Project description:Nanoplastics pollution is a rising environmental concern whose impacts on biodiversity and human health are far from being understood. This is particularly salient in aquatic ecosystems, where the majority of species depend on external fertilization for reproduction. Here we evaluated the effects of a short-term exposure to engineered polystyrene nanoplastics (NPs) in the zebrafish germ line to further explore their impact on reproduction. To this end, zebrafish (Danio rerio) were exposed to 5 mg/L of 45 nm polystyrene (PS)-NPs via water for 96h. We show that, in males, nanoplastics induced testicular histological alterations with abnormal sperm clustering and chromatin compaction, resulting in viable spermatozoa but with reduced motility. Moreover, in females we observed an alteration in oocyte stages frequencies during oogenesis, possibly reflecting alterations in oocyte growth. RNA-sequencing analysis in male testis links nanoplastic induced alterations in the expression of genes involved in chromatin structure, meiosis and DNA double-strand break formation and repair progression, and gametes recognition. Flow cytometry analysis revealed that the observed effects in males were directly due to nanoplastics penetrating the testicular barrier and being internalized within germline cells. Overall, our results demonstrate that acute exposure to NPs can compromise reproductive fitness, underscoring the environmental and health impacts of NPs pollution.
Project description:Plastic particles in water environment can adsorb heavy metals, leading to combined toxicity to aquatic organisms. However, current conclusions are mostly obtained based on cell population-average responses. Heterogeneity effects among cell populations in aquatic organisms remain unclear. This study analyzed the heterogeneity effects of 200 μg/L 100 nm polystyrene nanoplastics (PS-NPs), 50 μg/L lead (Pb), and their combined exposures on zebrafish intestine cells by single-cell RNA sequencing.A total of 38640 cells in the zebrafish intestine was obtained and identified as seven cell populations, including enterocytes, macrophages, neutrophils, B cells, T cells, enteroendocrine cells, and goblet cells.Co-exposure of PS-NPs and Pb caused similar transcriptome profiles with PS-NPs exposure in macrophages, which changed immunological recognition processes. The Pb exposure influenced the macrophages by direct cytotoxicity. However, the Pb alone and combined exposures induced similar modes of action in the enterocytes, including the generation of oxidative stress and abnormal lipid metabolism.
Project description:This study employed scRNA-seq to systematically analyze cellular proportions, differential gene expression, and the expression of enriched functional pathways in zebrafish brain tissues following SSRI exposure. Results revealed that distinct SSRI compounds disrupted core regulatory pathways of the serotonin neurotransmitter system through specific mechanisms, leading to significant gene expression heterogeneity in zebrafish brain cell populations. This research comprehensively elucidated the impacts of environmentally relevant concentration SSRI exposure on zebrafish brain cell populations, providing novel insights into the neurotoxic mechanisms of SSRIs in aquatic organisms.
Project description:Using 2 male and 2 female zebrafish (pool of 6) brain samples, we generated base-resolution DNA methylation maps to document sex-specific epigenetic differences. Here we generated single-nucleotide resoultion DNA methylation map of 4 zebrafish brain samples using Reduced Representation Bisulfite Sequencing (RRBS)
Project description:Purpose: Identify zebrafish control and csf1r-mutant brain transcriptomes Methods: RNA sequencing was performed on whole brain of control (3x), csf1ra-/- microglia (3x) and csf1ra-/-;b+/- microglia (3x) and csf1ra-/-;b-/- zebrafish. 10-20 million reads per sample were obtained. Reads were mapped to zebrafish genome GRC10. Results: We identified that microglia gene expression was reduced in csf1ra-/-;b+/- and csf1ra-/-;b-/;- mutant transcriptomes.
Project description:The proteome of human brain synapses is highly complex and mutated in over 130 diseases. This complexity arose from two whole genome duplications early in the vertebrate lineage. Zebrafish are used in modelling human diseases, however its synapse proteome is uncharacterised and whether the teleost-specific genome duplication (TSGD) influenced complexity is unknown. We report the first characterisation of the proteomes and ultrastructure of central synapses in zebrafish and analyse the importance of the TSGD. The TSGD increased overall synapse proteome complexity. The Post Synaptic Density (PSD) proteome of zebrafish had lower complexity than mammals and a highly conserved set of ~1000 proteins is shared across vertebrates. PSD ultrastructural features were also conserved. Lineage-specific proteome differences indicate vertebrate species evolved distinct synapse types and functions. The datasets are a resource for a wide range of studies and have important implications for the use of zebrafish in modelling human synaptic diseases.
Project description:We applied zebrafish whole genome microarrays to identify molecular effects of suvorexant, imipramine and a orexin antagonist from natural plant. Behavioral assays were performed to analyze for correlations between altered gene expression with effects on the organism level. Central nervous system drug induced gene expression in larval zebrafish brain was measured at 3 hours after exposure of 1uM suvorexant, 1uM imipramine, 10uM 8beta-(4'-Hydroxytigloyloxy) costunolide or 100uM 8beta-(4'-Hydroxytigloyloxy) costunolide. Three independent experiments were performed.Gene expression profile of brain tissue of 10uM 8beta-(4'-Hydroxytigloyloxy) costunolide treated larva showed closest similarity with suvorexant, as assumed by behavior profile.
Project description:Methylmercury (MeHg) is a ubiquitous environmental toxicant that is often detected in the tissues of fish-eating species. It has been well established that prenatal exposure to MeHg can lead to widespread brain damage and impaired neurological development resulting in defects ranging from severe cerebral palsy and cognitive deficits to impaired motor and sensory function. A wide range of environmental toxicants have been shown to induce transgenerational inheritance of diseases via changes in DNA methylation—a well-known epigenetic modification. Our previous research has demonstrated that developmental MeHg exposure may yield transgenerational inheritance of neurological dysfunction in adult F3-lineage zebrafish via quantitative neurobehavioral assays that evaluated the visual startle response, retinal electrophysiology, and locomotor function. The objective of the current study was to examine the correlation between neurobehavioral phenotypes and the transcriptome activity in the brain and retina of F3 zebrafish by RNA sequencing (RNAseq). Transcriptomic analyses of F3 generation MeHg-treated zebrafish (compared to control) revealed significant gene dysregulation in both the brain and retina. There were 1648 and 138 differentially expressed genes in the retina and brain, respectively (FDR <0.05). Thirty-five genes were commonly dysregulated in both organs. Gene set enrichment analysis revealed significantly enriched pathways including: neurodevelopment, visual functions, phototransduction, and motor movement. Moreover, commonly dysregulated genes were associated with circadian rhythm and metabolic pathways, as well as arginine and proline metabolism. To our knowledge, this is the first evidence of a transgenerational transcriptome induced by ancestral developmental exposure to MeHg in any species. If the transgenerational phenotypes, transcriptome, homologous biomarkers, or similar molecular pathways hold true for human populations, our findings have significant impact on global public health in terms of identifying the susceptible populations using biomarkers and preventing transgenerational inheritance of MeHg-induced neurobehavioral deficits.