015), each embryo grade implantation rate was recalculated, which led to the expansion of the inclusion criteria. Results The clinical pregnancy rate of the 34 cases in the first transfer group was 55.9% (19/34). Twin or multiple pregnancies did not occur. The cumulative pregnancy rate to date is 64% [(19+3)/34]. The first stage comprised 2.56% (12/468) of the patients offered elective single embryo transfers; the implantation rate was 58.3% (7/12). In the second stage, 14.29% (22/154) of the patients were eligible, and the implantation rate was 54.55% (12/22). Conclusion The implementation of an eSET program based on in-depth morphological embryo assessment combined with the calculation of the implantation potential of each embryo grade led to acceptable clinical outcomes and fewer multiple pregnancies in patients transferred two embryos. Each clinic should be aware of the implantation rates of each embryo grade in its own setting. PMID:29338137

  2. [How can we nowadays select the best embryo to transfer?].

    PubMed

    Alter, L; Boitrelle, F; Sifer, C

    2014-01-01

    Multiple pregnancies stand as the most common adverse outcome of assisted reproduction technologies (ART) and the dangers associated with those pregnancies have been reduced by doing elective single embryo transfers (e-SET). Many studies have shown that e-SET is compatible with a continuously high pregnancy rate per embryo transfer. Yet, it still becomes necessary to improve the selection process in order to define the quality of individual embryos - so that the ones we choose for transfer are more likely to implant. First, analysis of embryo morphology has greatly helped in this identification and remains the most relevant criterion for choosing the embryo. The introduction of time-lapse imaging provides new criteria predictive of implantation potential, but the real contribution of this system - including the benefit/cost ratio - seems to be not yet properly established. In this context, extended culture until blastocyst stage is an essential practice but it appears wise to keep it for a population showing a good prognosis. Then, the failure of aneuploid embryos to implant properly led to achieve preimplantation genetic screening (PGS) in order to increase pregnancy and delivery rates after ART. However, PGS by fluorescence in situ hybridization (FISH) at day 3 is a useless process - and may even be harmful. Another solution involves using comparative genomic hybridisation (CGH) and moving to blastocyst biopsy. Finally, it is envisaged that morphology will also be significantly aided by non-invasive analysis of biomarkers in the culture media that give a better reflection of whole-embryo physiology and function. Copyright © 2014. Published by Elsevier SAS.

  3. Susceptibility and antibody response of the laboratory model zebra finch (Taeniopygia guttata) to West Nile Virus

    USGS Publications Warehouse

    Hofmeister, Erik K.; Lund, Melissa; Shearn-Bochsler, Valerie I.; Balakrishnan, Christopher N.

    2017-01-01

    Since the introduction of West Nile virus (WNV) into North America in 1999 a number of passerine bird species have been found to play a role in the amplification of the virus. Arbovirus surveillance, observational studies and experimental studies have implicated passerine birds (songbirds, e.g., crows, American robins, house sparrows, and house finches) as significant reservoirs of WNV in North America, yet we lack a tractable passerine animal model for controlled studies of the virus. The zebra finch (Taeniopygia guttata) serves as a model system across a diversity of fields, and here we develop the zebra finch a songbird model for WNV. Like many natural hosts of WNV, we found that zebra finches developed sufficient viremia to serve as a competent host, yet in general resisted mortality from infection. In the Australian zebra finch (AZF) T. g. castanotis, we detected WNV in the majority of sampled tissues by 4 days post injection (dpi). However, WNV was not detected in tissues of sacrificed birds at 14 dpi, shortly after the development of detectable anti-WNV antibodies in the majority of birds indicating successful viral clearance. We compared susceptibility between the two zebra finch subspecies AZF and Timor zebra finch (TZF) T. g. guttata. Compared to AZF, WNV RNA was detected in a larger proportion of challenged TZF and molecular detection of virus in the serum of TZF was significantly higher than in AZF. Given the observed moderate host competence and disease susceptibility, we suggest that zebra finches are appropriate as models for the study of WNV and although underutilized in this respect, may be ideal models for the study of the many diseases carried and transmitted by songbirds.

  4. Zebra stripes in the Atacama Desert: Fossil evidence of overland flow

    NASA Astrophysics Data System (ADS)

    Owen, Justine J.; Dietrich, William E.; Nishiizumi, Kuni; Chong, Guillermo; Amundson, Ronald

    2013-01-01

    Some hillslopes in the hyperarid region of the Atacama Desert in northern Chile have surface clasts organized into distinct, contour-parallel bands separated by bare soil. We call the bands "zebra stripes" due to the contrast between the darkly varnished clasts and the light-colored, salt-rich soil. Gravel that comprises the zebra stripes is sorted such that the coarsest clasts are at the downslope front and fine progressively upslope. How and when the zebra stripes formed are perplexing questions, particularly in a region experiencing prolonged hyperaridity. Using GoogleEarth, satellite imagery, and field observations, we report the first quantitative and qualitative observations of zebra stripes in order to test hypotheses of the mechanisms and timing of their formation. We consider soil shrink-swell, seismic shaking, and overland flow as possible formation mechanisms, and find that overland flow is the most likely. Based on cosmogenic 10Be concentrations in surface clasts, salt deposition rates from the atmosphere, and content in the soils, we propose that the salt-rich soils began accumulating ~ 106 y ago and the zebra stripes formed 103-104 y at the latest. The zebra stripe pattern has been preserved due to the self-stabilization of the clasts within the stripes and the continued absence of life (which would disturb the surface, as seen at a wetter site to the south). We conclude that the occurrence of zebra stripes is diagnostic of a set of distinct characteristics of local and/or regional precipitation, soil, hillslope form, and bedrock type.

  5. The early-stage diagnosis of albinic embryos by applying optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Yang, Bor-Wen; Wang, Shih-Yuan; Wang, Yu-Yen; Cai, Jyun-Jhang; Chang, Chung-Hao

    2013-09-01

    Albinism is a kind of congenital disease of abnormal metabolism. Poecilia reticulata (guppy fish) is chosen as the model to study the development of albinic embryos as it is albinic, ovoviviparous and with short life period. This study proposed an imaging method for penetrative embryo investigation using optical coherence tomography. By imaging through guppy mother’s reproduction purse, we found the embryo’s eyes were the early-developed albinism features. As human’s ocular albinism typically appear at about four weeks old, it is the time to determine if an embryo will grow into an albino.

  6. Characterization of host plant resistance to zebra chip disease from species-derived potato genotypes and the identification of new sources of zebra chip resistance

    USDA-ARS?s Scientific Manuscript database

    ‘Candidatus Liberibacter solanacearum’ (Lso), an uncultivable phloem-limited phytopathogenic bacterium, is known to be associated with Zebra Chip disease (ZC), which represents a major threat to potato production in the US and elsewhere. This pathogen is transmitted by the phloem-feeding potato psyl...

  7. Biotechnology applied to fish reproduction: tools for conservation.

    PubMed

    de Siqueira-Silva, Diógenes Henrique; Saito, Taiju; Dos Santos-Silva, Amanda Pereira; da Silva Costa, Raphael; Psenicka, Martin; Yasui, George Shigueki

    2018-04-29

    This review discusses the new biotechnological tools that are arising and promising for conservation and enhancement of fish production, mainly regarding the endangered and the most economically important species. Two main techniques, in particular, are available to avoid extinction of endangered fish species and to improve the production of commercial species. Germ cell transplantation technology includes a number of approaches that have been studied, such as the transplantation of embryo-to-embryo blastomere, embryo-to-embryo differentiated PGC, larvae to larvae and embryo differentiated PGC, transplantation of spermatogonia from adult to larvae or between adults, and oogonia transplantation. However, the success of germ cell transplantation relies on the prior sterilization of fish, which can be performed at different stages of fish species development by means of several protocols that have been tested in order to achieve the best approach to produce a sterile fish. Among them, fish hybridization and triploidization, germline gene knockdown, hyperthermia, and chemical treatment deserve attention based on important results achieved thus far. This review currently used technologies and knowledge about surrogate technology and fish sterilization, discussing the stronger and the weaker points of each approach.

  8. Metabolomic Assessment of Embryo Viability

    PubMed Central

    Uyar, Asli; Seli, Emre

    2014-01-01

    Preimplantation embryo metabolism demonstrates distinctive characteristics associated with the developmental potential of embryos. On this basis, metabolite content of culture media was hypothesized to reflect the implantation potential of individual embryos. This hypothesis was tested in consecutive studies reporting a significant association between culture media metabolites and embryo development or clinical pregnancy. The need for a noninvasive, reliable, and rapid embryo assessment strategy promoted metabolomics studies in vitro fertilization (IVF) in an effort to increase success rates of single embryo transfers. With the advance of analytical techniques and bioinformatics, commercial instruments were developed to predict embryo viability using spectroscopic analysis of surplus culture media. However, despite the initial promising results from proof-of-principal studies, recent randomized controlled trials using commercial instruments failed to show a consistent benefit in improving pregnancy rates when metabolomics is used as an adjunct to morphology. At present, the application of metabolomics technology in clinical IVF laboratory requires the elimination of factors underlying inconsistent findings, when possible, and development of reliable predictive models accounting for all possible sources of bias throughout the embryo selection process. PMID:24515909

  9. Elective single-embryo transfer.

    PubMed

    2012-04-01

    As in vitro fertilization implantation rates have improved, the practice of transfering multiple embryos must be evaluated. The purpose of this document is to reassess the literature on elective single-embryo transfer, to provide guidance for patient selection, and to discuss barriers to utilization. Copyright © 2012 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  10. Laboratory techniques for human embryos.

    PubMed

    Geber, Selmo; Sales, Liana; Sampaio, Marcos A C

    2002-01-01

    This review is concerned with laboratory techniques needed for assisted conception, particularly the handling of gametes and embryos. Such methods are being increasingly refined. Successive stages of fertilization and embryogenesis require especial care, and often involve the use of micromanipulative methods for intracytoplasmic sperm injection (ICSI) or preimplantation genetic diagnosis. Embryologists must take responsibility for gamete collection and preparation, and for deciding on the means of insemination or ICSI. Embryos must be assessed in culture, during the 1-cell, cleaving and morula/blastocyst stages, and classified according to quality. Co-culture methods may be necessary. The best embryos for transfer must be selected and loaded into the transfer catheter. Embryos not transferred must be cryopreserved, which demands the correct application of current methods of media preparation, seeding and the correct speed for cooling and warming. Before too long, methods of detecting abnormal embryos and avoiding their transfer may become widespread.

  11. Genes, embryos, and future people.

    PubMed

    Glannon, Walter

    1998-07-01

    Testing embryonic cells for genetic abnormalities gives us the capacity to predict whether and to what extent people will exist with disease and disability. Moreover, the freezing of embryos for long periods of time enables us to alter the length of a normal human lifespan. After highlighting the shortcomings of somatic-cell gene therapy and germ-line genetic alteration, I argue that the testing and selective termination of genetically defective embryos is the only medically and morally defensible way to prevent the existence of people with severe disability, pain and suffering that make their lives not worth living for them on the whole. In addition, I consider the possible harmful effects on children born from frozen embryos after the deaths of their biological parents, or when their parents are at an advanced age. I also explore whether embryos have moral status and whether the prospects for disease-preventing genetic alteration can justify long-term cryopreservation of embryos.

  12. How the zebra got its stripes: a problem with too many solutions

    PubMed Central

    Larison, Brenda; Harrigan, Ryan J.; Thomassen, Henri A.; Rubenstein, Daniel I.; Chan-Golston, Alec M.; Li, Elizabeth; Smith, Thomas B.

    2015-01-01

    The adaptive significance of zebra stripes has thus far eluded understanding. Many explanations have been suggested, including social cohesion, thermoregulation, predation evasion and avoidance of biting flies. Identifying the associations between phenotypic and environmental factors is essential for testing these hypotheses and substantiating existing experimental evidence. Plains zebra striping pattern varies regionally, from heavy black and white striping over the entire body in some areas to reduced stripe coverage with thinner and lighter stripes in others. We examined how well 29 environmental variables predict the variation in stripe characteristics of plains zebra across their range in Africa. In contrast to recent findings, we found no evidence that striping may have evolved to escape predators or avoid biting flies. Instead, we found that temperature successfully predicts a substantial amount of the stripe pattern variation observed in plains zebra. As this association between striping and temperature may be indicative of multiple biological processes, we suggest that the selective agents driving zebra striping are probably multifarious and complex. PMID:26064590

  13. Use of on-site refugia to protect unionid populations from zebra mussel-induced mortality

    USGS Publications Warehouse

    Nichols, S. Jerrine; Black, M. Glen; Allen, Jeffrey D.

    2000-01-01

    Protecting unionid populations as zebra mussels spread into inland waterways has relied mainly on relocating at-risk animals into aquaculture facilities. While such relocations are the only viable management technique for some populations, facility availability is limited, leaving many unionids facing extirpation. Another management strategy is in-situ protection either by enhancing natural refugia or by creating managed refugia. We have reviewed all reports of natural refugia and found that refugia for unionids can be found in many areas. There are many habitats where zebra mussel colonization has been limited, or of a temporary nature. Within zebra mussel infested areas, unionid communities continue to survive in some shallow water sites such as estuaries, deltas, and lake-connected wetlands. Managed refugia can be created in areas where natural refugia do not exist. We present a case study on recent efforts to create refugia in an area with rapidly expanding zebra mussel populations. Preliminary analysis of unionid body condition indicates that removal of encrusted zebra mussels only once a year can improve unionid condition factors and decrease mortality. Natural and managed refugia can provide an additional conservation management option in some areas.

  14. Zebra textures in carbonate rocks: Fractures produced by the force of crystallization during mineral replacement

    NASA Astrophysics Data System (ADS)

    Wallace, Malcolm W.; Hood, Ashleigh v. S.

    2018-06-01

    Zebra textures are enigmatic banded fabrics that occur in many carbonate-hosted ore deposits, dolomite hydrocarbon reservoirs and carbonate successions globally. They consist of a variety of minerals and are characterised by parallel light and dark bands that occur at a millimetre- to centimetre-scale. Based on petrological evidence, there is general consensus that the dark bands formed by replacement of the carbonate host rock. Historically, more contention surrounds the origin of the light bands, but the dominant view is that these are mineral-filled cavities, which is supported by overwhelming textural evidence. Overall, the feature common to all versions of zebra textures is mineral replacement of the original carbonate host. We suggest that mineral replacement (and the force of crystallization) in association with open space generation is a viable mechanism for the development of zebra cavity systems. Dissolution and open space generation in either evaporites or carbonates adjacent to the site of replacement reactions is necessary to remove the confining pressure from the rock and to allow the development of fractures. The pressure of the growing replacement crystals within the carbonate pervasively splits the carbonate apart, producing thin strips of carbonate surrounded by open space. The fractures may then be subject to dissolution and are later filled by cements. Very regular stratabound zebra textures (as found in ore deposits like Cadjebut, Australia and San Vicente, Peru) may be related to stratabound dissolution (of evaporites or carbonates), whereas irregularly distributed zebra textures are more likely to be associated with irregular carbonate dissolution.

  15. The disassociation of visual and acoustic conspecific cues decreases discrimination by female zebra finches (Taeniopygia guttata).

    PubMed

    Campbell, Dana L M; Hauber, Mark E

    2009-08-01

    Female zebra finches (Taeniopygia guttata) use visual and acoustic traits for accurate recognition of male conspecifics. Evidence from video playbacks confirms that both sensory modalities are important for conspecific and species discrimination, but experimental evidence of the individual roles of these cue types affecting live conspecific recognition is limited. In a spatial paradigm to test discrimination, the authors used live male zebra finch stimuli of 2 color morphs, wild-type (conspecific) and white with a painted black beak (foreign), producing 1 of 2 vocalization types: songs and calls learned from zebra finch parents (conspecific) or cross-fostered songs and calls learned from Bengalese finch (Lonchura striata vars. domestica) foster parents (foreign). The authors found that female zebra finches consistently preferred males with conspecific visual and acoustic cues over males with foreign cues, but did not discriminate when the conspecific and foreign visual and acoustic cues were mismatched. These results indicate the importance of both visual and acoustic features for female zebra finches when discriminating between live conspecific males. Copyright 2009 APA, all rights reserved.

  16. Proximate and fatty acid composition of zebra (Equus quagga burchellii) muscle and subcutaneous fat.

    PubMed

    Hoffman, Louwrens C; Geldenhuys, Greta; Cawthorn, Donna-Mareè

    2016-08-01

    The meat from African game species is healthy, naturally produced and increasingly popular with consumers. Among these species, zebra (Equus quagga burchellii) are growing in number in South Africa, with the meat from surplus animals holding potential to contribute to food security and economic stability. Despite being consumed locally and globally, little information exists on the composition of zebra meat. This study aimed to determine the proximate composition of zebra meat as well as the fatty acid composition of the intramuscular (IMF) and subcutaneous (SCF) fat. Zebra longissimus lumborum muscle was shown to have a high mean protein content (22.29 g per 100 g) and low mean fat content (1.47 g per 100 g). High proportions of polyunsaturated fatty acids (PUFAs) were found in the IMF (41.15%) and SCF (37.71%), mainly comprising α-linolenic (C18:3n-3) and linoleic (C18:2n-6) acids. Furthermore, the IMF and SCF had favourable PUFA/saturated fatty acid ratios (>0.4) and omega-6/omega-3 ratios (<4), indicating that both components are healthy lipid food sources. This study has shed new light on the nutritional value of zebra meat, which will not only be important for food product labelling, nutritional education and incorporation into food composition databases, but will also be indispensable for marketing and export purposes. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  17. Seasonal effects of the zebra mussel (Dreissena polymorpha) on sediment denitrification rates in Pool 8 of the Upper Mississippi River

    USGS Publications Warehouse

    Bruesewitz, Denise A.; Tank, Jennifer L.; Bernot, Melody J.; Richardson, William B.; Strauss, Eric A.

    2006-01-01

    Zebra mussels (Dreissena polymorpha) have altered the structure of invaded ecosystems and exhibit characteristics that suggest they may influence ecosystem processes such as nitrogen (N) cycling. We measured denitrification rates seasonally on sediments underlying zebra mussel beds collected from the impounded zone of Navigation Pool 8 of the Upper Mississippi River. Denitrification assays were amended with nutrients to characterize variation in nutrient limitation of denitrification in the presence or absence of zebra mussels. Denitrification rates at zebra mussel sites were high relative to sites without zebra mussels in February 2004 (repeated measures analysis of variance (RM ANOVA), p = 0.005), potentially because of high NO3-N variability from nitrification of high NH4+ zebra mussel waste. Denitrification rates were highest in June 2003 (RM ANOVA, p 3-N concentrations during the study (linear regression, R2 = 0.72, p p ≤ 0.01). Examining how zebra mussels influence denitrification rates will aid in developing a more complete understanding of the impact of zebra mussels and more effective management strategies of eutrophic waters.

  18. Effects of temperature and aerial exposure on the BOD of waste zebra mussels removed from navigational locks.

    PubMed

    Aldridge, D W; Payne, B S

    2001-08-01

    This laboratory study evaluated the effects of temperature and aerial exposure on BOD5 (5-day BOD) of waste zebra mussels of the type generated by maintenance operations on dams and navigational locks. The term waste zebra mussels includes the mussels and their associated debris with the latter including sediment, feces, pseudofeces and other small aquatic organisms. The BOD5 of waste zebra mussel was evaluated after aerial exposure of 3 and 10 days at temperatures of 5, 10, and 20 degrees C. The mean BOD5 values for waste zebra mussels in this study ranged from 18,500 to 30,600 mg O2/l. Factorial ANOVA analysis revealed that both temperature and aerial exposure had a negative effect on waste zebra mussel BOD5 (P<0.05) but there was no significant interaction effect (P = 0.119). Multiple regression analysis predicted that for the range of treatment conditions used in this study each 1 degrees C increase in temperature reduced the waste zebra mussel BOD5 by 284mg O2/l or 0.93% of the maximum mean BOD5. Each I day increase in aerial exposure reduced waste zebra mussel BOD5 by 987 mg O2/l or 3.22% of the maximum mean BOD5. Aerial exposure of waste zebra mussels substantially reduces waste BOD5.

  19. PGS-FISH in reproductive medicine and perspective directions for improvement: a systematic review.

    PubMed

    Zamora, Sandra; Clavero, Ana; Gonzalvo, M Carmen; de Dios Luna Del Castillo, Juan; Roldán-Nofuentes, Jose Antonio; Mozas, Juan; Castilla, Jose Antonio

    2011-08-01

    Embryo selection can be carried out via morphological criteria or by using genetic studies based on Preimplantation Genetic Screening. In the present study, we evaluate the clinical validity of Preimplantation Genetic Screening with fluorescence in situ hybridization (PGS-FISH) compared with morphological embryo criteria. A systematic review was made of the bibliography, with the following goals: firstly, to determine the prevalence of embryo chromosome alteration in clinical situations in which the PGS-FISH technique has been used; secondly, to calculate the statistics of diagnostic efficiency (negative Likelihood Ratio), using 2 × 2 tables, derived from PGS-FISH. The results obtained were compared with those obtained from embryo morphology. We calculated the probability of transferring at least one chromosome-normal embryo when it was selected using either morphological criteria or PGS-FISH, and considered what diagnostic performance should be expected of an embryo selection test with respect to achieving greater clinical validity than that obtained from embryo morphology. After an embryo morphology selection that produced a negative result (normal morphology), the likelihood of embryo aneuploidies was found to range from a pre-test value of 65% (prevalence of embryo chromosome alteration registered in all the study groups) to a post-test value of 55% (Confidence interval: 50-61), while after PGS-FISH with a negative result (euploid), the post-test probability was 42% (Confidence interval: 35-49) (p < 0.05). The probability of transferring at least one euploid embryo was the same whether 3 embryos were selected according to morphological criteria or whether 2, selected by PGS-FISH, were transferred. Any embryo selection test, if it is to provide greater clinical validity than embryo morphology, must present a LR-value of 0.40 (Confidence interval: 0.32-0.51) in single embryo transfer, and 0.06 (CI: 0.05-0.07) in double embryo transfer. With currently

  20. City Fishing.

    ERIC Educational Resources Information Center

    Lange, Robert E.

    1979-01-01

    A program of supplying opportunities for fishing at locations within and near urban areas was developed. This effort included stocking, management of bodies of water for fishing, and presentation of fishing clinics for urban fishermen. (RE)

  1. Fish Hearing.

    ERIC Educational Resources Information Center

    Blaxter, J. H. S.

    1980-01-01

    Provides related information about hearing in fish, including the sensory stimulus of sound in the underwater environment, mechanoreceptors in fish, pressure perception and the swimbladder, specializations in sound conduction peculiar to certain fish families. Includes numerous figures. (CS)

  2. Transcriptome analysis of zebrafish embryos exposed to deltamethrin.

    PubMed

    Chueh, Tsung-Cheng; Hsu, Li-Sung; Kao, Chin-Ming; Hsu, Tung-Wei; Liao, Hung-Yu; Wang, Kuan-Yi; Chen, Ssu Ching

    2017-05-01

    Deltamethrin (DTM), a type II pyrethroid, is one of the most commonly used insecticides. The increased use of pyrethroid leads to potential adverse effects, particularly in sensitive populations such as children and pregnant women. None of the related studies was focused on the transcriptome responses in zebrafish embryos after treatment with DTM; therefore, RNA-seq, a high-throughput method, was performed to analyze the global expression of differential expressed genes (DEGs) in zebrafish embryos treated with DTM (40 and 80 μg/L) from fertilization to 48 h postfertilization (hpf) as compared with that in the control group (without DTM treatment). Two cDNA libraries were generated from treated embryos and one cDNA library from nontreated embryos, respectively. Over 92% of reads mapped to the reference in these three libraries. It was observed that many differential genes were expressed in comparison with embryos before and after DTM. The 20 most differentially expressed upregulated or downregulated genes were majorly involved in the signaling transduction. Validation of selected nine genes expression using qRT-PCR confirmed RNA-seq results. The transcriptome sequences were further subjected to gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, showing G-protein-coupled receptor signaling pathway and neuroactive ligand-receptor interaction, respectively, were most enriched. The data from this study contributed to a better understanding of the potential consequences of fish exposed to DTM, to an evaluation of the potential threat of DTM to fish populations in aquatic environments. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1548-1557, 2017. © 2016 Wiley Periodicals, Inc.

  3. Rotationally driven 'zebra stripes' in Earth's inner radiation belt.

    PubMed

    Ukhorskiy, A Y; Sitnov, M I; Mitchell, D G; Takahashi, K; Lanzerotti, L J; Mauk, B H

    2014-03-20

    Structured features on top of nominally smooth distributions of radiation-belt particles at Earth have been previously associated with particle acceleration and transport mechanisms powered exclusively by enhanced solar-wind activity. Although planetary rotation is considered to be important for particle acceleration at Jupiter and Saturn, the electric field produced in the inner magnetosphere by Earth's rotation can change the velocity of trapped particles by only about 1-2 kilometres per second, so rotation has been thought inconsequential for radiation-belt electrons with velocities of about 100,000 kilometres per second. Here we report that the distributions of energetic electrons across the entire spatial extent of Earth's inner radiation belt are organized in regular, highly structured and unexpected 'zebra stripes', even when the solar-wind activity is low. Modelling reveals that the patterns are produced by Earth's rotation. Radiation-belt electrons are trapped in Earth's dipole-like magnetic field, where they undergo slow longitudinal drift motion around the planet because of the gradient and curvature of the magnetic field. Earth's rotation induces global diurnal variations of magnetic and electric fields that resonantly interact with electrons whose drift period is close to 24 hours, modifying electron fluxes over a broad energy range into regular patterns composed of multiple stripes extending over the entire span of the inner radiation belt.

  4. Drinking Songs: Alcohol Effects on Learned Song of Zebra Finches

    PubMed Central

    Olson, Christopher R.; Owen, Devin C.; Ryabinin, Andrey E.; Mello, Claudio V.

    2014-01-01

    Speech impairment is one of the most intriguing and least understood effects of alcohol on cognitive function, largely due to the lack of data on alcohol effects on vocalizations in the context of an appropriate experimental model organism. Zebra finches, a representative songbird and a premier model for understanding the neurobiology of vocal production and learning, learn song in a manner analogous to how humans learn speech. Here we show that when allowed access, finches readily drink alcohol, increase their blood ethanol concentrations (BEC) significantly, and sing a song with altered acoustic structure. The most pronounced effects were decreased amplitude and increased entropy, the latter likely reflecting a disruption in the birds’ ability to maintain the spectral structure of song under alcohol. Furthermore, specific syllables, which have distinct acoustic structures, were differentially influenced by alcohol, likely reflecting a diversity in the neural mechanisms required for their production. Remarkably, these effects on vocalizations occurred without overt effects on general behavioral measures, and importantly, they occurred within a range of BEC that can be considered risky for humans. Our results suggest that the variable effects of alcohol on finch song reflect differential alcohol sensitivity of the brain circuitry elements that control different aspects of song production. They also point to finches as an informative model for understanding how alcohol affects the neuronal circuits that control the production of learned motor behaviors. PMID:25536524

  5. Neural correlates of nesting behavior in zebra finches (Taeniopygia guttata).

    PubMed

    Hall, Zachary J; Bertin, Marion; Bailey, Ida E; Meddle, Simone L; Healy, Susan D

    2014-05-01

    Nest building in birds involves a behavioral sequence (nest material collection and deposition in the nest) that offers a unique model for addressing how the brain sequences motor actions. In this study, we identified brain regions involved in nesting behavior in male and female zebra finches (Taeniopygia guttata). We used Fos immunohistochemistry to quantify production of the immediate early gene protein product Fos (a molecular indicator of neuronal activity) in the brain correlated this expression with the variation in nesting behavior. Using this technique, we found that neural circuitry involved in motor sequencing, social behavior, reward and motivation were active during nesting. Within pairs of nesting birds, the number of times a male picked up or deposited nesting material and the amount of time a female spent in the nest explained the variation in Fos expression in the anterior motor pathway, social behavior network, and reward neural circuits. Identification of the brain regions that are involved in nesting enables us to begin studying the roles of motor sequencing, context, and reward in construction behavior at the neural level. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Neural correlates of nesting behavior in zebra finches (Taeniopygia guttata)

    PubMed Central

    Hall, Zachary J.; Bertin, Marion; Bailey, Ida E.; Meddle, Simone L.; Healy, Susan D.

    2014-01-01

    Nest building in birds involves a behavioral sequence (nest material collection and deposition in the nest) that offers a unique model for addressing how the brain sequences motor actions. In this study, we identified brain regions involved in nesting behavior in male and female zebra finches (Taeniopygia guttata). We used Fos immunohistochemistry to quantify production of the immediate early gene protein product Fos (a molecular indicator of neuronal activity) in the brain correlated this expression with the variation in nesting behavior. Using this technique, we found that neural circuitry involved in motor sequencing, social behavior, reward and motivation were active during nesting. Within pairs of nesting birds, the number of times a male picked up or deposited nesting material and the amount of time a female spent in the nest explained the variation in Fos expression in the anterior motor pathway, social behavior network, and reward neural circuits. Identification of the brain regions that are involved in nesting enables us to begin studying the roles of motor sequencing, context, and reward in construction behavior at the neural level. PMID:24508238

  7. Efficient and Rapid Isolation of Early-stage Embryos from Arabidopsis thaliana Seeds

    PubMed Central

    Raissig, Michael T.; Gagliardini, Valeria; Jaenisch, Johan; Grossniklaus, Ueli; Baroux, Célia

    2013-01-01

    In flowering plants, the embryo develops within a nourishing tissue - the endosperm - surrounded by the maternal seed integuments (or seed coat). As a consequence, the isolation of plant embryos at early stages (1 cell to globular stage) is technically challenging due to their relative inaccessibility. Efficient manual dissection at early stages is strongly impaired by the small size of young Arabidopsis seeds and the adhesiveness of the embryo to the surrounding tissues. Here, we describe a method that allows the efficient isolation of young Arabidopsis embryos, yielding up to 40 embryos in 1 hr to 4 hr, depending on the downstream application. Embryos are released into isolation buffer by slightly crushing 250-750 seeds with a plastic pestle in an Eppendorf tube. A glass microcapillary attached to either a standard laboratory pipette (via a rubber tube) or a hydraulically controlled microinjector is used to collect embryos from droplets placed on a multi-well slide on an inverted light microscope. The technical skills required are simple and easily transferable, and the basic setup does not require costly equipment. Collected embryos are suitable for a variety of downstream applications such as RT-PCR, RNA sequencing, DNA methylation analyses, fluorescence in situ hybridization (FISH), immunostaining, and reporter gene assays. PMID:23770918

  8. Zebra Crossing Spotter: Automatic Population of Spatial Databases for Increased Safety of Blind Travelers

    PubMed Central

    Ahmetovic, Dragan; Manduchi, Roberto; Coughlan, James M.; Mascetti, Sergio

    2016-01-01

    In this paper we propose a computer vision-based technique that mines existing spatial image databases for discovery of zebra crosswalks in urban settings. Knowing the location of crosswalks is critical for a blind person planning a trip that includes street crossing. By augmenting existing spatial databases (such as Google Maps or OpenStreetMap) with this information, a blind traveler may make more informed routing decisions, resulting in greater safety during independent travel. Our algorithm first searches for zebra crosswalks in satellite images; all candidates thus found are validated against spatially registered Google Street View images. This cascaded approach enables fast and reliable discovery and localization of zebra crosswalks in large image datasets. While fully automatic, our algorithm could also be complemented by a final crowdsourcing validation stage for increased accuracy. PMID:26824080

  9. Acoustic fine structure may encode biologically relevant information for zebra finches.

    PubMed

    Prior, Nora H; Smith, Edward; Lawson, Shelby; Ball, Gregory F; Dooling, Robert J

    2018-04-18

    The ability to discriminate changes in the fine structure of complex sounds is well developed in birds. However, the precise limit of this discrimination ability and how it is used in the context of natural communication remains unclear. Here we describe natural variability in acoustic fine structure of male and female zebra finch calls. Results from psychoacoustic experiments demonstrate that zebra finches are able to discriminate extremely small differences in fine structure, which are on the order of the variation in acoustic fine structure that is present in their vocal signals. Results from signal analysis methods also suggest that acoustic fine structure may carry information that distinguishes between biologically relevant categories including sex, call type and individual identity. Combined, our results are consistent with the hypothesis that zebra finches can encode biologically relevant information within the fine structure of their calls. This study provides a foundation for our understanding of how acoustic fine structure may be involved in animal communication.

  10. The perception of regularity in an isochronous stimulus in zebra finches (Taeniopygia guttata) and humans.

    PubMed

    van der Aa, Jeroen; Honing, Henkjan; ten Cate, Carel

    2015-06-01

    Perceiving temporal regularity in an auditory stimulus is considered one of the basic features of musicality. Here we examine whether zebra finches can detect regularity in an isochronous stimulus. Using a go/no go paradigm we show that zebra finches are able to distinguish between an isochronous and an irregular stimulus. However, when the tempo of the isochronous stimulus is changed, it is no longer treated as similar to the training stimulus. Training with three isochronous and three irregular stimuli did not result in improvement of the generalization. In contrast, humans, exposed to the same stimuli, readily generalized across tempo changes. Our results suggest that zebra finches distinguish the different stimuli by learning specific local temporal features of each individual stimulus rather than attending to the global structure of the stimuli, i.e., to the temporal regularity. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. ZebraZoom: an automated program for high-throughput behavioral analysis and categorization

    PubMed Central

    Mirat, Olivier; Sternberg, Jenna R.; Severi, Kristen E.; Wyart, Claire

    2013-01-01

    The zebrafish larva stands out as an emergent model organism for translational studies involving gene or drug screening thanks to its size, genetics, and permeability. At the larval stage, locomotion occurs in short episodes punctuated by periods of rest. Although phenotyping behavior is a key component of large-scale screens, it has not yet been automated in this model system. We developed ZebraZoom, a program to automatically track larvae and identify maneuvers for many animals performing discrete movements. Our program detects each episodic movement and extracts large-scale statistics on motor patterns to produce a quantification of the locomotor repertoire. We used ZebraZoom to identify motor defects induced by a glycinergic receptor antagonist. The analysis of the blind mutant atoh7 revealed small locomotor defects associated with the mutation. Using multiclass supervised machine learning, ZebraZoom categorized all episodes of movement for each larva into one of three possible maneuvers: slow forward swim, routine turn, and escape. ZebraZoom reached 91% accuracy for categorization of stereotypical maneuvers that four independent experimenters unanimously identified. For all maneuvers in the data set, ZebraZoom agreed with four experimenters in 73.2–82.5% of cases. We modeled the series of maneuvers performed by larvae as Markov chains and observed that larvae often repeated the same maneuvers within a group. When analyzing subsequent maneuvers performed by different larvae, we found that larva–larva interactions occurred as series of escapes. Overall, ZebraZoom reached the level of precision found in manual analysis but accomplished tasks in a high-throughput format necessary for large screens. PMID:23781175

  12. [The destiny of cryopreserved embryos].

    PubMed

    Karpel, L; Achour-Frydman, N; Frydman, R; Flis-Trèves, M

    2007-12-01

    To know the psychological motivations of couples who keep their embryos so long (five years and more) and do not make a decision about them. We studied 84 couples refrained from making a decision on their cryopreserved embryos for at least five years. They were invited to fill out a questionnaire focusing on three points: the reasons of the indecision, their own representation of the cryopreserved embryos and their choice for the future: donation to another couple, to research, pregnancy or no solution for the moment. Mean (S.D.) women's and men's age were respectively, 38.8 (2.5)- and 41.3 (2.5)-years old. On average, three (1-9) embryos are preserved since 7.5 (5-12) years. Most of couples are parents. Four major reasons explain their attitudes: feeling of being too aged (25%), fear of a multiple pregnancy (45%), disagreement between members of couple (20%) and fear of failure (42.5%). Multiple choices were given to the future of the embryos: 25% wanted a pregnancy, 8% wanted to give them to infertile couples, 20% to research and 27.5% did not find any solution. Twenty percent were hesitating. The representation of those embryos is more symbolic than material. Most of the time, they see them like a potential child, a hope for the future or a brother or sister of their alive children. Those embryos are symbolized. They are a proof of fertility, a hope for another child. So, whatever the legal statement, couples will be in a dilemma because it is never easy for an infertile person to renounce to embryos, and the hope for children.

  13. The ZEBRA electric vehicle battery: power and energy improvements

    NASA Astrophysics Data System (ADS)

    Galloway, Roy C.; Haslam, Steven

    Vehicle trials with the first sodium/nickel chloride ZEBRA batteries indicated that the pulse power capability of the battery needed to be improved towards the end of the discharge. A research programme led to several design changes to improve the cell which, in combination, have improved the power of the battery to greater than 150 W kg -1 at 80% depth of discharge. Bench and vehicle tests have established the stability of the high power battery over several years of cycling. The gravimetric energy density of the first generation of cells was less than 100 Wh kg -1. Optimisation of the design has led to a cell with a specific energy of 120 Wh kg -1 or 86 Wh kg -1 for a 30 kWh battery. Recently, the cell chemistry has been altered to improve the useful capacity. The cell is assembled in the over-discharged state and during the first charge the following reactions occur: at 1.6 V: Al+4NaCl=NaAlCl 4+3Na; at 2.35 V: Fe+2NaCl=FeCl 2+2Na; at 2.58 V: Ni+2NaCl=NiCl 2+2 Na. The first reaction serves to prime the negative sodium electrode but occurs at too low a voltage to be of use in providing useful capacity. By minimising the aluminium content more NaCl is released for the main reactions to improve the capacity of the cell. This, and further composition optimisation, have resulted in cells with specific energies in excess of 140 Wh kg -1, which equates to battery energies>100 Wh kg -1. The present production battery, as installed in a Mercedes Benz A class electric vehicle, gives a driving range of 205 km (128 miles) in city and hill climbing. The cells with improved capacity will extend the practical driving range to beyond 240 km (150 miles).

  14. Developmental stress increases reproductive success in male zebra finches.

    PubMed

    Crino, Ondi L; Prather, Colin T; Driscoll, Stephanie C; Good, Jeffrey M; Breuner, Creagh W

    2014-11-22

    There is increasing evidence that exposure to stress during development can have sustained effects on animal phenotype and performance across life-history stages. For example, developmental stress has been shown to decrease the quality of sexually selected traits (e.g. bird song), and therefore is thought to decrease reproductive success. However, animals exposed to developmental stress may compensate for poor quality sexually selected traits by pursuing alternative reproductive tactics. Here, we examine the effects of developmental stress on adult male reproductive investment and success in the zebra finch (Taeniopygia guttata). We tested the hypothesis that males exposed to developmental stress sire fewer offspring through extra-pair copulations (EPCs), but invest more in parental care. To test this hypothesis, we fed nestlings corticosterone (CORT; the dominant avian stress hormone) during the nestling period and measured their adult reproductive success using common garden breeding experiments. We found that nestlings reared by CORT-fed fathers received more parental care compared with nestlings reared by control fathers. Consequently, males fed CORT during development reared nestlings in better condition compared with control males. Contrary to the prediction that developmental stress decreases male reproductive success, we found that CORT-fed males also sired more offspring and were less likely to rear non-genetic offspring compared with control males, and thus had greater overall reproductive success. These data are the first to demonstrate that developmental stress can have a positive effect on fitness via changes in reproductive success and provide support for an adaptive role of developmental stress in shaping animal phenotype. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  15. Fish stem cell cultures.

    PubMed

    Hong, Ni; Li, Zhendong; Hong, Yunhan

    2011-04-13

    Stem cells have the potential for self-renewal and differentiation. First stem cell cultures were derived 30 years ago from early developing mouse embryos. These are pluripotent embryonic stem (ES) cells. Efforts towards ES cell derivation have been attempted in other mammalian and non-mammalian species. Work with stem cell culture in fish started 20 years ago. Laboratory fish species, in particular zebrafish and medaka, have been the focus of research towards stem cell cultures. Medaka is the second organism that generated ES cells and the first that gave rise to a spermatogonial stem cell line capable of test-tube sperm production. Most recently, the first haploid stem cells capable of producing whole animals have also been generated from medaka. ES-like cells have been reported also in zebrafish and several marine species. Attempts for germline transmission of ES cell cultures and gene targeting have been reported in zebrafish. Recent years have witnessed the progress in markers and procedures for ES cell characterization. These include the identification of fish homologs/paralogs of mammalian pluripotency genes and parameters for optimal chimera formation. In addition, fish germ cell cultures and transplantation have attracted considerable interest for germline transmission and surrogate production. Haploid ES cell nuclear transfer has proven in medaka the feasibility of semi-cloning as a novel assisted reproductive technology. In this special issue on "Fish Stem Cells and Nuclear Transfer", we will focus our review on medaka to illustrate the current status and perspective of fish stem cells in research and application. We will also mention semi-cloning as a new development to conventional nuclear transfer.

  16. Fish Stem Cell Cultures

    PubMed Central

    Hong, Ni; Li, Zhendong; Hong, Yunhan

    2011-01-01

    Stem cells have the potential for self-renewal and differentiation. First stem cell cultures were derived 30 years ago from early developing mouse embryos. These are pluripotent embryonic stem (ES) cells. Efforts towards ES cell derivation have been attempted in other mammalian and non-mammalian species. Work with stem cell culture in fish started 20 years ago. Laboratory fish species, in particular zebrafish and medaka, have been the focus of research towards stem cell cultures. Medaka is the second organism that generated ES cells and the first that gave rise to a spermatogonial stem cell line capable of test-tube sperm production. Most recently, the first haploid stem cells capable of producing whole animals have also been generated from medaka. ES-like cells have been reported also in zebrafish and several marine species. Attempts for germline transmission of ES cell cultures and gene targeting have been reported in zebrafish. Recent years have witnessed the progress in markers and procedures for ES cell characterization. These include the identification of fish homologs/paralogs of mammalian pluripotency genes and parameters for optimal chimera formation. In addition, fish germ cell cultures and transplantation have attracted considerable interest for germline transmission and surrogate production. Haploid ES cell nuclear transfer has proven in medaka the feasibility of semi-cloning as a novel assisted reproductive technology. In this special issue on “Fish Stem Cells and Nuclear Transfer”, we will focus our review on medaka to illustrate the current status and perspective of fish stem cells in research and application. We will also mention semi-cloning as a new development to conventional nuclear transfer. PMID:21547056

  17. Danio rerio embryos on Prozac - Effects on the detoxification mechanism and embryo development.

    PubMed

    Cunha, V; Rodrigues, P; Santos, M M; Moradas-Ferreira, P; Ferreira, M

    2016-09-01

    In the past decade the presence of psychopharmaceuticals, including fluoxetine (FLU), in the aquatic environment has been associated with the increasing trend in human consumption of these substances. Aquatic organisms are usually exposed to chronic low doses and, therefore, risk assessments should evaluate the effects of these compounds in non-target organisms. Teleost fish possess an array of active defence mechanisms to cope with the deleterious effects of xenobiotics. These include ABC transporters, phase I and II of cellular detoxification and oxidative stress enzymes. Hence, the present study aimed at characterising the effect of FLU on embryo development of the model teleost zebrafish (Danio rerio) concomitantly with changes in the detoxification mechanisms during early developmental phases. Embryos were exposed to different concentrations of FLU (0.0015, 0.05, 0.1, 0.5 and 0.8μM) for 80hours post fertilization. Development was screened and the impact in the transcription of key genes, i.e., abcb4, abcc1, abcc2, abcg2, cyp1a, cyp3a65, gst, sod, cat, ahr, pxr, pparα, pparβ, pparγ, rxraa, rxrab, rxrbb, rxrga, rxrgb, raraa, rarab, rarga evaluated. In addition, accumulation assays were performed to measure the activity of ABC proteins and antioxidant enzymes (CAT and Cu/ZnSOD) after exposure to FLU. Embryo development was disrupted at the lowest FLU concentration tested (0.0015μM), which is in the range of concentrations found in WWTP effluents. Embryos exposed to higher concentrations of FLU decreased Cu/Zn SOD, and increased CAT (0.0015 and 0.5μM) enzymatic activity. Exposure to higher concentrations of FLU decreased the expression of most genes belonging to the detoxification system and upregulated cat at 0.0015μM of FLU. Most of the tested concentrations downregulated pparα, pparβ, pparγ, and raraa, rxraa, rxrab, rxrbb rxrgb and ahr gene expression while pxr was significantly up regulated at all tested concentrations. In conclusion, this study

  18. Lessons from Embryos: Haeckel's Embryo Drawings, Evolution, and Secondary Biology Textbooks

    ERIC Educational Resources Information Center

    Wellner, Karen L.

    2014-01-01

    In 1997, developmental biologist Michael Richardson compared his research team's embryo photographs to Ernst Haeckel's 1874 embryo drawings and called Haeckel's work "noncredible". "Science" soon published "Haeckel's Embryos: Fraud Rediscovered," and Richardson's comments further reinvigorated criticism of Haeckel by…

  19. Efficacy of Pseudomonas fluorescens (Pf-CL145A) spray dried powder for controlling zebra mussels adhering to test substrates

    USGS Publications Warehouse

    Luoma, James A.; Severson, Todd J.; Weber, Kerry L.; Mayer, Denise A.

    2015-01-01

    Approximately 30 days after exposure, zebra mussels were sorted into live and dead, and enumerated. Mean survival of zebra mussels in control treatments exceeded 95 percent. Mean survival of zebra mussels in the Lake Carlos WWC SDP-treated groups ranged from 0.5 to 2.1 percent and when compared at the same exposure duration, no difference was detected in survival between the 50 and 100 milligrams per liter (mg/L) treatment groups. Similarly, mean survival of zebra mussels in the Shawano Lake WWC SDP-treated groups ranged from 2.0 to 12.6 percent and when compared at the same exposure duration, no difference was detected in survival between the 50- and 100-mg/L treatment groups. Mean survival of zebra mussels in the Lake Carlos BI trial SDP-treated groups did not differ (p = 0.93) and was 18.1 and 18.0 percent in the 50- and 100-mg/L treatment groups, respectively. Mean survival of zebra mussels in the Shawano Lake BI trial SDP-treated groups differed (p < 0.01) and was 2.9 and 0.9 percent in the 50- and 100-mg/L treatment groups, respectively. Survival of zebra mussels assigned to the SDP-treated groups in the Lake Carlos WWC trial (12-hour exposure duration) differed from the survival of zebra mussels assigned to the SDP-treated groups in the Lake Carlos BI trial; however, after modification of the BI application technique, no difference (p = 0.22) was detected between the survival of zebra mussel in the Shawano Lake WWC (12-hour exposure duration) and BI trials.

  20. Immunohistochemical detection of polychlorinated biphenyls in field collected damselfish (Abudefduf sordidus; Pomacentridae) embryos and larvae.

    PubMed

    Lobel, Lisa M Kerr; Davis, Elizabeth A

    2002-01-01

    Antibodies against polychlorinated biphenyls (PCBs) were used to determine if immunohistochemical methods could detect PCBs in embryos and larvae of a territorial coral reef fish (Abudefduf sordidus; Pomacentridae) collected from Johnston Atoll, Central Pacific Ocean. Sites with differing levels of contamination were sampled, one with relatively high sediment PCB concentrations of up to 389.0 ng/g and another with low PCB concentrations of only 0.5 ng/g. Immunostaining suggested that PCB concentrations were higher in fish larvae from the PCB contaminated site and that PCB concentrations within abnormal embryos were higher than normal embryos from the same nest. This technique will be useful for detecting exposed populations in the field and assessing correlations with adverse effects, particularly in potential indicator organisms such as Abudefduf sordidus.

  1. Transient expression and activity of human DNA polymerase iota in loach embryos.

    PubMed

    Makarova, Irina V; Kazakov, Andrey A; Makarova, Alena V; Khaidarova, Nella V; Kozikova, Larisa V; Nenasheva, Valentina V; Gening, Leonid V; Tarantul, Vyacheslav Z; Andreeva, Ludmila E

    2012-02-01

    Human DNA polymerase iota (Pol ι) is a Y-family DNA polymerase with unusual biochemical properties and not fully understood functions. Pol ι preferentially incorporates dGTP opposite template thymine. This property can be used to monitor Pol ι activity in the presence of other DNA polymerases, e.g. in cell extracts of tissues and tumors. We have now confirmed the specificity and sensitivity of the method of Pol ι activity detection in cell extracts using an animal model of loach Misgurnus fossilis embryos transiently expressing human Pol ι. The overexpression of Pol ι was shown to be accompanied by an increase in abnormalities in development and the frequency of pycnotic nuclei in fish embryos. Further analysis of fish embryos with constitutive or regulated Pol ι expression may provide insights into Pol ι functions in vertebrate animals.

  2. Development of a molecular diagnostic system to discriminate Dreissena polymorpha (zebra mussel) and Dreissena bugensis (quagga mussel)

    USGS Publications Warehouse

    Hoy, M.S.; Kelly, K.; Rodriguez, R.J.

    2010-01-01

    A 3-primer PCR system was developed to discriminate invasive zebra (Dreissena polymorpha) and quagga (Dreissena bugensis) mussel. The system is based on: 1) universal primers that amplifies a region of the nuclear 28s rDNA gene from both species and 2) a species-specific primer complementary to either zebra or quagga mussel. The species-specific primers bind to sequences between the binding sites for the universal primers resulting in the amplification of two products from the target species and one product from the nontarget species. Therefore, nontarget products are positive amplification controls. The 3-primer system accurately discriminated zebra and quagga mussels from seven geographically distinct populations.

  3. SPATIALLY AND SPECTRALLY RESOLVED OBSERVATIONS OF A ZEBRA PATTERN IN A SOLAR DECIMETRIC RADIO BURST

    SciTech Connect

    Chen Bin; Bastian, T. S.; Gary, D. E.

    2011-07-20

    We present the first interferometric observation of a zebra-pattern radio burst with simultaneous high spectral ({approx}1 MHz) and high time (20 ms) resolution. The Frequency-Agile Solar Radiotelescope Subsystem Testbed (FST) and the Owens Valley Solar Array (OVSA) were used in parallel to observe the X1.5 flare on 2006 December 14. By using OVSA to calibrate the FST, the source position of the zebra pattern can be located on the solar disk. With the help of multi-wavelength observations and a nonlinear force-free field extrapolation, the zebra source is explored in relation to the magnetic field configuration. New constraints are placed onmore » the source size and position as a function of frequency and time. We conclude that the zebra burst is consistent with a double-plasma resonance model in which the radio emission occurs in resonance layers where the upper-hybrid frequency is harmonically related to the electron cyclotron frequency in a coronal magnetic loop.« less

  4. Zebra: a web server for bioinformatic analysis of diverse protein families.

    PubMed

    Suplatov, Dmitry; Kirilin, Evgeny; Takhaveev, Vakil; Svedas, Vytas

    2014-01-01

    During evolution of proteins from a common ancestor, one functional property can be preserved while others can vary leading to functional diversity. A systematic study of the corresponding adaptive mutations provides a key to one of the most challenging problems of modern structural biology - understanding the impact of amino acid substitutions on protein function. The subfamily-specific positions (SSPs) are conserved within functional subfamilies but are different between them and, therefore, seem to be responsible for functional diversity in protein superfamilies. Consequently, a corresponding method to perform the bioinformatic analysis of sequence and structural data has to be implemented in the common laboratory practice to study the structure-function relationship in proteins and develop novel protein engineering strategies. This paper describes Zebra web server - a powerful remote platform that implements a novel bioinformatic analysis algorithm to study diverse protein families. It is the first application that provides specificity determinants at different levels of functional classification, therefore addressing complex functional diversity of large superfamilies. Statistical analysis is implemented to automatically select a set of highly significant SSPs to be used as hotspots for directed evolution or rational design experiments and analyzed studying the structure-function relationship. Zebra results are provided in two ways - (1) as a single all-in-one parsable text file and (2) as PyMol sessions with structural representation of SSPs. Zebra web server is available at http://biokinet.belozersky.msu.ru/zebra .

  5. Automatic detection of zebra crossings from mobile LiDAR data

    NASA Astrophysics Data System (ADS)

    Riveiro, B.; González-Jorge, H.; Martínez-Sánchez, J.; Díaz-Vilariño, L.; Arias, P.

    2015-07-01

    An algorithm for the automatic detection of zebra crossings from mobile LiDAR data is developed and tested to be applied for road management purposes. The algorithm consists of several subsequent processes starting with road segmentation by performing a curvature analysis for each laser cycle. Then, intensity images are created from the point cloud using rasterization techniques, in order to detect zebra crossing using the Standard Hough Transform and logical constrains. To optimize the results, image processing algorithms are applied to the intensity images from the point cloud. These algorithms include binarization to separate the painting area from the rest of the pavement, median filtering to avoid noisy points, and mathematical morphology to fill the gaps between the pixels in the border of white marks. Once the road marking is detected, its position is calculated. This information is valuable for inventorying purposes of road managers that use Geographic Information Systems. The performance of the algorithm has been evaluated over several mobile LiDAR strips accounting for a total of 30 zebra crossings. That test showed a completeness of 83%. Non-detected marks mainly come from painting deterioration of the zebra crossing or by occlusions in the point cloud produced by other vehicles on the road.

  6. Camdeboo-Mountain Zebra National Park Corridor: Opportunities for conservation and socio-economic development

    Treesearch

    Matthew Norval

    2015-01-01

    The Wilderness Foundation, in partnership with South African National Parks has initiated a two year project in the Karoo; The Mountain Zebra-Camdeboo Corridor Project. Through either voluntary Contractual National Park or Protected Environment agreements, the project aims to work with, rather than displace, current conservation-compatible land-use practices such as...

  7. Song decrystallization in adult zebra finches does not require the song nucleus NIf.

    PubMed

    Roy, Arani; Mooney, Richard

    2009-08-01

    In adult male zebra finches, transecting the vocal nerve causes previously stable (i.e., crystallized) song to slowly degrade, presumably because of the resulting distortion in auditory feedback. How and where distorted feedback interacts with song motor networks to induce this process of song decrystallization remains unknown. The song premotor nucleus HVC is a potential site where auditory feedback signals could interact with song motor commands. Although the forebrain nucleus interface of the nidopallium (NIf) appears to be the primary auditory input to HVC, NIf lesions made in adult zebra finches do not trigger song decrystallization. One possibility is that NIf lesions do not interfere with song maintenance, but do compromise the adult zebra finch's ability to express renewed vocal plasticity in response to feedback perturbations. To test this idea, we bilaterally lesioned NIf and then transected the vocal nerve in adult male zebra finches. We found that bilateral NIf lesions did not prevent nerve section-induced song decrystallization. To test the extent to which the NIf lesions disrupted auditory processing in the song system, we made in vivo extracellular recordings in HVC and a downstream anterior forebrain pathway (AFP) in NIf-lesioned birds. We found strong and selective auditory responses to the playback of the birds' own song persisted in HVC and the AFP following NIf lesions. These findings suggest that auditory inputs to the song system other than NIf, such as the caudal mesopallium, could act as a source of auditory feedback signals to the song motor network.

  8. Nondestructive detection of zebra chip disease in potatoes using near-infrared spectroscopy

    USDA-ARS?s Scientific Manuscript database

    Near-Infrared (NIR) spectroscopy in the wavelength region from 900 nm to 2600 nm was evaluated as the basis for a rapid, non-destructive method for the detection of Zebra Chip disease in potatoes and the measurement of sugar concentrations in affected tubers. Using stepwise regression in conjunction...

  9. Zebra Mussel Antifouling Activity of the Marine Natural Product Aaptamine and Analogs

    PubMed Central

    Diers, Jeffrey A.; Bowling, John J.; Duke, Stephen O.; Wahyuono, Subagus; Kelly, Michelle; Hamann, Mark T.

    2016-01-01

    Several aaptamine derivatives were selected as potential zebra mussel (Dreissena polymorpha) antifoulants because of the noteworthy absence of fouling observed on Aaptos sponges. Sponges of the genus Aaptos collected in Manado, Indonesia consistently produce aaptamine-type alkaloids. To date, aaptamine and its derivatives have not been carefully evaluated for their antifoulant properties. Structure–activity relationship studies were conducted using several aaptamine derivatives in a zebra mussel antifouling assay. From these data, three analogs have shown significant antifouling activity against zebra mussel attachment. Aaptamine, isoaaptamine, and the demethylated aaptamine compounds used in the zebra mussel assay produced EC50 values of 24.2, 11.6, and 18.6 μM, respectively. In addition, neither aaptamine nor isoaaptamine produced a phytotoxic response (as high as 300 μM) toward a nontarget organism, Lemna pausicostata, in a 7-day exposure. The use of these aaptamine derivatives from Aaptos sp. as potential environmentally benign antifouling alternatives to metal-based paints and preservatives is significant, not only as a possible control of fouling organisms, but also to highlight the ecological importance of these and similar biochemical defenses. PMID:16718618

  10. Zebra Crossing: Walking in Two Continents Sharing and Celebrating Difference through Music

    ERIC Educational Resources Information Center

    Joseph, Dawn

    2011-01-01

    I use the metaphor "zebra crossing" in my reflective narrative to describe my plight and struggle as a non-white person growing up and working in Johannesburg, South Africa, during the apartheid era. This article considers and compares the notions of culture, diversity and identity as I now work in a tertiary institution in Melbourne,…

  11. Examining the role of tuber biochemistry in the development of zebra chip in stored potato tubers

    USDA-ARS?s Scientific Manuscript database

    Zebra chip disease (ZC), associated with infection by the bacterium ‘Candidatus Liberibacter solanacearum’ (Lso), is an emerging problem for potato growers in the United States, Mexico, and New Zealand. Although potato tubers exhibiting ZC symptoms will be rejected by processors, it remains possible...

  12. Variations in Zebra Chip disease expression and tuber biochemistry in response to vector density

    USDA-ARS?s Scientific Manuscript database

    This study examined effects of the number of ‘Candidatus Liberibacter solanacearum’ (Lso)-positive psyllids feeding on potatoes to Lso titers, zebra chip disease (ZC) symptom severity, and levels of amino acids, carbohydrates, and phenolics in tubers harvested weeks later. Red La Soda and Russet Nor...

  13. Evaluation of several chemical disinfectants for removing zebra mussels from unionid mussels

    USGS Publications Warehouse

    Waller, D.L.; Fisher, S.W.

    1998-01-01

    We evaluated the safety and effectiveness of chemical treatments for killing veliger and juvenile stages of the zebra mussel Dreissena polymorpha attached to unionid mussels. Static toxicity tests were conducted on eight unionid mussel species with common aquaculture chemicals (benzalkonium chloride, formalin, hydrogen peroxide, calcium chloride, potassium chloride, and sodium chloride). The concentration and duration of each chemical treatment tested had previously been found to kill zebra mussel veligers and juveniles. Several species (e.g., Elliptio dilatata, Lampsilis cardium, and Lasmigona complanata) incurred less than 10% mortality in chloride salt treatments, while in other species (e.g., Obliquaria reflexa and Leptodea fragilis) mortality varied greatly among treatment regimes. Treatments with benzalkonium chloride, formalin, and hydrogen peroxide were less than 90% effective on juvenile stages of zebra mussels and, therefore, were ruled out after preliminary trials. Limited application of specific chemical treatments may be feasible for more tolerant species; however, effective disinfection of unionid shells will require the use of chemical treatment followed by a quarantine period to completely remove zebra mussel larvae and juveniles.

  14. Equid herpesvirus 9 (EHV-9) isolates from zebras in Ontario, Canada, 1989 to 2007.

    PubMed

    Rebelo, Ana Rita; Carman, Susy; Shapiro, Jan; van Dreumel, Tony; Hazlett, Murray; Nagy, Éva

    2015-04-01

    The objective of this study was to identify and partially characterize 3 equid herpesviruses that were isolated postmortem from zebras in Ontario, Canada in 1989, 2002, and 2007. These 3 virus isolates were characterized by plaque morphology, restriction fragment length polymorphism (RFLP) of their genomic deoxyribonucleic acid (DNA), real-time polymerase chain reaction (PCR) assay, and sequence analyses of the full length of the glycoprotein G (gG) gene (ORF70) and a portion of the DNA polymerase gene (ORF30). The isolates were also compared to 3 reference strains of equid herpesvirus 1 (EHV-1). Using rabbit kidney cells, the plaques for the isolates from the zebras were found to be much larger in size than the EHV-1 reference strains. The RFLP patterns of the zebra viruses differed among each other and from those of the EHV-1 reference strains. Real-time PCR and sequence analysis of a portion of the DNA polymerase gene determined that the herpesvirus isolates from the zebras contained a G at nucleotide 2254 and a corresponding N at amino acid position 752, which suggested that they could be neuropathogenic EHV-1 strains. However, subsequent phylogenetic analysis of the gG gene suggested that they were EHV-9 and not EHV-1.

  15. ZENK expression following conspecific and heterospecific playback in the zebra finch auditory forebrain.

    PubMed

    Scully, Erin N; Hahn, Allison H; Campbell, Kimberley A; McMillan, Neil; Congdon, Jenna V; Sturdy, Christopher B

    2017-07-28

    Zebra finches (Taeniopygia guttata) are sexually dimorphic songbirds, not only in appearance but also in vocal production: while males produce both calls and songs, females only produce calls. This dimorphism provides a means to contrast the auditory perception of vocalizations produced by songbird species of varying degrees of relatedness in a dimorphic species to that of a monomorphic species, species in which both males and females produce calls and songs (e.g., black-capped chickadees, Poecile atricapillus). In the current study, we examined neuronal expression after playback of acoustically similar hetero- and conspecific calls produced by species of differing phylogenetic relatedness to our subject species, zebra finch. We measured the immediate early gene (IEG) ZENK in two auditory areas of the forebrain (caudomedial mesopallium, CMM, and caudomedial nidopallium, NCM). We found no significant differences in ZENK expression in either male or female zebra finches regardless of playback condition. We also discuss comparisons between our results and the results of a previous study conducted by Avey et al. [1] on black-capped chickadees that used similar stimulus types. These results are consistent with the previous study which also found no significant differences in expression following playback of calls produced by various heterospecific species and conspecifics [1]. Our results suggest that, similar to black-capped chickadees, IEG expression in zebra finch CMM and NCM is tied to the acoustic similarity of vocalizations and not the phylogenetic relatedness of the species producing the vocalizations. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Nutrient Recycling Impacts by Zebra Mussels in Harper’s Ferry Slough, Upper Mississippi River

    DTIC Science & Technology

    2000-12-01

    ing pro duc tiv ity in the slough (also see Caraco et al. (1997)). In Harper’s Ferry Slough and other aquatic sys tems, the mag ni tude of ze bra mus...the Upper Mississippi River with zebra mussels (Dreissena polymorpha),” Environ. Sci. Technol. 33, 4385-4390. ERDC WQTN-PD-07 December 2000 11 Caraco , N

  17. Characterization of physiological and molecular processes associated with potato response to Zebra chip disease

    USDA-ARS?s Scientific Manuscript database

    Transcriptional analyses were applied to identify molecular mechanisms associated with the response of leaf and root potato tissues to ‘Ca. Liberibacter solanacearum’ (Lso) infection, causal agent of zebra chip disease (ZC). Lso infection affected several host processes including defense response-, ...

  18. Song Decrystallization in Adult Zebra Finches Does Not Require the Song Nucleus NIf

    PubMed Central

    Roy, Arani; Mooney, Richard

    2009-01-01

    In adult male zebra finches, transecting the vocal nerve causes previously stable (i.e., crystallized) song to slowly degrade, presumably because of the resulting distortion in auditory feedback. How and where distorted feedback interacts with song motor networks to induce this process of song decrystallization remains unknown. The song premotor nucleus HVC is a potential site where auditory feedback signals could interact with song motor commands. Although the forebrain nucleus interface of the nidopallium (NIf) appears to be the primary auditory input to HVC, NIf lesions made in adult zebra finches do not trigger song decrystallization. One possibility is that NIf lesions do not interfere with song maintenance, but do compromise the adult zebra finch's ability to express renewed vocal plasticity in response to feedback perturbations. To test this idea, we bilaterally lesioned NIf and then transected the vocal nerve in adult male zebra finches. We found that bilateral NIf lesions did not prevent nerve section–induced song decrystallization. To test the extent to which the NIf lesions disrupted auditory processing in the song system, we made in vivo extracellular recordings in HVC and a downstream anterior forebrain pathway (AFP) in NIf-lesioned birds. We found strong and selective auditory responses to the playback of the birds' own song persisted in HVC and the AFP following NIf lesions. These findings suggest that auditory inputs to the song system other than NIf, such as the caudal mesopallium, could act as a source of auditory feedback signals to the song motor network. PMID:19515953

  19. Non-destructive NIR detection of Zebra Chip disease in whole potatoes (abstract)

    USDA-ARS?s Scientific Manuscript database

    Potatoes are the 4th biggest food crop worldwide and the leading vegetable crop in the U.S., accounting for 15 percent of vegetable sales. Over 50% of potatoes are consumed as processed products such as French fries and chips. Zebra Chip (ZC) is a disease of potatoes that causes brown discoloration ...

  20. First report of zebra chip disease and Candidatus Liberibacter solanacearum on potatoes in Idaho

    USDA-ARS?s Scientific Manuscript database

    In September of 2011, potato (Solanum tuberosum) tubers in a packing facility in (Idaho Falls???) were observed with internal discolorations suggestive of the zebra chip disease (ZC). Symptoms were observed in 1-2% of tubers of Russet Burbank and Russet Norkotah and included brown spots and streak...

  1. Working towards developing potato tolerance of zebra chip disease: a food science perspective

    USDA-ARS?s Scientific Manuscript database

    Potato zebra chip is a major threat to worldwide potato production and is caused by ‘Candidatus Liberibacter solanacearum’ (Lso), which is vectored by potato psyllids. Albeit control can be achieved by use of insecticides to limit psyllid populations and therefore Lso spread, the recent development ...

  2. Toxic effects of brominated indoles and phenols on zebrafish embryos.

    PubMed

    Kammann, U; Vobach, M; Wosniok, W

    2006-07-01

    Organobromine compounds in the marine environment have been the focus of growing attention in past years. In contrast to anthropogenic brominated flame retardants, other brominated compounds are produced naturally, e.g., by common polychaete worms and algae. Brominated phenols and indoles assumed to be of biogenic origin have been detected in water and sediment extracts from the German Bight. These substances as well as some of their isomers have been tested with the zebrafish embryo test and were found to cause lethal as well as nonlethal malformations. The zebrafish test was able to detect a log K(OW)-related toxicity for bromophenols, suggesting nonpolar narcosis as a major mode of action. Different effect patterns could be observed for brominated indoles and bromophenols. The comparison of effective concentrations in the zebrafish embryo test with the concentrations determined in water samples suggests the possibility that brominated indoles may affect early life stages of marine fish species in the North Sea.

  3. Zebrafish Embryo as an In Vivo Model for Behavioral and Pharmacological Characterization of Methylxanthine Drugs.

    PubMed

    Basnet, Ram Manohar; Guarienti, Michela; Memo, Maurizio

    2017-03-09

    Zebrafish embryo is emerging as an important tool for behavior analysis as well as toxicity testing. In this study, we compared the effect of nine different methylxanthine drugs using zebrafish embryo as a model. We performed behavioral analysis, biochemical assay and Fish Embryo Toxicity (FET) test in zebrafish embryos after treatment with methylxanthines. Each drug appeared to behave in different ways and showed a distinct pattern of results. Embryos treated with seven out of nine methylxanthines exhibited epileptic-like pattern of movements, the severity of which varied with drugs and doses used. Cyclic AMP measurement showed that, despite of a significant increase in cAMP with some compounds, it was unrelated to the observed movement behavior changes. FET test showed a different pattern of toxicity with different methylxanthines. Each drug could be distinguished from the other based on its effect on mortality, morphological defects and teratogenic effects. In addition, there was a strong positive correlation between the toxic doses (TC 50 ) calculated in zebrafish embryos and lethal doses (LD 50 ) in rodents obtained from TOXNET database. Taken together, all these findings elucidate the potentiality of zebrafish embryos as an in vivo model for behavioral and toxicity testing of methylxanthines and other related compounds.

  4. Chromosomal mosaicism in mouse two-cell embryos after paternal exposure to acrylamide

    SciTech Connect

    Marchetti, Francesco; Bishop, Jack; Lowe, Xiu

    2008-10-14

    Chromosomal mosaicism in human preimplantation embryos is a common cause ofspontaneous abortions, however, our knowledge of its etiology is limited. We used multicolor fluorescence in situ hybridization (FISH) painting to investigate whether paternally-transmitted chromosomal aberrations result in mosaicism in mouse 2-cell embryos. Paternal exposure to acrylamide, an important industrial chemical also found in tobacco smoke and generated during the cooking process of starchy foods, produced significant increases in chromosomally defective 2-cell embryos, however, the effects were transient primarily affecting the postmeiotic stages of spermatogenesis. Comparisons with our previous study of zygotes demonstrated similar frequencies of chromosomally abnormal zygotes and 2-cellmore » embryos suggesting that there was no apparent selection against numerical or structural chromosomal aberrations. However, the majority of affected 2-cell embryos were mosaics showing different chromosomal abnormalities in the two blastomeric metaphases. Analyses of chromosomal aberrations in zygotes and 2-cell embryos showed a tendency for loss of acentric fragments during the first mitotic division ofembryogenesis, while both dicentrics and translocations apparently underwent propersegregation. These results suggest that embryonic development can proceed up to the end of the second cell cycle of development in the presence of abnormal paternal chromosomes and that even dicentrics can persist through cell division. The high incidence of chromosomally mosaic 2-cell embryos suggests that the first mitotic division of embryogenesis is prone to missegregation errors and that paternally-transmitted chromosomal abnromalities increase the risk of missegregation leading to embryonic mosaicism.« less

  5. A comparison of two mobile electrode arrays for increasing mortality of Lake Trout embryos

    USGS Publications Warehouse

    Brown, Peter J.; Guy, Christopher S.; Meeuwig, Michael H.

    2017-01-01

    Conservation of sport fisheries and populations of several native fishes in the western United States is dependent on sustained success of removal programs targeting invasive Lake Trout Salvelinus namaycush. Gill-netting of spawning adults is one strategy used to decrease spawning success; however, additional complementary methods are needed to disrupt Lake Trout reproduction where bycatch in gill nets is unacceptable. We developed and tested two portable electrode arrays designed to increase Lake Trout embryo mortality in known spawning areas. Both arrays were powered by existing commercial electrofishing equipment. However, one array was moved across the substrate to simulate being towed behind a boat (i.e., towed array), while the other array was lowered from a boat and energized when sedentary (i.e., sedentary array). The arrays were tested on embryos placed within substrates of known spawning areas. Both arrays increased mortality of embryos (>90%) at the surface of substrates, but only the sedentary array was able to increase mortality to >90% at deeper burial depths. In contrast, embryos at increasingly deeper depths exhibited progressively lower mortality when exposed to the towed array. Mortality of embryos placed under 20 cm of substrate and exposed to the towed array was not significantly different from that of unexposed embryos in a control group. We suggest that the sedentary array could be used as a viable approach for increasing mortality of Lake Trout embryos buried to 20 cm and that it could be modified to be effective at deeper depths.

  6. Effects of cryopreservation at various temperatures on the survival of kelp grouper (Epinephelus moara) embryos from fertilization with cryopreserved sperm.

    PubMed

    Tian, Yongsheng; Chen, Zhangfan; Tang, Jiang; Duan, Huimin; Zhai, Jieming; Li, Bo; Ma, Wenhui; Liu, Jiangchun; Hou, Yunxia; Sun, Zhengxiang

    2017-04-01

    Fish embryo cryopreservation is highly important for the long-term preservation of genomic and genetic information; however, few successful cases of fish embryo cryopreservation have been reported over the past 60 years. This is the first study to use Epinephelus moara embryos from fertilization with cryopreserved sperm as experimental material. Embryos that developed to the 16-22 somite stage and tail-bud stage were treated with the vitrification solution PMG3T according to a five-step equilibration method and cryopreserved at various temperatures and storage duration. Only 19.9 ± 9.2% of 16-22 somite stage embryos and 1.3 ± 1.1% of tail-bud stage embryos survived when cooled at 4 °C for 60 min. In total, 8.0 ± 3.0% of 16-22 somite stage embryos survived when cooled at -25.7 °C for 30 min, 22.4 ± 4.7% of tail-bud stage embryos survived after 45 min of cooling at -25.7 °C, and none survived after 60 min. Only 2.0 ± 2.7% of embryos survived when cryopreserved at -140 °C for 20 min. However, 9.7% of tail-bud stage embryos survived after cryopreservation in liquid nitrogen (-196 °C) for 2 h. Most surviving embryos developed normally. Embryonic volume decreased and spherical segments appeared when embryos were treated with higher concentrations of vitrification solution. Additionally, the volume recovered gradually after rinsing with sucrose and seawater. This is the first estimate of the survival of E. moara embryos and larvae after cryopreservation. These findings provide a foundation for further explorations of fish embryo cryopreservation techniques. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Bioaccumulation of lipophilic substances in fish early life stages

    SciTech Connect

    Petersen, G.I.; Kristensen, P.

    1998-07-01

    Accumulation of {sup 14}C-labeled polycyclic aromatic hydrocarbons, naphthalene, phenanthrene, pyrene, and benzo(a)pyrene and polychlorinated biphenyl (PCB) congeners PCB 31 and PCB 105 with a log octanol/water partition coefficient (K{sub ow}) range from 3.37 to 6.5 was investigated in eggs and larvae of zebra fish (Brachydanio rerio), and in larvae of cod (Gadus morhua), herring (Clupea harengus), and turbot (Scophthalmus maximus). Significant differences in the uptake and elimination rate constants between eggs and larvae of zebra fish were seen. The low rate of uptake and the lower elimination rate of eggs did, however, lead to bioconcentration factors (BCFs) comparable to thosemore » for larvae. As biotransformation of xenobiotics in embryonic and larval stages was indicated to be insignificant compared to juvenile/adult stages, body burdens of readily biotransformed chemicals may be higher in fish early life stages. Because weight and lipid content did not differ much between the investigated species, the main reason for the variability in BCFs between marine species and freshwater species was considered to be caused by differences in exposure temperatures that affect the degree of biotransformation. Due to the smaller size of larvae and thus an increased total surface of the membranes per unit fish weight, steady-state conditions were reached at a faster r/ate in early life stages than in juvenile/adult life stages. The lipid-normalized bioconcentration factors (BCF{sub L}) were linearly related to K{sub ow} but BCF{sub L} was, in general, higher than K{sub ow}, indicating that octanol is not a suitable surrogate for fish lipids. Differences in bioconcentration kinetics between larvae and juvenile/adult life stages are considered to be the main reason for the higher sensitivity, with respect to external effect concentrations, generally obtained for early life stages of fish.« less

  8. Endometrial preparation for women undergoing embryo transfer with frozen embryos or embryos derived from donor oocytes.

    PubMed

    Glujovsky, Demián; Pesce, Romina; Fiszbajn, Gabriel; Sueldo, Carlos; Hart, Roger J; Ciapponi, Agustín

    2010-01-20

    If a fresh embryo, assisted reproductive technology procedure cycle is unsuccessful and there are frozen embryos available, a frozen-thawed embryo transfer is performed. In some specific cases women may undergo oocyte donation treatment. In both situations the endometrium is primed by the administration of estrogen and progesterone. To prevent the possibility of spontaneous ovulation, gonadotropin-releasing hormone (GnRH) agonists are frequently used. To evaluate the most effective endometrial preparation for women undergoing transfer with frozen embryos or embryos from donor oocytes with regard to the subsequent live birth rate. We searched the Cochrane Menstrual Disorders and Subfertility Group Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE, EMBASE, LILACS, and abstracts of reproductive societies' meetings (from inception). No language restrictions were applied. Experts in the field were contacted. Randomised controlled trials evaluating endometrial preparation in women undergoing fresh donor cycles and frozen embryo transfers. Two review authors independently applied the inclusion criteria, assessed trial risk of bias, and extracted data. Twenty two randomised controlled trials were included. Five studies analysed the use of a GnRH agonist versus control. No significant benefit was demonstrated when using GnRH agonists. No evidence of statistically significant benefit was found for one GnRH agonist over another, or vaginal over intramuscular progesterone administration. No difference in pregnancy rate was demonstrated when no treatment was compared to aspirin, steroids, ovarian stimulation, or human chorionic gonadotropin (hCG) prior to embryo transfer, although using hCG several times before the oocyte retrieval decreases the pregnancy rate. Finally, when oocyte recipients were studied further, starting progesterone on the day of oocyte pick-up (OPU) or the day after OPU produced a significantly higher

  9. Selective auditory grouping by zebra finches: testing the iambic-trochaic law.

    PubMed

    Spierings, Michelle; Hubert, Jeroen; Ten Cate, Carel

    2017-07-01

    Humans have a strong tendency to spontaneously group visual or auditory stimuli together in larger patterns. One of these perceptual grouping biases is formulated as the iambic/trochaic law, where humans group successive tones alternating in pitch and intensity as trochees (high-low and loud-soft) and alternating in duration as iambs (short-long). The grouping of alternations in pitch and intensity into trochees is a human universal and is also present in one non-human animal species, rats. The perceptual grouping of sounds alternating in duration seems to be affected by native language in humans and has so far not been found among animals. In the current study, we explore to which extent these perceptual biases are present in a songbird, the zebra finch. Zebra finches were trained to discriminate between short strings of pure tones organized as iambs and as trochees. One group received tones that alternated in pitch, a second group heard tones alternating in duration, and for a third group, tones alternated in intensity. Those zebra finches that showed sustained correct discrimination were next tested with longer, ambiguous strings of alternating sounds. The zebra finches in the pitch condition categorized ambiguous strings of alternating tones as trochees, similar to humans. However, most of the zebra finches in the duration and intensity condition did not learn to discriminate between training stimuli organized as iambs and trochees. This study shows that the perceptual bias to group tones alternating in pitch as trochees is not specific to humans and rats, but may be more widespread among animals.

  10. Zebra Finch Song Phonology and Syntactical Structure across Populations and Continents-A Computational Comparison.

    PubMed

    Lachlan, Robert F; van Heijningen, Caroline A A; Ter Haar, Sita M; Ten Cate, Carel

    2016-01-01

    Learned bird songs are often characterized by a high degree of variation between individuals and sometimes between populations, while at the same time maintaining species specificity. The evolution of such songs depends on the balance between plasticity and constraints. Captive populations provide an opportunity to examine signal variation and differentiation in detail, so we analyzed adult male zebra finch (Taeniopygia guttata) songs recorded from 13 populations across the world, including one sample of songs from wild-caught males in their native Australia. Cluster analysis suggested some, albeit limited, evidence that zebra finch song units belonged to universal, species-wide categories, linked to restrictions in vocal production and non-song parts of the vocal repertoire. Across populations, songs also showed some syntactical structure, although any song unit could be placed anywhere within the song. On the other hand, there was a statistically significant differentiation between populations, but the effect size was very small, and its communicative significance dubious. Our results suggest that variation in zebra finch songs within a population is largely determined by species-wide constraints rather than population-specific features. Although captive zebra finch populations have been sufficiently isolated to allow them to genetically diverge, there does not appear to have been any divergence in the genetically determined constraints that underlie song learning. Perhaps more surprising is the lack of locally diverged cultural traditions. Zebra finches serve as an example of a system where frequent learning errors may rapidly create within-population diversity, within broad phonological and syntactical constraints, and prevent the formation of long-term cultural traditions that allow populations to diverge.

  11. Feminists on the inalienability of human embryos.

    PubMed

    McLeod, Carolyn; Baylis, Francoise

    2006-01-01

    The feminist literature against the commodification of embryos in human embryo research includes an argument to the effect that embryos are "intimately connected" to persons, or morally inalienable from them. We explore why embryos might be inalienable to persons and why feminists might find this view appealing. But, ultimately, as feminists, we reject this view because it is inconsistent with full respect for women's reproductive autonomy and with a feminist conception of persons as relational, embodied beings. Overall, feminists should avoid claims about embryos' being inalienable to persons in arguments for or against the commodification of human embryos.

  12. Comparison of prehatch C-start responses in rainbow trout and lake trout embryos by means of a tactile stimulus test

    USGS Publications Warehouse

    Wright, P.J.; Noltie, Douglas B.; Tillitt, D.E.

    2003-01-01

    The C-start in teleost fishes, a type of startle response, mediates the ability to respond to abrupt, unexpected stimuli and is characterized by a short-latency, C-type fast start acceleration. In prehatch fish embryos, the C-start appears necessary for mechanical breakdown of the egg chorion and successful hatching by way of increased embryo movement and distribution of the hatching enzymes. In later stages, the C-start plays an important role in predator avoidance. Using tactile stimulation, we evaluated the C-start response in rainbow trout Oncorhynchus mykiss at 170 degree-days, when 6.6% of embryos exhibited C-starts, and lake trout Salvelinus namaycush embryos at 320 degree-days, when 23% of embryos exhibited C-starts. Triplicate groups of embryos were later tested at three developmental stages: early (220 and 360 degree-days for rainbow trout and lake trout, respectively), middle (260 and 480 degree-days, respectively), and late (320 and 560 degree-days, respectively). The proportion of trout embryos exhibiting C-start increased through time, such that 100% had responded by the late stage, just prior to hatching. C-starts could be obtained by repeated stimulation, and the relative activity of the embryos (based on the number of flexures per stimulus) also increased over time. Rainbow trout and lake trout showed very similar C-start responses at parallel developmental stages, and these patterns of response were similar to those reported in other fish species.

  13. In Amnio MRI of Mouse Embryos

    PubMed Central

    Roberts, Thomas A.; Norris, Francesca C.; Carnaghan, Helen; Savery, Dawn; Wells, Jack A.; Siow, Bernard; Scambler, Peter J.; Pierro, Agostino; De Coppi, Paolo; Eaton, Simon; Lythgoe, Mark F.

    2014-01-01

    Mouse embryo imaging is conventionally carried out on ex vivo embryos excised from the amniotic sac, omitting vital structures and abnormalities external to the body. Here, we present an in amnio MR imaging methodology in which the mouse embryo is retained in the amniotic sac and demonstrate how important embryonic structures can be visualised in 3D with high spatial resolution (100 µm/px). To illustrate the utility of in amnio imaging, we subsequently apply the technique to examine abnormal mouse embryos with abdominal wall defects. Mouse embryos at E17.5 were imaged and compared, including three normal phenotype embryos, an abnormal embryo with a clear exomphalos defect, and one with a suspected gastroschisis phenotype. Embryos were excised from the mother ensuring the amnion remained intact and stereo microscopy was performed. Embryos were next embedded in agarose for 3D, high resolution MRI on a 9.4T scanner. Identification of the abnormal embryo phenotypes was not possible using stereo microscopy or conventional ex vivo MRI. Using in amnio MRI, we determined that the abnormal embryos had an exomphalos phenotype with varying severities. In amnio MRI is ideally suited to investigate the complex relationship between embryo and amnion, together with screening for other abnormalities located outside of the mouse embryo, providing a valuable complement to histology and existing imaging methods available to the phenotyping community. PMID:25330230

  14. A dominance shift from the zebra mussel to the invasive quagga mussel may alter the trophic transfer of metals.

    PubMed

    Matthews, Jonathan; Schipper, Aafke M; Hendriks, A Jan; Yen Le, T T; Bij de Vaate, Abraham; van der Velde, Gerard; Leuven, Rob S E W

    2015-08-01

    Bioinvasions are a major cause of biodiversity and ecosystem changes. The rapid range expansion of the invasive quagga mussel (Dreissena rostriformis bugensis) causing a dominance shift from zebra mussels (Dreissena polymorpha) to quagga mussels, may alter the risk of secondary poisoning to predators. Mussel samples were collected from various water bodies in the Netherlands, divided into size classes, and analysed for metal concentrations. Concentrations of nickel and copper in quagga mussels were significantly lower than in zebra mussels overall. In lakes, quagga mussels contained significantly higher concentrations of aluminium, iron and lead yet significantly lower concentrations of zinc66, cadmium111, copper, nickel, cobalt and molybdenum than zebra mussels. In the river water type quagga mussel soft tissues contained significantly lower concentrations of zinc66. Our results suggest that a dominance shift from zebra to quagga mussels may reduce metal exposure of predator species. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Early responses to zebra mussels in the Great Lakes: a journey from information vacuum to policy and regulation

    USGS Publications Warehouse

    Griffiths, Ronald W.; Schloesser, Don W.; Kovalak, William P.

    2013-01-01

    Invasive species such as zebra mussels pose a threat to the economies and environments of coastal and fresh-water habitats around the world. Consequently, it is important that government policies and programs be adequate to protect these waters from invaders. This chapter documents key events that took place in the early years (1988-1991) of zebra mussel colonization of the Laurentian Great Lakes and evaluates government responses (policies and programs) to this disruptive, invasive, freshwater species.

  16. Fish Dishes.

    ERIC Educational Resources Information Center

    Derby, Marie

    2003-01-01

    Describes an art project that was inspired by Greek pottery, specifically dishes shaped as fish. Explains that fourth-grade students drew a fish shape that was later used to create their clay version of the fish. Discusses how the students examined the pottery to make decisions about color and design. (CMK)

  17. Single-embryo transfer versus multiple-embryo transfer.

    PubMed

    Gerris, Jan

    2009-01-01

    Despite the progress made in assisted reproductive technology, live birth rates remain disappointingly low. Multiple-embryo transfer has been an accepted practice with which to increase the success rate. This has led to a higher incidence of multiple-order births compared with natural conception, which not only increase the risk of mortality and morbidity to both mother and children but are also associated with social and economic consequences. Elective single-embryo transfer (eSET) was developed in an effort to increase singleton pregnancies in assisted reproduction. Studies comparing eSET with multiple-embryo transfer highlight the benefit of this approach and suggest that, with careful patient selection and the transfer of good-quality embryos, the risk of a multiple-order pregnancy can be reduced without significantly decreasing live birth rates. Although the use of eSET has gradually increased in clinical practice, its acceptance has been limited by factors such as availability of funding and awareness of the procedure. An open discussion of eSET is warranted in an effort to enable a broader understanding by physicians and patients of the merits of this approach. Ultimately, eSET may provide a more cost-effective, potentially safer approach to patients undergoing assisted reproduction technology.

  18. Transition of cell numbers in bovine preimplantation embryos: in vivo collected and in vitro produced embryos.

    PubMed

    Ushijima, Hitoshi; Akiyama, Kiyoshi; Tajima, Toshio

    2008-08-01

    The total cell numbers (TCNs) of bovine embryos collected from superovulated donors (VIVO embryos) were counted 0-9 d after ovulation to quantify the developmental process. Using numerical analysis of embryo development, we also compared the developmental process of VIVO embryos, in vitro-fertilized (IVF) embryos and nuclear transfer (NT) embryos obtained from enucleated oocytes and blastomere nuclei. The TCNs of embryos were measured using the air-dry method. Cleavage divisions (CD) of the embryos were obtained using logarithmic transformation of the TCN. The TCN of the VIVO embryos increased significantly (P<0.001) with time. The relationship between the CD of the VIVO embryos at 0-9 d after ovulation and age in days was described by a linear equation with a high correlation (y=1.03x+0.16, r=0.99), showing that CD occurs about once each day for all blastomeres. However, compared to the VIVO embryos, the TCN of the IVF embryos did not increase from 3-4 d nor after 7 d; the TCN of the NT embryos did not increase after 7 d (P>0.05). The results suggest a delay in development at these developmental stages. The slopes of regression lines of the IVF and NT embryos were significantly (P<0.001) smaller, indicating that quantification of the developmental process of VIVO embryos according to TCN and CD would be useful as criteria for numerical evaluation of the developmental process of bovine in vitro produced embryos.

  19. Factorial microarray analysis of zebra mussel (Dreissena polymorpha: Dreissenidae, Bivalvia) adhesion

    PubMed Central

    2010-01-01

    Background The zebra mussel (Dreissena polymorpha) has been well known for its expertise in attaching to substances under the water. Studies in past decades on this underwater adhesion focused on the adhesive protein isolated from the byssogenesis apparatus of the zebra mussel. However, the mechanism of the initiation, maintenance, and determination of the attachment process remains largely unknown. Results In this study, we used a zebra mussel cDNA microarray previously developed in our lab and a factorial analysis to identify the genes that were involved in response to the changes of four factors: temperature (Factor A), current velocity (Factor B), dissolved oxygen (Factor C), and byssogenesis status (Factor D). Twenty probes in the microarray were found to be modified by one of the factors. The transcription products of four selected genes, DPFP-BG20_A01, EGP-BG97/192_B06, EGP-BG13_G05, and NH-BG17_C09 were unique to the zebra mussel foot based on the results of quantitative reverse transcription PCR (qRT-PCR). The expression profiles of these four genes under the attachment and non-attachment were also confirmed by qRT-PCR and the result is accordant to that from microarray assay. The in situ hybridization with the RNA probes of two identified genes DPFP-BG20_A01 and EGP-BG97/192_B06 indicated that both of them were expressed by a type of exocrine gland cell located in the middle part of the zebra mussel foot. Conclusions The results of this study suggested that the changes of D. polymorpha byssogenesis status and the environmental factors can dramatically affect the expression profiles of the genes unique to the foot. It turns out that the factorial design and analysis of the microarray experiment is a reliable method to identify the influence of multiple factors on the expression profiles of the probesets in the microarray; therein it provides a powerful tool to reveal the mechanism of zebra mussel underwater attachment. PMID:20509938

  20. 9 CFR 98.9 - Embryos refused entry.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Embryos refused entry. 98.9 Section 98... EMBRYOS AND ANIMAL SEMEN Ruminant and Swine Embryos from Regions Free of Rinderpest and Foot-and-Mouth Disease; and Embryos of Horses and Asses § 98.9 Embryos refused entry. Any embryo refused entry into the...

  1. 9 CFR 98.9 - Embryos refused entry.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Embryos refused entry. 98.9 Section 98... EMBRYOS AND ANIMAL SEMEN Ruminant and Swine Embryos from Regions Free of Rinderpest and Foot-and-Mouth Disease; and Embryos of Horses and Asses § 98.9 Embryos refused entry. Any embryo refused entry into the...

  2. 9 CFR 98.9 - Embryos refused entry.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Embryos refused entry. 98.9 Section 98... EMBRYOS AND ANIMAL SEMEN Ruminant and Swine Embryos from Regions Free of Rinderpest and Foot-and-Mouth Disease; and Embryos of Horses and Asses § 98.9 Embryos refused entry. Any embryo refused entry into the...

  3. 9 CFR 98.9 - Embryos refused entry.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Embryos refused entry. 98.9 Section 98... EMBRYOS AND ANIMAL SEMEN Ruminant and Swine Embryos from Regions Free of Rinderpest and Foot-and-Mouth Disease; and Embryos of Horses and Asses § 98.9 Embryos refused entry. Any embryo refused entry into the...

  4. 9 CFR 98.9 - Embryos refused entry.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Embryos refused entry. 98.9 Section 98... EMBRYOS AND ANIMAL SEMEN Ruminant and Swine Embryos from Regions Free of Rinderpest and Foot-and-Mouth Disease; and Embryos of Horses and Asses § 98.9 Embryos refused entry. Any embryo refused entry into the...

  5. Untwisting the Caenorhabditis elegans embryo.

    PubMed

    Christensen, Ryan Patrick; Bokinsky, Alexandra; Santella, Anthony; Wu, Yicong; Marquina-Solis, Javier; Guo, Min; Kovacevic, Ismar; Kumar, Abhishek; Winter, Peter W; Tashakkori, Nicole; McCreedy, Evan; Liu, Huafeng; McAuliffe, Matthew; Mohler, William; Colón-Ramos, Daniel A; Bao, Zhirong; Shroff, Hari

    2015-12-03

    The nematode Caenorhabditis elegans possesses a simple embryonic nervous system with few enough neurons that the growth of each cell could be followed to provide a systems-level view of development. However, studies of single cell development have largely been conducted in fixed or pre-twitching live embryos, because of technical difficulties associated with embryo movement in late embryogenesis. We present open-source untwisting and annotation software (http://mipav.cit.nih.gov/plugin_jws/mipav_worm_plugin.php) that allows the investigation of neurodevelopmental events in late embryogenesis and apply it to track the 3D positions of seam cell nuclei, neurons, and neurites in multiple elongating embryos. We also provide a tutorial describing how to use the software (Supplementary file 1) and a detailed description of the untwisting algorithm (Appendix). The detailed positional information we obtained enabled us to develop a composite model showing movement of these cells and neurites in an 'average' worm embryo. The untwisting and cell tracking capabilities of our method provide a foundation on which to catalog C. elegans neurodevelopment, allowing interrogation of developmental events in previously inaccessible periods of embryogenesis.

  6. Embryo adoption: Some further considerations

    PubMed Central

    Patterson, Colin

    2015-01-01

    Recent discussions of embryo adoption have sought to make sense of the teaching of the Congregation for the Doctrine of the Faith (CDF) document Dignitas personae which appeared to provide a negative judgment on such a practice. This article aims to provide a personalist account of the process of fertilization and implantation that might serve as the basis for the negative judgment of the CDF document. In doing so, it relies upon the idea that a person, including an embryo, is not to be considered in isolation, but always in relation to God and to others. This approach extends the substantialist conceptualizations commonly employed in discussions of this issue. More generally, the article seeks to highlight the value of a personalist re-framing for an understanding of the moral questions surrounding the beginning of life. Lay summary: This article seeks to make sense of what appears to be a clear-cut rejection, set out in the Congregation for the Doctrine of the Faith (CDF) document Dignitas personae, of the proposal for women to “adopt” surplus frozen embryos. It draws upon more recently developed modes of philosophical/theological reasoning to argue that, in human procreation, both fertilization and implantation represent constitutive dimensions of divine creative activity and so must be protected from manipulative technological intervention. Since embryo adoption requires this kind of technology, it makes sense for the Church document not to approve it. PMID:25698841

  7. Untwisting the Caenorhabditis elegans embryo

    PubMed Central

    Christensen, Ryan Patrick; Bokinsky, Alexandra; Santella, Anthony; Wu, Yicong; Marquina-Solis, Javier; Guo, Min; Kovacevic, Ismar; Kumar, Abhishek; Winter, Peter W; Tashakkori, Nicole; McCreedy, Evan; Liu, Huafeng; McAuliffe, Matthew; Mohler, William; Colón-Ramos, Daniel A; Bao, Zhirong; Shroff, Hari

    2015-01-01

    The nematode Caenorhabditis elegans possesses a simple embryonic nervous system with few enough neurons that the growth of each cell could be followed to provide a systems-level view of development. However, studies of single cell development have largely been conducted in fixed or pre-twitching live embryos, because of technical difficulties associated with embryo movement in late embryogenesis. We present open-source untwisting and annotation software (http://mipav.cit.nih.gov/plugin_jws/mipav_worm_plugin.php) that allows the investigation of neurodevelopmental events in late embryogenesis and apply it to track the 3D positions of seam cell nuclei, neurons, and neurites in multiple elongating embryos. We also provide a tutorial describing how to use the software (Supplementary file 1) and a detailed description of the untwisting algorithm (Appendix). The detailed positional information we obtained enabled us to develop a composite model showing movement of these cells and neurites in an 'average' worm embryo. The untwisting and cell tracking capabilities of our method provide a foundation on which to catalog C. elegans neurodevelopment, allowing interrogation of developmental events in previously inaccessible periods of embryogenesis. DOI: http://dx.doi.org/10.7554/eLife.10070.001 PMID:26633880

  8. Embryo adoption: Some further considerations.

    PubMed

    Patterson, Colin

    2015-02-01

    Recent discussions of embryo adoption have sought to make sense of the teaching of the Congregation for the Doctrine of the Faith (CDF) document Dignitas personae which appeared to provide a negative judgment on such a practice. This article aims to provide a personalist account of the process of fertilization and implantation that might serve as the basis for the negative judgment of the CDF document. In doing so, it relies upon the idea that a person, including an embryo, is not to be considered in isolation, but always in relation to God and to others. This approach extends the substantialist conceptualizations commonly employed in discussions of this issue. More generally, the article seeks to highlight the value of a personalist re-framing for an understanding of the moral questions surrounding the beginning of life. Lay summary: This article seeks to make sense of what appears to be a clear-cut rejection, set out in the Congregation for the Doctrine of the Faith (CDF) document Dignitas personae, of the proposal for women to "adopt" surplus frozen embryos. It draws upon more recently developed modes of philosophical/theological reasoning to argue that, in human procreation, both fertilization and implantation represent constitutive dimensions of divine creative activity and so must be protected from manipulative technological intervention. Since embryo adoption requires this kind of technology, it makes sense for the Church document not to approve it.

  9. Embryo-larval toxicity tests with the African catfish (Clarias gariepinus): comparative sensitivity of endpoints.

    PubMed

    Nguyen, L T H; Janssen, C R

    2002-02-01

    Embryo-larval toxicity tests with the African catfish (Clarias gariepinus) were performed to assess the comparative sensitivity of different endpoints. Measured test responses included embryo and larval survival, hatching, morphological development, and larval growth. Chromium, cadmium, copper, sodium pentachlorphenol (NaPCP), and malathion were used as model toxicants. Hatching was not affected by any of the chemicals tested, and embryo survival was only affected by chromium at > or = 36 mg/L. The growth of larvae was significantly reduced at > or = 11 mg/L Cr, > or = 0.63 mg/L Cu, > or = 0.03 mg/L NaPCP, and > or = 1.25 mg/L malathion. Morphological development of C. gariepinus was affected by all of the toxicants tested. Different types of morphological aberrations were observed, i.e., reduction of pigmentation in fish exposed to cadmium and copper, yolk sac edema in fish exposed to NaPCP and malathion, and deformation of the notochord in fish exposed to chromium and malathion. The sensitivity of the endpoints measured can be summarized as follows: growth > abnormality > larval survival > embryo survival > hatching.

  10. Effect of vitrification solutions on survival rate of cryopreserved Epinephelus moara embryos.

    PubMed

    Tian, Y S; Zhang, J J; Li, Z T; Tang, J; Cheng, M L; Wu, Y P; Ma, W H; Pang, Z F; Li, W S; Zhai, J M; Li, B

    2018-06-01

    Embryo cryopreservation is important for long-term preservation of germplasm and assisted reproduction. However, it is still very difficult to obtain viable embryos from cryopreserved fish embryos. In this study, embryos of Epinephelus moara were used to investigate the effects of various cryopreservation methods. Embryos in stages 10 pairs somite (10S), 18 pairs somite (18S), 22 pairs somite (22S), tail-bud (TB), embryo twitching (ET) and pre-hatch (PH) were treated with five-step equilibrium penetration in 40% PMG3T vitrification solution, which contained 15.75% 1,2-propylene glycol, 10.50% Methanol, 8.75% Glycerol and 5.00% Trehalose. We found that 18S, 22S, TB and ET stage embryos had higher survival rates and were more tolerant to the vitrification solution. Five-step equilibrium treatments on the embryos at the tail-bud stage were performed using two vitrification solutions: 40% PMG3T and 40% PMG3S, which consisted of 15.75% 1,2-propylene glycol, 10.50% Methanol, 8.75% Glycerol and 5.00% Sucrose. The embryonic survival rate under PMG3S treatment (63.36%) was significantly higher than PMG3T treatment (43.93%) (P < 0.05). PMG3S and PMG3T with concentrations of 35%, 40% and 45% were tested on tail-bud stage embryos. Higher concentration of the vitrification solution led to significantly lower embryonic survival rate (P < 0.05). The survival rate was 36.79-72.05% in PMG3S, and 37.11-55.18% in PMG3T, and there were non-significant differences in embryonic development and malformation rates among the groups treated with different concentrations. The embryonic normal development rates in PMG3S and PMG3T were 21.27% and 11.04%, and the malformation rates were 36.13% and 31.04%, respectively. The optimum treatment condition was 40 min using 40% PMG3S on embryos at the tail-bud stage. Both PMG3S and PMG3T were used for cryopreserving embryos at 16 pairs somite, tail-bud and ET stage in liquid nitrogen, where we obtained 190 surviving embryos, and 44 fishes

  11. Inhibition of the thioredoxin system in the brain and liver of zebra-seabreams exposed to waterborne methylmercury

    SciTech Connect

    Branco, Vasco, E-mail: vbranco@ipimar.pt; Marine Environment and Biodiversity Unit, National Institute for Biological Resources; Canario, Joao, E-mail: jcanario@ipimar.pt

    2011-03-01

    Mercury compounds were recently found to interact in vitro with the thioredoxin system, inhibiting both Thioredoxin (Trx) and Thioredoxin reductase (TrxR). In order to evaluate if Trx and TrxR are affected in vivo by methylmercury (MeHg), we exposed juvenile zebra-seabreams to different concentrations of this toxicant in water for 28 days followed by a 14-day depuration period. Methylmercury accumulated to a larger extent in the kidney and liver of fishes, but decreased significantly during the depuration. During the exposure, MeHg percentage in the liver reached levels above 90% of total mercury (HgT) decreasing to 60% of HgT by the endmore » of the depuration period. In the kidney, MeHg accounted for 50-70% of HgT. In the brain and muscle, mercury accumulated throughout the exposure with all mercury being MeHg. The total mercury kept increasing in these organs during the depuration period. However, in the brain, this increase in HgT was accompanied by a decrease in the MeHg percentage ({approx} 10%). In the liver, both Trx and TrxR activities were significantly reduced (TrxR - 40%; Trx - 70%) by the end of the exposure, but recovered to control levels (100%) during the depuration. In the brain, both enzymes where inhibited during the depuration period (TrxR - 75%; Trx - 70%) when some production of inorganic mercury was detected. Activity of glutathione reductase showed increased levels when TrxR activity was low, suggesting complementarity between both systems. These results indicate that in vivo the thioredoxin system is a toxicological target for MeHg with TrxR being particularly affected.« less

  12. Embryo density and medium volume effects on early murine embryo development.

    PubMed

    Canseco, R S; Sparks, A E; Pearson, R E; Gwazdauskas, F C

    1992-10-01

    One-cell mouse embryos were used to determine the effects of drop size and number of embryos per drop for optimum development in vitro. Embryos were collected from immature C57BL6 female mice superovulated with pregnant mare serum gonadotropin and human chorionic gonadotropin and mated by CD1 males. Groups of 1, 5, 10, or 20 embryos were cultured in 5-, 10-, 20-, or 40-microliters drops of CZB under silicon oil at 37.5 degrees C in a humidified atmosphere of 5% CO2 and 95% air. Development score for embryos cultured in 10 microliters was higher than that of embryos cultured in 20 or 40 microliters. Embryos cultured in groups of 5, 10, or 20 had higher development scores than embryos cultured singly. The highest development score was obtained by the combination of 5 embryos per 10-microliters drop. The percentage of live embryos in 20 or 40 microliters was lower than that of embryos cultured in 10 microliters. Additionally, the percentage of live embryos cultured singly was lower than that of embryos cultured in groups. Our results suggest that a stimulatory interaction occurs among embryos possibly exerted through the secretion of growth factors. This effect can be diluted if the embryos are cultured in large drops or singly.

  13. Zinc and cadmium accumulation in single zebrafish ( Danio rerio) embryos — A total reflection X-ray fluorescence spectrometry application

    NASA Astrophysics Data System (ADS)

    Mages, Margarete; Bandow, Nicole; Küster, Eberhard; Brack, Werner; von Tümpling, Wolf

    2008-12-01

    Trace metals such as Cadmium (Cd) and Zinc (Zn) are known to exhibit adverse effects on many aquatic organisms including early life stages of fish. In contact with contaminated sediment, fish eggs and embryos may be exposed to metals via the water phase as well as via direct contact with contaminated particles. This may result in body burdens that are difficult to predict and may vary according to individual micro scale exposure conditions. The highly sensitive total reflection X-ray fluorescence spectrometry (TXRF) may provide a tool to analyse individual embryos for internal contaminant concentrations and thus helps to develop a better understanding of dose-response relationships. To test this hypothesis, embryos of Danio rerio were exposed to Cd and Zn spiked sediment in different treatments applying an ion exchange resin for modification of bioavailable concentrations. The TXRF analysis indicated individual embryos with dramatically enhanced exposure compared to other individuals despite uniform exposure conditions on a macro scale. Ion exchanger reduced embryo Zn concentrations to values close to control value with a comparably low standard deviation. Cadmium concentrations in embryos were in the range of 4000 to 7000 µg/g with a median of 5740 µg/g. A commercial ion exchanger reduced individual body burdens by a factor 50 to 100. Individual peak body burdens of up to 3160 µg/g were accompanied by reduced weight of the fish eggs due to early death i.e. coagulation. The investigation of exposure and effects on an individual-based scale may significantly help to reduce uncertainty and inconsistencies occurring in conventional analysis of pooled fish embryo samples.

  14. Medaka embryonic stem cells are capable of generating entire organs and embryo-like miniatures.

    PubMed

    Hong, Ni; He, Bei Ping; Schartl, Manfred; Hong, Yunhan

    2013-03-01

    Embryonic stem (ES) cells have the potency to produce many cell types of the embryo and adult body. Upon transplantation into early host embryos, ES cells are able to differentiate into various specialized cells and contribute to host tissues and organs of all germ layers. Here we present data in the fish medaka (Oryzias latipes) that ES cells have a novel ability to form extra organs and even embryo-like miniatures. Upon transplantation as individual cells according to the standard procedure, ES cells distributed widely to various organ systems of 3 germ layers. Upon transplantation as aggregates, ES cells were able to form extra organs, including the hematopoietic organ and contracting heart. We show that localized ES cell transplantation often led to the formation of extra axes that comprised essentially of either host cells or donor ES cells. These extra axes were associated with the head region of the embryo proper or formed at ectopic sites on the yolk sac. Surprisingly, certain ectopic axes were even capable of forming embryo-like miniatures. We conclude that ES cells have the ability to form entire organs and even embryo-like miniatures under proper environmental conditions. This finding points to a new possibility to generate ES cell-derived axes and organs.

  15. Fish Rhabdoviruses

    USGS Publications Warehouse

    Kurath, G.; Winton, J.

    2008-01-01

    Many important viral pathogens of fish are members of the family Rhabdoviridae. The viruses in this large group cause significant losses in populations of wild fish as well as among fish reared in aquaculture. Fish rhabdoviruses often have a wide host and geographic range, and infect aquatic animals in both freshwater and seawater. The fish rhabdoviruses comprise a diverse collection of isolates that can be placed in one of two quite different groups: isolates that are members of the established genusNovirhabdovirus, and those that are most similar to members of the genus Vesiculovirus. Because the diseases caused by fish rhabdoviruses are important to aquaculture, diagnostic methods for their detection and identification are well established. In addition to regulations designed to reduce the spread of fish viruses, a significant body of research has addressed methods for the control or prevention of diseases caused by fish rhabdoviruses, including vaccination. The number of reported fish rhabdoviruses continues to grow as a result of the expansion of aquaculture, the increase in global trade, the development of improved diagnostic methods, and heightened surveillance activities. Fish rhabdoviruses serve as useful components of model systems to study vertebrate virus disease, epidemiology, and immunology.

  16. Caudal thoracic air sac cannulation in zebra finches for isoflurane anesthesia.

    PubMed

    Nilson, Paige Crystal; Teramitsu, Ikuko; White, Stephanie Ann

    2005-04-30

    Small songbirds such as the zebra finch are commonly used for studies on the neural mechanisms that underlie vocal learning. For these studies, survival surgeries are often performed that involve animal anesthesia and stereotaxic stabilization for localization of specific brain regions. Here we describe air sac cannulation as a novel method for delivering isoflurane gas to zebra finches for anesthesia during neurosurgery. Advantages of this method include that it leaves the bird's head free for stereotaxic targeting and does not interfere with the beak clamps that are often used to position and stabilize the head. It additionally allows for the use of the inhalant anesthetic, isoflurane, which is an appealing alternative to injectable anesthetics because it provides fast, minimally stressful induction, and low subject and personnel toxicity. The use of isoflurane also prevents overdosing and lengthy postoperative recovery times.

  17. Biomechanics of predator-prey arms race in lion, zebra, cheetah and impala

    NASA Astrophysics Data System (ADS)

    Wilson, Alan M.; Hubel, Tatjana Y.; Wilshin, Simon D.; Lowe, John C.; Lorenc, Maja; Dewhirst, Oliver P.; Bartlam-Brooks, Hattie L. A.; Diack, Rebecca; Bennitt, Emily; Golabek, Krystyna A.; Woledge, Roger C.; McNutt, J. Weldon; Curtin, Nancy A.; West, Timothy G.

    2018-02-01

    The fastest and most manoeuvrable terrestrial animals are found in savannah habitats, where predators chase and capture running prey. Hunt outcome and success rate are critical to survival, so both predator and prey should evolve to be faster and/or more manoeuvrable. Here we compare locomotor characteristics in two pursuit predator-prey pairs, lion-zebra and cheetah-impala, in their natural savannah habitat in Botswana. We show that although cheetahs and impalas were universally more athletic than lions and zebras in terms of speed, acceleration and turning, within each predator-prey pair, the predators had 20% higher muscle fibre power than prey, 37% greater acceleration and 72% greater deceleration capacity than their prey. We simulated hunt dynamics with these data and showed that hunts at lower speeds enable prey to use their maximum manoeuvring capacity and favour prey survival, and that the predator needs to be more athletic than its prey to sustain a viable success rate.

  18. FoxP2 isoforms delineate spatiotemporal transcriptional networks for vocal learning in the zebra finch

    PubMed Central

    Day, Nancy F; Kimball, Todd Haswell; Aamodt, Caitlin M; Heston, Jonathan B; Hilliard, Austin T; Xiao, Xinshu; White, Stephanie A

    2018-01-01

    Human speech is one of the few examples of vocal learning among mammals yet ~half of avian species exhibit this ability. Its neurogenetic basis is largely unknown beyond a shared requirement for FoxP2 in both humans and zebra finches. We manipulated FoxP2 isoforms in Area X, a song-specific region of the avian striatopallidum analogous to human anterior striatum, during a critical period for song development. We delineate, for the first time, unique contributions of each isoform to vocal learning. Weighted gene coexpression network analysis of RNA-seq data revealed gene modules correlated to singing, learning, or vocal variability. Coexpression related to singing was found in juvenile and adult Area X whereas coexpression correlated to learning was unique to juveniles. The confluence of learning and singing coexpression in juvenile Area X may underscore molecular processes that drive vocal learning in young zebra finches and, by analogy, humans. PMID:29360038

  19. Biomechanics of predator-prey arms race in lion, zebra, cheetah and impala.

    PubMed

    Wilson, Alan M; Hubel, Tatjana Y; Wilshin, Simon D; Lowe, John C; Lorenc, Maja; Dewhirst, Oliver P; Bartlam-Brooks, Hattie L A; Diack, Rebecca; Bennitt, Emily; Golabek, Krystyna A; Woledge, Roger C; McNutt, J Weldon; Curtin, Nancy A; West, Timothy G

    2018-02-08

    The fastest and most manoeuvrable terrestrial animals are found in savannah habitats, where predators chase and capture running prey. Hunt outcome and success rate are critical to survival, so both predator and prey should evolve to be faster and/or more manoeuvrable. Here we compare locomotor characteristics in two pursuit predator-prey pairs, lion-zebra and cheetah-impala, in their natural savannah habitat in Botswana. We show that although cheetahs and impalas were universally more athletic than lions and zebras in terms of speed, acceleration and turning, within each predator-prey pair, the predators had 20% higher muscle fibre power than prey, 37% greater acceleration and 72% greater deceleration capacity than their prey. We simulated hunt dynamics with these data and showed that hunts at lower speeds enable prey to use their maximum manoeuvring capacity and favour prey survival, and that the predator needs to be more athletic than its prey to sustain a viable success rate.

  20. Ammonium detection by formation of colored zebra-bands in a detecting tube.

    PubMed

    Hori, Tatsuaki; Niki, Keizou; Kiso, Yoshiaki; Oguchi, Tatsuo; Kamimoto, Yuki; Yamada, Toshiro; Nagai, Masahiro

    2010-06-15

    Ammonium ion was colorized by means of a diazo coupling reaction with 2-phenylphenol, where the color development reaction was conducted within 3min by using boric acid as a catalyst. The resulting colored solution (0.5ml) was supplied by suction to a detecting tube consisting of a nonwoven fabric test strip (2mm wide, 1mm thick, 150mm long) impregnated with benzylcetyldimethylammonium chloride in a stripe pattern and enclosed in a heat-shrinkable tube. When the colored solution was supplied to the detecting tube, blue zebra-bands formed, and the ammonium concentration was determined by counting the number of zebra-bands. The detection range was 1-20mg-Nl(-1). Ammonium ion in actual domestic wastewater samples was successfully detected by means of this method.

  1. Comparative morphology of zebra (Dreissena polymorpha) and quagga (Dreissena bugensis) mussel sperm: Light and electron microscopy

    USGS Publications Warehouse

    Walker, G.K.; Black, M.G.; Edwards, C.A.

    1996-01-01

    Adult zebra (Dreissena polymorpha) and quagga (Dreissena bugensis) mussels were induced to release large quantities of live spermatozoa by the administration of 5-hydroxytryptamine (serotonin). Sperm were photographed alive using phase-contrast microscopy and were fixed subsequently with glutaraldehyde followed by osmium tetroxide for eventual examination by transmission or scanning electron microscopy. The sperm of both genera are of the ect-aquasperm type. Their overall dimensions and shape allow for easy discrimination at the light and scanning electron microscopy level. Transmission electron microscopy of the cells reveals a barrel-shaped nucleus in zebra mussel sperm and an elongated nucleus in quagga mussel sperm. In both species, an acrosome is cradled in a nuclear fossa. The ultrastructure of the acrosome and axial body, however, is distinctive for each species. The structures of the midpiece are shown, including a unique mitochondrial "skirt" that includes densely packed parallel cristae and extends in a narrow sheet from the mitochondria.

  2. Differences in toxicity of anionic and cationic PAMAM and PPI dendrimers in zebrafish embryos and cancer cell lines

    SciTech Connect

    Bodewein, Lambert

    Dendrimers are an emerging class of polymeric nanoparticles with beneficial biomedical applications like early diagnostics, in vitro gene transfection or controlled drug delivery. However, the potential toxic impact of exposure on human health or the environment is often inadequately defined. Thus, polyamidoamine (PAMAM) dendrimers of generations G3.0, 3.5, 4.0, 4.5 and 5.0 and polypropylenimine (PPI) dendrimers G3.0, 4.0 and 5.0 were tested in zebrafish embryos for 96 h and human cancer cell lines for 24 h, to assess and compare developmental in vivo toxicity with cytotoxicity. The zebrafish embryo toxicity of cationic PAMAM and PPI dendrimers increased over time, withmore » EC50 values ranging from 0.16 to just below 1.7 μM at 24 and 48 hpf. The predominant effects were mortality, plus reduced heartbeat and blood circulation for PPI dendrimers. Apoptosis in the embryos increased in line with the general toxicity concentration-dependently. Hatch and dechorionation of the embryos increased the toxicity, suggesting a protective role of the chorion. Lower generation dendrimers were more toxic in the embryos whereas the toxicity in the HepG2 and DU145 cell lines increased with increasing generation of cationic PAMAMs and PPI dendrimers. HepG2 were less sensitive than DU145 cells, with IC50 values ≥ 402 μM (PAMAMs) and ≤ 240 μM (PPIs) for HepG2 and ≤ 13.24 μM (PAMAMs) and ≤ 12.84 μM (PPIs) for DU145. Neither in fish embryos nor cells toxicity thresholds were determinable for anionic PAMAM G3.5 and G4.5. The study demonstrated that the cytotoxicity underestimated the in-vivo toxicity of the dendrimers in the fish embryos. - Highlights: • Zebrafish embryo toxicity of cationic PAMAM and PPI dendrimers increased over time. • Zebrafish embryo toxicity of cationic dendrimers did not increase with generation. • Cationic dendrimers induced apoptosis in zebrafish embryos. • Toxicity of cationic dendrimers was lower in HepG2 and DU145 than zebrafish

  3. An approach to successful freezing of demi-embryos derived from day-7 bovine embryos.

    PubMed

    Niemann, H; Brem, G; Sacher, B; Smidt, D; Kräusslich, H

    1986-04-01

    The developmental capacity of frozen/thawed bisected embryos (n = 33) derived from day-7 bovine embryos was investigated and compared to ordinary embryos after freezing and thawing (n = 28) and to freshly bisected embryos (n = 19). The freezing and thawing protocol was identical for ordinary and demi-embryos. The percentage of intact embryos classified as excellent, good, or poor after thawing was 92.9 and 96.3% for ordinary and demi-embryos, respectively. Pregnancy rates of 53.8 (8 15 ), 46.2 (6 13 ), and 47.5% (9 19 ) were obtained when frozen/thawed ordinary embryos and frozen/thawed demi-embryos classified as excellent or good and sealed with an additional zona pellucida from hatched pig blastocysts or freshly bisected embryos were transferred. One pair of identical twins resulted from the transfer of frozen/thawed demi-embryos sealed with an additional zona pellucida. Transfer of four frozen/thawed demi-embryos without an additional zona pellucida led to one pregnancy. In contrast, demi-embryos derived from frozen/thawed ordinary embryos (n = 8) as well as frozen/thawed demi-embryos classified as poor (n = 6) did not result in any pregnancies although two halves were transferred per recipient. It is concluded that sealing the punctured zona pellucida improves the developmental capacity of frozen/thawed demi-embryos derived from day-7 bovine embryos, and freezing demi-embryos is more efficient compared to the splitting of frozen/thawed ordinary embryos.

  4. An experimental assessment of the imaging quality of the low energy gamma-ray telescope ZEBRA

    NASA Technical Reports Server (NTRS)

    Butler, R. C.; Caroli, E.; Dicocco, G.; Natalucci, L.; Spada, G.; Spizzichino, A.; Stephen, J. B.; Carter, J. N.; Charalambous, P. M.; Dean, A. J.

    1985-01-01

    One gamma-ray detection plane of the ZEBRA telescope, consisting of nine position sensitive scintillation crystal bars designed to operate over the spectral range 0.2 to 10 MeV, has been constructed in the laboratory. A series of experimental images has been generated using a scaled down flight pattern mask in conjunction with a diverging gamma-ray beam. Point and extended sources have been imaged in order to assess quantitatively the performance of the system.

  5. Same-sex partner preference in zebra finches: pairing flexibility and choice.

    PubMed

    Tomaszycki, Michelle L; Zatirka, Brendon P

    2014-11-01

    This study examined flexibility and choice in same-sex pair-bonding behavior in adult zebra finches (Taeniopygia guttata). Zebra finches form life-long monogamous relationships and extra pair behavior is very low, making them an ideal species in which to study same-sex pairing. We examined same-sex behaviors using both semi-naturalistic choice paradigms and skewed sex ratios. In the first experiment, we allowed zebra finches to pair in aviaries with equal sex ratios as part of multiple experiments. On average, 6.4% (N = 78) of unmanipulated pairs were same-sex: all but one was female-female. In a second experiment, we identified pairs from same-sex cages and selected 20 total same-sex pairs (10 of each sex). We then gave pairs a chance to court and pair with members of the opposite sex and observed their behavior for three days. Females did not retain their partner, but most paired with males. In contrast, some males did retain their partner. Similarly, females were more likely to engage in pairing behaviors with males than with their partners or other females whereas males were equally likely to engage in same-sex and opposite-sex pairing behaviors. These findings suggest that same-sex partnerships in zebra finches can be facultative, based on the sex ratio of the group in which they live, but can also be a choice, when opportunities to pair with opposite-sex individuals are possible. Furthermore, it is possible that females are more flexible in this choice of same-sex partnerships than are males.

  6. Quality of public information matters in mate-choice copying in female zebra finches.

    PubMed

    Kniel, Nina; Schmitz, Jennifer; Witte, Klaudia

    2015-01-01

    Mate-choice copying is a form of social learning in which an individual gains information about potential mates by observing conspecifics. However, it is still unknown what kind of information drives the decision of an individual to copy the mate choice of others. Among zebra finches (Taeniopygia guttata castanotis), only females (not males) copy the mate choice of others. We tested female zebra finches in a binary choice test where they, first, could choose between two males of different phenotypes: one unadorned male and one male artificially adorned with a red feather on the forehead. After this mate-choice test, females could observe a single unadorned male and a pair of zebra finches, i.e. a wild-type female and her adorned mate. Pair interactions were either restricted to acoustic and visual communication (clear glass screen between pair mates) or acoustic communication alone (opaque screen between pair mates). After the observation period, females could again choose between new males of the two phenotypes in a second mate-choice test. In experiments with a clear glass screen, time spent with the respective males changed between the two mate-choice tests, and females preferred adorned over unadorned males during the second mate-choice test. In experiments with an opaque screen, time spent with the respective males did not change between the two mate-choice tests, although females lost an initial preference for unadorned males. Our results demonstrate that the quality of the received public information (visual and acoustic interaction of the observed pair) influences mate-choice copying in female zebra finches.

  7. Noninvasive diffusive optical imaging of the auditory response to birdsong in the zebra finch

    PubMed Central

    Lee, James V.; Maclin, Edward L.; Low, Kathy A.; Gratton, Gabriele; Fabiani, Monica; Clayton, David F.

    2013-01-01

    Songbirds communicate by learned vocalizations with concomitant changes in neurophysiological and genomic activities in discrete parts of the brain. Here we tested a novel implementation of diffusive optical imaging (also known as diffuse optical imaging, DOI) for monitoring brain physiology associated with vocal signal perception. DOI noninvasively measures brain activity using red and near-infrared light delivered through optic fibers (optodes) resting on the scalp. DOI does not harm subjects, so it raises the possibility of repeatedly measuring brain activity and the effects of accumulated experience in the same subject over an entire life span, all while leaving tissue intact for further study. We developed a custom-made apparatus for interfacing optodes to the zebra finch (Taeniopygia guttata) head using 3D modeling software and rapid prototyping technology, and applied it to record responses to presentations of birdsong in isoflurane-anesthetized zebra finches. We discovered a subtle but significant difference between the hemoglobin spectra of zebra finches and mammals which has a major impact in how hemodynamic responses are interpreted in the zebra finch. Our measured responses to birdsong playback were robust, highly repeatable, and readily observed in single trials. Responses were complex in shape and closely paralleled responses described in mammals. They were localized to the caudal medial portion of the brain, consistent with response localization from prior gene expression, electrophysiological, and functional magnetic resonance imaging studies. These results define an approach for collecting neurophysiological data from songbirds that should be applicable to diverse species and adaptable for studies in awake behaving animals. PMID:23322445

  8. Muskmelon embryo rescue techniques using in vitro embryo culture.

    PubMed

    Nuñez-Palenius, Hector Gordon; Ramírez-Malagón, Rafael; Ochoa-Alejo, Neftalí

    2011-01-01

    Among the major cucurbit vegetables, melon (Cucumis melo) has one of the greatest polymorphic fruit types and botanical varieties. Some melon fruits have excellent aroma, variety of flesh colors, deeper flavor, and more juice compared to other cucurbits. Despite numerous available melon cultivars, some of them are exceedingly susceptible to several diseases. The genetic background carrying the genes for tolerance and/or resistance for those diseases is found in wild melon landraces. Unfortunately, the commercial melon varieties are not able to produce viable hybrids when crossed with their wild melon counterparts. Plant tissue culture techniques are needed to surpass those genetic barriers. In vitro melon embryo rescue has played a main role to obtain viable hybrids originated from commercial versus wild melon crosses. In this chapter, an efficient and simple embryo rescue melon protocol is thoroughly described.

  9. [Resection of the recurrent third branchial fistula under gastroscope with assistance of yellow zebra guidewire].

    PubMed

    Feng, X; Huang, Z C; Tao, F; Ou, X L

    2016-02-01

    To investigate clinical aspects and a new operative method for resecting third branchial fistula. The clinical aspects of 4 patients with third branchial fistula were retrospectively analyzed. It is difficult to locate the inner orifice of fistula through neck path due to tiny diameter of inner orifice. The inner orifice could be found and closed effectively by inserting yellow zebra guidewire from sinus piriformis with gastroscope. The mucous membrane of sinus piriformis could not be damaged due to the soft pointed end of yellow zebra guidewire. 4 cases were treated successfully without pharyngeal fistula or recurrent laryngeal nerve injury. No recurrent infections were found in all cases with follows-up of 6-66 months. Ineffectiveness of radiography with meglumine diatrizoate or oral administration of methylene blue before operation indicates tiny fistula. In this case, resection of third branchial fistula with the assistance of gastroscope and yellow zebra guidewire under general anesthesia can be performed. This innovative method of diagnosis and treatment is worth of application clinically.

  10. Zebra Finch Mates Use Their Forebrain Song System in Unlearned Call Communication

    PubMed Central

    Ter Maat, Andries; Trost, Lisa; Sagunsky, Hannes; Seltmann, Susanne; Gahr, Manfred

    2014-01-01

    Unlearned calls are produced by all birds whereas learned songs are only found in three avian taxa, most notably in songbirds. The neural basis for song learning and production is formed by interconnected song nuclei: the song control system. In addition to song, zebra finches produce large numbers of soft, unlearned calls, among which “stack” calls are uttered frequently. To determine unequivocally the calls produced by each member of a group, we mounted miniature wireless microphones on each zebra finch. We find that group living paired males and females communicate using bilateral stack calling. To investigate the role of the song control system in call-based male female communication, we recorded the electrical activity in a premotor nucleus of the song control system in freely behaving male birds. The unique combination of acoustic monitoring together with wireless brain recording of individual zebra finches in groups shows that the neuronal activity of the song system correlates with the production of unlearned stack calls. The results suggest that the song system evolved from a brain circuit controlling simple unlearned calls to a system capable of producing acoustically rich, learned vocalizations. PMID:25313846

  11. Batteries: An Advanced Na-FeCl2 ZEBRA Battery for Stationary Energy Storage Application

    SciTech Connect

    Li, Guosheng; Lu, Xiaochuan; Kim, Jin Yong

    2015-06-17

    Sodium-metal chloride batteries, ZEBRA, are considered as one of the most important electrochemical devices for stationary energy storage applications because of its advantages of good cycle life, safety, and reliability. However, sodium-nickel chloride (Na-NiCl2) batteries, the most promising redox chemistry in ZEBRA batteries, still face great challenges for the practical application due to its inevitable feature of using Ni cathode (high materials cost). In this work, a novel intermediate-temperature sodium-iron chloride (Na-FeCl2) battery using a molten sodium anode and Fe cathode is proposed and demonstrated. The first use of unique sulfur-based additives in Fe cathode enables Na-FeCl2 batteries can bemore » assembled in the discharged state and operated at intermediate-temperature (<200°C). The results in this work demonstrate that intermediate-temperature Na-FeCl2 battery technology could be a propitious solution for ZEBRA battery technologies by replacing the traditional Na-NiCl2 chemistry.« less

  12. Immediate early gene expression following exposure to acoustic and visual components of courtship in zebra finches.

    PubMed

    Avey, Marc T; Phillmore, Leslie S; MacDougall-Shackleton, Scott A

    2005-12-07

    Sensory driven immediate early gene expression (IEG) has been a key tool to explore auditory perceptual areas in the avian brain. Most work on IEG expression in songbirds such as zebra finches has focused on playback of acoustic stimuli and its effect on auditory processing areas such as caudal medial mesopallium (CMM) caudal medial nidopallium (NCM). However, in a natural setting, the courtship displays of songbirds (including zebra finches) include visual as well as acoustic components. To determine whether the visual stimulus of a courting male modifies song-induced expression of the IEG ZENK in the auditory forebrain we exposed male and female zebra finches to acoustic (song) and visual (dancing) components of courtship. Birds were played digital movies with either combined audio and video, audio only, video only, or neither audio nor video (control). We found significantly increased levels of Zenk response in the auditory region CMM in the two treatment groups exposed to acoustic stimuli compared to the control group. The video only group had an intermediate response, suggesting potential effect of visual input on activity in these auditory brain regions. Finally, we unexpectedly found a lateralization of Zenk response that was independent of sex, brain region, or treatment condition, such that Zenk immunoreactivity was consistently higher in the left hemisphere than in the right and the majority of individual birds were left-hemisphere dominant.

  13. Evaluation of Best Practices for the Euthanasia of Zebra Finches (Taeniopygia guttata)

    PubMed Central

    Scott, Kathleen E; Bracchi, Lauren A; Lieberman, Mia T; Hill, Nichola J; Caron, Tyler J; Patterson, Mary M

    2017-01-01

    Although zebra finches (Taeniopygia guttata) have been used in biomedical research for many years, no published reports are available about euthanizing these small birds. In this study, we compared 5 methods for zebra finch euthanasia: sodium pentobarbital (NaP) given intracoelomically with physical restraint but no anesthesia; isoflurane anesthesia followed by intracoelomic injection of NaP; and CO2 asphyxiation at 20%, 40%, and 80% chamber displacement rates (percentage of chamber volume per minute). Birds undergoing euthanasia were videorecorded and scored by 2 observers for behaviors potentially related to discomfort or distress. Time to recumbency and time until respiratory arrest (RA) were also assessed. RA was achieved faster by using NaP in a conscious bird compared to using isoflurane anesthesia followed by NaP; however, neither method caused behaviors that might affect animal welfare, such as open-mouth breathing, to any appreciable extent. Among the CO2 treatment groups, there was an inverse correlation between the chamber displacement rate used and the duration of open-mouth breathing, onset of head retroflexion, and time to RA. The results demonstrate that the intracoelomic administration of NaP in an awake, restrained zebra finch is a rapid and effective method of euthanasia. If CO2 is used to euthanize these birds, a high displacement rate (for example, 80%) will minimize the duration of the procedure and associated behaviors. PMID:29256376

  14. Evaluation of Best Practices for the Euthanasia of Zebra Finches (Taeniopygia guttata).

    PubMed

    Scott, Kathleen E; Bracchi, Lauren A; Lieberman, Mia T; Hill, Nichola J; Caron, Tyler J; Patterson, Mary M

    2017-11-01

    Although zebra finches (Taeniopygia guttata) have been used in biomedical research for many years, no published reports are available about euthanizing these small birds. In this study, we compared 5 methods for zebra finch euthanasia: sodium pentobarbital (NaP) given intracoelomically with physical restraint but no anesthesia; isoflurane anesthesia followed by intracoelomic injection of NaP; and CO2 asphyxiation at 20%, 40%, and 80% chamber displacement rates (percentage of chamber volume per minute). Birds undergoing euthanasia were videorecorded and scored by 2 observers for behaviors potentially related to discomfort or distress. Time to recumbency and time until respiratory arrest (RA) were also assessed. RA was achieved faster by using NaP in a conscious bird compared to using isoflurane anesthesia followed by NaP; however, neither method caused behaviors that might affect animal welfare, such as open-mouth breathing, to any appreciable extent. Among the CO2 treatment groups, there was an inverse correlation between the chamber displacement rate used and the duration of open-mouth breathing, onset of head retroflexion, and time to RA. The results demonstrate that the intracoelomic administration of NaP in an awake, restrained zebra finch is a rapid and effective method of euthanasia. If CO2 is used to euthanize these birds, a high displacement rate (for example, 80%) will minimize the duration of the procedure and associated behaviors.

  15. Comparative biology of zebra mussels in Europe and North America: an overview

    USGS Publications Warehouse

    Mackie, Gerald L.; Schloesser, Don W.

    1996-01-01

    SYNOPSIS. Since the discovery of the zebra mussel, Dreissena polymorpha, in the Great Lakes in 1988 comparisons have been made with mussel populations in Europe and the former Soviet Union. These comparisons include: Population dynamics, growth and mortality rates, ecological tolerances and requirements, dispersal rates and patterns, and ecological impacts. North American studies, mostly on the zebra mussel and a few on a second introduced species, the quagga mussel, Dreissena bugensis, have revealed some similarities and some differences. To date it appears that North American populations of zebra mussels are similar to European populations in their basic biological characteristics, population growth and mortality rates, and dispersal mechanisms and rates. Relative to European populations differences have been demonstrated for: (1) individual growth rates; (2) life spans; (3) calcium and pH tolerances and requirements; (4) potential distribution limits; and (5) population densities of veligers and adults. In addition, studies on the occurrence of the two dreissenid species in the Great Lakes are showing differences in their modes of life, depth distributions, and growth rates. As both species spread throughout North America, comparisons between species and waterbodies will enhance our ability to more effectively control these troublesome species.

  16. Zebra finch mates use their forebrain song system in unlearned call communication.

    PubMed

    Ter Maat, Andries; Trost, Lisa; Sagunsky, Hannes; Seltmann, Susanne; Gahr, Manfred

    2014-01-01

    Unlearned calls are produced by all birds whereas learned songs are only found in three avian taxa, most notably in songbirds. The neural basis for song learning and production is formed by interconnected song nuclei: the song control system. In addition to song, zebra finches produce large numbers of soft, unlearned calls, among which "stack" calls are uttered frequently. To determine unequivocally the calls produced by each member of a group, we mounted miniature wireless microphones on each zebra finch. We find that group living paired males and females communicate using bilateral stack calling. To investigate the role of the song control system in call-based male female communication, we recorded the electrical activity in a premotor nucleus of the song control system in freely behaving male birds. The unique combination of acoustic monitoring together with wireless brain recording of individual zebra finches in groups shows that the neuronal activity of the song system correlates with the production of unlearned stack calls. The results suggest that the song system evolved from a brain circuit controlling simple unlearned calls to a system capable of producing acoustically rich, learned vocalizations.

  17. Primary structure of pancreatic polypeptide from four species of Perissodactyla (Przewalski's horse, zebra, rhino, tapir).

    PubMed

    Henry, J S; Lance, V A; Conlon, J M

    1991-12-01

    Pancreatic polypeptide (PP) has been purified from extracts of the pancreas of four species of odd-toed ungulates (Perissodactyla): Przewalski's horse, mountain zebra, white rhinoceros, and mountain tapir. The amino acid sequence of Przewalski's horse pancreatic polypeptide was established as Ala-Pro-Met-Glu-Pro-Val-Tyr-Pro-Gly-Asp10-Asn- Ala-Thr-Pro-Glu-Gln-Met-Ala-Gln-Tyr20-Ala-Ala-Glu-Leu-Arg-Arg-Tyr- Ile-Asn-Met30 - Leu-Thr-Arg-Pro-Arg-Tyr.NH2. Zebra PP was identical to Przewalski's horse PP, rhinoceros PP contained three substitutions relative to the horse (Ser for Ala1, Leu for Met3, and Glu for Gln16), and tapir PP contained one substitution relative to the horse (Leu for Met3). On the basis of morphological characteristics and the fossil record, the rhinocerotids are classified with the tapirids in the suborder Ceratomorpha, whereas the horse and zebra belong to a separate suborder, Hippomorpha. On the basis of structural similarity of the PP molecules, however, it would appear that the tapir is more closely related to the horse than to the rhinoceros. These observations provide a further example of the need for extreme caution when inferring taxonomic or phylogenetic relationships between species from the structures of homologous peptides.

  18. A Daily Oscillation in the Fundamental Frequency and Amplitude of Harmonic Syllables of Zebra Finch Song

    PubMed Central

    Wood, William E.; Osseward, Peter J.; Roseberry, Thomas K.; Perkel, David J.

    2013-01-01

    Complex motor skills are more difficult to perform at certain points in the day (for example, shortly after waking), but the daily trajectory of motor-skill error is more difficult to predict. By undertaking a quantitative analysis of the fundamental frequency (FF) and amplitude of hundreds of zebra finch syllables per animal per day, we find that zebra finch song follows a previously undescribed daily oscillation. The FF and amplitude of harmonic syllables rises across the morning, reaching a peak near mid-day, and then falls again in the late afternoon until sleep. This oscillation, although somewhat variable, is consistent across days and across animals and does not require serotonin, as animals with serotonergic lesions maintained daily oscillations. We hypothesize that this oscillation is driven by underlying physiological factors which could be shared with other taxa. Song production in zebra finches is a model system for studying complex learned behavior because of the ease of gathering comprehensive behavioral data and the tractability of the underlying neural circuitry. The daily oscillation that we describe promises to reveal new insights into how time of day affects the ability to accomplish a variety of complex learned motor skills. PMID:24312654

  19. Great Lakes clams find refuge from zebra mussels in restored, lake-connected marsh (Ohio)

    USGS Publications Warehouse

    Nichols, S. Jerrine; Wilcox, Douglas A.

    2004-01-01

    Since the early 1990s, more than 95 percent of the freshwater clams once found in Lake Erie have died due to the exotic zebara mussel (Dreissena polymorpha). Zebra mussels attach themselves to native clams in large numbers, impeding the ability of the clams to eat and burrow. However, in 1996, we discovered a population of native clams in Metzger Marsh in western Lake Erie (about 50 miles [80 km] east of Toledo) that were thriving despite the longtime presence of zebra mussel in surrounding waters. At that time, Metzger Marsh was undergoing extensive restoration, including construction of a dike to replace the eroded barrier beach and of a water-control structure to maintain hydrologic connections with the lake (Wilcox and Whillans 1999). The restoration plan called for a drawdown of water levels to promote plant growth from the seedbank -- a process that would also destroy most of the clam population. State and federal resource managers recommended removing as many clams as possible to a site that was isolated from zebra mussels, and then returning them to the marsh after it was restored. We removed about 7,000 native clams in 1996 and moved them back to Metzger Marsh in 1999.

  20. Zebra Alphaherpesviruses (EHV-1 and EHV-9): Genetic Diversity, Latency and Co-Infections.

    PubMed

    Abdelgawad, Azza; Damiani, Armando; Ho, Simon Y W; Strauss, Günter; Szentiks, Claudia A; East, Marion L; Osterrieder, Nikolaus; Greenwood, Alex D

    2016-09-20

    Alphaherpesviruses are highly prevalent in equine populations and co-infections with more than one of these viruses' strains frequently diagnosed. Lytic replication and latency with subsequent reactivation, along with new episodes of disease, can be influenced by genetic diversity generated by spontaneous mutation and recombination. Latency enhances virus survival by providing an epidemiological strategy for long-term maintenance of divergent strains in animal populations. The alphaherpesviruses equine herpesvirus 1 (EHV-1) and 9 (EHV-9) have recently been shown to cross species barriers, including a recombinant EHV-1 observed in fatal infections of a polar bear and Asian rhinoceros. Little is known about the latency and genetic diversity of EHV-1 and EHV-9, especially among zoo and wild equids. Here, we report evidence of limited genetic diversity in EHV-9 in zebras, whereas there is substantial genetic variability in EHV-1. We demonstrate that zebras can be lytically and latently infected with both viruses concurrently. Such a co-occurrence of infection in zebras suggests that even relatively slow-evolving viruses such as equine herpesviruses have the potential to diversify rapidly by recombination. This has potential consequences for the diagnosis of these viruses and their management in wild and captive equid populations.

  1. Induction of autophagy improves embryo viability in cloned mouse embryos

    PubMed Central

    Shen, XingHui; Zhang, Na; Wang, ZhenDong; Bai, GuangYu; Zheng, Zhong; Gu, YanLi; Wu, YanShuang; Liu, Hui; Zhou, DongJie; Lei, Lei

    2015-01-01

    Autophagy is an essential cellular mechanism that degrades cytoplasmic proteins and organelles to recycle their components. Moreover, autophagy is essential for preimplantation development in mammals. Here we show that autophagy is also important for reprogramming in somatic cell nuclear transfer (SCNT). Our data indicate that unlike fertilized oocytes, autophagy is not triggered in SCNT embryos during 6 hours of activation. Mechanistically, the inhibited autophagic induction during SCNT activation is due to the cytochalasin B (CB) caused depolymerization of actin filaments. In this study, we induced autophagy during SCNT activation by rapamycin and pp242, which could restore the expected level of autophagy and significantly enhance the development of SCNT embryos to the blastocyst stage when compared with the control (68.5% and 68.7% vs. 41.5%, P < 0.05). Furthermore, the treatment of rapamycin and pp242 accelerates active DNA demethylation indicated by the conversion of 5 mC to 5 hmC, and treatment of rapamycin improves degradation of maternal mRNA as well. Thus, our findings reveal that autophagy is important for development of SCNT embryos and inhibited autophagic induction during SCNT activation might be one of the serious causes of low efficiency of SCNT. PMID:26643778

  2. Acute Toxicity, Respiratory Reaction, and Sensitivity of Three Cyprinid Fish Species Caused by Exposure to Four Heavy Metals

    PubMed Central

    Wang, Hongjun; Liang, Youguang; Li, Sixin; Chang, Jianbo

    2013-01-01

    Using 3 cyprinid fish species zebra fish, rare minnow, and juvenile grass carp, we conducted assays of lethal reaction and ventilatory response to analyze sensitivity of the fish to 4 heavy metals. Our results showed that the 96 h LC50 of Hg2+ to zebra fish, juvenile grass carp, and rare minnow were 0.14 mg L−1, 0.23 mg L−1, and 0.10 mg L−1, respectively; of Cu2+0.17 mg L−1, 0.09 mg L−1, and 0.12 mg L−1 respectively; of Cd2+6.5 mg L−1, 18.47 mg L−1, 5.36 mg L−1, respectively; and of Zn2+44.48 mg L−1, 31.37 mg L−1, and 12.74 mg L−1, respectively. Under a 1-h exposure, the ventilatory response to the different heavy metals varied. Ventilatory frequency (Vf) and amplitude (Va) increased in zebra fish, juvenile grass carp, and rare minnows exposed to Hg2+ and Cu2+ (P<0.05), and the Vf and Va of the 3 species rose initially and then declined when exposed to Cd2+. Zn2+ had markedly different toxic effects than the other heavy metals, whose Vf and Va gradually decreased with increasing exposure concentration (P<0.05). The rare minnow was the most highly susceptible of the 3 fish species to the heavy metals, with threshold effect concentrations (TEC) of 0.019 mg L−1, 0.046 mg L−1, 2.142 mg L−1, and 0.633 mg L−1 for Hg2+, Cu2+, Cd2+, and Zn2+, respectively. Therefore, it is feasible to use ventilatory parameters as a biomarker for evaluating the pollution toxicity of metals and to recognize early warning signs by using rare minnows as a sensor. PMID:23755209

  3. The thermal regime and species composition of fish and invertebrates in Kelly Warm Spring, Grand Teton National Park, Wyoming

    USGS Publications Warehouse

    Harper, David; Farag, Aida

    2017-01-01

    We evaluated the thermal regime and relative abundance of native and nonnative fish and invertebrates within Kelly Warm Spring and Savage Ditch, Grand Teton National Park, Wyoming. Water temperatures within the system remained relatively warm year-round with mean temperatures >20 °C near the spring source and >5 °C approximately 2 km downstream of the source. A total of 7 nonnative species were collected: Convict/Zebra Cichlid (Cichlasoma nigrofasciatum), Green Swordtail (Xiphophorus hellerii), Tadpole Madtom (Noturus gyrinus), Guppy (Poecilia reticulata), Goldfish (Carassius auratus), red-rimmed melania snail (Melanoides tuberculata), and American bullfrog tadpoles (Lithobates catesbeianus). Nonnative fish (Zebra Cichlids and Green Swordtails), red-rimmed melania snails, and bullfrog tadpoles dominated the upper 2 km of the system. Abundance estimates of the Zebra Cichlid exceeded 12,000 fish/km immediately downstream of the spring source. Relative abundance of native species increased movingdownstream as water temperatures attenuated with distance from the thermally warmed spring source; however, nonnative species were captured 4 km downstream from the spring. Fish diseases were prevalent in both native and nonnative fish from the Kelly Warm Spring pond. Clinostomum marginatum, a trematode parasite, was found in native species samples, and the tapeworm Diphyllobothrium dendriticum was present in samples from nonnative species. Diphyllobothrium dendriticum is rare in Wyoming. Salmonella spp. were also found in some samples of nonnative species. These bacteria are associated with aquarium fish and aquaculture and are generally not found in the wild.

  4. Development of a transient expression assay for detecting environmental oestrogens in zebrafish and medaka embryos

    PubMed Central

    2012-01-01

    Background Oestrogenic contaminants are widespread in the aquatic environment and have been shown to induce adverse effects in both wildlife (most notably in fish) and humans, raising international concern. Available detecting and testing systems are limited in their capacity to elucidate oestrogen signalling pathways and physiological impacts. Here we developed a transient expression assay to investigate the effects of oestrogenic chemicals in fish early life stages and to identify target organs for oestrogenic effects. To enhance the response sensitivity to oestrogen, we adopted the use of multiple tandem oestrogen responsive elements (EREc38) in a Tol2 transposon mediated Gal4ff-UAS system. The plasmid constructed (pTol2_ERE-TATA-Gal4ff), contains three copies of oestrogen response elements (3ERE) that on exposure to oestrogen induces expression of Gal4ff which this in turn binds Gal4-responsive Upstream Activated Sequence (UAS) elements, driving the expression of a second reporter gene, EGFP (Enhanced Green Fluorescent Protein). Results The response of our construct to oestrogen exposure in zebrafish embryos was examined using a transient expression assay. The two plasmids were injected into 1–2 cell staged zebrafish embryos, and the embryos were exposed to various oestrogens including the natural steroid oestrogen 17ß-oestradiol (E2), the synthetic oestrogen 17α- ethinyloestradiol (EE2), and the relatively weak environmental oestrogen nonylphenol (NP), and GFP expression was examined in the subsequent embryos using fluorescent microscopy. There was no GFP expression detected in unexposed embryos, but specific and mosaic expression of GFP was detected in the liver, heart, somite muscle and some other tissue cells for exposures to steroid oestrogen treatments (EE2; 10 ng/L, E2; 100 ng/L, after 72 h exposures). For the NP exposures, GFP expression was observed at 10 μg NP/L after 72 h (100 μg NP/L was toxic to the fish). We also demonstrate that

  5. Embryo density may affect embryo quality during in vitro culture in a microwell group culture dish.

    PubMed

    Lehner, Adam; Kaszas, Zita; Murber, Akos; Rigo, Janos; Urbancsek, Janos; Fancsovits, Peter

    2017-08-01

    Culturing embryos in groups is a common practice in mammalian embryology. Since the introduction of different microwell dishes, it is possible to identify oocytes or embryos individually. As embryo density (embryo-to-volume ratio) may affect the development and viability of the embryos, the purpose of this study was to assess the effect of different embryo densities on embryo quality. Data of 1337 embryos from 228 in vitro fertilization treatment cycles were retrospectively analyzed. Embryos were cultured in a 25 μl microdrop in a microwell group culture dish containing 9 microwells. Three density groups were defined: Group 1 with 2-4 (6.3-12.5 μl/embryo), Group 2 with 5-6 (4.2-5.0 μl/embryo), and Group 3 with 7-9 (2.8-3.6 μl/embryo) embryos. Proportion of good quality embryos was higher in Group 2 on both days (D2: 18.9 vs. 31.5 vs. 24.7%; p < 0.001; D3: 19.7 vs. 27.1 vs. 21.2%; p = 0.029; Group 1. vs. Group 2. vs. Group 3). Cell number on Day 3 differed between Groups 1 and 2 (6.8 ± 2.2; 7.3 ± 2.1; p = 0.004) and Groups 2 and 3 (7.3 ± 2.1 vs. 7.0 ± 2.0; p = 0.014). Culturing 5-6 embryos together in a culture volume of 25 μl may benefit embryo quality. As low egg number, position, and distance of the embryos may influence embryo quality, results should be interpreted with caution.

  6. Human embryo culture media comparisons.

    PubMed

    Pool, Thomas B; Schoolfield, John; Han, David

    2012-01-01

    Every program of assisted reproduction strives to maximize pregnancy outcomes from in vitro fertilization and selecting an embryo culture medium, or medium pair, consistent with high success rates is key to this process. The common approach is to replace an existing medium with a new one of interest in the overall culture system and then perform enough cycles of IVF to see if a difference is noted both in laboratory measures of embryo quality and in pregnancy. This approach may allow a laboratory to select one medium over another but the outcomes are only relevant to that program, given that there are well over 200 other variables that may influence the results in an IVF cycle. A study design that will allow for a more global application of IVF results, ones due to culture medium composition as the single variable, is suggested. To perform a study of this design, the center must have a patient caseload appropriate to meet study entrance criteria, success rates high enough to reveal a difference if one exists and a strong program of quality assurance and control in both the laboratory and clinic. Sibling oocytes are randomized to two study arms and embryos are evaluated on day 3 for quality grades. Inter and intra-observer variability are evaluated by kappa statistics and statistical power and study size estimates are performed to bring discriminatory capability to the study. Finally, the complications associated with extending such a study to include blastocyst production on day 5 or 6 are enumerated.

  7. Enhance beef cattle improvement by embryo biotechnologies.

    PubMed

    Wu, B; Zan, L

    2012-10-01

    Embryo biotechnology has become one of the prominent high businesses worldwide. This technology has evolved through three major changes, that is, traditional embryo transfer (in vivo embryo production by donor superovulation), in vitro embryo production by ovum pick up with in vitro fertilization and notably current cloning technique by somatic cell nuclear transfer and transgenic animal production. Embryo biotechnology has widely been used in dairy and beef cattle industry and commercial bovine embryo transfer has become a large international business. Currently, many developed biotechnologies during the period from early oocyte stage to pre-implantation embryos can be used to create new animal breeds and accelerate genetic progression. Based on recent advances in embryo biotechnologies and authors current studies, this review will focus on a description of the application of this technology to beef cattle improvement and discuss how to use this technology to accelerate beef cattle breeding and production. The main topics of this presentation include the following: (i) how to increase calf production numbers from gametes including sperm and oocyte; (ii) multiple ovulation and embryo transfer breeding schemes; (iii) in vitro fertilization and intracytoplasm sperm injection in bovine; (iv) pronuclear development and transgenic animals; (v) sex selection from sperm and embryos; (vi) cloning and androgenesis; (vii) blastocyst development and embryonic stem cells; (viii) preservation of beef cattle genetic resources; and (ix) conclusions. © 2011 Blackwell Verlag GmbH.

  8. Texture Fish

    ERIC Educational Resources Information Center

    Stone, Julie

    2007-01-01

    In an effort to provide an opportunity for her first graders to explore texture through an engaging subject, the author developed a three-part lesson that features fish in a mixed-media artwork: (1) Exploring Textured Paint; (2) Creating the Fish; and (3) Role Playing. In this lesson, students effectively explore texture through painting, drawing,…

  9. Methods for conducting bioassays using embryos and larvae of Pacific herring, Clupea pallasi.

    PubMed

    Dinnel, Paul A; Middaugh, Douglas P; Schwarck, Nathan T; Farren, Heather M; Haley, Richard K; Hoover, Richard A; Elphick, James; Tobiason, Karen; Marshall, Randall R

    2011-02-01

    The rapid decrease of several stocks of Pacific herring, Clupea pallasi, in Puget Sound, Washington, has led to concerns about the effects of industrial and nonpoint source contamination on the embryo and larval stages of this and related forage fish species. To address these concerns, the state of Washington and several industries have funded efforts to develop embryo and larval bioassay protocols that can be used by commercial laboratories for routine effluent testing. This article presents the results of research to develop herring embryo and larval bioassay protocols. Factors evaluated during protocol development included temperature, salinity, dissolved oxygen (DO), light intensity, photoperiod, larval feeding regimes, use of brine and artificial sea salts, gonad sources, collection methods, and egg quality.

  10. Using Digital Images of the Zebra Finch Song System as a Tool to Teach Organizational Effects of Steroid Hormones: A Free Downloadable Module

    ERIC Educational Resources Information Center

    Grisham, William; Schottler, Natalie A.; Beck McCauley, Lisa M.; Pham, Anh P.; Ruiz, Maureen L.; Fong, Michelle C.; Cui, Xinran

    2011-01-01

    Zebra finch song behavior is sexually dimorphic: males sing and females do not. The neural system underlying this behavior is sexually dimorphic, and this sex difference is easy to quantify. During development, the zebra finch song system can be altered by steroid hormones, specifically estradiol, which actually masculinizes it. Because of the…

  11. [Relationship between mitochondrial DNA copy number, membrane potential of human embryo and embryo morphology].

    PubMed

    Zhao, H; Teng, X M; Li, Y F

    2017-11-25

    Objective: To explore the relationship between the embryo with the different morphological types in the third day and its mitochondrial copy number, the membrane potential. Methods: Totally 117 embryos with poor development after normal fertilization and were not suitable transferred in the fresh cycle and 106 frozen embryos that were discarded voluntarily by infertility patients with in vitro fertilization-embryo transfer after successful pregnancy were selected. According to evaluation of international standard in embryos, all cleavage stage embryos were divided into class Ⅰ frozen embryo group ( n= 64), class Ⅱ frozen embryo group ( n= 42) and class Ⅲ fresh embryonic group (not transplanted embryos; n= 117). Real-time PCR and confocal microscopy methods were used to detect mitochondrial DNA (mtDNA) copy number and the mitochondrial membrane potential of a single embryo. The differences between embryo quality and mtDNA copy number and membrane potential of each group were compared. Results: The copy number of mtDNA and the mitochondrial membrane potential in class Ⅲ fresh embryonic group [(1.7±1.0)×10(5) copy/μl, 1.56±0.32] were significantly lower than those in class Ⅰ frozen embryo group [(3.4±1.7)×10(5) copy/μl, 2.66±0.21] and class Ⅱ frozen embryo group [(2.6±1.2)×10(5) copy/μl, 1.80±0.32; all P< 0.05]. The copy number of mtDNA and the mitochondrial membrane potential in classⅠ frozen embryo group were significantly higher than those in classⅡ frozen embryo group (both P< 0.05). Conclusion: The mtDNA copy number and the mitochondrial membrane potential of embryos of the better quality embryo are higher.

  12. Embryo deaths in reproduction and embryo research: a reply to Murphy's double effect argument.

    PubMed

    Devolder, Katrien

    2013-08-01

    The majority of embryos created in natural reproduction die spontaneously within a few weeks of conception. Some have argued that, therefore, if one believes the embryo is a person (in the normative sense) one should find 'natural' reproduction morally problematic. An extension of this argument holds that, if one accepts embryo deaths in natural reproduction, consistency requires that one also accepts embryo deaths that occur in (i) assisted reproduction via in vitro fertilisation (IVF) and (ii) embryo research. In a recent paper in this journal, Timothy Murphy criticises both the initial argument and its extension. Murphy argues that double-effect reasoning can justify embryo deaths both in natural reproduction and IVF, but not in embryo research. Thus, according to Murphy, one can, without being inconsistent, (1) believe the embryo is a person and accept natural reproduction and IVF, and (2) accept natural reproduction and IVF, while rejecting embryo research on the ground that it involves embryo deaths. I show that Murphy's argument is problematic because double effect cannot justify embryo deaths in standard IVF practices. The problem is that the proportionality criterion of double effect is not met by such practices. Thus, Murphy's argument fails to support (1) and (2). An implication of his argument failing to support (2) is that it does not defeat the position I have defended in the past-that if one accepts standard IVF practices one should also accept embryo research, including research with embryos created solely for that purpose.

  13. Fish assemblages

    USGS Publications Warehouse

    McGarvey, Daniel J.; Falke, Jeffrey A.; Li, Hiram W.; Li, Judith; Hauer, F. Richard; Lamberti, G.A.

    2017-01-01

    Methods to sample fishes in stream ecosystems and to analyze the raw data, focusing primarily on assemblage-level (all fish species combined) analyses, are presented in this chapter. We begin with guidance on sample site selection, permitting for fish collection, and information-gathering steps to be completed prior to conducting fieldwork. Basic sampling methods (visual surveying, electrofishing, and seining) are presented with specific instructions for estimating population sizes via visual, capture-recapture, and depletion surveys, in addition to new guidance on environmental DNA (eDNA) methods. Steps to process fish specimens in the field including the use of anesthesia and preservation of whole specimens or tissue samples (for genetic or stable isotope analysis) are also presented. Data analysis methods include characterization of size-structure within populations, estimation of species richness and diversity, and application of fish functional traits. We conclude with three advanced topics in assemblage-level analysis: multidimensional scaling (MDS), ecological networks, and loop analysis.

  14. Fish bioacoustics.

    PubMed

    Ladich, Friedrich

    2014-10-01

    Bony fishes have evolved a diversity of sound generating mechanisms and produce a variety of sounds. By contrast to sound generating mechanisms, which are lacking in several taxa, all fish species possess inner ears for sound detection. Fishes may also have various accessory structures such as auditory ossicles to improve hearing. The distribution of sound generating mechanisms and accessory hearing structures among fishes indicates that acoustic communication was not the driving force in their evolution. It is proposed here that different constraints influenced hearing and sound production during fish evolution, namely certain life history traits (territoriality, mate attraction) in the case of sound generating mechanisms, and adaptation to different soundscapes (ambient noise conditions) in accessory hearing structures (Ecoacoustical constraints hypothesis). Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Fish Alternatives in Environmental Risk Assessment: Overview of the Current Landscape

    EPA Science Inventory

    The need for alternative testing strategies has recently expanded into the realm of environmental risk assessment leading to the development of new alternatives to standard aquatic vertebrate testing such as the OECD 203 acute fish toxicity test. The fish embryo test (FET) is one...

  16. Preimplantation genetic haplotyping a new application for diagnosis of translocation carrier's embryos- preliminary observations of two robertsonian translocation carrier families.

    PubMed

    Shamash, Jana; Rienstein, Shlomit; Wolf-Reznik, Haike; Pras, Elon; Dekel, Michal; Litmanovitch, Talia; Brengauz, Masha; Goldman, Boleslav; Yonath, Hagith; Dor, Jehoshua; Levron, Jacob; Aviram-Goldring, Ayala

    2011-01-01

    Preimplantation genetic diagnosis using fluorescence in-situ hybridization (PGD-FISH) is currently the most common reproductive solution for translocation carriers. However, this technique usually does not differentiate between embryos carrying the balanced form of the translocation and those carrying the homologous normal chromosomes. We developed a new application of preimplantation genetic haplotyping (PGH) that can identify and distinguish between all forms of the translocation status in cleavage stage embryos prior to implantation. Polymorphic markers were used to identify and differentiate between the alleles that carry the translocation and those that are the normal homologous chromosomes. Embryos from two families of robertsonian translocation carriers were successfully analyzed using polymorphic markers haplotyping. Our preliminary results indicate that the PGH is capable of distinguishing between normal, balanced and unbalanced translocation carrier embryos. This method will improve PGD and will enable translocation carriers to avoid transmission of the translocation and the associated medical complications to offspring.

  17. Oxygen decline in biotesting of environmental samples--is there a need for consideration in the acute zebrafish embryo assay?

    PubMed

    Küster, Eberhard; Altenburger, Rolf

    2008-12-01

    Environmental samples such as groundwater, sediment pore water, native or freeze dried sediments may be difficult to analyze for toxic effects with organismic aquatic bioassays. These samples might evoke low oxygen concentration or oxygen depletion during the test. The toxicity assessment could thus be confounded by low oxygen concentrations. The acute zebrafish embryo assay was used to analyze the influence of oxygen deficit on the embryonic development in the first 48 h post fertilization. Embryos were exposed to varying oxygen concentrations ranging from <30 to >80% oxygen saturation of water. A clear concentration dependent retardation of fish embryo development was observed. Because of a retarded development toxic thresholds of environmental samples which might include substances slowing down the development will be altered. For the purpose of identification of critical contaminants in complex environmental samples, it is proposed to actively aerate environmental samples which are likely to be oxygen depleted during the duration of the zebrafish embryo bioassay. 2008 Wiley Periodicals, Inc.

  18. 9 CFR 98.20 - Embryos refused entry.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Embryos refused entry. 98.20 Section... CERTAIN ANIMAL EMBRYOS AND ANIMAL SEMEN Ruminant and Swine Embryos From Regions Where Rinderpest or Foot-and-Mouth Disease Exists § 98.20 Embryos refused entry. If any embryos are determined to be ineligible...

  19. 9 CFR 98.16 - The embryo collection unit.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false The embryo collection unit. 98.16... CERTAIN ANIMAL EMBRYOS AND ANIMAL SEMEN Ruminant and Swine Embryos From Regions Where Rinderpest or Foot-and-Mouth Disease Exists § 98.16 The embryo collection unit. Ruminant and swine embryos may be...

  20. 9 CFR 98.16 - The embryo collection unit.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false The embryo collection unit. 98.16... CERTAIN ANIMAL EMBRYOS AND ANIMAL SEMEN Ruminant and Swine Embryos From Regions Where Rinderpest or Foot-and-Mouth Disease Exists § 98.16 The embryo collection unit. Ruminant and swine embryos may be...

  1. 9 CFR 98.20 - Embryos refused entry.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Embryos refused entry. 98.20 Section... CERTAIN ANIMAL EMBRYOS AND ANIMAL SEMEN Ruminant and Swine Embryos From Regions Where Rinderpest or Foot-and-Mouth Disease Exists § 98.20 Embryos refused entry. If any embryos are determined to be ineligible...

  2. 9 CFR 98.20 - Embryos refused entry.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Embryos refused entry. 98.20 Section... CERTAIN ANIMAL EMBRYOS AND ANIMAL SEMEN Ruminant and Swine Embryos From Regions Where Rinderpest or Foot-and-Mouth Disease Exists § 98.20 Embryos refused entry. If any embryos are determined to be ineligible...

  3. 9 CFR 98.16 - The embryo collection unit.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false The embryo collection unit. 98.16... CERTAIN ANIMAL EMBRYOS AND ANIMAL SEMEN Ruminant and Swine Embryos From Regions Where Rinderpest or Foot-and-Mouth Disease Exists § 98.16 The embryo collection unit. Ruminant and swine embryos may be...

  4. 9 CFR 98.20 - Embryos refused entry.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Embryos refused entry. 98.20 Section... CERTAIN ANIMAL EMBRYOS AND ANIMAL SEMEN Ruminant and Swine Embryos From Regions Where Rinderpest or Foot-and-Mouth Disease Exists § 98.20 Embryos refused entry. If any embryos are determined to be ineligible...

  5. 9 CFR 98.16 - The embryo collection unit.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false The embryo collection unit. 98.16... CERTAIN ANIMAL EMBRYOS AND ANIMAL SEMEN Ruminant and Swine Embryos From Regions Where Rinderpest or Foot-and-Mouth Disease Exists § 98.16 The embryo collection unit. Ruminant and swine embryos may be...

  6. 9 CFR 98.20 - Embryos refused entry.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Embryos refused entry. 98.20 Section... CERTAIN ANIMAL EMBRYOS AND ANIMAL SEMEN Ruminant and Swine Embryos From Regions Where Rinderpest or Foot-and-Mouth Disease Exists § 98.20 Embryos refused entry. If any embryos are determined to be ineligible...

  7. 9 CFR 98.16 - The embryo collection unit.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false The embryo collection unit. 98.16... CERTAIN ANIMAL EMBRYOS AND ANIMAL SEMEN Ruminant and Swine Embryos From Regions Where Rinderpest or Foot-and-Mouth Disease Exists § 98.16 The embryo collection unit. Ruminant and swine embryos may be...

  8. Methanol as a cryoprotectant for equine embryos.

    PubMed

    Bass, L D; Denniston, D J; Maclellan, L J; McCue, P M; Seidel, G E; Squires, E L

    2004-09-15

    Equine embryos (n=43) were recovered nonsurgically 7-8 days after ovulation and randomly assigned to be cryopreserved in one of two cryoprotectants: 48% (15M) methanol (n=22) or 10% (136 M) glycerol (n=21). Embryos (300-1000 microm) were measured at five intervals after exposure to glycerol (0, 2, 5, 10 and 15 min) or methanol (0, 15, 35, 75 and 10 min) to determine changes (%) in diameter over time (+/-S.D.). Embryos were loaded into 0.25-ml plastic straws, sealed, placed in a programmable cell freezer and cooled from room temperature (22 degrees C) to -6 degrees C. Straws were then seeded, held at -6 degrees C for 10 min and then cooled to -33 degrees C before being plunged into liquid nitrogen. Two or three embryos within a treatment group were thawed and assigned to be either cultured for 12 h prior to transfer or immediately nonsurgically transferred to a single mare. Embryo diameter decreased in all embryos upon initial exposure to cryoprotectant. Embryos in methanol shrank and recovered slightly to 76+/-8 % of their original diameter; however, embryos in glycerol continued to shrink, reaching 57+/-6 % of their original diameter prior to cryopreservation. Survival rates of embryos through Day 16 of pregnancy were 38 and 23%, respectively (P>0.05) for embryos cryopreserved in the presence of glycerol or methanol. There was no difference in pregnancy rates of mares receiving embryos that were cultured prior to transfer or not cultured (P>0.05). Preliminary experiments indicated that 48% methanol was not toxic to fresh equine embryos but methanol provided no advantage over glycerol as a cryoprotectant for equine blastocysts.

  9. Chronic toxicity of azo and anthracenedione dyes to embryo-larval fathead minnow.

    PubMed

    Parrott, Joanne L; Bartlett, Adrienne J; Balakrishnan, Vimal K

    2016-03-01

    The toxicity of selected azo and anthracenedione dyes was studied using chronic exposures of embryo-larval fathead minnows (Pimephales promelas). Newly fertilized fathead minnow embryos were exposed through the egg stage, past hatching, through the larval stage (until 14 days post-hatch), with dye solutions renewed daily. The anthracenedione dyes Acid Blue 80 (AB80) and Acid Blue 129 (AB129) caused no effects in larval fish at the highest measured concentrations tested of 7700 and 6700 μg/L, respectively. Both azo dyes Disperse Yellow 7 (DY7) and Sudan Red G (SRG) decreased survival of larval fish, with LC50s (based on measured concentrations of dyes in fish exposure water) of 25.4 μg/L for DY7 and 16.7 μg/L for SRG. Exposure to both azo dyes caused a delayed response, with larval fish succumbing 4-10 days after hatch. If the exposures were ended at the embryo stage or just after hatch, the potency of these two dyes would be greatly underestimated. Concentrations of dyes that we measured entering the Canadian environment were much lower than those that affected larval fish survival in the current tests. In a total of 162 samples of different municipal wastewater effluents from across Canada assessed for these dyes, all were below detection limits. The similarities of the structures and larval fish responses for the two azo and two anthracenedione dyes in this study support the use of read-across data for risk assessment of these classes of compounds. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  10. Comparison of effects of albendazole sulfoxide on in vitro produced bovine embryos and rat embryos.

    PubMed

    Piscopo, S E; Smoak, I W

    1997-09-01

    To evaluate and compare effects of albendazole sulfoxide (ABZSO) on rat embryos and bovine embryos produced in vitro. In vitro produced bovine embryos. Rat embryos recovered from naturally bred Sprague-Dawley rats. 4- and 8-cell bovine embryos were randomly allocated to ABZSO or vehicle control groups. After 48 hours, embryos were evaluated for cell number and blastomere morphology. Rat embryos of similar stages, flushed from the uterine tube on gestational day 2-5, were randomly allocated to treatment or control groups. After 24 hours, embryos were evaluated as described previously. 44% of control bovine embryos divided in culture (> or = 16-cell stage). Fifteen percent of the controls had morphologic abnormalities, including disparity in blastomere size and cytoplasmic vacuoles and stippling. Treated (> or = 1 microgram of ABZSO/ml) bovine embryos differed (P < 0.0001) from controls, with 4% development and 93% abnormal morphology. Forty-five percent of control rat embryos divided in culture. Treated (> or = 500 ng of ABZSO/ml) rat embryos differed (P < 0.0003) from controls with regard to ability to divide. There were no consistent morphologic abnormalities in rat embryos. In vitro produced bovine embryos were susceptible to ABZSO at a concentration > or = 1 microgram/ ml, resulting in decreased ability to divide and presence of gross morphologic abnormalities. Rat embryos produced in vivo and exposed in vitro to ABZSO at a concentration > or = 500 ng/ml had decreased ability to divide in culture. Despite severe effects of ABZSO (> or = 1 microgram/ml) on bovine embryo development in vitro, it is beyond the scope of this study to speculate whether a therapeutic dosage of albendazole (10 mg/kg of body weight) would result in necessary concentrations of ABZSO in vivo to disrupt embryogenesis.

  11. Arthropod parasites of springbok, gemsbok, kudus, giraffes and Burchell's and Hartmann's zebras in the Etosha and Hardap Nature Reserves, Namibia.

    PubMed

    Horak, I G; Anthonissen, M; Krecek, R C; Boomker, J

    1992-12-01

    A total of 48 springbok, 48 gemsbok, 23 kudus and 6 giraffes were examined for ticks and lice, while 9 Burchell's zebras and 6 Hartmann's mountain zebras were examined only for ticks. Springbok and gemsbok were shot in both the Etosha National Park in the north and the Hardap Nature Reserve in the south of Namibia. All the other animals were shot in the Etosha National Park. A total of 7 ixodid tick species and 8 lice species were recovered. The springbok carried few ticks. The adults of a Rhipicephalus sp. (near R. oculatus) were most numerous on the gemsbok, especially during November. The kudus were the only animals harbouring Rhipicephalus zambeziensis. Adult Hyalomma truncatum, followed by adult Hyalomma marginatum rufipes, were most abundant on the giraffes and adult Rhipicephalus evertsi mimeticus were commonest on the zebras.

  12. Fishing Forecasts

    NASA Technical Reports Server (NTRS)

    1988-01-01

    ROFFS stands for Roffer's Ocean Fishing Forecasting Service, Inc. Roffer combines satellite and computer technology with oceanographic information from several sources to produce frequently updated charts sometimes as often as 30 times a day showing clues to the location of marlin, sailfish, tuna, swordfish and a variety of other types. Also provides customized forecasts for racing boats and the shipping industry along with seasonal forecasts that allow the marine industry to formulate fishing strategies based on foreknowledge of the arrival and departure times of different fish. Roffs service exemplifies the potential for benefits to marine industries from satellite observations. Most notable results are reduced search time and substantial fuel savings.

  13. One Fish, Two Fish, Redfish, You Fish!

    ERIC Educational Resources Information Center

    White, Katherine; Timmons, Maryellen; Medders, Paul

    2011-01-01

    The recreational fishing activity presented in this article provides a hands-on, problem-based experience for students; it unites biology, math, economics, environmental policy, and population dynamics concepts. In addition, the activity allows students to shape environmental policy in a realistic setting and evaluate their peers' work. By…

  14. Behavioral thermoregulation by turtle embryos

    PubMed Central

    Du, Wei-Guo; Zhao, Bo; Chen, Ye; Shine, Richard

    2011-01-01

    Mobile ectothermic animals can control their body temperatures by selecting specific thermal conditions in the environment, but embryos—trapped within an immobile egg and lacking locomotor structures—have been assumed to lack that ability. Falsifying that assumption, our experimental studies show that even early stage turtle embryos move within the egg to exploit small-scale spatial thermal heterogeneity. Behavioral thermoregulation is not restricted to posthatching life and instead may be an important tactic in every life-history stage. PMID:21606350

  15. Immunohistochemical localization of cocaine- and amphetamine-regulated transcript peptide (CARTp) in the brain of the pigeon (Columba livia) and zebra finch (Taeniopygia guttata).

    PubMed

    Gutierrez-Ibanez, Cristian; Iwaniuk, Andrew N; Jensen, Megan; Graham, David J; Pogány, Ákos; Mongomery, Benjamin C; Stafford, James L; Luksch, Harald; Wylie, Douglas R

    2016-12-15

    Cocaine- and amphetamine-regulated transcript peptides (CARTp) are neuropeptides that act as neurotransmitters in the brain of vertebrates. The expression of CARTp has been characterized in teleosts, amphibians, and several mammalian species, but comparative data in reptiles and birds are nonexistent. In this study, we show the distribution of immunoreactivity against CART peptides (CARTp-ir) in the brains of two bird species: the pigeon (Columba livia) and zebra finch (Taeniopygia guttata). We found CARTp-ir cells and terminals in the brains of both, but no major differences between the two species. As in mammals, teleost fish, and amphibians, CARTp-ir terminals and cells were abundant in subpallial regions, particularly the striatum and nucleus accumbens. We also found CARTp-ir cells and terminals in the hypothalamus, and a large number of CARTp-ir terminals in the substantia nigra, ventral tegmental area, periaqueductal gray, parabrachial nucleus, and dorsal vagal complex. However, in contrast to other vertebrates, CARTp-ir was not found in the olfactory bulb. In addition there was almost no CARTp-ir in the pallium or the hippocampal formation, and little CARTp-ir in the cerebellum. The conserved expression of CARTp in the subpallium, hypothalamus, and dorsal vagal complex of birds suggests that some of the functions of CARTp, such as regulation of food intake and interactions with the social control network and mesolimbic reward system, are conserved among vertebrates. J. Comp. Neurol. 524:3747-3773, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  16. Diversity of Aplochiton Fishes (Galaxiidea) and the Taxonomic Resurrection of A. marinus

    PubMed Central

    Arias, Carlos; Cárdenas, Leyla

    2013-01-01

    Aplochiton is a small genus of galaxiid fishes endemic to Patagonia and the Falkland Islands whose taxonomy is insufficiently resolved. Recent genetic analyses confirmed the existence of only two closely related species, Aplochiton taeniatus and Aplochiton zebra, while a third controversial species, Aplochiton marinus, remained lost to synonymy with A. taeniatus. Using an integrative taxonomy framework, we studied original samples and published sequences from a broad range in western Patagonia and the Falkland Islands, and generated robust species hypotheses based on single-locus (Cytochrome Oxidase subunit I; COI) species-delineation methods and known diagnostic morphological characters analyzed in a multivariate context. Results revealed three distinct evolutionary lineages that morphologically resemble, in important respects, existing nominal species descriptions. Interestingly, the lineage associated with A. marinus was unambiguously identifiable (100% accuracy) both from the genetic and morphological viewpoints. In contrast, the morphology of A. taeniatus and A. zebra overlapped substantially, mainly due to the high variability of A. taeniatus. Discriminant function analysis aided the identification of these species with 83.9% accuracy. Hence, for their unambiguous identification, genetic screening is needed. A. marinus has seldom been documented, and when recorded, it has always been found in sites with clear marine influence. It is possible that only A. marinus preserves a life cycle related to the sea akin to the hypothesized ancestral galaxiid. We did not find evidence of claimed diadromy in A. taeniatus or A. zebra, and, therefore, these should be regarded as freshwater species. Finally, a lack of phylogeographic patterns and overrepresentation of uncommon haplotypes suggested demographic expansions in recent evolutionary time, especially of A. zebra, in line with the hypothesis of large-scale range expansion and lineage spread in western Patagonia. PMID

  17. Mate call as reward: Acoustic communication signals can acquire positive reinforcing values during adulthood in female zebra finches (Taeniopygia guttata).

    PubMed

    Hernandez, Alexandra M; Perez, Emilie C; Mulard, Hervé; Mathevon, Nicolas; Vignal, Clémentine

    2016-02-01

    Social stimuli can have rewarding properties and promote learning. In birds, conspecific vocalizations like song can act as a reinforcer, and specific song variants can acquire particular rewarding values during early life exposure. Here we ask if, during adulthood, an acoustic signal simpler and shorter than song can become a reward for a female songbird because of its particular social value. Using an operant choice apparatus, we showed that female zebra finches display a preferential response toward their mate's calls. This reinforcing value of mate's calls could be involved in the maintenance of the monogamous pair-bond of the zebra finch. (c) 2016 APA, all rights reserved).

  18. Body size-dependent Cd accumulation in the zebra mussel Dreissena polymorpha from different routes.

    PubMed

    Tang, Wen-Li; Evans, Douglas; Kraemer, Lisa; Zhong, Huan

    2017-02-01

    Understanding body size-dependent metal accumulation in aquatic organisms (i.e., metal allometry) is critical in interpreting biomonitoring data. While growth has received the most attention, little is known about controls of metal exposure routes on metal allometry. Here, size-dependent Cd accumulation in zebra mussels (Dreissena polymorpha) from different routes were investigated by exposing mussels to A.( 111 Cd spiked algae+ 113 Cd spiked river water) or B.( 111 Cd spiked sediments+ 113 Cd spiked river water). After exposure, 111 Cd or 113 Cd levels in mussel tissue were found to be negatively correlated with tissue weight, while Cd allometry coefficients (b values) were dependent on Cd exposure routes: -0.664 for algae, -0.241 for sediments and -0.379 for river water, compared to -0.582 in un-exposed mussels. By comparing different Cd exposure routes, we found that size-dependent Cd bioaccumulation from algae or river water could be more responsible for the overall size-dependent Cd accumulation in mussels, and the relative importance of the two sources was dependent on mussel size ranges: Cadmium obtained from algae (algae-Cd) was more important in size-dependent Cd accumulation in smaller mussels (tissue dry weight < 5 mg), while river water-Cd became more important in larger individuals (tissue dry weight > 5 mg). In contrast, sediment-Cd contributed only a small amount to Cd accumulation in zebra mussels and may have little effect on size-dependent Cd bioaccumulation. Our results suggest that size-dependent Cd accumulation in mussels could be largely affected by exposure routes, which should be considered when trying to interpret Cd biomonitoring data of zebra mussels. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Behavioural and physiological effects of population density on domesticated Zebra Finches (Taeniopygia guttata) held in aviaries.

    PubMed

    Poot, Hanneke; ter Maat, Andries; Trost, Lisa; Schwabl, Ingrid; Jansen, René F; Gahr, Manfred

    2012-02-01

    Zebra Finches (Taeniopygia guttata) are highly social and monogamous birds that display relatively low levels of aggression and coordinate group life mainly by means of vocal communication. In the wild, small groups may congregate to larger flocks of up to 150-350 birds. Little is known, however, about possible effects of population density on development in captivity. Investigating density effects on physiology and behaviour might be helpful in identifying optimal group size, in order to optimise Zebra Finch wellbeing. A direct effect of population density on development and reproduction was found: birds in lower density conditions produced significantly more and larger (body mass, tarsus length) surviving offspring than birds in high density conditions. Furthermore, offspring in low density aviaries produced slightly longer song motifs and more different syllables than their tutors, whereas offspring in high density aviaries produced shorter motifs and a smaller or similar number of different syllables than their tutors. Aggression levels within the populations were low throughout the experiment, but the number of aggressive interactions was significantly higher in high density aviaries. Baseline corticosterone levels did not differ significantly between high- and low density aviaries for either adult or offspring birds. On day 15 post hatching, brood size and baseline corticosterone levels were positively correlated. On days 60 and 100 post hatching this correlation was no longer present. The results of this study prove that population density affects various aspects of Zebra Finch development, with birds living in low population density conditions having an advantage over those living under higher population density conditions. Copyright © 2011 Elsevier Inc. All rights reserved.

  20. Zebra finches have a light-dependent magnetic compass similar to migratory birds.

    PubMed

    Pinzon-Rodriguez, Atticus; Muheim, Rachel

    2017-04-01

    Birds have a light-dependent magnetic compass that provides information about the spatial alignment of the geomagnetic field. It is proposed to be located in the avian retina and mediated by a light-induced, radical-pair mechanism involving cryptochromes as sensory receptor molecules. To investigate how the behavioural responses of birds under different light spectra match with cryptochromes as the primary magnetoreceptor, we examined the spectral properties of the magnetic compass in zebra finches. We trained birds to relocate a food reward in a spatial orientation task using magnetic compass cues. The birds were well oriented along the trained magnetic compass axis when trained and tested under low-irradiance 521 nm green light. In the presence of a 1.4 MHz radio-frequency electromagnetic (RF)-field, the birds were disoriented, which supports the involvement of radical-pair reactions in the primary magnetoreception process. Birds trained and tested under 638 nm red light showed a weak tendency to orient ∼45 deg clockwise of the trained magnetic direction. Under low-irradiance 460 nm blue light, they tended to orient along the trained magnetic compass axis, but were disoriented under higher irradiance light. Zebra finches trained and tested under high-irradiance 430 nm indigo light were well oriented along the trained magnetic compass axis, but disoriented in the presence of a RF-field. We conclude that magnetic compass responses of zebra finches are similar to those observed in nocturnally migrating birds and agree with cryptochromes as the primary magnetoreceptor, suggesting that light-dependent, radical-pair-mediated magnetoreception is a common property for all birds, including non-migratory species. © 2017. Published by The Company of Biologists Ltd.

  1. Clinical evaluation of frozen/thawed embryo transfer following transport of oocytes and embryos

    PubMed Central

    2004-01-01

    Background and Aims:  We evaluated the efficacy of the transport oocyte/embryo frozen/thawed embryo transfer method, in which oocytes or embryos were transported from satellite clinics to the main assisted reproductive technology (ART) center, and surplus embryos were placed in cryopreservation. Methods:  We evaluated 41 cycles in 34 patients in the transport oocyte group (TO group). In the TO group the oocytes were collected at the satellite clinics, transported to the main ART center and underwent in vitro fertilization or intracytoplasmic sperm injection. Surplus embryos were used for frozen/thawed embryo transfer. We also evaluated 17 cycles in 10 patients in the transport embryo group (TE group), where surplus embryos were transported to the main ART center and used for frozen/thawed embryo transfer; and 189 cycles in 134 patients in the center group (C group), where surplus embryos collected at the same time at the main ART center were used for frozen/thawed embryo transfer. Oocytes were transported from satellite clinics in HEPES buffered human tubal fluid (HTF) culture medium, and embryos in 30% synthetic serum substitute + HEPES buffered HTF, using a portable incubator we devised. Results:  The proportions of undamaged embryos after freeze/thawing were 47% for the C group, 46% for the TO group, and 46% for the TE group. The numbers of embryos transferred were 2.0 ± 0.7 for the C group, 2.0 ± 0.6 for the TO group, and 2.2 ± 0.4 for the TE group. The rate of embryo transfer was 63% for the C group, 68% for the TO group, and 76% for the TE group. Pregnancy rates per patient were 16% for the C group, 24% for the TO group, and 40% for the TE group. The embryo survival rates (number of embryos with ≥50% viable blastomeres/total number of embryos) were 55% for the C group, 60% for the TO group, and 54% for the TE group. No significant differences were seen between the C group and either the TO or TE groups in any of these parameters

  2. High-density genetic map of Miscanthus sinensis reveals inheritance of zebra stripe

    SciTech Connect

    Liu, Siyao; Clark, Lindsay V.; Swaminathan, Kankshita

    Miscanthus is a perennial C4 grass that has recently become an important bioenergy crop. The efficiency of breeding improved Miscanthus biomass cultivars could be greatly increased by marker-assisted selection. Thus, a high-density genetic map is critical to Miscanthus improvement. In this study, a mapping population of 261 F1 progeny was developed from a cross between two diploid M. sinensis cultivars, ‘Strictus’ and ‘Kaskade’. High-density genetic maps for the two parents were produced with 3044 newly developed single nucleotide polymorphisms (SNPs) obtained from restriction site-associated DNA sequencing, and 138 previously mapped GoldenGate SNPs. The female parent (‘Strictus’) map spanned 1599 cM,more » with 1989 SNPs on 19 linkage groups, and an average intermarker spacing of 0.8 cM. The length of the male parent (‘Kaskade’) map was 1612 cM, with 1821 SNPs, and an average intermarker spacing of 0.9 cM. The utility of the map was confirmed by locating quantitative trait loci (QTL) for the zebra-striped trait, which was segregating in this population. Three QTL for zebra-striped presence/absence (zb1, zb2 on LG 7, and zb3 on LG 10) and three for zebra-striped intensity (zbi1, zbi2, zbi3 on LGs 7, 10, 3) were identified. Each allele that caused striping was recessive. Incomplete penetrance was observed for each zb QTL, but penetrance was greatest when two or more zb QTL were homozygous for the causative alleles. Similarly, the intensity of striping was greatest when two or more zbi QTL were homozygous for alleles that conferred the trait. Comparative mapping indicated putative correspondence between zb3 and/or zbi2 on LG 10 to previously sequenced genes conferring zebra stripe in maize and rice. These results demonstrate that the new map is useful for identifying marker–trait associations. The mapped markers will become a valuable community resource, facilitating comparisons among studies and the breeding of Miscanthus.« less

  3. High-density genetic map of Miscanthus sinensis reveals inheritance of zebra stripe

    DOE PAGES

    Liu, Siyao; Clark, Lindsay V.; Swaminathan, Kankshita; ...

    2015-05-06

    Miscanthus is a perennial C4 grass that has recently become an important bioenergy crop. The efficiency of breeding improved Miscanthus biomass cultivars could be greatly increased by marker-assisted selection. Thus, a high-density genetic map is critical to Miscanthus improvement. In this study, a mapping population of 261 F1 progeny was developed from a cross between two diploid M. sinensis cultivars, ‘Strictus’ and ‘Kaskade’. High-density genetic maps for the two parents were produced with 3044 newly developed single nucleotide polymorphisms (SNPs) obtained from restriction site-associated DNA sequencing, and 138 previously mapped GoldenGate SNPs. The female parent (‘Strictus’) map spanned 1599 cM,more » with 1989 SNPs on 19 linkage groups, and an average intermarker spacing of 0.8 cM. The length of the male parent (‘Kaskade’) map was 1612 cM, with 1821 SNPs, and an average intermarker spacing of 0.9 cM. The utility of the map was confirmed by locating quantitative trait loci (QTL) for the zebra-striped trait, which was segregating in this population. Three QTL for zebra-striped presence/absence (zb1, zb2 on LG 7, and zb3 on LG 10) and three for zebra-striped intensity (zbi1, zbi2, zbi3 on LGs 7, 10, 3) were identified. Each allele that caused striping was recessive. Incomplete penetrance was observed for each zb QTL, but penetrance was greatest when two or more zb QTL were homozygous for the causative alleles. Similarly, the intensity of striping was greatest when two or more zbi QTL were homozygous for alleles that conferred the trait. Comparative mapping indicated putative correspondence between zb3 and/or zbi2 on LG 10 to previously sequenced genes conferring zebra stripe in maize and rice. These results demonstrate that the new map is useful for identifying marker–trait associations. The mapped markers will become a valuable community resource, facilitating comparisons among studies and the breeding of Miscanthus.« less

  4. Use of alternating and pulsed direct current electrified fields for zebra mussel control

    USGS Publications Warehouse

    Luoma, James A.; Dean, Jan C.; Severson, Todd J.; Wise, Jeremy K.; Barbour, Matthew

    2017-01-01

    Alternatives to chemicals for controlling dreissenid mussels are desirable for environmental compatibility, but few alternatives exist. Previous studies have evaluated the use of electrified fields for stunning and/or killing planktonic life stages of dreissenid mussels, however, the available literature on the use of electrified fields to control adult dreissenid mussels is limited. We evaluated the effects of sinusoidal alternating current (AC) and 20% duty cycle square-wave pulsed direct current (PDC) exposure on the survival of adult zebra mussels at water temperatures of 10, 15, and 22 °C. Peak voltage gradients of ~ 17 and 30 Vp/cm in the AC and PDC exposures, respectively, were continuously applied for 24, 48, or 72 h. Peak power densities ranged from 77,999 to 107,199 µW/cm3 in the AC exposures and 245,320 to 313,945 µW/cm3 in the PDC exposures. The peak dose ranged from 6,739 to 27,298 Joules/cm3 and 21,306 to 80,941 Joules/cm3 in the AC and PDC exposures, respectively. The applied power ranged from 16.6 to 68.9 kWh in the AC exposures and from 22.2 to 86.4 kWh in the PDC exposures. Mortality ranged from 2.7 to 92.7% in the AC exposed groups and from 24.0 to 98.7% in PDC exposed groups. Mortality increased with corresponding increases in water temperature and exposure duration, and we observed more zebra mussel mortality in the PDC exposures. Exposures conducted with AC required less of a peak dose (Joules/cm3) but more applied power (kWh) to achieve the same level of adult zebra mussel mortality as corresponding PDC exposures. The results demonstrate that 20% duty cycle square-wave PDC requires less energy than sinusoidal AC to inducing the same level of adult zebra mussel mortality.

  5. Chromatin immunoprecipitation of mouse embryos.

    PubMed

    Voss, Anne K; Dixon, Mathew P; McLennan, Tamara; Kueh, Andrew J; Thomas, Tim

    2012-01-01

    During prenatal development, a large number of different cell types are formed, the vast majority of which contain identical genetic material. The basis of the great variety in cell phenotype and function is the differential expression of the approximately 25,000 genes in the mammalian genome. Transcriptional activity is regulated at many levels by proteins, including members of the basal transcriptional apparatus, DNA-binding transcription factors, and chromatin-binding proteins. Importantly, chromatin structure dictates the availability of a specific genomic locus for transcriptional activation as well as the efficiency, with which transcription can occur. Chromatin immunoprecipitation (ChIP) is a method to assess if chromatin modifications or proteins are present at a specific locus. ChIP involves the cross linking of DNA and associated proteins and immunoprecipitation using specific antibodies to DNA-associated proteins followed by examination of the co-precipitated DNA sequences or proteins. In the last few years, ChIP has become an essential technique for scientists studying transcriptional regulation and chromatin structure. Using ChIP on mouse embryos, we can document the presence or absence of specific proteins and chromatin modifications at genomic loci in vivo during mammalian development. Here, we describe a ChIP technique adapted for mouse embryos.

  6. A presomite human embryo of Horizon VII.

    PubMed Central

    Rewell, R E; Harrison, R G

    1976-01-01

    A presomite embryo of Horizon VII aged approximately 18 days is described and illustrated. It is compared with some other embryos of a similar age, and a considerable variation of histological characteristics within the same Horizon is noted. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 PMID:1254532

  7. Neural network classification of sweet potato embryos

    NASA Astrophysics Data System (ADS)

    Molto, Enrique; Harrell, Roy C.

    1993-05-01

    Somatic embryogenesis is a process that allows for the in vitro propagation of thousands of plants in sub-liter size vessels and has been successfully applied to many significant species. The heterogeneity of maturity and quality of embryos produced with this technique requires sorting to obtain a uniform product. An automated harvester is being developed at the University of Florida to sort embryos in vitro at different stages of maturation in a suspension culture. The system utilizes machine vision to characterize embryo morphology and a fluidic based separation device to isolate embryos associated with a pre-defined, targeted morphology. Two different backpropagation neural networks (BNN) were used to classify embryos based on information extracted from the vision system. One network utilized geometric features such as embryo area, length, and symmetry as inputs. The alternative network utilized polar coordinates of an embryo's perimeter with respect to its centroid as inputs. The performances of both techniques were compared with each other and with an embryo classification method based on linear discriminant analysis (LDA). Similar results were obtained with all three techniques. Classification efficiency was improved by reducing the dimension of the feature vector trough a forward stepwise analysis by LDA. In order to enhance the purity of the sample selected as harvestable, a reject to classify option was introduced in the model and analyzed. The best classifier performances (76% overall correct classifications, 75% harvestable objects properly classified, homogeneity improvement ratio 1.5) were obtained using 8 features in a BNN.

  8. IN VITRO CULTURE OF POSTIMPLANTATION HAMSTER EMBRYOS

    EPA Science Inventory

    In vitro culture of intact rat and mouse embryos has been described extensively, but information on the culture of other species is sparse. The present study examined some culture requirements of early somite stage hamster embryos and assessed the embryotoxic effects of sodium sa...

  9. The Virtual Embryo Project (v-Embryo™)

    EPA Science Inventory

    The v-Embryo is a far reaching new research program at the US EPA to develop a working computer model of a mammalian embryo that can be used to better understand the prenatal risks posed by environmental chemicals and to eventually predict a chemical's potential developmental tox...

  10. Novel embryo selection techniques to increase embryo implantation in IVF attempts.

    PubMed

    Sigalos, George Α; Triantafyllidou, Olga; Vlahos, Nikos F

    2016-11-01

    The final success of an IVF attempt depends on several steps and decisions taken during the ovarian stimulation, the oocyte retrieval, the embryo culture and the embryo transfer. The final selection of the embryos most likely to implant is the final step in this process and the responsibility of the lab. Apart from strict morphologic criteria that historically have been used in embryo selection, additional information on genetic, metabolomic and morphokinetic characteristics of the embryo is recently combined to morphology to select the embryo most likely to produce a pregnancy. In this manuscript, we review the most recent information on the current methods used for embryo selection presenting the predictive capability of each one. A literature search was performed on Pubmed, Medline and Cochrane Database of Systematic Reviews for published studies using appropriate key words and phrases with no limits placed on time. It seems that the combination of morphologic criteria in conjunction to embryo kinetics as documented by time-lapse technology provides the most reliable information on embryo quality. Blastocyst biopsy with subsequent comprehensive chromosome analysis allows the selection of the euploid embryos with the higher implantation potential. Embryo time-lapse imaging and blastocyst biopsy combined to comprehensive chromosome analysis are the most promising technologies to increase pregnancy rates and reduce the possibility of multiple pregnancies. However, further studies will demonstrate the capability of routinely using these technologies to significantly improve IVF outcomes.

  11. Development of a new screening assay to identify proteratogenic substances using zebrafish danio rerio embryo combined with an exogenous mammalian metabolic activation system (mDarT).

    PubMed

    Busquet, François; Nagel, Roland; von Landenberg, Friedrich; Mueller, Stefan O; Huebler, Nicole; Broschard, Thomas H

    2008-07-01

    The assessment of teratogenic effects of chemicals is generally performed using in vivo teratogenicity assays, for example, in rats or rabbits. We have developed an in vitro teratogenicity assay using the zebrafish Danio rerio embryo combined with an exogenous mammalian metabolic activation system (MAS), able to biotransform proteratogenic compounds. Cyclophosphamide (CPA) and ethanol were used as proteratogens to test the efficiency of this assay. Briefly, the zebrafish embryos were cocultured at 2 hpf (hours postfertilization) with the test material at varying concentrations, induced male rat liver microsomes and nicotinamide adenine dinucleotide phosphate (reduced) for 60 min at 32 degrees C under moderate agitation in Tris-buffer. The negative control (test material alone) and the MAS control (MAS alone) were incubated in parallel. For each test group, 20 eggs were used for statistical robustness. Afterward fish embryos were transferred individually into 24-well plates filled with fish medium for 48 h at 26 degrees C with a 12-h light cycle. Teratogenicity was scored after 24 and 48 hpf using morphological endpoints. No teratogenic effects were observed in fish embryos exposed to the proteratogens alone, that is, without metabolic activation. In contrast, CPA and ethanol induced abnormalities in fish embryos when coincubated with microsomes. The severity of malformations increased with increasing concentrations of the proteratogens. We conclude that the application of microsomes will improve and refine the D. rerio teratogenicity assay as a predictive and valuable alternative method to screen teratogenic substances.

  12. Effects of multi-well plate incubation on embryo-larval development in the fathead minnow (Pimephales promelas).

    PubMed

    Marentette, Julie R; Sullivan, Cheryl A; Lavalle, Christine; Shires, Kallie; Parrott, Joanne L

    2015-01-01

    Fathead minnow embryos and larvae are frequently used in toxicology, including short-term embryo-only tests which often use small volumes of test solution. The effect that such conditions may have on fathead minnow development has yet to be explicitly described. Here we compared rates of embryonic development in fathead minnow embryos reared under standard light and temperature conditions with a range of possible methods. All methods yielded excellent control survival. We demonstrated that fathead minnow embryos incubated in a range of small volumes in multi-well plates (500 μL to 2 mL per embryo) did not substantially vary in developmental rate, but flexed less frequently as embryos, hatched smaller, later and with larger yolk-sacs, and initiated feeding later than embryos reared in an excess of solution (20 mL per embryo) with or without supplemental aeration. Faster hatch and growth were promoted with an orbital shaker, but growth benefits were not sustained into the larval stage. Developmental differences persisted in larvae reared to 20 days post-fertilization when monitoring ceased, but growth differences did not magnify and in some measurements partially resolved. To our knowledge we are the first to report effects of incubation in multi-well plates in any fish taxa. As our data revealed that the eleutheroembryonic stage for fathead minnow may be prolonged in multi-well plates, this may allow the use of longer toxicity tests using fathead minnow embryos without conflicting with existing animal welfare legislation in many countries. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

  13. Physiological and molecular determinants of embryo implantation

    PubMed Central

    Zhang, Shuang; Lin, Haiyan; Kong, Shuangbo; Wang, Shumin; Wang, Hongmei; Wang, Haibin; Armant, D. Randall

    2014-01-01

    Embryo implantation involves the intimate interaction between an implantation-competent blastocyst and a receptive uterus, which occurs in a limited time period known as the window of implantation. Emerging evidence shows that defects originating during embryo implantation induce ripple effects with adverse consequences on later gestation events, highlighting the significance of this event for pregnancy success. Although a multitude of cellular events and molecular pathways involved in embryo-uterine crosstalk during implantation have been identified through gene expression studies and genetically engineered mouse models, a comprehensive understanding of the nature of embryo implantation is still missing. This review focuses on recent progress with particular attention to physiological and molecular determinants of blastocyst activation, uterine receptivity, blastocyst attachment and uterine decidualization. A better understanding of underlying mechanisms governing embryo implantation should generate new strategies to rectify implantation failure and improve pregnancy rates in women. PMID:23290997

  14. Potential of human twin embryos generated by embryo splitting in assisted reproduction and research.

    PubMed

    Noli, Laila; Ogilvie, Caroline; Khalaf, Yacoub; Ilic, Dusko

    2017-03-01

    Embryo splitting or twinning has been widely used in veterinary medicine over 20 years to generate monozygotic twins with desirable genetic characteristics. The first human embryo splitting, reported in 1993, triggered fierce ethical debate on human embryo cloning. Since Dolly the sheep was born in 1997, the international community has acknowledged the complexity of the moral arguments related to this research and has expressed concerns about the potential for reproductive cloning in humans. A number of countries have formulated bans either through laws, decrees or official statements. However, in general, these laws specifically define cloning as an embryo that is generated via nuclear transfer (NT) and do not mention embryo splitting. Only the UK includes under cloning both embryo splitting and NT in the same legislation. On the contrary, the Ethics Committee of the American Society for Reproductive Medicine does not have a major ethical objection to transferring two or more artificially created embryos with the same genome with the aim of producing a single pregnancy, stating that 'since embryo splitting has the potential to improve the efficacy of IVF treatments for infertility, research to investigate the technique is ethically acceptable'. Embryo splitting has been introduced successfully to the veterinary medicine several decades ago and today is a part of standard practice. We present here an overview of embryo splitting experiments in humans and non-human primates and discuss the potential of this technology in assisted reproduction and research. A comprehensive literature search was carried out using PUBMED and Google Scholar databases to identify studies on embryo splitting in humans and non-human primates. 'Embryo splitting' and 'embryo twinning' were used as the keywords, alone or in combination with other search phrases relevant to the topics of biology of preimplantation embryos. A very limited number of studies have been conducted in humans and non

  15. Undernutrition affects embryo quality of superovulated ewes.

    PubMed

    Abecia, J A; Forcada, F; Palacín, I; Sánchez-Prieto, L; Sosa, C; Fernández-Foren, A; Meikle, A

    2015-02-01

    To determine the effect of undernutrition on embryo production and quality in superovulated sheep, 45 ewes were allocated into two groups to be fed diets that provided 1.5 (control, C; n = 20) or 0.5 (low nutrition, L; n = 25) times daily requirements for maintenance, from oestrous synchronization with intravaginal sponges to embryo collection. Embryos were collected 7 days after the onset of oestrus (day 0). Low nutrition resulted in lower live weight and body condition at embryo collection (P < 0.05). Diet (P < 0.01) and day of sampling (P < 0.001) significantly affected plasma non-esterified fatty acid (NEFA) and insulin concentrations. Plasma leptin concentrations decreased on day 7 only in L ewes. A significant effect of dietary treatment (P < 0.05) and day (P < 0.0001) was observed on plasma insulin-like growth factor (IGF)-I concentrations. The number of recovered oocytes and embryos did not differ between the groups (L: 15.4 ± 0.4; C: 12.4 ± 0.4). Recovery rate was lower (P < 0.05) in the L (60%) than in the C group (73%). The total number of embryos and number of viable-transferable embryos (5.0 ± 0.3 and 3.4 ± 0.3 embryos, respectively) of the L group were lower (P < 0.1) when compared with controls (8.4 ± 0.4 and 6.2 ± 0.4 embryos, respectively). Undernutrition during the period of superovulation and early embryonic development reduced total and viable number of embryos. These effects might be mediated by disruption of endocrine homeostasis, oviduct environment and/or oocyte quality.

  16. Contrasting results from molecular and pedigree-based population diversity measures in captive zebra highlight challenges facing genetic management of zoo populations.

    PubMed

    Ito, Hideyuki; Ogden, Rob; Langenhorst, Tanya; Inoue-Murayama, Miho

    2017-01-01

    Zoo conservation breeding programs manage the retention of population genetic diversity through analysis of pedigree records. The range of demographic and genetic indices determined through pedigree analysis programs allows the conservation of diversity to be monitored relative to the particular founder population for a species. Such approaches are based on a number of well-documented founder assumptions, however without knowledge of actual molecular genetic diversity there is a risk that pedigree-based measures will be misinterpreted and population genetic diversity misunderstood. We examined the genetic diversity of the captive populations of Grevy's zebra, Hartmann's mountain zebra and plains zebra in Japan and the United Kingdom through analysis of mitochondrial DNA sequences. Very low nucleotide variability was observed in Grevy's zebra. The results were evaluated with respect to current and historic diversity in the wild, and indicate that low genetic diversity in the captive population is likely a result of low founder diversity, which in turn suggests relatively low wild genetic diversity prior to recent population declines. Comparison of molecular genetic diversity measures with analogous diversity indices generated from the studbook data for Grevy's zebra and Hartmann's mountain zebra show contrasting patterns, with Grevy's zebra displaying markedly less molecular diversity than mountain zebra, despite studbook analysis indicating that the Grevy's zebra population has substantially more founders, greater effective population size, lower mean kinship, and has suffered less loss of gene diversity. These findings emphasize the need to validate theoretical estimates of genetic diversity in captive breeding programs with empirical molecular genetic data. Zoo Biol. 36:87-94, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  17. Refrigeration of rainbow trout gametes and embryos.

    PubMed

    Babiak, Igor; Dabrowski, Konrad

    2003-12-01

    Prolonged access to early embryos composed of undifferentiated, totipotent blastomeres is desirable in situations when multiple collections of gametes are not possible. The objective of the present study is to examine whether the refrigeration of rainbow trout Oncorhynchus mykiss gametes and early embryos would be a suitable, reliable, and efficient tool for prolonging the availability of early developmental stages up to the advanced blastula stage. The study was conducted continuously during fall, winter, and spring spawning seasons. In all, more than 500 experimental variants were performed involving individual samples from 26 females and 33 males derived from three strains. These strains represented three possible circumstances. In optimal one, gametes from good quality donors were obtained soon after ovulation. In the two non-optimal sources, either donors were of poor genetic quality or gametes were collected from a distant location and transported as unfertilized gametes. A highly significant effect of variability of individual sample quality on efficiency of gamete and embryo refrigeration was revealed. The source of gametes significantly affected viability of refrigerated oocytes and embryos, but not spermatozoa. On average, oocytes from optimal source retained full fertilization viability for seven days of chilled storage, significantly longer than from non-optimal sources. Spermatozoa, regardless of storage method, retained full fertilization ability for the first week of storage. Refrigeration of embryos at 1.4+/-0.4 degrees C significantly slowed the development. Two- week-old embryos were still in blastula stage. Average survival rate of embryos refrigerated for 10 days and then transferred to regular incubation temperatures of 9-14 degrees C was 92% in optimal and 51 and 71% in non-optimal source variants. No effect of gamete and embryo refrigeration on the occurrence of developmental abnormalities was observed. Cumulative refrigeration of oocytes and

  18. Courtship song preferences in female zebra finches are shaped by developmental auditory experience.

    PubMed

    Chen, Yining; Clark, Oliver; Woolley, Sarah C

    2017-05-31

    The performance of courtship signals provides information about the behavioural state and quality of the signaller, and females can use such information for social decision-making (e.g. mate choice). However, relatively little is known about the degree to which the perception of and preference for differences in motor performance are shaped by developmental experiences. Furthermore, the neural substrates that development could act upon to influence the processing of performance features remains largely unknown. In songbirds, females use song to identify males and select mates. Moreover, female songbirds are often sensitive to variation in male song performance. Consequently, we investigated how developmental exposure to adult male song affected behavioural and neural responses to song in a small, gregarious songbird, the zebra finch. Zebra finch males modulate their song performance when courting females, and previous work has shown that females prefer the high-performance, female-directed courtship song. However, unlike females allowed to hear and interact with an adult male during development, females reared without developmental song exposure did not demonstrate behavioural preferences for high-performance courtship songs. Additionally, auditory responses to courtship and non-courtship song were altered in adult females raised without developmental song exposure. These data highlight the critical role of developmental auditory experience in shaping the perception and processing of song performance. © 2017 The Author(s).

  19. Social interaction with a tutor modulates responsiveness of specific auditory neurons in juvenile zebra finches.

    PubMed

    Yanagihara, Shin; Yazaki-Sugiyama, Yoko

    2018-04-12

    Behavioral states of animals, such as observing the behavior of a conspecific, modify signal perception and/or sensations that influence state-dependent higher cognitive behavior, such as learning. Recent studies have shown that neuronal responsiveness to sensory signals is modified when animals are engaged in social interactions with others or in locomotor activities. However, how these changes produce state-dependent differences in higher cognitive function is still largely unknown. Zebra finches, which have served as the premier songbird model, learn to sing from early auditory experiences with tutors. They also learn from playback of recorded songs however, learning can be greatly improved when song models are provided through social communication with tutors (Eales, 1989; Chen et al., 2016). Recently we found a subset of neurons in the higher-level auditory cortex of juvenile zebra finches that exhibit highly selective auditory responses to the tutor song after song learning, suggesting an auditory memory trace of the tutor song (Yanagihara and Yazaki-Sugiyama, 2016). Here we show that auditory responses of these selective neurons became greater when juveniles were paired with their tutors, while responses of non-selective neurons did not change. These results suggest that social interaction modulates cortical activity and might function in state-dependent song learning. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Chick Development and Asynchroneous Hatching in the Zebra Finch (Taeniopygia guttata castanotis).

    PubMed

    Ikebuchi, Maki; Okanoya, Kazuo; Hasegawa, Toshikazu; Bischof, Hans-Joachim

    2017-10-01

    The mode of hatching in birds has important impacts on both parents and chicks, including the costs and risks of breeding for parents, and sibling competition in a clutch. Birds with multiple eggs in a single clutch often begin incubating when most eggs are laid, thereby reducing time of incubation, nursing burden, and sibling competition. In some songbirds and some other species, however, incubation starts immediately after the first egg is laid, and the chicks thus hatch asynchronously. This may result in differences in parental care and in sibling competition based on body size differences among older and younger chicks, which in turn might produce asynchronous development among siblings favoring the first hatchling, and further affect the development and fitness of the chicks after fledging. To determine whether such processes in fact occur in the zebra finch, we observed chick development in 18 clutches of zebra finches. We found that there were effects of asynchronous hatching, but these were smaller than expected and mostly not significant. Our observations suggest that the amount of care given to each chick may be equated with such factors as a camouflage effect of the down feathers, and that the low illumination within the nest also complicates the determination of the hatching order by the parents.

  1. Effect of Infection by Beauveria bassiana and Metarhizium anisopliae on the Feeding of Uvarovistia zebra

    PubMed Central

    Mohammadbeigi, A.; Port, G.

    2015-01-01

    To identify the susceptibility of long-horned grasshoppers to entomopathogenic fungi, the effect of infection with the fungi Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Clavicipitaceae) and Metarhizium anisopliae (Metchnikoff) Sorokin (Hypocreales: Clavicipitaceae) on food consumption by Uvarovistia zebra (Uvarov) (Orthoptera: Tettigoniidae) was investigated. Preliminary results showed that both fungi had a negative effect on food consumption of the insects. For both fungi a significant reduction of food consumption and faeces production by insects were observed between the highest spore concentration (5 × 106 spores/ml) and other treatments. Compared with control insects, the insects treated with 5 × 106 spores/ml of B. bassiana and M. anisopliae showed 60 and 63% reduction in mean food consumption/insect, respectively. The corrected cumulative percent mortality of the insects treated with the highest concentration of B. bassiana and M. anisopliae were 57.7 and 55.5%, respectively. This was the first account of these entomopathogenic fungi being used against a species from this family, therefore based on the results obtained from this research, it could be said that the fungi have pathogenicity effect on U. zebra as a long-horned grasshopper.

  2. Effects of zebra mussels on food webs: Interactions with juvenile bluegill and water residence time

    USGS Publications Warehouse

    Richardson, W.B.; Bartsch, L.A.

    1997-01-01

    We evaluated how water residence time mediated the impact of zebra mussels Dreissena polymorpha and bluegill sunfish Lepomis macrochirus on experimental food webs established in 1100-1 outdoor mesocosms. Water residence time was manipulated as a surrogate for seston resupply - a critical variable affecting growth and survival of suspension-feeding invertebrates. We used a 2 x 2 x 2 factorial experimental design with eight treatment combinations (3 replicates/treatment) including the presence or absence of Dreissena (2000 per m2), juvenile bluegill (40 per mesocosm), and short (1100 1 per d) or long (220 1 per d) water residence time. Measures of seston concentration (chlorophyll a, turbidity and suspended solids) were greater in the short- compared to long water-residence mesocosms, but intermediate in short water-residence mesocosms containing Dreissena. Abundance of rotifers (Keratella and Polyarthra) was reduced in Dreissena mesocosms and elevated in short residence time mesocosms. Cladocera abundance, in general, was unaffected by the presence of Dreissena; densities were higher in short-residence time mesocosms, and reduced in the presence of Lepomis. The growth of juvenile Lepomis were unaffected by Dreissena because of abundant benthic food. The final total mass of Dreissena was significantly greater in short- than long-residence mesocosms. Impacts of Dreissena on planktonic food webs may not only depend on the density of zebra mussels but also on the residence time of the surrounding water and the resupply of seston. ?? 1997 Kluwer Academic Publishers.

  3. Non-intrusive torque measurement for rotating shafts using optical sensing of zebra-tapes

    NASA Astrophysics Data System (ADS)

    Zappalá, D.; Bezziccheri, M.; Crabtree, C. J.; Paone, N.

    2018-06-01

    Non-intrusive, reliable and precise torque measurement is critical to dynamic performance monitoring, control and condition monitoring of rotating mechanical systems. This paper presents a novel, contactless torque measurement system consisting of two shaft-mounted zebra tapes and two optical sensors mounted on stationary rigid supports. Unlike conventional torque measurement methods, the proposed system does not require costly embedded sensors or shaft-mounted electronics. Moreover, its non-intrusive nature, adaptable design, simple installation and low cost make it suitable for a large variety of advanced engineering applications. Torque measurement is achieved by estimating the shaft twist angle through analysis of zebra tape pulse train time shifts. This paper presents and compares two signal processing methods for torque measurement: rising edge detection and cross-correlation. The performance of the proposed system has been proven experimentally under both static and variable conditions and both processing approaches show good agreement with reference measurements from an in-line, invasive torque transducer. Measurement uncertainty has been estimated according to the ISO GUM (Guide to the expression of uncertainty in measurement). Type A analysis of experimental data has provided an expanded uncertainty relative to the system full-scale torque of  ±0.30% and  ±0.86% for the rising edge and cross-correlation approaches, respectively. Statistical simulations performed by the Monte Carlo method have provided, in the worst case, an expanded uncertainty of  ±1.19%.

  4. Transcriptional response to West Nile virus infection in the zebra finch (Taeniopygia guttata)

    USGS Publications Warehouse

    Newhouse, Daniel J.; Hofmeister, Erik K.; Balakrishnan, Christopher N.

    2017-01-01

    West Nile virus (WNV) is a widespread arbovirus that imposes a significant cost to both human and wildlife health. WNV exists in a bird-mosquito transmission cycle in which passerine birds act as the primary reservoir host. As a public health concern, the mammalian immune response to WNV has been studied in detail. Little, however, is known about the avian immune response to WNV. Avian taxa show variable susceptibility to WNV and what drives this variation is unknown. Thus, to study the immune response to WNV in birds, we experimentally infected captive zebra finches (Taeniopygia guttata). Zebra finches provide a useful model, as like many natural avian hosts they are moderately susceptible to WNV and thus provide sufficient viremia to infect mosquitoes. We performed RNAseq in spleen tissue during peak viremia to provide an overview of the transcriptional response. In general, we find strong parallels with the mammalian immune response to WNV, including upregulation of five genes in the Rig-I-like receptor signalling pathway, and offer insights into avian-specific responses. Together with complementary immunological assays, we provide a model of the avian immune response to WNV and set the stage for future comparative studies among variably susceptible populations and species.

  5. Skin-deep diagnosis: affective bias and zebra retreat complicating the diagnosis of systemic sclerosis.

    PubMed

    Miller, Chad S

    2013-01-01

    Nearly half of medical errors can be attributed to an error of clinical reasoning or decision making. It is estimated that the correct diagnosis is missed or delayed in between 5% and 14% of acute hospital admissions. Through understanding why and how physicians make these errors, it is hoped that strategies can be developed to decrease the number of these errors. In the present case, a patient presented with dyspnea, gastrointestinal symptoms and weight loss; the diagnosis was initially missed when the treating physicians took mental short cuts and used heuristics as in this case. Heuristics have an inherent bias that can lead to faulty reasoning or conclusions, especially in complex or difficult cases. Affective bias, which is the overinvolvement of emotion in clinical decision making, limited the available information for diagnosis because of the hesitancy to acquire a full history and perform a complete physical examination in this patient. Zebra retreat, another type of bias, is when a rare diagnosis figures prominently on the differential diagnosis but the physician retreats for various reasons. Zebra retreat also factored in the delayed diagnosis. Through the description of these clinical reasoning errors in an actual case, it is hoped that future errors can be prevented or inspiration for additional research in this area will develop.

  6. Juvenile zebra finches learn the underlying structural regularities of their fathers’ song

    PubMed Central

    Menyhart, Otília; Kolodny, Oren; Goldstein, Michael H.; DeVoogd, Timothy J.; Edelman, Shimon

    2015-01-01

    Natural behaviors, such as foraging, tool use, social interaction, birdsong, and language, exhibit branching sequential structure. Such structure should be learnable if it can be inferred from the statistics of early experience. We report that juvenile zebra finches learn such sequential structure in song. Song learning in finches has been extensively studied, and it is generally believed that young males acquire song by imitating tutors (Zann, 1996). Variability in the order of elements in an individual’s mature song occurs, but the degree to which variation in a zebra finch’s song follows statistical regularities has not been quantified, as it has typically been dismissed as production error (Sturdy et al., 1999). Allowing for the possibility that such variation in song is non-random and learnable, we applied a novel analytical approach, based on graph-structured finite-state grammars, to each individual’s full corpus of renditions of songs. This method does not assume syllable-level correspondence between individuals. We find that song variation can be described by probabilistic finite-state graph grammars that are individually distinct, and that the graphs of juveniles are more similar to those of their fathers than to those of other adult males. This grammatical learning is a new parallel between birdsong and language. Our method can be applied across species and contexts to analyze complex variable learned behaviors, as distinct as foraging, tool use, and language. PMID:26005428

  7. Statistics and classification of the microwave zebra patterns associated with solar flares

    SciTech Connect

    Tan, Baolin; Tan, Chengming; Zhang, Yin

    2014-01-10

    The microwave zebra pattern (ZP) is the most interesting, intriguing, and complex spectral structure frequently observed in solar flares. A comprehensive statistical study will certainly help us to understand the formation mechanism, which is not exactly clear now. This work presents a comprehensive statistical analysis of a big sample with 202 ZP events collected from observations at the Chinese Solar Broadband Radio Spectrometer at Huairou and the Ondŕejov Radiospectrograph in the Czech Republic at frequencies of 1.00-7.60 GHz from 2000 to 2013. After investigating the parameter properties of ZPs, such as the occurrence in flare phase, frequency range, polarization degree,more » duration, etc., we find that the variation of zebra stripe frequency separation with respect to frequency is the best indicator for a physical classification of ZPs. Microwave ZPs can be classified into three types: equidistant ZPs, variable-distant ZPs, and growing-distant ZPs, possibly corresponding to mechanisms of the Bernstein wave model, whistler wave model, and double plasma resonance model, respectively. This statistical classification may help us to clarify the controversies between the existing various theoretical models and understand the physical processes in the source regions.« less

  8. Copper in indigenous and transplanted zebra mussels in relation to changing water concentrations and body weight

    SciTech Connect

    Mersch, J.; Wagner, P.; Pihan, J.C.

    Zebra mussels, Dreissena polymorpha, were collected monthly from a copper-contaminated reservoir over a period of nearly 3 years. Copper concentrations in the organisms showed marked fluctuations reflecting changes in the water contamination. Bioconcentration patterns were influenced by the specific capacity of this sentinel organism to biologically integrate the continuously evolving water pollution; the sampling pattern, which inevitably introduced a certain subjectivity into monitoring results; and weight changes in the animals within the yearly cycle. Consequently, the successive monthly indications obtained with the zebra mussels provided a current biological assessment of a complex dynamic contamination situation. In a second experiment, cagedmore » mussels from three different populations were transferred for 3 months into the reservoir and sampled on six occasions. Mortality rates, attachment capacity, and a condition index revealed no substantial fitness disturbances in the transplanted organisms. Differences in dry weight throughout the experiment were attributable to the initial characteristics of each population. The influence of body mass on monitoring results was eliminated by replacing copper concentrations ({micro}g/g dry weight) with copper burdens ({micro}g/specimen). In terms of copper burdens, the three transplanted populations exhibited very similar metal patterns. Moderate quantitative differences between introduced and indigenous populations were interpreted as the result of physiological adaptation of the indigenous mussels to their contaminated environment. This study showed that the transfer technique with D. polymorpha is a useful tool for active biomonitoring programs.« less

  9. Book review: Biology and management of invasive quagga and zebra mussels in the western United States

    USGS Publications Warehouse

    Benson, Amy J.

    2017-01-01

    Water is a precious and limited commodity in the western United States and its conveyance is extremely important. Therefore, it is critical to do as much as possible to prevent the spread of two species of dreissenid mussels, both non-native and highly invasive aquatic species already well-established in the eastern half of the United States. This book addresses the occurrences of the two dreissenid mussels in the West, the quagga mussel and the zebra mussel, that are both known to negatively impact water delivery systems and natural ecosystems. It is edited by two researchers whom have extensive experience working with the mussels in the West and is composed of 34 chapters, or articles, written by a variety of experts.Book information: Biology and Management of Invasive Quagga and Zebra Mussels in the Western United States. Edited by Wai Hing Wong and Shawn L. Gerstenberger. Boca Raton (Florida): CRC Press (Taylor & Francis Group). $149.95. xx + 545 p.; ill.; index. ISBN: 978-1-4665-9561-3. [Compact Disc included.] 2015.

  10. Modelling the Risk Posed by the Zebra Mussel Dreissena polymorpha: Italy as a Case Study

    NASA Astrophysics Data System (ADS)

    Bosso, Luciano; De Conno, Carmelina; Russo, Danilo

    2017-08-01

    We generated a risk map to forecast the potential effects of the spreading of zebra mussels Dreissena polymorpha across the Italian territory. We assessed the invader's potential impact on rivers, lakes, watersheds and dams at a fine-grained scale and detected those more at risk that should be targeted with appropriate monitoring. We developed a MaxEnt model and employed weighted overlay analyses to detect the species' potential distribution and generate risk maps for Italy. D. polymorpha has a greater probability of occurring at low to medium altitudes in areas characterised by fluviatile deposits of major streams. Northern and central Italy appear more at risk. Some hydroelectric power dams are at high risk, while most dams for irrigation, drinkable water reservoirs and other dam types are at medium to low risk. The lakes and rivers reaches (representing likely expansion pathways) at medium-high or high risk mostly occur in northern and central Italy. We highlight the importance of modelling potential invasions on a country scale to achieve the sufficient resolution needed to develop appropriate monitoring plans and prevent the invader's harmful effects. Further high-resolution risk maps are needed for other regions partly or not yet colonised by the zebra mussel.

  11. In Vivo Recording of Single-Unit Activity during Singing in Zebra Finches

    PubMed Central

    Okubo, Tatsuo S.; Mackevicius, Emily L.; Fee, Michale S.

    2015-01-01

    The zebra finch is an important model for investigating the neural mechanisms that underlie vocal production and learning. Previous anatomical and gene expression studies have identified an interconnected set of brain areas in this organism that are important for singing. To advance our understanding of how these various brain areas act together to learn and produce a highly stereotyped song, it is necessary to record the activity of individual neurons during singing. Here, we present a protocol for recording single-unit activity in freely moving zebra finches during singing using a miniature, motorized microdrive. It includes procedures for both the microdrive implant surgery and the electrophysiological recordings. There are several advantages of this technique: (1) high-impedance electrodes can be used in the microdrive to obtain well-isolated single units; (2) a motorized microdrive is used to remotely control the electrode position, allowing neurons to be isolated without handling the bird, and (3) a lateral positioner is used to move electrodes into fresh tissue before each penetration, allowing recordings from well-isolated neurons over the course of several weeks. We also describe the application of the antidromic stimulation and the spike collision test to identify neurons based on the axonal projection patterns. PMID:25342072

  12. The roles of vocal and visual interactions in social learning zebra finches: A video playback experiment.

    PubMed

    Guillette, Lauren M; Healy, Susan D

    2017-06-01

    The transmission of information from an experienced demonstrator to a naïve observer often depends on characteristics of the demonstrator, such as familiarity, success or dominance status. Whether or not the demonstrator pays attention to and/or interacts with the observer may also affect social information acquisition or use by the observer. Here we used a video-demonstrator paradigm first to test whether video demonstrators have the same effect as using live demonstrators in zebra finches, and second, to test the importance of visual and vocal interactions between the demonstrator and observer on social information use by the observer. We found that female zebra finches copied novel food choices of male demonstrators they saw via live-streaming video while they did not consistently copy from the demonstrators when they were seen in playbacks of the same videos. Although naive observers copied in the absence of vocalizations by the demonstrator, as they copied from playback of videos with the sound off, females did not copy where there was a mis-match between the visual information provided by the video and vocal information from a live male that was out of sight. Taken together these results suggest that video demonstration is a useful methodology for testing social information transfer, at least in a foraging context, but more importantly, that social information use varies according to the vocal interactions, or lack thereof, between the observer and the demonstrator. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  13. Habitat shift in invading species: Zebra and quagga mussel population characteristics on shallow soft substrates

    USGS Publications Warehouse

    Berkman, P.A.; Garton, D.W.; Haltuch, M.A.; Kennedy, G.W.; Febo, L.R.

    2000-01-01

    Unexpected habitat innovations among invading species are illustrated by the expansion of dreissenid mussels across sedimentary environments in shallow water unlike the hard substrates where they are conventionally known. In this note, records of population characteristics of invading zebra (Dreissena polymorpha) and quagga (Dreissena bugensis) mussels from 1994 through 1998 are reported from shallow (less than 20 m) sedimentary habitats in western Lake Erie. Haphazard SCUBA collections of these invading species indicated that combined densities of zebra and quagga mussels ranged from 0 to 32,500 individuals per square meter between 1994 and 1998, with D. polymorpha comprising 75-100% of the assemblages. These mixed mussel populations, which were attached by byssal threads to each other and underlying sand-grain sediments, had size-frequency distributions that were typical of colonizing populations on hard substrates. Moreover, the presence of two mussel cohorts within the 1994 samples indicated that these species began expanding onto soft substrates not later than 1992, within 4 years of their initial invasion in western Lake Erie. Such historical data provide baselines for interpreting adaptive innovations, ecological interactions and habitat shifts among the two invading dreissenid mussel species in North America.

  14. Involvement of Apoptosis in Host-Parasite Interactions in the Zebra Mussel

    PubMed Central

    Minguez, Laëtitia; Brulé, Nelly; Sohm, Bénédicte; Devin, Simon; Giambérini, Laure

    2013-01-01

    The question of whether cell death by apoptosis plays a biological function during infection is key to understanding host-parasite interactions. We investigated the involvement of apoptosis in several host-parasite systems, using zebra mussels Dreissena polymorpha as test organisms and their micro- and macroparasites. As a stress response associated with parasitism, heat shock proteins (Hsp) can be induced. In this protein family, Hsp70 are known to be apoptosis inhibitors. Mussels were diagnosed for their respective infections by standard histological methods; apoptosis was detected using the TUNEL methods on paraffin sections and Hsp70 by immunohistochemistry on cryosections. Circulating hemocytes were the main cells observed in apoptosis whereas infected tissues displayed no or few apoptotic cells. Parasitism by intracellular bacteria Rickettsiales-like and the trematode Bucephalus polymorphus were associated with the inhibition of apoptosis whereas ciliates Ophryoglena spp. or the trematode Phyllodistomum folium did not involve significant differences in apoptosis. Even if some parasites were able to modulate apoptosis in zebra mussels, we did not see evidence of any involvement of Hsp70 on this mechanism. PMID:23785455

  15. Differences in depredation by small predators limit the use of plasticine and zebra finch eggs in artificial-nest studies

    Treesearch

    Thomas J. Maier; Richard M. DeGraaf

    2001-01-01

    Small mammals, such as mice and voles, have been implicated as major egg predators of Neotropical migrant passerines by field studies using soft plasticine eggs or the very small eggs of Zebra Finch (Taeniopygia guttata). Nevertheless, the effort required to depredate these commonly used egg surrogates may be less than that required to depredate the...

  16. Changes in sex steroid hormone levels reflect the reproductive status of captive female zebra sharks (Stegostoma fasciatum).

    PubMed

    Nozu, Ryo; Murakumo, Kiyomi; Yano, Nagisa; Furuyama, Rina; Matsumoto, Rui; Yanagisawa, Makio; Sato, Keiichi

    2018-03-03

    Captive breeding in aquaria is a useful means for ex situ preservation of threatened elasmobranch species. To promote captive breeding, it is important to determine the female reproductive status. However, information regarding reproductive status in female elasmobranchs is limited. Here, we used zebra sharks, Stegostoma fasciatum, as a model for elasmobranch reproduction in captivity. We investigated the relationships among changes in the sex steroid hormone levels, follicle size, and egg-laying period to develop indicators for the female reproductive status. We confirmed that mature female zebra sharks undergo an annual reproductive cycle. Additionally, we showed that the variations in sex steroid hormone levels correlated with reproductive status in mature female zebra sharks. Plasma estradiol-17ß (E2) concentrations increased two months before ovarian follicle development and decreased along with follicle regression. Interestingly, E2 levels were inversely correlated with water temperature (R = -0.901). Moreover, high levels of testosterone (T) correlated well with the laying period. These results strongly suggest that E2 is an indicator for ovarian follicle development, and that T is a useful indicator for both the onset and end of the egg-laying period in captive zebra sharks. Copyright © 2018 Elsevier Inc. All rights reserved.

  17. The effects of Zebra Chip disease development and bacterial titer on biochemical properties in relation to the time of infection

    USDA-ARS?s Scientific Manuscript database

    Potato tuber biochemical responses to ‘Candidatus’ Liberibacter solanacearum (Lso), the causal agent of Zebra chip disease, were evaluated both within infected tubers and across different infection dates. Tuber biochemistry also was related to symptom severity and bacterial titer. Symptom severity w...

  18. Zebra Chip disease and potato biochemistry: Tuber physiological changes in response to ‘Candidatus Liberibacter solanacearum’ infection over time

    USDA-ARS?s Scientific Manuscript database

    Zebra chip disease (ZC), putatively caused by ‘Candidatus Liberibacter solanacearum’ (Lso), is of increasing concern to potato production in Mexico, the United States, and New Zealand. However, little is known about host tuber physiological changes that result in ZC symptom formation. This study exp...

  19. Characterization of the Serralysin-like gene of 'Ca. Liberibacter solanacearum' associated with Potato Zebra Chip disease

    USDA-ARS?s Scientific Manuscript database

    The non-culturable bacterium ‘Candidatus Liberibacter solanacearum’ (Lso) is the causative agent of zebra chip disease in potato. Computational analysis of the Lso genome revealed a serralysin-like gene based on conserved domains characteristic of genes encoding metalloprotease enzymes similar to se...

  20. Association of promising germplasm exhibiting tolerance to psyllids, aphids, and zebra chip disease with foliar host chemistry

    USDA-ARS?s Scientific Manuscript database

    Long term, sustainable management of zebra chip disease of potato, caused by “Candidatus Liberibacter solanacearum” (Lso) and vectored by potato psyllids (Bactericera cockerelli Sulc), will require development of new cultivars resistant or tolerant to infection and/or capable of reducing spread. The...

  1. Sex bias and dosage compensation in the zebra finch versus chicken genomes: General and specialized patterns among birds

    PubMed Central

    Itoh, Yuichiro; Replogle, Kirstin; Kim, Yong-Hwan; Wade, Juli; Clayton, David F.; Arnold, Arthur P.

    2010-01-01

    We compared global patterns of gene expression between two bird species, the chicken and zebra finch, with regard to sex bias of autosomal versus Z chromosome genes, dosage compensation, and evolution of sex bias. Both species appear to lack a Z chromosome–wide mechanism of dosage compensation, because both have a similar pattern of significantly higher expression of Z genes in males relative to females. Unlike the chicken Z chromosome, which has female-specific expression of the noncoding RNA MHM (male hypermethylated) and acetylation of histone 4 lysine 16 (H4K16) near MHM, the zebra finch Z chromosome appears to lack the MHM sequence and acetylation of H4K16. The zebra finch also does not show the reduced male-to-female (M:F) ratio of gene expression near MHM similar to that found in the chicken. Although the M:F ratios of Z chromosome gene expression are similar across tissues and ages within each species, they differ between the two species. Z genes showing the greatest species difference in M:F ratio were concentrated near the MHM region of the chicken Z chromosome. This study shows that the zebra finch differs from the chicken because it lacks a specialized region of greater dosage compensation along the Z chromosome, and shows other differences in sex bias. These patterns suggest that different avian taxa may have evolved specific compensatory mechanisms. PMID:20357053

  2. Characterizing zebra chip symptom severity and identifying spectral signatures associated with 'Candidatus Liberibacter solanacearum' infected potato tubers

    USDA-ARS?s Scientific Manuscript database

    Zebra chip (ZC) is a disease of potatoes, which is associated with the bacteria ‘Candidatus Liberibacter solanacearum’ (Lso). Lso is transmitted by the potato psyllid, Bactericera cockerelli (Šulc) (Hemiptera: Triozidae). ZC reduces yield and quality, as it results in discoloration of the vascular ...

  3. Toxicity of weathered Deepwater Horizon oil to bay anchovy (Anchoa mitchilli) embryos.

    PubMed

    O'Shaughnessy, Kathryn A; Forth, Heather; Takeshita, Ryan; Chesney, Edward J

    2018-02-01

    The BP-contracted Deepwater Horizon Macondo well blowout occurred on 20 April 2010 and lasted nearly three months. The well released millions of barrels of crude oil into the northern Gulf of Mexico, causing extensive impacts on pelagic, benthic, and estuarine fish species. The bay anchovy (Anchoa mitchilli) is an important zooplanktivore in the Gulf, serving as an ecological link between lower trophic levels and pelagic predatory fish species. Bay anchovy spawn from May through November in shallow inshore and estuarine waters throughout the Gulf. Because their buoyant embryos are a dominant part of the inshore ichthyoplankton throughout the summer, it is likely bay anchovy embryos encountered oil in coastal estuaries during the summer and fall of 2010. Bay anchovy embryos were exposed to a range of concentrations of two field-collected Deepwater Horizon oils as high-energy and low-energy water accommodated fractions (HEWAFs and LEWAFs, respectively) for 48h. The median lethal concentrations (LC 50 ) were lower in exposures with the more weathered oil (HEWAF, 1.48µg/L TPAH50; LEWAF, 1.58µg/L TPAH50) compared to the less weathered oil (HEWAF, 3.87µg/L TPAH50; LEWAF, 4.28µg/L TPAH50). To measure delayed mortality and life stage sensitivity between embryos and larvae, an additional 24h acute HEWAF exposure using the more weathered oil was run followed by a 24h grow-out period. Here the LC 50 was 9.71µg/L TPAH50 after the grow-out phase, suggesting a toxic effect of oil at the embryonic or hatching stage. We also found that exposures prepared with the more weathered Slick B oil produced lower LC 50 values compared to the exposures prepared with Slick A oil. Our results demonstrate that even relatively acute environmental exposure times can have a detrimental effect on bay anchovy embryos. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. An examination of surface epithelium structures of the embryo across the genus Poeciliopsis (Poeciliidae).

    PubMed

    Panhuis, Tami M; Fris, Megan; Tuhela, Laura; Kwan, Lucia

    2017-12-01

    In viviparous, teleost fish, with postfertilization maternal nutrient provisioning, embryonic structures that facilitate maternal-fetal nutrient transfer are predicted to be present. For the family Poeciliidae, only a handful of morphological studies have explored these embryonic specializations. Here, we present a comparative morphological study in the viviparous poeciliid genus, Poeciliopsis. Using microscopy techniques, we examine the embryonic surface epidermis of Poeciliopsis species that vary in their level of postfertilization maternal nutrient provisioning and placentation across two phylogenetic clades and three independent evolutionary origins of placentation. We focus on surface features of the embryo that may facilitate maternal-fetal nutrient transfer. Specifically, we studied cell apical-surface morphology associated with the superficial epithelium that covers the body and sac (yolk and pericardial) of embryos at different developmental stages. Scanning electron microscopy revealed common surface epithelial cells across species, including pavement cells with apical-surface microridges or microvilli and presumed ionocytes and/or mucus-secreting cells. For three species, in the mid-stage embryos, the surface of the body and sac were covered in microvillus epithelium. The remaining species did not display microvillus epithelium at any of the stages examined. Instead, their epithelium of the body and sac were composed of cells with apical-surface microridges. For all species, in the late stage embryos, the surface of the body proper was composed of apical-surface microridges in a "fingerprint-like arrangement." Despite the differences in the surface epithelium of embryos across Poeciliopsis species and embryonic developmental stages, this variation was not associated with the level of postfertilization maternal nutrient provisioning. We discuss these results in light of previous morphological studies of matrotrophic, teleost fish, phylogenetic

  5. Differences in toxicity of anionic and cationic PAMAM and PPI dendrimers in zebrafish embryos and cancer cell lines.

    PubMed

    Bodewein, Lambert; Schmelter, Frank; Di Fiore, Stefano; Hollert, Henner; Fischer, Rainer; Fenske, Martina

    2016-08-15

    Dendrimers are an emerging class of polymeric nanoparticles with beneficial biomedical applications like early diagnostics, in vitro gene transfection or controlled drug delivery. However, the potential toxic impact of exposure on human health or the environment is often inadequately defined. Thus, polyamidoamine (PAMAM) dendrimers of generations G3.0, 3.5, 4.0, 4.5 and 5.0 and polypropylenimine (PPI) dendrimers G3.0, 4.0 and 5.0 were tested in zebrafish embryos for 96h and human cancer cell lines for 24h, to assess and compare developmental in vivo toxicity with cytotoxicity. The zebrafish embryo toxicity of cationic PAMAM and PPI dendrimers increased over time, with EC50 values ranging from 0.16 to just below 1.7μM at 24 and 48hpf. The predominant effects were mortality, plus reduced heartbeat and blood circulation for PPI dendrimers. Apoptosis in the embryos increased in line with the general toxicity concentration-dependently. Hatch and dechorionation of the embryos increased the toxicity, suggesting a protective role of the chorion. Lower generation dendrimers were more toxic in the embryos whereas the toxicity in the HepG2 and DU145 cell lines increased with increasing generation of cationic PAMAMs and PPI dendrimers. HepG2 were less sensitive than DU145 cells, with IC50 values≥402μM (PAMAMs) and ≤240μM (PPIs) for HepG2 and ≤13.24μM (PAMAMs) and ≤12.84μM (PPIs) for DU145. Neither in fish embryos nor cells toxicity thresholds were determinable for anionic PAMAM G3.5 and G4.5. The study demonstrated that the cytotoxicity underestimated the in-vivo toxicity of the dendrimers in the fish embryos. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Embryo cryopreservation and preeclampsia risk.

    PubMed

    Sites, Cynthia K; Wilson, Donna; Barsky, Maya; Bernson, Dana; Bernstein, Ira M; Boulet, Sheree; Zhang, Yujia

    2017-11-01

    To determine whether assisted reproductive technology (ART) cycles involving cryopreserved-warmed embryos are associated with the development of preeclampsia. Retrospective cohort study. IVF clinics and hospitals. A total of 15,937 births from ART: 9,417 singleton and 6,520 twin. We used linked ART surveillance, birth certificate, and maternal hospitalization discharge data, considering resident singleton and twin births from autologous or donor eggs from 2005-2010. We compared the frequency of preeclampsia diagnosis for cryopreserved-warmed versus fresh ET and used multivariable logistic regression to adjust for confounders. Among pregnancies conceived with autologous eggs resulting in singletons, preeclampsia was greater after cryopreserved-warmed versus fresh ET (7.51% vs. 4.29%, adjusted odds ratio = 2.17 [95% CI 1.67-2.82]). Preeclampsia without and with severe features, preeclampsia with preterm delivery, and chronic hypertension with superimposed preeclampsia were more frequent after cryopreserved-warmed versus fresh ET (3.99% vs. 2.55%; 2.95% vs. 1.41%; 2.76 vs. 1.48%; and 0.95% vs. 0.43%, respectively). Among pregnancies from autologous eggs resulting in twins, the frequency of preeclampsia with severe features (9.26% vs. 5.70%) and preeclampsia with preterm delivery (14.81% vs. 11.74%) was higher after cryopreserved versus fresh transfers. Among donor egg pregnancies, rates of preeclampsia did not differ significantly between cryopreserved-warmed and fresh ET (10.78% vs. 12.13% for singletons and 28.0% vs. 25.15% for twins). Among ART pregnancies conceived using autologous eggs resulting in live births, those involving transfer of cryopreserved-warmed embryos, as compared with fresh ETs, had increased risk for preeclampsia with severe features and preeclampsia with preterm delivery. Copyright © 2017 American Society for Reproductive Medicine. All rights reserved.

  7. [Association of human chorionic gonadotropin level in embryo culture media with early embryo development].

    PubMed

    Wang, Haiying; Zhang, Renli; Han, Dong; Liu, Caixia; Cai, Jiajie; Bi, Yanling; Wen, Anmin; Quan, Song

    2014-06-01

    To investigate the association of human chorionic gonadotropin (HCG) level on day 3 of embryo culture with embryo development. Spent culture media were collected from individually cultured embryos on day 3 of in vitro fertilization and embryo transfer (IVF-ET) cycles. HCG concentration in the culture media was measured using an ELISA kit and its association with embryo development was assessed. In the 163 samples of embryo culture media from 60 patients, HCG was positive in 153 sample (93.8%) with a mean level of 0.85 ± 0.43 mIU/ml. The concentration of hCG in the culture media increased gradually as the number of blastomeres increased (F=2.273, P=0.03), and decreased as the morphological grade of the embryo was lowered (F=3.900, P=0.02). ELISA is capable of detecting HCG levels in spent culture media of embryos on day 3 of in vitro culture. The concentration of HCG in spent culture media is positively correlated with the status of early embryo development and implantation rate and thus serves as a useful marker for embryo selection in IVF-ET procedure.

  8. Photoautotrophic Culture of Coffea arabusta Somatic Embryos: Photosynthetic Ability and Growth of Different Stage Embryos

    PubMed Central

    AFREEN, F.; ZOBAYED, S. M. A.; KOZAI, T.

    2002-01-01

    Coffea arabusta somatic embryos were cultured and development of stomata, rate of CO2 fixation or production, chlorophyll content and chlorophyll fluorescence were studied in embryos at different stages of development. Cotyledonary and germinated embryos have photosynthetic capacity, although pretreatment at a high photosynthetic photon flux (PPF) (100 µmol m–2 s–1) for 14 d increased photosynthetic ability. Except in a very small number of cases, stomata did not develop fully in precotyledonary stage embryos and were absent in torpedo stage embryos. Low chlorophyll content (90–130 µg g–1 fresh mass) was noted in torpedo and precotyledonary stage embryos compared with cotyledonary and germinated embryos (300–500 µg g–1 fresh mass). Due to the absence of stomata and low chlorophyll content in the torpedo and precotyledonary stage embryos, the photosynthetic rate was low and, in some cases, CO2 production was observed. These data suggest that the cotyledonary stage is the earliest stage that can be cultured photoautotrophically to ensure plantlet development. When grown photoautotrophically (in a sugar‐free medium with CO2 enrichment in the culture headspace and high photosynthetic photon flux), torpedo and precotyledonary stage embryos lost 20–25 % of their initial dry mass after 60 d of culture. However, in cotyledonary and germinated embryos, the dry mass of each embryo increased by 10 and 50 %, respectively. By using a porous supporting material, growth (especially root growth) was increased in cotyledonary stage embryos. In addition, photoautotrophic conditions, high PPF (100–150 µmol m–2 s–1) and increased CO2 concentration (1100 µmol mol–1) were found to be necessary for the development of plantlets from cotyledonary stage embryos. PMID:12125763

  9. Accelerated Evolution of PAK3- and PIM1-like Kinase Gene Families in the Zebra Finch, Taeniopygia guttata

    PubMed Central

    Kong, Lesheng; Lovell, Peter V.; Heger, Andreas; Mello, Claudio V.; Ponting, Chris P.

    2010-01-01

    Genes encoding protein kinases tend to evolve slowly over evolutionary time, and only rarely do they appear as recent duplications in sequenced vertebrate genomes. Consequently, it was a surprise to find two families of kinase genes that have greatly and recently expanded in the zebra finch (Taeniopygia guttata) lineage. In contrast to other amniotic genomes (including chicken) that harbor only single copies of p21-activated serine/threonine kinase 3 (PAK3) and proviral integration site 1 (PIM1) genes, the zebra finch genome appeared at first to additionally contain 67 PAK3-like (PAK3L) and 51 PIM1-like (PIM1L) protein kinase genes. An exhaustive analysis of these gene models, however, revealed most to be incomplete, owing to the absence of terminal exons. After reprediction, 31 PAK3L genes and 10 PIM1L genes remain, and all but three are predicted, from the retention of functional sites and open reading frames, to be enzymatically active. PAK3L, but not PIM1L, gene sequences show evidence of recurrent episodes of positive selection, concentrated within structures spatially adjacent to N- and C-terminal protein regions that have been discarded from zebra finch PAK3L genes. At least seven zebra finch PAK3L genes were observed to be expressed in testis, whereas two sequences were found transcribed in the brain, one broadly including the song nuclei and the other in the ventricular zone and in cells resembling Bergmann's glia in the cerebellar Purkinje cell layer. Two PIM1L sequences were also observed to be expressed with broad distributions in the zebra finch brain, one in both the ventricular zone and the cerebellum and apparently associated with glial cells and the other showing neuronal cell expression and marked enrichment in midbrain/thalamic nuclei. These expression patterns do not correlate with zebra finch-specific features such as vocal learning. Nevertheless, our results show how ancient and conserved intracellular signaling molecules can be co

  10. Glassfrog embryos hatch early after parental desertion.

    PubMed

    Delia, Jesse R J; Ramírez-Bautista, Aurelio; Summers, Kyle

    2014-06-22

    Both parental care and hatching plasticity can improve embryo survival. Research has found that parents can alter hatching time owing to a direct effect of care on embryogenesis or via forms of care that cue the hatching process. Because parental care alters conditions critical for offspring development, hatching plasticity could allow embryos to exploit variation in parental behaviour. However, this interaction of parental care and hatching plasticity remains largely unexplored. We tested the hypothesis that embryos hatch early to cope with paternal abandonment in the glassfrog Hyalinobatrachium fleischmanni (Centrolenidae). We conducted male-removal experiments in a wild population, and examined embryos' response to conditions with and without fathers. Embryos hatched early when abandoned, but extended development in the egg stage when fathers continued care. Paternal care had no effect on developmental rate. Rather, hatching plasticity was due to embryos actively hatching at different developmental stages, probably in response to deteriorating conditions without fathers. Our experimental results are supported by a significant correlation between the natural timing of abandonment and hatching in an unmanipulated population. This study demonstrates that embryos can respond to conditions resulting from parental abandonment, and provides insights into how variation in care can affect selection on egg-stage adaptations.

  11. Glassfrog embryos hatch early after parental desertion

    PubMed Central

    Delia, Jesse R. J.; Ramírez-Bautista, Aurelio; Summers, Kyle

    2014-01-01

    Both parental care and hatching plasticity can improve embryo survival. Research has found that parents can alter hatching time owing to a direct effect of care on embryogenesis or via forms of care that cue the hatching process. Because parental care alters conditions critical for offspring development, hatching plasticity could allow embryos to exploit variation in parental behaviour. However, this interaction of parental care and hatching plasticity remains largely unexplored. We tested the hypothesis that embryos hatch early to cope with paternal abandonment in the glassfrog Hyalinobatrachium fleischmanni (Centrolenidae). We conducted male-removal experiments in a wild population, and examined embryos' response to conditions with and without fathers. Embryos hatched early when abandoned, but extended development in the egg stage when fathers continued care. Paternal care had no effect on developmental rate. Rather, hatching plasticity was due to embryos actively hatching at different developmental stages, probably in response to deteriorating conditions without fathers. Our experimental results are supported by a significant correlation between the natural timing of abandonment and hatching in an unmanipulated population. This study demonstrates that embryos can respond to conditions resulting from parental abandonment, and provides insights into how variation in care can affect selection on egg-stage adaptations. PMID:24789892

  12. Characterization of embryo-specific genes

    SciTech Connect

    Sung, Z.R.

    1988-01-01

    The objective of the proposed research is to characterize the structure and function of a set of genes whose expression is regulated in embryo development, and that are not expressed in mature tissues -- the embryogenic genes. In order to isolate these genes, we immunized a rabbit with total extracts of somatic embryos of carrot, and enriched the anti-embryo antiserum for antibodies reacting with extracts of carrot somatic embryos. Using this enriched antiserum, we screened a lambda gt11 cDNA library constructed from embryo poly A{sup +} RNA, and isolated 10 cDNA clones that detect embryogenic mRNAs. Monospecific antibodies have beenmore » purified for proteins corresponding to each cDNA sequence. Four cDNA clones were further characterized in terms of the expression of their corresponding mRNA and protein in somatic embryos of carrot. In some cases, comparable gene sequences or products have been detected in somatic and zygotic embryos of other plant species. The characteristics of these 4 cDNA clones -- clone Nos. 8, 59, and 66 -- are described in this report. 3 figs.« less

  13. Development of the Fish Medaka in Microgravity

    NASA Technical Reports Server (NTRS)

    Wolgemuth, Debra J.

    1995-01-01

    The goal of these experiments was to determine the effect of microgravity on the early development of the fish medaka. There were two objectives for this flight series. The primary objective was to assess the effects of microgravity on different stages of development and to ascertain whether the relevant developmental questions can be addressed at the gross morphological level or if the issues involve more subtle questions about regulation at the molecular and cellular levels. The secondary objective was the assessment of the utility of flight hardware with the capabilities to perform embryological studies. We have been able to take advantage of the flight testing phase of the STL-B hardware to also study the effects of microgravity on the early development of the fish, Medaka. Our initial studies involved monitoring the early Medaka development and raising flight embryos for breeding. Images of the developing embryos were collected either via video which was either taken by the astronauts or broadcast to Earth. Sample video images were digitized and stored on a hard drive resident within the on-board STL-B unit. Embryos were fixed at specific intervals, returned to Earth and are being analyzed for the timing and location of molecular events associated with controlling the morphological pattern for the onset of adult structures.

  14. The effect of oil sands tailings pond sediments on embryo-larval walleye (Sander vitreus).

    PubMed

    Raine, J C; Turcotte, D; Tumber, V; Peru, K M; Wang, Z; Yang, C; Headley, J V; Parrott, J L

    2017-10-01

    Walleye (Sander vitreus) are a commercially important North American fish species that inhabit the Athabasca River. This river flows through the Athabasca oil sands where natural sources of bitumen erode from the McMurray formation. Little information is available on responses of walleye embryos to oil sands tailings pond sediments in a laboratory setting. The current study describes the design and implementation of a daily-renewal bioassay to assess the potential effects of tailings pond sediments from the Athabasca oil sands area on walleye development. Developing walleye embryos were exposed to increasing concentrations of two tailings pond sediments (collected in the Athabasca oil sands area) until the completion of yolk absorption in control fish. Sediments from the tailings pond represent a mixture of polycyclic aromatic hydrocarbons (PAHs) and alkylated PAHs. During the 31 day exposure, the walleye were examined for mortalities, weight, length and developmental abnormalities to provide an initial evaluation of the effects of the oil sands tailings pond sediments. Walleye embryo survival differed between the tailings pond sediments, and survival decreased with increasing sediment concentration. Alkylated PAH content differed between the two tailings pond sediments and lower embryo survival corresponded to higher total and alkylated PAH content. Tailings pond sediment-exposed walleye exhibited a delay in development, as well as increased percentages of larvae with heart and yolk sac edema, and cranial and spinal malformations. These abnormalities in development are often associated with PAH and alkylated PAH exposure. This study provides an exposure design that can be used to assess sediment toxicity to early developmental stages of a fish species not commonly tested in the lab, and lays the groundwork for future studies with this and other difficult-to-culture species. These results offer information on the potential effects of tailings pond sediments

  15. An argument for the chicken embryo as a model for the developmental toxicological effects of the polyhalogenated aromatic hydrocarbons (PHAHs)

    SciTech Connect

    Henshel, D.S.

    1996-12-31

    This article will present the argument that the chicken embryo is especially appropriate as an animal model for studying the mechanism of the developmental toxicological effects of the polyhalogenated aromatic hydrocarbons (PHAHs). The PHAHs are a group of toxicologically related compounds including, in part, the polychlorinated dibenzodioxins, dibenzofurans and biphenyls. The chicken (Gallus gallus) embryo is relatively sensitive to the toxicological effects of the PHAHs being approximately two orders of magnitude more sensitive than the mature bird. The chicken embryo has been used to demonstrate general toxicological teratogeneicity, hepatotoxicity and neurotoxicity. Many of these effects, or analogous effects, have alsomore » been observed in mammals and fish. Thus, most animals appear to respond to the PHAHs with a similar toxicological profile, indicating that many of the biomarkers used for the PHAHs are valid across a number of species, including the chicken. Furthermore, the chicken embryo is relatively inexpensive to use for toxicity testing. In addition, all effects detected are due to direct effects on the embryo and are not complicated by maternal interactions. In short, for sensitivity, ease of use, cost and applicability of results to other animals, the chicken embryo is an excellent animal model for evaluation of the mechanism underlying the developmental toxicological effects of the PHAHs.« less

  16. Deep cytoplasmic rearrangements in ventralized Xenopus embryos

    NASA Technical Reports Server (NTRS)

    Brown, E. E.; Denegre, J. M.; Danilchik, M. V.

    1993-01-01

    Following fertilization in Xenopus, dramatic rearrangements of the egg cytoplasm relocalize maternally synthesized egg components. During the first cell cycle the vegetal yolk mass rotates relative to the egg surface, toward the sperm entry point (SEP) (J. P. Vincent, G. F. Oster, and J. C. Gerhart, 1986, Dev. Biol. 113, 484-500), while concomitant deep cytoplasmic rearrangements occur in the animal hemisphere (M. V. Danilchik and J. M. Denegre, 1991, Development 111, 845-856). In this paper we examine the role of vegetal yolk mass rotation in producing the animal cytoplasmic rearrangements. We inhibited rotation by uv-irradiating embryos during the first cell cycle, a treatment that yields an extremely ventralized phenotype. Both uv-irradiated embryos and unirradiated control embryos show cytoplasmic rearrangements in the animal hemisphere during the first cell cycle. Cytoplasmic rearrangements on the SEP side of the embryo associated with the path of the sperm pronucleus, plus a swirl on the anti-SEP (dorsal) side, are seen, whether or not yolk mass rotation has occurred. This result suggests a role for the expanding sperm aster in directing animal hemisphere cytoplasmic movements. In unirradiated control embryos the anti-SEP (dorsal) swirl is larger than that in uv-irradiated embryos and often extends into the vegetal hemisphere, consistent with the animal cytoplasm having been pulled dorsally and vegetally by the sliding vegetal yolk mass. Thus the yolk mass rotation may normally enhance the dorsalward cytoplasmic movement, begun by the sperm aster, enough to induce normal axis formation. We extended our observations of unirradiated control and uv-irradiated embryos through early cleavages. The vegetal extent of the anti-SEP (dorsal) swirl pattern seen in control embryos persists through the early cleavage period, such that labeled animal cytoplasm extends deep into dorsal third-tier blastomeres at the 32-cell stage. Significantly, in uv-irradiated embryos

  17. Vitrification-based cryopreservation of Drosophila embryos

    SciTech Connect

    Schreuders, P.D.; Mazur, P.

    1994-12-31

    Currently, over 30,000 strains of Drosophila melanogaster are maintained by geneticists through regular transfer of breeding stocks. A more cost effective solution is to cryopreserve their embryos. Cooling and warming rates >10,000{degrees}C/min. are required to prevent chilling injury. To avoid the lethal intracellular ice normally produced at such high cooling rates, it is necessary to use {ge}50% (w/w) concentrations of glass-inducing solutes to vitrify the embryos. Differential scanning calorimetry (DSC) is used to develop and evaluate ethylene glycol and polyvinyl pyrrolidone based vitrification solutions. The resulting solution consists of 8.5M ethylene glycol + 10% polyvinylpyrrolidone in D-20 Drosophila culture medium.more » A two stage method is used for the introduction and concentration of these solutes within the embryo. The method reduces the exposure time to the solution and, consequently, reduces toxicity. Both DSC and freezing experiments suggest that, while twelve-hour embryos will vitrify using cooling rates >200{degrees}C/min., they will devitrify and be killed with even moderately rapid warming rates of {approximately}1,900{degrees}C/min. Very rapid warming ({approximately}100,000{degrees}C/min.) results in variable numbers of successfully cryopreserved embryos. This sensitivity to warming rite is typical of devitrification. The variability in survival is reduced using embryos of a precisely determined embryonic stage. The vitrification of the older, fifteen-hour, embryos yields an optimized hatching rate of 68%, with 35 - 40% of the resulting larvae developing to normal adults. This Success rite in embryos of this age may reflect a reduced sensitivity to limited devitrification or a more even distribution of the ethylene glycol within the embryo.« less

  18. Identification, localisation and functional implication of 26RFa orthologue peptide in the brain of zebra finch (Taeniopygia guttata).

    PubMed

    Tobari, Y; Iijima, N; Tsunekawa, K; Osugi, T; Haraguchi, S; Ubuka, T; Ukena, K; Okanoya, K; Tsutsui, K; Ozawa, H

    2011-09-01

    Several neuropeptides with the C-terminal Arg-Phe-NH(2) (RFa) sequence have been identified in the hypothalamus of a variety of vertebrates. The present study was conducted to isolate novel RFa peptides from the zebra finch brain. Peptides were isolated by immunoaffinity purification using an antibody that recognises avian RFa peptides. The isolated peptide consisted of 25 amino acids with RFa at its C-terminus. The sequence was SGTLGNLAEEINGYNRRKGGFTFRFa. Alignment of the peptide with vertebrate 26RFa has revealed that the identified peptide is the zebra finch 26RFa. We also cloned the precursor cDNA encoding this peptide. Synteny analysis of the gene showed a high conservation of this gene among vertebrates. In addition, we cloned the cDNA encoding a putative 26RFa receptor, G protein-coupled receptor 103 (GPR103) in the zebra finch brain. GPR103 cDNA encoded a 432 amino acid protein that has seven transmembrane domains. In situ hybridisation analysis in the brain showed that the expression of 26RFa mRNA is confined to the anterior-medial hypothalamic area, ventromedial nucleus of the hypothalamus and the lateral hypothalamic area, the brain regions that are involved in the regulation of feeding behaviour, whereas GPR103 mRNA is distributed throughout the brain in addition to the hypothalamic nuclei. When administered centrally in free-feeding male zebra finches, 26RFa increased food intake 24 h after injection without body mass change. Diencephalic GPR103 mRNA expression was up-regulated by fasting for 10 h. Our data suggest that the hypothalamic 26RFa-its receptor system plays an important role in the central control of food intake and energy homeostasis in the zebra finch. © 2011 The Authors. Journal of Neuroendocrinology © 2011 Blackwell Publishing Ltd.

  19. Humoral response of captive zebra sharks Stegostoma fasciatum to salivary gland proteins of the leech Branchellion torpedinis.

    PubMed

    Marancik, David P; Leary, John H; Fast, Mark M; Flajnik, Martin F; Camus, Alvin C

    2012-10-01

    Parasitism by the marine leech Branchellion torpedinis is known to cause disease and mortality in captive elasmobranchs and is difficult to control when inadvertently introduced into public aquaria. Preliminary characterization of the salivary gland transcriptome of B. torpedinis has identified anticoagulants, proteases, and immunomodulators that may be secreted into host tissues to aid leech feeding. This retrospective study examined antigen-specific serum IgM responses in captive zebra sharks Stegostoma fasciatum to leech salivary gland extract. Antibody response was examined by ELISA and Western blot assays in 20 serum samples from six zebra sharks, with a 5 year history of leech infection, and 18 serum samples from 8 captive bred zebra sharks, with no history of leech exposure. ELISA demonstrated significantly higher serum IgM titers to salivary gland extract in exposed zebra sharks compared to the non-exposed population. No obvious trends in antibody titers were appreciated in exposed zebra sharks over a four-year period. One-dimensional and two-dimensional Western blot assays revealed IgM targeted specific salivary gland proteins within the 40, 55, 70 and 90 kD range. Antigenic proteins identified by liquid chromatography-tandem mass spectrometry and de novo peptide sequencing include a secreted disintegrin, metalloproteinase and thrombospondin motif containing protein (ADAMTS), tubulin, aldehyde dehydrogenase and two unknown proteins. Humoral immune responses to leech salivary gland proteins warrants further investigation as there may be options to exploit immune mechanisms to reduce parasite burdens in aquaria. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Moral qualms, future persons, and embryo research.

    PubMed

    Shaw, David Martin

    2008-05-01

    Many people have moral qualms about embryo research, feeling that embryos must deserve some kind of protection, if not so much as is afforded to persons. This paper will show that these qualms serve to camouflage motives that are really prudential, at the cost of also obscuring the real ethical issues at play in the debate concerning embryo research and therapeutic cloning. This in turn leads to fallacious use of the Actions/Omissions Distinction and ultimately neglects the duties that we have towards future persons.

  1. Gone Fishing.

    ERIC Educational Resources Information Center

    Olson-Demme, Hillary; Kisiel, Jim

    2003-01-01

    Presents a hands-on activity in which students create a model of an ocean ecosystem to gain an understanding of how humans can alter biodiversity through their actions. Uses differing levels of fishing technology to explore the concepts of sustainability and overfishing. (Author/SOE)

  2. Karuk Fishing.

    ERIC Educational Resources Information Center

    Bennett, Ruth, Ed.; Goodwin, Norman

    A booklet on traditional fishing practices of the Karuk Indians of northwestern California is presented in the formal, literary English speech of Norman Goodwin, a Karuk medicine man involved in preserving ancient tribal traditions. Empirical information and personal narratives are combined in descriptions of different kinds of nets, social rules…

  3. Commercial Fishing.

    ERIC Educational Resources Information Center

    Florida State Dept. of Education, Tallahassee. Div. of Vocational Education.

    This document is a curriculum framework for a program in commercial fishing to be taught in Florida secondary and postsecondary institutions. This outline covers the major concepts/content of the program, which is designed to prepare students for employment in occupations with titles such as net fishers, pot fishers, line fishers, shrimp boat…

  4. Effect of embryo source and recipient progesterone environment on embryo development in cattle.

    PubMed

    Lonergan, P; Woods, A; Fair, T; Carter, F; Rizos, D; Ward, F; Quinn, K; Evans, A

    2007-01-01

    The aim of the present study was to examine the effect of embryo source (in vivo v. in vitro) and the progesterone environment into which it was transferred on Day 7 on embryo survival and size on Day 13. Day 7 blastocysts were produced either in vivo using superovulation, artificial insemination and non-surgical embryo recovery or in vitro using in vitro maturation, fertilisation and culture. In order to produce animals with divergent progesterone concentrations, following synchronisation recipients were either superovulated (High progesterone; n = 10) or not (Control progesterone; n = 10). Ten blastocysts, produced either in vivo or in vitro, were transferred to each recipient on Day 7. Both groups were killed on Day 13. The mean progesterone concentration from Day 7 to Day 13 (the period when the embryos were in the uterus) in the High and Control progesterone recipients was 36.32 +/- 1.28 and 10.30 +/- 0.51 ng mL(-1), respectively. Of the in vivo embryos transferred, the overall recovery rate at Day 13 was 64%, which was higher (P < 0.001) than that of 20% for the in vitro embryos transferred. The mean area of embryos recovered from High progesterone recipients was 3.86 +/- 0.45 mm(2) (n = 28) compared with 1.66 +/- 0.38 mm(2) (n = 24) for embryos recovered from Control progesterone recipients (P < 0.001). Similarly, the origin of the embryo used for transfer affected embryo size on Day 13. In summary, the recovery rate of blastocysts was higher for in vivo- than in vitro-derived embryos. Blastocyst size was approximately 2.3-fold greater in recipients with high compared with normal progesterone. The present study lends strong support to the hypothesis that an earlier rise in progesterone after conception stimulates blastocyst growth and the development of competent embryos.

  5. Evolutionary analysis of the jacalin-related lectin family genes in 11 fishes.

    PubMed

    Cao, Jun; Lv, Yueqing

    2016-09-01

    Jacalin-related lectins are a type of carbohydrate-binding proteins, which are distributed across a wide variety of organisms and involved in some important biological processes. The evolution of this gene family in fishes is unknown. Here, 47 putative jacalin genes in 11 fish species were identified and divided into 4 groups through phylogenetic analysis. Conserved gene organization and motif distribution existed in each group, suggesting their functional conservation. Some fishes have eleven jacalin genes, while others have only one or zero gene in their genomes, suggesting dynamic changes in the number of jacalin genes during the evolution of fishes. Intragenic recombination played a key role in the evolution of jacalin genes. Synteny analyses of jacalin genes in some fishes implied conserved and dynamic evolution characteristics of this gene family and related genome segments. Moreover, a few functional divergence sites were identified within each group pairs. Divergent expression profiles of the zebra fish jacalin genes were further investigated in different stresses. The results provided a foundation for exploring the characterization of the jacalin genes in fishes and will offer insights for additional functional studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Exploring the zebra finch Taeniopygia guttata as a novel animal model for the speech-language deficit of fragile X syndrome.

    PubMed

    Winograd, Claudia; Ceman, Stephanie

    2012-01-01

    Fragile X syndrome (FXS) is the most common cause of inherited intellectual disability and presents with markedly atypical speech-language, likely due to impaired vocal learning. Although current models have been useful for studies of some aspects of FXS, zebra finch is the only tractable lab model for vocal learning. The neural circuits for vocal learning in the zebra finch have clear relationships to the pathways in the human brain that may be affected in FXS. Further, finch vocal learning may be quantified using software designed specifically for this purpose. Knockdown of the zebra finch FMR1 gene may ultimately enable novel tests of therapies that are modality-specific, using drugs or even social strategies, to ameliorate deficits in vocal development and function. In this chapter, we describe the utility of the zebra finch model and present a hypothesis for the role of FMRP in the developing neural circuitry for vocalization.

  7. Testing the embryo, testing the fetus.

    PubMed

    Ehrich, K; Farsides, B; Williams, C; Scott, Rosamund

    2007-12-01

    This paper stems from an ethnographic, multidisciplinary study that explored the views and experiences of practitioners and scientists on social, ethical and clinical dilemmas encountered when working in the area of PGD for serious genetic disorders. We focus here on staff perceptions and experiences of working with embryos and helping women/couples to make choices that will result in selecting embryos for transfer and disposal of 'affected' embryos, compared to the termination of affected pregnancies following PND. Analysis and discussion of our data led us to consider the possible advantages of PGD and whether a gradualist account of the embryo's and fetus's moral status can account for all of these, particularly since a gradualist account concentrates on the significance of time (developmental stage) and makes no comment as to the significance of place (in-vitro, in-utero).

  8. Tissue morphodynamics shaping the early mouse embryo.

    PubMed

    Sutherland, Ann E

    2016-07-01

    Generation of the elongated vertebrate body plan from the initially radially symmetrical embryo requires comprehensive changes to tissue form. These shape changes are generated by specific underlying cell behaviors, coordinated in time and space. Major principles and also specifics are emerging, from studies in many model systems, of the cell and physical biology of how region-specific cell behaviors produce regional tissue morphogenesis, and how these, in turn, are integrated at the level of the embryo. New technical approaches have made it possible more recently, to examine the morphogenesis of the mouse embryo in depth, and to elucidate the underlying cellular mechanisms. This review focuses on recent advances in understanding the cellular basis for the early fundamental events that establish the basic form of the embryo. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Hybrids of sugar pine by embryo culture

    Treesearch

    E. C. Stone; J. W. Duffield

    1950-01-01

    A modified embryo culture technique was used to facilitate germination of seed obtained after pollinating sugar pine with pollen from blister rust- resistant Armand and Korean pines. Resulting seedlings appear to be hybrids.

  10. Muscle activation patterns and motor anatomy of Anna's hummingbirds Calypte anna and zebra finches Taeniopygia guttata.

    PubMed

    Donovan, Edward R; Keeney, Brooke K; Kung, Eric; Makan, Sirish; Wild, J Martin; Altshuler, Douglas L

    2013-01-01

    Flying animals exhibit profound transformations in anatomy, physiology, and neural architecture. Although much is known about adaptations in the avian skeleton and musculature, less is known about neuroanatomy and motor unit integration for bird flight. Hummingbirds are among the most maneuverable and specialized of vertebrate fliers, and two unusual neuromuscular features have been previously reported: (1) the pectoralis major has a unique distribution pattern of motor end plates (MEPs) compared with all other birds and (2) electromyograms (EMGs) from the hummingbird's pectoral muscles, the pectoralis major and the supracoracoideus, show activation bursts composed of one or a few spikes that appear to have a very consistent pattern. Here, we place these findings in a broader context by comparing the MEPs, EMGs, and organization of the spinal motor neuron pools of flight muscles of Anna's hummingbird Calypte anna, zebra finches Taeniopygia guttata, and, for MEPs, several other species. The previously shown MEP pattern of the hummingbird pectoralis major is not shared with its closest taxonomic relative, the swift, and appears to be unique to hummingbirds. MEP arrangements in previously undocumented wing muscles show patterns that differ somewhat from other avian muscles. In the parallel-fibered strap muscles of the shoulder, MEP patterns appear to relate to muscle length, with the smallest muscles having fibers that span the entire muscle. MEP patterns in pennate distal wing muscles were the same regardless of size, with tightly clustered bands in the middle portion of the muscle, not evenly distributed bands over the muscle's entire length. Muscle activations were examined during slow forward flight in both species, during hovering in hummingbirds, and during slow ascents in zebra finches. The EMG bursts of a wing muscle, the pronator superficialis, were highly variable in peak number, size, and distribution across wingbeats for both species. In the pectoralis

  11. Song exposure regulates known and novel microRNAs in the zebra finch auditory forebrain

    PubMed Central

    2011-01-01

    Background In an important model for neuroscience, songbirds learn to discriminate songs they hear during tape-recorded playbacks, as demonstrated by song-specific habituation of both behavioral and neurogenomic responses in the auditory forebrain. We hypothesized that microRNAs (miRNAs or miRs) may participate in the changing pattern of gene expression induced by song exposure. To test this, we used massively parallel Illumina sequencing to analyse small RNAs from auditory forebrain of adult zebra finches exposed to tape-recorded birdsong or silence. Results In the auditory forebrain, we identified 121 known miRNAs conserved in other vertebrates. We also identified 34 novel miRNAs that do not align to human or chicken genomes. Five conserved miRNAs showed significant and consistent changes in copy number after song exposure across three biological replications of the song-silence comparison, with two increasing (tgu-miR-25, tgu-miR-192) and three decreasing (tgu-miR-92, tgu-miR-124, tgu-miR-129-5p). We also detected a locus on the Z sex chromosome that produces three different novel miRNAs, with supporting evidence from Northern blot and TaqMan qPCR assays for differential expression in males and females and in response to song playbacks. One of these, tgu-miR-2954-3p, is predicted (by TargetScan) to regulate eight song-responsive mRNAs that all have functions in cellular proliferation and neuronal differentiation. Conclusions The experience of hearing another bird singing alters the profile of miRNAs in the auditory forebrain of zebra finches. The response involves both known conserved miRNAs and novel miRNAs described so far only in the zebra finch, including a novel sex-linked, song-responsive miRNA. These results indicate that miRNAs are likely to contribute to the unique behavioural biology of learned song communication in songbirds. PMID:21627805

  12. “Bird Song Metronomics”: Isochronous Organization of Zebra Finch Song Rhythm

    PubMed Central

    Norton, Philipp; Scharff, Constance

    2016-01-01

    The human capacity for speech and vocal music depends on vocal imitation. Songbirds, in contrast to non-human primates, share this vocal production learning with humans. The process through which birds and humans learn many of their vocalizations as well as the underlying neural system exhibit a number of striking parallels and have been widely researched. In contrast, rhythm, a key feature of language, and music, has received surprisingly little attention in songbirds. Investigating temporal periodicity in bird song has the potential to inform the relationship between neural mechanisms and behavioral output and can also provide insight into the biology and evolution of musicality. Here we present a method to analyze birdsong for an underlying rhythmic regularity. Using the intervals from one note onset to the next as input, we found for each bird an isochronous sequence of time stamps, a “signal-derived pulse,” or pulseS, of which a subset aligned with all note onsets of the bird's song. Fourier analysis corroborated these results. To determine whether this finding was just a byproduct of the duration of notes and intervals typical for zebra finches but not dependent on the individual duration of elements and the sequence in which they are sung, we compared natural songs to models of artificial songs. Note onsets of natural song deviated from the pulseS significantly less than those of artificial songs with randomized note and gap durations. Thus, male zebra finch song has the regularity required for a listener to extract a perceived pulse (pulseP), as yet untested. Strikingly, in our study, pulsesS that best fit note onsets often also coincided with the transitions between sub-note elements within complex notes, corresponding to neuromuscular gestures. Gesture durations often equaled one or more pulseS periods. This suggests that gesture duration constitutes the basic element of the temporal hierarchy of zebra finch song rhythm, an interesting parallel to the

  13. Monochorionic triplets after single embryo transfer.

    PubMed

    Rísquez, Francisco; Gil, Mónica; D'Ommar, Gustavo; Poo, María; Sosa, Anna; Piras, Marta

    2004-10-01

    A 40-year-old patient underwent intracytoplasmic sperm injection and assisted hatching, and a single embryo was transferred. Ultrasonography demonstrated a single gestational sac containing monochorionic tri-amniotic pregnancy. Several factors that have been implicated in the aetiology of monozygotic triple pregnancies after IVF appear to be present in this case. To avoid multiple pregnancies after IVF, it is time to have definite predictive factors for the occurrence of monozygotic multiple pregnancies as well as transferring only a single embryo.

  14. Assessment of the lethal and sublethal effects of 20 environmental chemicals in zebrafish embryos and larvae by using OECD TG 212.

    PubMed

    Horie, Yoshifumi; Yamagishi, Takahiro; Takahashi, Hiroko; Shintaku, Youko; Iguchi, Taisen; Tatarazako, Norihisa

    2017-10-01

    Fish embryo toxicity tests are used to assess the lethal and sublethal effects of environmental chemicals in aquatic organisms. Previously, we used a short-term toxicity test published by the Organization for Economic Co-operation and Development (test no. 212: Fish, Short-term Toxicity Test on Embryo and Sac-Fry Stages [OECD TG 212]) to assess the lethal and sublethal effects of aniline and several chlorinated anilines in zebrafish embryos and larvae. To expand upon this previous study, we used OECD TG 212 in zebrafish embryos and larvae to assess the lethal and sublethal effects of 20 additional environmental chemicals that included active pharmaceutical ingredients, pesticides, metals, aromatic compounds or chlorinated anilines. Zebrafish embryos (Danio rerio) were exposed to the test chemicals until 8 days post-fertilization. A delayed lethal effect was induced by 16 of the 20 test chemicals, and a positive correlation was found between heart rate turbulence and mortality. We also found that exposure to the test chemicals at concentrations lower than the lethal concentration induced the sublethal effects of edema, body curvature and absence of swim-bladder inflation. In conclusion, the environmental chemicals assessed in the present study induced both lethal and sublethal effects in zebrafish embryos and larvae, as assessed by using OECD TG 212. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  15. Dioxin effects on wood duck (Aix sponsa) embryos from sites near paper mills

    SciTech Connect

    Beeman, D.K.; Melancon, M.J.; Fleming, W.J.

    Biological and biochemical variables were studied in wood duck embryos from four dioxin-contaminated sites near paper mills in the Southeastern United States and three reference sites. Sites were selected based on a history of dioxin contamination in both sediments and fish. In addition, wood duck embryos collected downstream from an Arkansas Superfund site with demonstrated dioxin-induced reproductive impairment served as positive controls. Whole clutches of eggs were collected from the wild after fifteen days of incubation and mechanically incubated. Two embryos per clutch were sacrificed at pipping and liver monooxygenase activities (BROD, EROD and MROD) were quantified. Hatching success wasmore » determined for the remainder of the nest. Preliminary results indicate no difference in monooxygenase activities across sites even though the authors have previously demonstrated induction of monooxygenase activity in wood duck embryos in laboratory studies. In addition, there were no differences in weight at pipping, liver weight and liver weight to body weight ratios. No differences were seen in hatching success or weight at hatch nor were there any gross morphological abnormalities. This may indicate that exposure of wood ducks nesting near these pulp paper mills is below those which cause elevated monooxygenase activities and reproductive impairment.« less

  16. Toxic effects of triazophos on rare minnow (Gobiocypris rarus) embryos and larvae.

    PubMed

    Zhu, Bin; Gong, Yu-Xin; Liu, Lei; Li, Dong-Liang; Wang, Yuan; Ling, Fei; Wang, Gao-Xue

    2014-08-01

    Triazophos (TAP) has been widely used in agriculture for controlling insect pests and is a known organophosphorus pesticide. Due to TAP characteristics, such as high chemical and photochemical stability, its potential toxicity to aquatic organisms has gained great interest. To explore the potential developmental toxicity of TAP, Gobiocypris rarus embryos and larvae were exposed to various concentrations of TAP (0.1-15 mg L(-1)) until 72 h. Results showed that values of 72 h LC50 and EC50 were 7.44 and 5.60 mg L(-1) for embryos, 2.52 and 1.37 mg L(-1) for larvae. Increased malformation, decreased heart rate and body length provide a gradual concentration-dependent pattern. Enzyme activities and mRNA levels were significantly changed even at low concentration (0.05 mg L(-1) for embryos and 0.01 mg L(-(1) for larvae). Overall, the present study points out that TAP is likely a risk to the early development of G. rarus. The information presented in this study will be helpful in better understanding the toxicity induced by TAP in fish embryos and larvae. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. The red tide toxin, brevetoxin, induces embryo toxicity and developmental abnormalities.

    PubMed Central

    Kimm-Brinson, K L; Ramsdell, J S

    2001-01-01

    Brevetoxins are lipophilic polyether toxins produced by the red tide dinoflagellate Gymnodinium breve, and their neurotoxic effects on adult animals have been documented. In this study, we characterized adverse developmental effects of brevetoxin-1 (PbTx-1) using an exposure paradigm that parallels the maternal oocyte transfer of toxin. Medaka fish (Oryzias latipes) embryos were exposed to PbTx-1 via microinjection of toxin reconstituted in a triolein oil droplet. Embryos microinjected with doses of 0.1-8.0 ng/egg (ppm) of brevetoxin-1 exhibited pronounced muscular activity (hyperkinesis) after embryonic day 4. Upon hatching, morphologic abnormalities were commonly found in embryos at the following lowest adverse effect levels: 1.0-3.0 ppm, lateral curvature of the spinal column; 3.1-3.4 ppm, herniation of brain meninges through defects in the skull; and 3.4-4.0 ppm, malpositioned eye. Hatching abnormalities were also commonly observed at brevetoxin doses of 2.0 ppm and higher with head-first, as opposed to the normal tail-first, hatching, and doses > 4.1 ng/egg produced embryos that developed but failed to hatch. Given the similarity of developmental processes found between higher and lower vertebrates, teratogenic effects of brevetoxins have the potential to occur among different phylogenetic classes. The observation of developmental abnormalities after PbTx-1 exposure identifies a new spectrum of adverse effects that may be expected to occur following exposure to G. breve red tide events. PMID:11335186

  18. Cryopreservation of Arachis pintoi (leguminosae) somatic embryos.

    PubMed

    Rey, H Y; Faloci, M; Medina, R; Dolce, N; Engelmann, F; Mroginski, L

    2013-01-01

    In this study, we successfully cryopreserved cotyledonary somatic embryos of diploid and triploid Arachis pintoi cytotypes using the encapsulation-dehydration technique. The highest survival rates were obtained when somatic embryos were encapsulated in calcium alginate beads and precultured in agitated (80 rpm) liquid establishment medium (EM) with daily increasing sucrose concentration (0.50, 0.75, and 1.0 M). The encapsulated somatic embryos were then dehydrated with silica gel for 5 h to 20% moisture content (fresh weight basis) and cooled either rapidly (direct immersion in liquid nitrogen, LN) or slowly (1 degree C per min from 25 degree C to -30 degree C followed by immersion in LN). Beads were kept in LN for a minimum of 1 h and then were rapidly rewarmed in a 30 degree C water-bath for 2 min. Finally, encapsulated somatic embryos were post-cultured in agitated (80 rpm) liquid EM with daily decreasing sucrose concentration (0.75 and 0.5 M) and transferred to solidified EM. Using this protocol, we obtained 26% and 30% plant regeneration from cryopreserved somatic embryos of diploid and triploid cytotypes. No morphological abnormalities were observed in any of the plants regenerated from cryopreserved embryos and their genetic stability was confirmed with 10 isozyme systems and nine RAPD profiles.

  19. Experimenting with embryos: can philosophy help?

    PubMed

    Heyd, David

    1996-10-01

    Beyond the well-known ethical issues involved in medical experimentation on human subjects, experimenting with embryos raises unique and particularly hard problems. Besides the psychological obstacles connected with the fear of "playing God" and the awe with which we hold the process of the creation of human beings, there are three philosophical problems which are the main subject of the article: 1. The logical problem of circularity: the morality of experimenting on embryos is dependent on the status of the embryo, which in turn is partly decided by experimentation; 2. The metaphysical problem: experiments are justified by the benefits they bring to human subjects; but it is doubtful whether an early embryo is a "subject" and whether coming into being is a "benefit"; 3. The moral problem: the standard constraint on medical experiments is that they benefit either the individual subject or at least members of a relevantly defined group of patients suffering from the same syndrome. But embryo experimentation is often associated with potential cure to people of a completely different category (like geriatric patients). Finally, the article discusses the limits of the force of philosophical arguments in the formation of actual policies for regulating such practices as experimenting with embryos. The widely-shared fourteen-day limit is shown to be a sound practical compromise despite the difficulties in justifying it philosophically.

  20. Mitochondrial DNA content in embryo culture medium is significantly associated with human embryo fragmentation.

    PubMed

    Stigliani, S; Anserini, P; Venturini, P L; Scaruffi, P

    2013-10-01

    Is the amount of cell-free DNA released by human embryos into culture medium correlated with embryo morphological features? The mitochondrial DNA (mtDNA) content of culture medium is significantly associated with the fragmentation rate on Days 2 and 3 of embryo development, whether the oocyte came from women ≤ 35 or >35 years old. Cellular fragmentation is often utilized as one of the morphological parameters for embryo quality assessment. The amount of cellular fragments is considered to be an important morphological parameter for embryo implantation potential. It has been hypothesized that fragments are apoptotic bodies or anuclear cytoplasmatic pieces of blastomeres, although no definitive conclusion has been drawn about their pathogenesis. Human fertilized oocytes were individually cultured from Day 1 to Days 2 and 3. A total of 800 samples (166 spent media from Day 2 and 634 from Day 3) were enrolled into the present study. Double-stranded DNA (dsDNA) was quantified in 800 spent embryo culture media by Pico Green dye fluorescence assay. After DNA purification, genomic DNA (gDNA) and mtDNA were profiled by specific quantitative PCR. Statistical analyses defined correlations among DNA contents, embryo morphology and maternal age. Different independent tests confirmed the presence of DNA into embryo culture medium and, for the first time, we demonstrate that both gDNA and mtDNA are detectable in the secretome. The amount of DNA is larger in embryos with bad quality cleavage compared with high-grade embryos, suggesting that the DNA profile of culture medium is an objective marker for embryo quality assessment. In particular, DNA profiles are significantly associated with fragmentation feature (total dsDNA: P = 0.0010; mtDNA; P = 0.0247) and advanced maternal age. It is necessary to establish whether DNA profiling of spent embryo culture medium is a robust onsite test that can improve the prediction of blastulation, implantation and/or pregnancy rate. The

  1. Fish gelatin.

    PubMed

    Boran, Gokhan; Regenstein, Joe M

    2010-01-01

    Gelatin is a multifunctional ingredient used in foods, pharmaceuticals, cosmetics, and photographic films as a gelling agent, stabilizer, thickener, emulsifier, and film former. As a thermoreversible hydrocolloid with a narrower gap between its melting and gelling temperatures, both of which are below human body temperature, gelatin provides unique advantages over carbohydrate-based gelling agents. Gelatin is mostly produced from pig skin, and cattle hides and bones. Some alternative raw materials have recently gained attention from both researchers and the industry not just because they overcome religious concerns shared by Jews and Muslims but also because they provide, in some cases, technological advantages over mammalian gelatins. Fish skins from a number of fish species are among the other sources that have been comprehensively studied as sources for gelatin production. Fish skins have a significant potential for the production of high-quality gelatin with different melting and gelling temperatures over a much wider range than mammalian gelatins, yet still have a sufficiently high gel strength and viscosity. Gelatin quality is industrially determined by gel strength, viscosity, melting or gelling temperatures, the water content, and microbiological safety. For gelatin manufacturers, yield from a particular raw material is also important. Recent experimental studies have shown that these quality parameters vary greatly depending on the biochemical characteristics of the raw materials, the manufacturing processes applied, and the experimental settings used for quality control tests. In this review, the gelatin quality achieved from different fish species is reviewed along with the experimental procedures used to determine gelatin quality. In addition, the chemical structure of collagen and gelatin, the collagen-gelatin conversion, the gelation process, and the gelatin market are discussed. Copyright © 2010 Elsevier Inc. All rights reserved.

  2. Keynote presentation: Looking for Zebras When There Are Only Horses (Abstract)

    NASA Astrophysics Data System (ADS)

    Conti, D. M.

    2018-06-01

    (Abstract only) How many times have each of us thought we had made a "scientific discovery" only to realize that we were the victim of our own operational, instrumentation, or processing errors? With amateur astronomers contributing more and more to pro/am collaborations, the quality and credibility of our participation is becoming even more important. This keynote presentation will review some of the common pitfalls in producing research-grade photometry results and will give examples of some "horses" that we thought were really "zebras." In addition, it will present some procedures and new techniques for obtaining higher precision photometry. These will be especially useful in helping amateur astronomers better identify false positives in support of the upcoming TESS exoplanet mission.

  3. Canal construction destroys the barrier between major European invasion lineages of the zebra mussel.

    PubMed Central

    Müller, Jakob C; Hidde, Dennis; Seitz, Alfred

    2002-01-01

    Since the mid-1980s the zebra mussel, Dreissena polymorpha, Pallas 1771, has become the protagonist of a spectacular freshwater invasion in North America due to its large economic and biological impact. Several genetic studies on American populations have failed to detect any large-scale geographical patterns. In western Europe, where D. polymorpha has been a classical invader from the Pontocaspian since the early 19th century, the situation is strikingly different. Here, we show with genetic markers that two major western European invasion lineages with lowered genetic variability within and among populations can be discriminated. These two invasion lineages correspond with two separate navigable waterways to western Europe. We found a rapid and asymmetrical genetic interchange of the two invasion lines after the construction of the Main-Danube canal in 1992, which interconnected the two waterways across the main watershed. PMID:12061957

  4. Form of Dietary Methylmercury does not Affect Total Mercury Accumulation in the Tissues of Zebra Finch.

    PubMed

    Varian-Ramos, Claire W; Whitney, Margaret; Rice, Gary W; Cristol, Daniel A

    2017-07-01

    Exposure to mercury in humans, other mammals, and birds is primarily dietary, with mercury in the methylated form and bound to cysteine in the tissues of prey items. Yet dosing studies are generally carried out using methylmercury chloride. Here we tested whether the accumulation of total mercury in zebra finch blood, egg, muscle, liver, kidney or brain differed depending on whether dietary mercury was complexed with chloride or cysteine. We found no effect of form of mercury on tissue accumulation. Some previous studies have found lower accumulation of mercury in tissues of animals fed complexed mercury. Much remains to be understood about what happens to ingested mercury once it enters the intestines, but our results suggest that dietary studies using methylmercury chloride in birds will produce similar tissue accumulation levels to those using methylmercury cysteine.

  5. Sex-dependent effects of nutrition on telomere dynamics in zebra finches (Taeniopygia guttata)

    PubMed Central

    Noguera, Jose C.; Metcalfe, Neil B.; Boner, Winnie; Monaghan, Pat

    2015-01-01

    At a cellular level, oxidative stress is known to increase telomere attrition, and hence cellular senescence and risk of disease. It has been proposed that dietary micronutrients play an important role in telomere protection due to their antioxidant properties. We experimentally manipulated dietary micronutrients during early life in zebra finches (Taeniopygia guttata). We found no effects of micronutrient intake on telomere loss during chick growth. However, females given a diet high in micronutrients during sexual maturation showed reduced telomere loss; there was no such effect in males. These results suggest that micronutrients may influence rates of cellular senescence, but differences in micronutrient requirement and allocation strategies, probably linked to the development of sexual coloration, may underlie sex differences in response. PMID:25716087

  6. A neural circuit mechanism for regulating vocal variability during song learning in zebra finches.

    PubMed

    Garst-Orozco, Jonathan; Babadi, Baktash; Ölveczky, Bence P

    2014-12-15

    Motor skill learning is characterized by improved performance and reduced motor variability. The neural mechanisms that couple skill level and variability, however, are not known. The zebra finch, a songbird, presents a unique opportunity to address this question because production of learned song and induction of vocal variability are instantiated in distinct circuits that converge on a motor cortex analogue controlling vocal output. To probe the interplay between learning and variability, we made intracellular recordings from neurons in this area, characterizing how their inputs from the functionally distinct pathways change throughout song development. We found that inputs that drive stereotyped song-patterns are strengthened and pruned, while inputs that induce variability remain unchanged. A simple network model showed that strengthening and pruning of action-specific connections reduces the sensitivity of motor control circuits to variable input and neural 'noise'. This identifies a simple and general mechanism for learning-related regulation of motor variability.

  7. Patterns of call communication between group-housed zebra finches change during the breeding cycle.

    PubMed

    Gill, Lisa F; Goymann, Wolfgang; Ter Maat, Andries; Gahr, Manfred

    2015-10-06

    Vocal signals such as calls play a crucial role for survival and successful reproduction, especially in group-living animals. However, call interactions and call dynamics within groups remain largely unexplored because their relation to relevant contexts or life-history stages could not be studied with individual-level resolution. Using on-bird microphone transmitters, we recorded the vocalisations of individual zebra finches (Taeniopygia guttata) behaving freely in social groups, while females and males previously unknown to each other passed through different stages of the breeding cycle. As birds formed pairs and shifted their reproductive status, their call repertoire composition changed. The recordings revealed that calls occurred non-randomly in fine-tuned vocal interactions and decreased within groups while pair-specific patterns emerged. Call-type combinations of vocal interactions changed within pairs and were associated with successful egg-laying, highlighting a potential fitness relevance of calling dynamics in communication systems.

  8. Kinematics of flap-bounding flight in the zebra finch over a wide range of speeds

    PubMed

    Tobalske; Peacock; Dial

    1999-07-01

    It has been proposed elsewhere that flap-bounding, an intermittent flight style consisting of flapping phases interspersed with flexed-wing bounds, should offer no savings in average mechanical power relative to continuous flapping unless a bird flies 1.2 times faster than its maximum range speed (Vmr). Why do some species use intermittent bounds at speeds slower than 1.2Vmr? The 'fixed-gear hypothesis' suggests that flap-bounding is used to vary mean power output in small birds that are otherwise constrained by muscle physiology and wing anatomy to use a fixed muscle shortening velocity and pattern of wing motion at all flight speeds; the 'body-lift hypothesis' suggests that some weight support during bounds could make flap-bounding flight aerodynamically advantageous in comparison with continuous flapping over most forward flight speeds. To test these predictions, we studied high-speed film recordings (300 Hz) of wing and body motion in zebra finches (Taenopygia guttata, mean mass 13.2 g, N=4) taken as the birds flew in a variable-speed wind tunnel (0-14 m s-1). The zebra finches used flap-bounding flight at all speeds, so their flight style was unique compared with that of birds that facultatively shift from continuous flapping or flap-gliding at slow speeds to flap-bounding at fast speeds. There was a significant effect of flight speed on all measured aspects of wing motion except percentage of the wingbeat spent in downstroke. Changes in angular velocity of the wing indicated that contractile velocity in the pectoralis muscle changed with flight speed, which is not consistent with the fixed-gear hypothesis. Although variation in stroke-plane angle relative to the body, pronation angle of the wing and wing span at mid-upstroke showed that the zebra finch changed within-wingbeat geometries according to speed, a vortex-ring gait with a feathered upstroke appeared to be the only gait used during flapping. In contrast, two small species that use continuous flapping

  9. Spawning of zebra mussels (Dreissena polymorpha) and rearing of veligers under laboratory conditions

    USGS Publications Warehouse

    Nichols, S. Jerrine; Nalepa, Thomas F.; Schloesser, Donald W.

    1992-01-01

    The spawning cycle of the zebra mussel, Dreissena polymorpha, is amenable to laboratory manipulations. Techniques are presented that can be used to initiate spawning and rear veligers from fertilized egg to settlement stage. Spawning can be induced in sexually mature mussels by temperature flucuations or by the addition of ripe gametes. Embryonic survival is excellent until the straight-hinge stage when the first wave of mortality occurs, usually due to improper food. The second critical stage of development occurs just prior to settlement when mortality increases again. Veliger mortality averaged over 90% from egg to settlement. The results indicate that obtaining large numbers of veligers for laboratory experiments to be conducted year-round is difficult.

  10. Increased Mortality in a Colony of Zebra Finches Exposed to Continuous Light

    PubMed Central

    Snyder, Jessica M; Molk, Denise M; Treuting, Piper M

    2013-01-01

    Over a 1-mo period, increased morbidity and mortality occurred in a flock of zebra finches (Taeniopygia guttata). Complete postmortem examination was performed on 6 of the affected birds, 4 of which subsequently were diagnosed with the avian gastric yeast previously known as megabacteriosis (Macrorhabdus ornithogaster). The remaining 2 birds were diagnosed with a cloacal abscess and with large bowel perforation and peritonitis. All the birds had been prophylactically treated with amphotericin B for megabacteria 2 mo previously. An environmental assessment revealed that the light cycle had been altered, and the birds were being exposed to constant light. With correction of the light cycle, the health of the birds improved dramatically. The remaining birds were treated again with amphotericin B, and baseline mortality returned to normal. The birds in this report show several similarities to previous reports of sleep deprivation syndrome in mammals. PMID:23849414

  11. The use of the geomagnetic field for short distance orientation in zebra finches.

    PubMed

    Voss, Joe; Keary, Nina; Bischof, Hans-Joachim

    2007-07-02

    Although the ability to use the Earth's magnetic field for long distance orientation and navigation has been demonstrated in many animals, the search for the appropriate receptor has not yet finished. It is also not entirely clear whether the use of magnetic field information is restricted to specialists like migrating birds, or whether it is a sense that is also suited to short distance orientation by avian species. We successfully trained nonmigratory zebra finches in a four-choice food-search task to use the natural magnetic field as well as an experimentally shifted field for short distance orientation, supporting the view that magnetic field perception may be a sense existing in all bird species. By using a conditioning technique in a standard laboratory animal, our experiments will provide an ideal basis for the search for the physiological mechanisms of magnetic field perception.

  12. Mid-Atomic-Number Cylindrical Wire Array Precursor Plasma Studies on Zebra

    DOE PAGES

    Stafford, A; Safronova, A. S.; Kantsyrev, V. L.; ...

    2014-12-30

    The precursor plasmas from low wire number cylindrical wire arrays (CWAs) were previously shown to radiate at temperatures >300 eV for Ni-60 (94% Cu and 6% Ni) wires in experiments on the 1-MA Zebra generator. Continued research into precursor plasmas has studied additional midatomic-number materials including Cu and Alumel (95% Ni, 2% Al, 2% Mn, and 1% Si) to determine if the >300 eV temperatures are common for midatomic-number materials. Additionally, current scaling effects were observed by performing CWA precursor experiments at an increased current of 1.5 MA using a load current multiplier. Our results show an increase in amore » linear radiation yield of ~50% (16 versus 10 kJ/cm) for the experiments at increased current. However, plasma conditions inferred through the modeling of X-ray time-gated spectra are very similar for the precursor plasma in both current conditions.« less

  13. In situ growth of juvenile zebra mussels in a regulated stream

    USGS Publications Warehouse

    French, John R. P.; Nichols, S. Jerrine; Craig, Jaquelyn M.; Allen, Jeffery D.; Black, M. Glen

    2006-01-01

    We investigated the in situ growth of juvenile zebra mussels (Dreissena polymorpha) in a reach of the Huron River (southeast Michigan) below a dam with a control gate that regulates water levels. Growth was significantly different among sample dates over a five-month-long monitoring season. Mean growth of mussels generally decreased from 0.093 mm/day just above the dam to 0.067 mm/day 4 km downstream, then increased to 0.091 mm/day at end of the 17-km-long study area. Significant differences among sites were most numerous in August during a severe drought when discharges fell substantially. Growth was positively correlated with discharges (R2 = 0.94, p a levels in the study area, however, was weak (R2 = 0.69, p < 0.1). Our study suggests that discharge may be one controlling factor for dreissenid populations in small streams.

  14. Double plasma resonance instability as a source of solar zebra emission

    NASA Astrophysics Data System (ADS)

    Benáček, J.; Karlický, M.

    2018-03-01

    Context. The double plasma resonance (DPR) instability plays a basic role in the generation of solar radio zebras. In the plasma, consisting of the loss-cone type distribution of hot electrons and much denser and colder background plasma, this instability generates the upper-hybrid waves, which are then transformed into the electromagnetic waves and observed as radio zebras. Aims: In the present paper we numerically study the double plasma resonance instability from the point of view of the zebra interpretation. Methods: We use a 3-dimensional electromagnetic particle-in-cell (3D PIC) relativistic model. We use this model in two versions: (a) a spatially extended "multi-mode" model and (b) a spatially limited "specific-mode" model. While the multi-mode model is used for detailed computations and verifications of the results obtained by the "specific-mode" model, the specific-mode model is used for computations in a broad range of model parameters, which considerably save computational time. For an analysis of the computational results, we developed software tools in Python. Results: First using the multi-mode model, we study details of the double plasma resonance instability. We show how the distribution function of hot electrons changes during this instability. Then we show that there is a very good agreement between results obtained by the multi-mode and specific-mode models, which is caused by a dominance of the wave with the maximal growth rate. Therefore, for computations in a broad range of model parameters, we use the specific-mode model. We compute the maximal growth rates of the double plasma resonance instability with a dependence on the ratio between the upper-hybrid ωUH and electron-cyclotron ωce frequency. We vary temperatures of both the hot and background plasma components and study their effects on the resulting growth rates. The results are compared with the analytical ones. We find a very good agreement between numerical and analytical growth

  15. Gene evolution and gene expression after whole genome duplication in fish: the PhyloFish database.

    PubMed

    Pasquier, Jeremy; Cabau, Cédric; Nguyen, Thaovi; Jouanno, Elodie; Severac, Dany; Braasch, Ingo; Journot, Laurent; Pontarotti, Pierre; Klopp, Christophe; Postlethwait, John H; Guiguen, Yann; Bobe, Julien

    2016-05-18

    With more than 30,000 species, ray-finned fish represent approximately half of vertebrates. The evolution of ray-finned fish was impacted by several whole genome duplication (WGD) events including a teleost-specific WGD event (TGD) that occurred at the root of the teleost lineage about 350 million years ago (Mya) and more recent WGD events in salmonids, carps, suckers and others. In plants and animals, WGD events are associated with adaptive radiations and evolutionary innovations. WGD-spurred innovation may be especially relevant in the case of teleost fish, which colonized a wide diversity of habitats on earth, including many extreme environments. Fish biodiversity, the use of