Transcriptome and computational approaches highlighting the molecular regulation of Zacco platypus induced by mesocosm exposure to common disinfectant chlorine.

Chlorine (Cl2) is a disinfectant often used in swimming pools and water treatment facilities. However, it is released into aquatic ecosystems, where it may harm non-targeted organisms. Here, we performed a mesocosm experiment exposing Zacco platypus (Z. platypus) to biocide Cl2 for 30 days (30 d) at two days' time points 15 days (15 d) and 30 d samples were collected. Here, Z. platypus was exposed to a sublethal concentration (0.1 mg/L) of Cl2, and comparative transcriptomics analyses were performed to determine their response mechanisms at the molecular level. According to RNA sequencing of the whole-body transcriptome, 860 and 1189 differentially expressed genes (DEGs) were identified from the 15 d and 30 d responses to Cl2, respectively. After enrichment analysis of GO (Gene Ontology) functions and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways, identified DEGs were demonstrated to be associated with a variety of functions, including "ion binding and transmembrane transporters". Cl2 also induced oxidative stress in Z. platypus by increasing the levels of reactive oxygen species (ROS) while decreasing the catalase (CAT) content and the levels of solute carrier family 22 member 11 (slc22a11), Caspase-8 (casp-8), inducible nitric oxide synthase (NOS2), cytosolic phospholipase A2 gamma (PLA2G4). However, Z. platypus still allows recovery during stress suspension by increasing the expression levels of solute carrier family proteins. The GO and KEGG annotation results revealed that the expression of DEGs were related to the detoxification process, immune response, and antioxidant mechanism. Additionally, protein-protein interaction networks (PPI) and cytoHubba analyses identified sixteen hub genes and their interaction. These findings elucidate the regulation of various DEGs and signaling pathways in response to Cl2 exposure, which will improve our knowledge and laid foundation for further investigation of the toxicity of Cl2 to Z. platypus.

Assessing the Impact of Meteorological Factors on COVID-19 Seasonality in Metropolitan Chennai, India.

Meteorological factors may influence coronavirus disease 2019 (COVID-19) transmission. Due to the small number of time series studies, the relative importance of seasonality and meteorological factors is still being debated. From March 2020 to April 2021, we evaluated the impact of meteorological factors on the transmission of COVID-19 in Chennai, India. Understanding how the COVID-19 pandemic spreads over the year is critical to developing public health strategies. Correlation models were used to examine the influence of meteorological factors on the transmission of COVID-19. The results revealed seasonal variations in the number of COVID-19-infected people. COVID-19 transmission was greatly aggravated by temperature, wind speed, nitric oxide (NO) and barometric pressure (BP) during summer seasons, whereas wind speed and BP aggravated COVID-19 transmission during rainy seasons. Furthermore, PM 2.5, NO and BP aggravated COVID-19 transmission during winter seasons. However, their relationships fluctuated seasonally. Our research shows that seasonal influences must be considered when developing effective interventions.

Transformation Products of Emerging Pollutants Explored Using Non-Target Screening: Perspective in the Transformation Pathway and Toxicity Mechanism-A Review.

The scientific community has increasingly focused on forming transformation products (TPs) from environmental organic pollutants. However, there is still a lot of discussion over how these TPs are generated and how harmful they are to living terrestrial or aquatic organisms. Potential transformation pathways, TP toxicity, and their mechanisms require more investigation. Non-target screening (NTS) via high-resolution mass spectrometry (HRMS) in model organisms to identify TPs and the formation mechanism on various organisms is the focus of this review. Furthermore, uptake, accumulation process, and potential toxicity with their detrimental consequences are summarized in various organisms. Finally, challenges and future research initiatives, such as performing NTS in a model organism, characterizing and quantifying TPs, and evaluating future toxicity studies on TPs, are also included in this review.

Gut bacteria Vibrio sp. and Aeromonas sp. trigger the expression levels of proinflammatory cytokine: First evidence from the germ-free zebrafish.

Gut microbiota plays a central part in the regulation of multiple host metabolic pathways, such as homeostasis, immunostasis, mucosa permeability, and even brain development. Though, slight known about the function of an individual gut bacterium in zebrafish. In this study, germ-free (GF) and conventionally reared (CV) zebrafish models utilized for studying the role of gut bacteria Vibrio sp. and Aeromonas sp. After the analysis of gut microbial profile in zebrafish male and female at three-month age, Proteobacteria and Fusobacteria dominated the main composition of zebrafish intestinal microflora. However, the relative richness of them was different base on gender variance. Aeromonas sp. and Vibrio sp. belonging to Proteobacteria phylum of bacteria were isolated from zebrafish gut, and their potential capacities to trigger innate immunity were investigated. In gut microbiota absence, the expression levels of the innate immunity genes in the GF group were not significantly changed compared to the CV group. After exposure to Aeromonas sp. and Vibrio sp., the expression levels of myd88, TLRs-, and inflammation-related genes were increased in both GF and CV groups, except tlr2 and NLRs-related genes. However, the expression level of NF-κB and JNK/AP-1 pathway genes were all decreased after exposure to Aeromonas sp. and Vibrio sp. in both GF and CV groups. Interestingly, inflammation-related genes (tnfa, tnfb, and il1ß) were activated in the CV group, and there were not significantly changed in the GF group, indicating that other bacteria were indispensable for Aeromonas sp. or Vibrio sp. to activate the inflammation response. Taken together, this is the first study of gut bacteria Vibrio sp. and Aeromonas sp. prompting the innate immune response using the GF and CV zebrafish model.

Acute and chronic effects of polystyrene microplastics on brine shrimp: First evidence highlighting the molecular mechanism through transcriptome analysis.

Microplastics contamination is one of the leading environmental catastrophes for the marine ecosystem, but the molecular toxicity mechanism of those microplastics remains elusive. This study aims to determine the acute and chronic toxicity after exposure to polystyrene microplastics in brine shrimp with various concentrations. Our results demonstrated that acute exposure to polystyrene microplastics induced no significant effects on the survival of brine shrimp. Interestingly, the concentration-dependent increase in both bioaccumulation and the generation of reactive oxygen species (ROS) was observed after acute and chronic exposure. Moreover, the histopathology analysis revealed the deformation of epithelial cells in the midgut region after both acute exposures at 100 mg/L and chronic exposure at 1 mg/L to polystyrene microplastics. To elucidate the underlying mechanisms of microplastics-mediated toxicity, the transcriptome analysis was performed after chronic exposure, and the result showed 721 differentially expressed genes (DEGs) associated with 156 known KEGG pathways. 292 DEGs genes were significantly upregulated and 429 genes were significantly downregulated. The transcriptome analysis further revealed the DEGs related pathways. Taken together, this study not only highlighted the negative effects but also provided detailed sequencing data from transcriptome profiling to enhance our understanding of the molecular toxicity of polystyrene microplastics in brine shrimp.

Multi-elemental concentration in different body parts of Sepiella inermis by inductively coupled plasma mass spectrometry.

The present study examined the accumulation of metal on Sepiella inermis from the Mudasalodai Landing Center, from southeast coastal region of India. Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine metals including aluminium, boron, cadmium, cobalt, chromium, copper, iron, manganese, magnesium, nickel, lead and zinc. The results showed that metal concentration in S. inermis detected in the head, arm, mantle, eye, ink, liver and nidamental gland with higher concentration of magnesium up to 992.78 mg/kg, and tentacle showed maximum concentration of aluminium 306.72 mg/kg. Further, copper found in low concentration ranges from 0.04 to 0.55 mg/kg in different parts of S. inermis. Heavy metal like cadmium detected high in tentacle with 0.24 mg/kg, and the manganese present in eye was 0.55 mg/kg. However, no accumulation of nickel was found in the tentacle part.

Toxicity studies of nanofabricated palladium against filariasis and malaria vectors.

The present study was carried out to establish the biofabrication of palladium nanoparticles (PdNPs) using the plant leaf extract of Tinospora cordifolia Miers and its toxicity studies on the larvae of filariasis vector, Culex quinquefasciatus Say and malaria vector, Anopheles subpictus Grassi. The biofabricated PdNPs were characterized by using UV-visible spectrum, FTIR, XRD, FESEM, EDX and HRTEM. HRTEM confirmed the PdNPs were slightly agglomerated and spherical in shape and the average size was 16 nm. Gas chromatography and mass spectrometry analysis result revealed that the major constituent present in the T. cordifolia leaf extract is 2,4-di-tert-butylphenol (31.79%) whereas the minor compounds are 1-hexadecanol (7.97%), 1-octadecanol (7.70%), 1-eicosanol (6.85%), behenic alcohol (5.36%), 1-tetradecene (6.22%), cyclotetradecane (6.23%), 1-hexadecene (7.97%), 1-octadecene (7.70%), 1-eicosene (6.85%), and 1-docosene (5.36%). T. cordifolia leaf extract exhibited the larvicidal activity against the fourth instar larvae of C. quinquefasciatus and A. subpictus with the values of LC50 = 59.857 and 54.536 mg/L; LC90 = 113.445 and 108.940 mg/L, respectively. The highest toxicity was observed in the biofabricated PdNPs against the fourth instar larvae of C. quinquefasciatus and A. subpictus with the values of LC50 = 6.090 and 6.454 mg/L; LC90 = 13.689 and 13.849 mg/L, respectively. Concerning non-target effects, Poecilia reticulata were exposed to PdNPs for 24 h and did not exhibit any noticeable toxicity. Overall, our findings strongly suggest that PdNPs is a perfect ecological and inexpensive approach for the control of filariasis and malaria vectors.

Enhanced cytotoxic activity of AgNPs on retinoblastoma Y79 cell lines synthesised using marine seaweed Turbinaria ornata.

Retinoblastoma is the most common intraocular malignancy basically occurs among children below five. Certain ocular treatments such as surgery, radiation therapy and chemotherapy are more likely to cause side effects. Here, a rapid method of synthesising silver nanoparticles (AgNPs) from the brown seaweed Turbinaria ornata and its cytotoxic efficacy against the retinoblastoma Y79 cell lines was studied. The AgNPs synthesis was determined by Ultraviolet-visible spectroscopy and was further characterised by X-ray diffraction, High-resolution transmission electron microscopy, zeta potential, Energy-dispersive X-ray spectroscopy, thermogravimetric analysis, Fourier transform infrared spectrum and inductively coupled plasma-mass spectroscopy techniques. The synthesised AgNPs were found to be very stable and finely dispersed. The total phenolic content of the synthesised AgNPs was estimated at 43±2.52 mg/g gallic acid equivalent and the nanoparticles exhibited good scavenging activity analysed by 2, 2'-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) assay. Moreover, cytotoxicity of synthesised AgNPs against in vitro retinoblastoma Y79 cell lines showed a dose-dependent response with an inhibitory concentration (IC50) of 10.5 µg/mL. These results suggest that AgNPs could be a promising anticancer agent with enhanced activity in ocular treatment.