Project description:Aerobic biodegradation in aquatic and marine environments of textile microfibers released to the environment during home laundering.
Project description:Chemical modifications to the tails of histone proteins act as gene regulators that play a pivotal role in adaptive responses to environmental stress. Determining the short and long term kinetics of histone marks is essential for understanding their functions in adaptation. We used Caenorhabditis elegans as a model organism to study the histone modification kinetics in response to environmental stress, taking advantage of their ability to live in both terrestrial and aquatic environments. We investigated the multigenerational genome-wide dynamics of five histone marks (H3K4me3, H3K27me3, H4K20me1, H3K36me1, and H3K9me3) by maintaining P0 animals on terrestrial (agar plates), F1 in aquatic cultures, and F2 back on terrestrial environments. We determined the distributions of histone marks in the gene promoter regions and found that H4K20me1, H3K36me1, and H3K9me3 showed up to eleven-fold differences in density, whereas H3K4me3 and H3K27me3 remained highly constant during adaptation from terrestrial to aquatic environments. Furthermore, we predicted that up to five combinations of histone marks can co-occupy single gene promoters and confirmed the colocalization of these histone marks by structured illumination microscopy. The co-occupancy increases with environment changes and different co-occupancy patterns contribute to variances in gene expressions and thereby presents a supporting evidence for the histone code hypothesis.
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).