ABSTRACT: Impact of exposure to environmentally-relevant concentrations of ionic silver and nanosilver on thyroid hormone-dependent postembryonic development of the North American bullfrog (Rana catesbeiana)
Project description:Nanoparticles (<100 nm) are engineered to have unique physico-chemical properties compared to their larger counterparts. Nanosilver (nAg) is the most prevalent nanoparticle in consumer products due to its strong antimicrobial action. While nAg toxicity at high concentrations has been well described, the potential for sublethal effects at or below regulatory guidelines is relatively unknown. Amphibian metamorphosis is mediated by thyroid hormone (TH) and can be precociously induced by the addition of exogenous hormone. Low concentrations of nAg have been shown to disrupt TH-dependent responses in cultured premetamorphic Rana catesbeiana tadpole tail fin. The present study examined the effects of exposure to an environmentally relevant concentration (6 µg/L) of either nAg or ionic silver (iAg) on premetamorphic tadpoles in the absence and presence of exogenous TH. Disruption of thyroid hormone-mediated signalling in brain and liver transcriptomes was evaluated using the MAGEX cDNA microarray.
Project description:Effects of Acute Exposure to the Non-steroidal Anti-inflammatory Drug Ibuprofen on the Developing North American Bullfrog (Rana catesbeiana) Tadpole
Project description:An anthropogenic chemical contaminant commonly identified in aquatic receiving environments is the non-steroidal anti-inflammatory drug (NSAID), ibuprofen(IBF). While the role of ibuprofen in target organisms is known, there exists a paucity of data on the impact of exposure to non-target wildlife species. In the case of frog species, normal development and environmental fitness involves the actions of the thyroid hormones (THs), particularly at key points in the life cycle. We investigated whether exposure of premetamorphic North American bullfrog (Rana catesbeiana) tadpoles to IBF altered their response to treatment with an exogenous dose of thyroid hormone (T3).
Project description:Transcriptomes of thyroid hormone-exposed Rana [Lithobates] catesbeiana cultured back skin in warm, cold, and temperature shift conditions
Project description:An anthropogenic chemical contaminant commonly identified in aquatic receiving environments is the non-steroidal anti-inflammatory drug (NSAID), ibuprofen(IBF). While the role of ibuprofen in target organisms is known, there exists a paucity of data on the impact of exposure to non-target wildlife species. In the case of frog species, normal development and environmental fitness involves the actions of the thyroid hormones (THs), particularly at key points in the life cycle. We investigated whether exposure of premetamorphic North American bullfrog (Rana catesbeiana) tadpoles to IBF altered their response to treatment with an exogenous dose of thyroid hormone (T3). Six animals randomly selected from each treatment were examined for the status of the hepatic transcriptome using MAGEX DNA array analysis.
