Project description:Pharmaceutical chemicals used in human medicine are released into surface waters via municipal effluents and pose a risk for aquatic organisms. Among these substances are selective serotonin reuptake inhibitors (SSRIs) which can affect aquatic organisms at sub ppb concentrations. To better understand biochemical pathways influenced by SSRIs, evaluate changes in the transcriptome, and identify gene transcripts with potential for biomarkers of exposure to SSRIs; larval zebrafish Danio rerio were exposed (96 h) to two concentrations (25 and 250 µg/L) of the SSRIs, fluoxetine and sertraline, and changes in global gene expression were evaluated (Affymetrix GeneChip® Zebrafish Array). Significant changes in gene expression (>=1.7 fold change, p<0.05) were determined with Partek® Genomics Suite Gene Expression Data Analysis System and ontology analysis was conducted using Molecular Annotation System 3. The number of genes differentially expressed after fluoxetine exposure was 288 at 25 µg/L and 131 at 250 µg/L; and after sertraline exposure was 33 at 25 µg/L and 52 at 250 µg/L. Five genes were differentially regulated in all treatments relative to control, suggesting that both SSRIs share some similar molecular pathways. Among them, expression of the gene coding for FK506 binding protein 5 (FKBP5), which is annotated to stress response regulation, was highly down-regulated in all treatments (results confirmed by qRT-PCR). Gene ontology analysis indicated that regulation of stress response and cholinesterase activity were critical functions influenced by these SSRIs, and suggested that changes in the transcription of FKBP5 or acetylcholinesterase could be useful biomarkers of SSRIs exposure in wild fish.
Project description:Transcriptome analysis of the Zebrafish model of Diamond-Blackfan Anemia from RPS19 deficiency via p53-dependent and -independent pathways
Project description:Pharmaceutical chemicals used in human medicine are released into surface waters via municipal effluents and pose a risk for aquatic organisms. Among these substances are selective serotonin reuptake inhibitors (SSRIs) which can affect aquatic organisms at sub ppb concentrations. To better understand biochemical pathways influenced by SSRIs, evaluate changes in the transcriptome, and identify gene transcripts with potential for biomarkers of exposure to SSRIs; larval zebrafish Danio rerio were exposed (96 h) to two concentrations (25 and 250 µg/L) of the SSRIs, fluoxetine and sertraline, and changes in global gene expression were evaluated (Affymetrix GeneChip® Zebrafish Array). Significant changes in gene expression (>=1.7 fold change, p<0.05) were determined with Partek® Genomics Suite Gene Expression Data Analysis System and ontology analysis was conducted using Molecular Annotation System 3. The number of genes differentially expressed after fluoxetine exposure was 288 at 25 µg/L and 131 at 250 µg/L; and after sertraline exposure was 33 at 25 µg/L and 52 at 250 µg/L. Five genes were differentially regulated in all treatments relative to control, suggesting that both SSRIs share some similar molecular pathways. Among them, expression of the gene coding for FK506 binding protein 5 (FKBP5), which is annotated to stress response regulation, was highly down-regulated in all treatments (results confirmed by qRT-PCR). Gene ontology analysis indicated that regulation of stress response and cholinesterase activity were critical functions influenced by these SSRIs, and suggested that changes in the transcription of FKBP5 or acetylcholinesterase could be useful biomarkers of SSRIs exposure in wild fish. Zebrafish (Danio rerio) were obtained from the Zebrafish Research Facility maintained at the Center for Environmental Biotechnology at the University of Tennessee. Fish husbandry, spawning, and experimental procedures were conducted with approval from the UT Insititutional Animal Care and Use Committee (Protocol #1690-1007). Water for holding fish and conducting experiments (hereafter referred to as fish water) consisted of MilliQ water (Millipore, Bedford, MA) with ions added: 19 mg/L NaHCO3, 1 mg/L sea salt (Instant Ocean Synthetic Sea Salt, Mentor, OH), 10 mg/L CaSO4, 10 mg/L MgSO4, 2 mg/L KCl. Embroyos were obtained by spawning adult fish with no history of contaminant exposure. Fertilization of embryos took place at the same time (<15 minutes), such that larvae used in experiments were of similar age at the time of exposure. All activities (maintenance of adult fish, spawning, and experiments) were conducted in an environmental chamber with a temperature of 27 +/- 1 C and 14:10h light:dark photoperiod. Larval zebrafish (72 hpf) were exposed for 96 h in 200ml fish water containing appropirate amount of SSRI stock (i.e. fluoxetine or sertraline). There were four SSRIs treatments (25 and 250 ug/L fluoxetine and 25 and 250 ug/L sertraline) and one control (no SSRIs) with triplicate beakers and each beaker contained about 100 larval fish. During exposure for 96 hours, beakers were kept covered to prevent water evaporation and fish were not fed (i.e., fish consumed their yolk sac).
Project description:The exon junction complex (EJC) is composed of three core proteins Rbm8a, Magoh and Eif4a3 and is thought to play a role in several post-transcriptional processes. In this study we focus on understanding the role of EJC in zebrafish development. We identified transcriptome-wide binding sites of EJC in zebrafish via RNA:protein immunoprecipitation followed by deep sequencing (RIP-Seq). We find that, as in human cells, zebrafish EJC is deposited about 24 nts upstream of exon-exon junctions. We also identify transcripts regulated by Rbm8a and Magoh in zebrafish embryos using whole embryo RNA-seq from rbm8a mutant, magoh mutant and wild-type sibling embryos. This study shows that nonsense mediated mRNA decay is dysregulated in zebrafish EJC mutants.
Project description:Zebrafish populations recently collected from the wild differ from domesticated populations in anxiety-related behaviors. We measured anxiety-related behaviors in wild and domesticated zebrafish populations and performed a multi-brain region transcriptional comparison using microarrays to try to understand the genetic changes that accompany behavioral adaptation to domestication. We performed a microarray analysis comparing the midbrain and telencephalon brain regions of male and female adult zebrafish from four populations varying in domestication history (Wild: Nadia (N) and Pargana (P), and Domesticated: Scientific Hatchery (S) and Transgenic Mosaic 1 (T)). We collected 16 samples per brain region (4 samples per zebrafish population, with 1 telencephalon sample missing for the S population). We attempted to maintain equal sex ratios within each zebrafish population, but this was not always possible due to sex biases within some populations.