Daphnia magna
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PROVIDER: PRJNA320519 | ENA |
REPOSITORIES: ENA
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Project description:Molecular impact of juvenile hormone agonists on neonatal Daphnia magna
| PRJNA208588 | ENA
Project description:Daphnia magna has been used extensively to evaluate organism- and population-level responses to pollutants in acute toxicity and reproductive toxicity tests. We have previously reported that exposure to juvenile hormone (JH) agonists results in a reduction of reproductive function and production of male offspring in a cyclic parthenogenesis, D. magna. Recent advances in molecular techniques have provided tools to better understand the responses to pollutants in aquatic organisms including D. magna. DNA microarray was used to evaluate gene expression profiles of neonatal daphnids exposed to JH agonists; methoprene (125, 250 and 500 ppb), fenoxycarb (0.5, 1 and 2 ppb), and epofenonane (50, 100 and 200 ppb). Exposure to these JH analogs resulted in chemical specific patterns of gene expression. The heat map analyses based on hierarchical clustering revealed a similar pattern between treatments with a high dose of methoprene and with epofenonane. In contrast, treatment with low to middle doses of methoprene resulted in similar profiles to fenoxycarb treatments. Hemoglobin and JH epoxide hydrolase genes clustered to be JH-responsive genes. These data suggest that fenoxycarb has high activity as a JH agonist, methoprene shows high toxicity and epofenonane works through a different mechanism compared with other JH analogs, agreeing with data of previously reported toxicity tests. In conclusion, D. magna DNA microarray is useful for classification of JH analogs and identification of JH-responsive genes. Juvenile hormone agonists induced gene expression in daphnids neonates was measured at 48 hours after exposure to methoprene (125, 250, 500 ppb), fenoxycarb (0.5, 1, 2 ppb), epofenonane (50, 100, 200) and DMF as a control. Three independent experiments were performed at each chemicals.
2013-12-31 | E-GEOD-47990 | biostudies-arrayexpress
Project description:Daphnia magna has been used extensively to evaluate organism- and population-level responses to pollutants in acute toxicity and reproductive toxicity tests. We have previously reported that exposure to juvenile hormone (JH) agonists results in a reduction of reproductive function and production of male offspring in a cyclic parthenogenesis, D. magna. Recent advances in molecular techniques have provided tools to better understand the responses to pollutants in aquatic organisms including D. magna. DNA microarray was used to evaluate gene expression profiles of neonatal daphnids exposed to JH agonists; methoprene (125, 250 and 500 ppb), fenoxycarb (0.5, 1 and 2 ppb), and epofenonane (50, 100 and 200 ppb). Exposure to these JH analogs resulted in chemical specific patterns of gene expression. The heat map analyses based on hierarchical clustering revealed a similar pattern between treatments with a high dose of methoprene and with epofenonane. In contrast, treatment with low to middle doses of methoprene resulted in similar profiles to fenoxycarb treatments. Hemoglobin and JH epoxide hydrolase genes clustered to be JH-responsive genes. These data suggest that fenoxycarb has high activity as a JH agonist, methoprene shows high toxicity and epofenonane works through a different mechanism compared with other JH analogs, agreeing with data of previously reported toxicity tests. In conclusion, D. magna DNA microarray is useful for classification of JH analogs and identification of JH-responsive genes.
2013-12-31 | GSE47990 | GEO
Project description:Juvenile hormone (JH) and JH agonists have been reported to induce male offspring production in various daphnids including Daphnia magna. We have recently established a short-term in vivo screening method to detect chemicals having JH activity, induction of male offspring, using adult D. magna. Diofenolan has been developed to be a JH agonist in insects, but no male induction in daphniids has been studied. In this study, we found the male offspring induction by diofenolan with a short-term in vivo screening method, and the most potent male offspring production activity among JH analogs studied using the OECD TG211 Annex 7. Transcriptome analysis of diofenolan-exposed D. magna showed up-regulation of JH-responsive genes. These results clearly demonstrated that diofenolan has JH activities in D. magna using the short-term in vivo screening assay, OECD TG211 Annex 7 and microarray analysis.
2014-12-01 | GSE53570 | GEO
Project description:This SuperSeries is composed of the following subset Series: GSE29854: Daphnia magna exposed to narcotics and polar narcotics - aniline GSE29856: Daphnia magna exposed to narcotics and polar narcotics - 4-chloroaniline GSE29857: Daphnia magna exposed to narcotics and polar narcotics - 3,5-dichloroaniline GSE29858: Daphnia magna exposed to narcotics and polar narcotics - 2,3,4-trichloroaniline GSE29862: Daphnia magna exposed to narcotics and polar narcotics - ethanol GSE29864: Daphnia magna exposed to narcotics and polar narcotics - isopropanol GSE29867: Daphnia magna exposed to narcotics and polar narcotics - methanol Refer to individual Series
2012-02-01 | E-GEOD-29993 | biostudies-arrayexpress
Project description:An EST project for the water flea, Daphnia magna, is underway
| PRJNA13037 | ENA
Project description:Microarray analyses were used to evaluate patterns of gene transcription following exposure of the waterflea Daphnia magna to two natural and one anthropogenic stressor. cDNA microarrays compiled of three life stage specific and three stressor-specific EST libraries, yielding 1734 different EST sequences, were used. We exposed the water flea Daphnia magna to three stressors known to exert strong selection in natural populations of this species i.e. a sublethal concentration of the pesticide carbaryl, infective spores of the endoparasite Pasteuria ramosa, and fish predation risk mimicked by exposure to fish kairomones. A total of 148 gene fragments were differentially expressed compared to the control. Most gene fragments were downregulated under stress (82.4% downregulation compared to 17.6% upregulation) irrespective of the treatment. In approximately 5% of the cases up- or downregulation depended on stressor identity. Based on a PCA, we could identify two different groups within our exposure treatments: small and big gene expression differences compared to the control condition. The treatments parasite 96h exposure, carbaryl 144h of exposure and fish 144h of exposure are combined in the high stress group.
2013-09-01 | GSE24322 | GEO
Project description:7 daphnia magna life stages from embryo development till adult were profiled using a new custom made microarray on a 4*160K platform
2017-04-01 | GSE90810 | GEO
Project description:Stressor mRNA expression profiling of three different stressors in the water flea Daphnia magna
| PRJNA132847 | ENA
Project description:The freshwater zooplankton Daphnia magna has been used for the validation of chemical toxicity tests such as OECD Test Guideline 202 and 211. Previously, it has been demonstrated that treatment of juvenile hormones (JHs) or their analogs to mother daphnids could induce male offspring production. Based on this funding, a rapid screening method for detection of chemical with JH-activity was recently developed by using adult D. magna. This screening system can validate whether arbitrary chemical has JH-activity by investigating the male offspring inducibility. Although this short-term screening system will be possible to enhance a throughput of detection efficiency, JH-responsive genes in the ovary including developing oocytes at JH-sensitive period for male sex determination are still largely undescribed. Here, we conducted comparative microarray analyses using ovary treated by fenoxycarb (Fx; artificial JH agonist) and methyl farnesoate (MF; a putative innate JH in daphnids) to make the comprehensive gene catalogs in response to JH molecules in ovary including developing oocytes at JH-sensitive period for male sex determination. We successfully created the comprehensive ovarian gene catalogs in response to Fx and MF. Furthermore, we demonstrated that the hemoglobin genes are well-conserved JH-responsive element even in the ovary, and a potential toxic effect of JH agonist is suppression of vitellogenin gene expression that might cause reduction of offspring number. This is first report demonstrating the differential transcriptomics profiles between MF and artificial JH agonist in D. magna ovary, making it possible for understanding the tissue-specific mode-of-action of JH molecule.
2017-05-01 | GSE81083 | GEO