ABSTRACT: The pesticide fipronil affects transcriptional networks related to mitochondrial dysfunction and methylation in zebrafish embryos (Danio rerio)
Project description:The phenylpyrazole fipronil is a widely used insecticide designed to inhibit γ -amino-butyric acid (GABA) receptors, the major inhibitory neurotransmitter in the central nervous system. Fipronil has been detected in some water systems in the ng/L range, and is reported to be neurotoxic. To address the risks associated with fipronil exposure, we measured morphological, physiological, and molecular responses in zebrafish (Danio rerio) embryos following a 48 hour exposure (20 ng/L – 2 mg/L). Survival was not different than controls following treatments below 200 µg fipronil/L but was ~20% higher with concentrations above 200 µg fipronil/L. Once the embryos hatched, they underwent a 7 day depuration phase. At 9 days post-fertilization (9 dpf), body length and notochord length were not different than controls for any dose. To assess sub-lethal effects, transcriptome profiling was conducted in 9 dpf larvae following 48 hour exposure + 7 dpf depuration to environmentally relevant concentrations of fipronil (200 ng fipronil/L), as well as two higher concentrations of the pesticide (200 µg fipronil/L and 2 mg fipronil/L). Transcriptome profiling revealed that all three concentrations affected pathways related to chromosome condensation and the metabolism of estrogens and androgens as well as genes related to methylation. In addition, 200 ng fipronil/L down-regulated genes related to the circadian clock, histone and DNA methylation, and histone acetylation, while the highest dose increased networks related to immune function (e.g. lectin-induced complement pathway and the alternative complement pathway). The two highest concentrations of fipronil increased the expression of transcriptional networks associated with mitochondrial respiratory chain dysfunction and mitochondrial protein transport. As such, we exposed 24 hpf embryos to fipronil for 24 hours and measured oxygen consumption rate to assess mitochondrial function. There were no differences in basal and maximal respiration in the embryos nor ATP production, and fipronil did not affect mitochondrial bioenergetics. This study suggests that fipronil at environmentally relevant concentrations does not adversely affect the survival or morphology of fish embryos, however sub-lethal endpoints should be examined to more fully characterize the long term effects of fipronil exposure in larval fish.
Project description:Comparison of gene expression profiles from Danio rerio embryos of wiltype, miR-101a and miR-29a treated animals. The RNA-seq data comprise 3 groups. Jena Centre for Systems Biology of Ageing - JenAge (www.jenage.de)
Project description:In triplicate for each condition, 12 WT and acbd6 F0 crispant Danio rerio (zebrafish) embryos were incubated with 20 μM YnMyr for 24 h, either between 48-72 hpf or 96-120 hpf. After labelling, zebrafish were washed twice with fresh egg water, deyolked, flash frozen in liquid nitrogen and stored at -80°C until further analysis.
Project description:Dieldrin is a legacy pesticide that has multiple modes of action (MOA) that include being an estrogen receptor agonist, GABA receptor antagonist, and a chemical that disrupts mitochondrial function. There is also evidence that dieldrin exposure is significantly associated with an increased risk for neurodegeneration in humans. The objective of this thesis was to clarify the effects of dieldrin in the hypothalamus, the major neuroendocrine region of the brain, in the zebrafish (Danio rerio). Zebrafish were fed pellets containing 0.03, 0.15, or 1.8 µg/g dieldrin for 21 days and a global gene expression analysis was performed to characterize cellular processes and pathways affected by dieldrin.
Project description:This project aimed at identifying developmental stage specific transcript profiles for catecholaminergic neurons in embryos and early larvae of zebrafish (Danio rerio). Catecholaminergic neurons were labeled using transgenic zebrafish strains to drive expression of GFP. At stages 24, 36, 72 and 96 hrs post fertilization, embryos were dissociated and GFP expressing cells sorted by FACS. Isolated RNAs were processed using either polyA selection and libray generation or NanoCAGE. This is the first effort to determine stage specific mRNA profiles of catecholaminergic neurons in zebrafish.
Project description:In triplicate for each condition, 12 WT and acbd6 F0 crispant Danio rerio (zebrafish) embryos were incubated with 20 μM YnMyr for 24 h, either between 48-72 hpf or 96-120 hpf. After labelling, zebrafish were washed twice with fresh egg water, deyolked, flash frozen in liquid nitrogen and stored at -80°C until further analysis.
Project description:Comparison of Danio rerio liver for 2 age groups treated with Rotenone. The RNA-seq data comprisess two age groups treated with Rotenone. Jena Centre for Systems Biology of Ageing - JenAge (www.jenage.de)
Project description:Comparison of temporal gene expression profiles from Danio rerio skin. The RNA-seq data comprise 3 age groups at 5, 24 and 30 months. Jena Centre for Systems Biology of Ageing - JenAge (www.jenage.de)
Project description:This SuperSeries is composed of the following subset Series: GSE37163: Gene expression data from time course of fin regeneration in Danio rerio (part 1) GSE37164: Gene expression data from time course of fin regeneration in Danio rerio (part 2) Refer to individual Series
