Project description:Poison frogs sequester chemical defenses from their diet of leaf litter arthropods for defense against predation. Little is known about the physiological adaptations that confer this unusual bioaccumulation ability. We conducted an alkaloid-feeding experiment with the Diablito poison frog (Oophaga sylvatica) to determine how quickly alkaloids are accumulated and how toxins modify frog physiology using quantitative proteomics. Diablito frogs rapidly accumulated the alkaloid decahydroquinoline within four days, and dietary alkaloid exposure modified protein abundance in the intestines, liver, and skin. Many proteins that increased in abundance with toxin accumulation are plasma glycoproteins, including the complement system and the toxin-binding protein saxiphilin. Other protein classes that change in abundance with toxin accumulation are membrane proteins involved in small molecule transport and metabolism. Overall, this work shows poison frogs can rapidly accumulate alkaloids, which alter carrier protein abundance, initiate an immune response, and alter small molecule transport and metabolism dynamics across tissues
Project description:Polychlorinated diphenyl ethers are lipophilic, persistent, and bioaccumulable compounds widely used as flame-retardants. These are chemicals of increasing environmental concern due to their lipophilic, persistent, and bioaccumulable characteristics. The objective of this study was to analyze the potential bioavailability and bioaccumulation of BDE-209 as a source of toxicity. Zebrafish embryos were exposed for 8 days to sediments spiked with an environmentally relevant concentration of BDE-209. We analyzed gene expression changes, thyroid function, and several markers for neurotoxicity. Results of this research highlight the need to consider the capability of BDE-209 to be bioavailable and bioaccumulate, indicating the potential hazardous effects.
Project description:Poly- and perfluorinated alkyl substances (PFAS) are a group of persistent organic pollutants. Plants can accumulate PFAS but their effect on plant physiology at the molecular level is not understood yet. We used hydroponically-grown maize plants treated with a combination of eleven different PFAS (each at 100 µg L-1) to investigate their bioaccumulation and effects on the growth, physiology and their impact on the root proteome. From the root proteome analysis, we identified 75 differentially abundant proteins, mostly involved in cellular metabolic and biosynthetic processes, translation and cytoskeletal reorganization. Results were validated using quantitative real-time PCR and further substantiated using amino acid and fatty acid profiling.
Project description:Transcriptional profiling of the digestive gland tissue of female mussel Mytilus galloprovincialis exposed to TCDD, n-TiO2 and their binary mixture Background: Exposure of marine organisms to pollutant mixtures may affect the pattern of contaminant uptake/bioaccumulation, as well as of gene expression in the tissues. Despite the growing concern over the potential biological impact of nanoparticles (NPs) in the aquatic environment, little is known about their interactions with other pollutants.We have recently shown that in the marine mussel Mytilus galloprovincialis exposure to n-TiO2, one of the most widespread type of NPs in use, in combination with 2,3,7,8-TCDD, chosen as model organic xenobiotic, can exert antagonistic or synergistic effects on different biomarkers from the molecular to the tissue level, depending on cell/tissue and type of measured response. An integrated approach involving immunhistochemical and transcriptomic analysis was employed to clarify the itteractive effects of n-TiO2 and TCDD in mussels digestive gland. In particular,TCDD bioaccumulation was evaluated utilizing specific anti-TCDD fluorescent antibodies. Moreover, immunohistochemical evaluation of antioxidant and cytoskeletal components was performed. To provide clues about how the molecular response to the investigated compounds is modulated, we used a cDNA microarray with1673 sequences. In animals exposed only to TiO2, functional genomics analysis of the microarray data (48 differentially expressed genes (DEGs)) highlighted three biological processes, largely dominated by the up-regulation of microtubule-based movement-related genes. Exposure to 2,3,7,8-TCDD yielded 49 DEGs exhibiting distinct patterns in terms of biological processes. Finally, exposure to the mixture rendered 62 GEGs characterized by the regulation of response to chemical stimulus, microtubule-based movement and intracellular signal transduction. Our data should be carefully considered in view of the biological effects of emerging pollutants, particularly in case of mixture chemicals. Transcriptional profiling of the digestive gland tissue of female mussel Mytilus galloprovincialis exposed to TCDD, n-TiO2 and their binary mixture