Revolutionizing aquatic eco-environmental monitoring: Utilizing the RPA-Cas-FQ detection platform for zooplankton.

The integration of recombinase polymerase amplification (RPA) with CRISPR/Cas technology has revolutionized molecular diagnostics and pathogen detection due to its unparalleled sensitivity and trans-cleavage ability. However, its potential in the ecological and environmental monitoring scenarios for aquatic ecosystems remains largely unexplored, particularly in accurate qualitative/quantitative detection, and its actual performance in handling complex real environmental samples. Using zooplankton as a model, we have successfully optimized the RPA-CRISPR/Cas12a fluorescence detection platform (RPA-Cas-FQ), providing several crucial "technical tips". Our findings indicate the sensitivity of CRISPR/Cas12a alone is 5 × 109 copies/reaction, which can be dramatically increased to 5 copies/reaction when combined with RPA. The optimized RPA-Cas-FQ enables reliable qualitative and semi-quantitative detection within 50 min, and exhibits a good linear relationship between fluorescence intensity and DNA concentration (R2 = 0.956-0.974***). Additionally, we developed a rapid and straightforward identification procedure for single zooplankton by incorporating heat-lysis and DNA-barcode techniques. We evaluated the platform's effectiveness using real environmental DNA (eDNA) samples from the Three Gorges Reservoir, confirming its practicality. The eDNA-RPA-Cas-FQ demonstrated strong consistency (Kappa = 0.43***) with eDNA-Metabarcoding in detecting species presence/absence in the reservoir. Furthermore, the two semi-quantitative eDNA technologies showed a strong positive correlation (R2 = 0.58-0.87***). This platform also has the potential to monitor environmental pollutants by selecting appropriate indicator species. The novel insights and methodologies presented in this study represent a significant advancement in meeting the complex needs of aquatic ecosystem protection and monitoring.

Neurotoxicity and the potential molecular mechanisms of mono-2-ethylhexyl phthalic acid (MEHP) in zebrafish.

Mono-2-ethylhexyl phthalic acid (MEHP) is the most toxic metabolite of plasticizer di-2-ethylhexyl phthalic acid (DEHP), and there is limited information available on the effects of MEHP on neurotoxicity. This study aims to examine the neurotoxicity of MEHP and preliminarily explore its potential molecular mechanisms. We found that MEHP impeded the growth of zebrafish embryos and the neurodevelopmental-related gene expression at environmentally relevant concentrations. MEHP exposure also induces oxidative stress response and brain cell apoptosis accompanied by a decrease in acetylcholinesterase (AChE) activity in zebrafish larvae. RNA-Seq and bioinformatics analysis showed that MEHP treatment altered the nervous system, neurogenic diseases, and visual perception pathways. The locomotor activity in dark-to-light cycles and phototaxis test confirmed the abnormal neural behavior of zebrafish larvae. Besides, the immune system has produced a large number of differentially expressed genes related to neural regulation. Inflammatory factor IL1ß and IL-17 signaling pathways highly respond to MEHP, indicating that inflammation caused by immune system imbalance is a potential mechanism of MEHP-induced neurotoxicity. This study expands the understanding of the toxicity and molecular mechanisms of MEHP, providing a new perspective for in-depth neurotoxicity exploration of similar compounds.

Recent advances in micro (nano) plastics in the environment: Distribution, health risks, challenges and future prospects.

Environmental micro(nano)plastics have become a significant global pollution problem due to the widespread use of plastic products. In this review, we summarized the latest research advances on micro(nano)plastics in the environment, including their distribution, health risks, challenges, and future prospect. Micro(nano)plastics have been found in a variety of environmental media, such as the atmosphere, water bodies, sediment, and especially marine systems, even in remote places like Antarctica, mountain tops, and the deep sea. The accumulation of micro(nano)plastics in organisms or humans through ingestion or other passive ways poses a series of negative impacts on metabolism, immune function, and health. Moreover, due to their large specific surface area, micro(nano)plastics can also adsorb other pollutants, causing even more serious effects on animal and human health. Despite the significant health risks posed by micro(nano)plastics, there are limitations in the methods used to measure their dispersion in the environment and their potential health risks to organisms. Therefore, further research is needed to fully understand these risks and their impacts on the environment and human health. Taken together, the challenges of micro(nano)plastics analysis in the environment and organisms must be addressed, and future research prospects need to be identified. Governments and individuals must take action to reduce plastic waste and minimize the negative impact of micro(nano)plastics on the environment and human health.